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/*
 * MPEG-4 ALS decoder
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 * Copyright (c) 2009 Thilo Borgmann <thilo.borgmann _at_ mail.de>
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 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/**
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 * @file
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 * MPEG-4 ALS decoder
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 * @author Thilo Borgmann <thilo.borgmann _at_ mail.de>
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 */

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#include <inttypes.h>

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#include "avcodec.h"
#include "get_bits.h"
#include "unary.h"
#include "mpeg4audio.h"
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#include "bgmc.h"
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#include "bswapdsp.h"
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#include "internal.h"
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#include "mlz.h"
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#include "libavutil/samplefmt.h"
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#include "libavutil/crc.h"
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#include "libavutil/softfloat_ieee754.h"
#include "libavutil/intfloat.h"
#include "libavutil/intreadwrite.h"
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#include <stdint.h>

/** Rice parameters and corresponding index offsets for decoding the
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 *  indices of scaled PARCOR values. The table chosen is set globally
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 *  by the encoder and stored in ALSSpecificConfig.
 */
static const int8_t parcor_rice_table[3][20][2] = {
    { {-52, 4}, {-29, 5}, {-31, 4}, { 19, 4}, {-16, 4},
      { 12, 3}, { -7, 3}, {  9, 3}, { -5, 3}, {  6, 3},
      { -4, 3}, {  3, 3}, { -3, 2}, {  3, 2}, { -2, 2},
      {  3, 2}, { -1, 2}, {  2, 2}, { -1, 2}, {  2, 2} },
    { {-58, 3}, {-42, 4}, {-46, 4}, { 37, 5}, {-36, 4},
      { 29, 4}, {-29, 4}, { 25, 4}, {-23, 4}, { 20, 4},
      {-17, 4}, { 16, 4}, {-12, 4}, { 12, 3}, {-10, 4},
      {  7, 3}, { -4, 4}, {  3, 3}, { -1, 3}, {  1, 3} },
    { {-59, 3}, {-45, 5}, {-50, 4}, { 38, 4}, {-39, 4},
      { 32, 4}, {-30, 4}, { 25, 3}, {-23, 3}, { 20, 3},
      {-20, 3}, { 16, 3}, {-13, 3}, { 10, 3}, { -7, 3},
      {  3, 3}, {  0, 3}, { -1, 3}, {  2, 3}, { -1, 2} }
};


/** Scaled PARCOR values used for the first two PARCOR coefficients.
 *  To be indexed by the Rice coded indices.
 *  Generated by: parcor_scaled_values[i] = 32 + ((i * (i+1)) << 7) - (1 << 20)
 *  Actual values are divided by 32 in order to be stored in 16 bits.
 */
static const int16_t parcor_scaled_values[] = {
    -1048544 / 32, -1048288 / 32, -1047776 / 32, -1047008 / 32,
    -1045984 / 32, -1044704 / 32, -1043168 / 32, -1041376 / 32,
    -1039328 / 32, -1037024 / 32, -1034464 / 32, -1031648 / 32,
    -1028576 / 32, -1025248 / 32, -1021664 / 32, -1017824 / 32,
    -1013728 / 32, -1009376 / 32, -1004768 / 32,  -999904 / 32,
     -994784 / 32,  -989408 / 32,  -983776 / 32,  -977888 / 32,
     -971744 / 32,  -965344 / 32,  -958688 / 32,  -951776 / 32,
     -944608 / 32,  -937184 / 32,  -929504 / 32,  -921568 / 32,
     -913376 / 32,  -904928 / 32,  -896224 / 32,  -887264 / 32,
     -878048 / 32,  -868576 / 32,  -858848 / 32,  -848864 / 32,
     -838624 / 32,  -828128 / 32,  -817376 / 32,  -806368 / 32,
     -795104 / 32,  -783584 / 32,  -771808 / 32,  -759776 / 32,
     -747488 / 32,  -734944 / 32,  -722144 / 32,  -709088 / 32,
     -695776 / 32,  -682208 / 32,  -668384 / 32,  -654304 / 32,
     -639968 / 32,  -625376 / 32,  -610528 / 32,  -595424 / 32,
     -580064 / 32,  -564448 / 32,  -548576 / 32,  -532448 / 32,
     -516064 / 32,  -499424 / 32,  -482528 / 32,  -465376 / 32,
     -447968 / 32,  -430304 / 32,  -412384 / 32,  -394208 / 32,
     -375776 / 32,  -357088 / 32,  -338144 / 32,  -318944 / 32,
     -299488 / 32,  -279776 / 32,  -259808 / 32,  -239584 / 32,
     -219104 / 32,  -198368 / 32,  -177376 / 32,  -156128 / 32,
     -134624 / 32,  -112864 / 32,   -90848 / 32,   -68576 / 32,
      -46048 / 32,   -23264 / 32,     -224 / 32,    23072 / 32,
       46624 / 32,    70432 / 32,    94496 / 32,   118816 / 32,
      143392 / 32,   168224 / 32,   193312 / 32,   218656 / 32,
      244256 / 32,   270112 / 32,   296224 / 32,   322592 / 32,
      349216 / 32,   376096 / 32,   403232 / 32,   430624 / 32,
      458272 / 32,   486176 / 32,   514336 / 32,   542752 / 32,
      571424 / 32,   600352 / 32,   629536 / 32,   658976 / 32,
      688672 / 32,   718624 / 32,   748832 / 32,   779296 / 32,
      810016 / 32,   840992 / 32,   872224 / 32,   903712 / 32,
      935456 / 32,   967456 / 32,   999712 / 32,  1032224 / 32
};


/** Gain values of p(0) for long-term prediction.
 *  To be indexed by the Rice coded indices.
 */
static const uint8_t ltp_gain_values [4][4] = {
    { 0,  8, 16,  24},
    {32, 40, 48,  56},
    {64, 70, 76,  82},
    {88, 92, 96, 100}
};

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/** Inter-channel weighting factors for multi-channel correlation.
 *  To be indexed by the Rice coded indices.
 */
static const int16_t mcc_weightings[] = {
    204,  192,  179,  166,  153,  140,  128,  115,
    102,   89,   76,   64,   51,   38,   25,   12,
      0,  -12,  -25,  -38,  -51,  -64,  -76,  -89,
   -102, -115, -128, -140, -153, -166, -179, -192
};


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/** Tail codes used in arithmetic coding using block Gilbert-Moore codes.
 */
static const uint8_t tail_code[16][6] = {
    { 74, 44, 25, 13,  7, 3},
    { 68, 42, 24, 13,  7, 3},
    { 58, 39, 23, 13,  7, 3},
    {126, 70, 37, 19, 10, 5},
    {132, 70, 37, 20, 10, 5},
    {124, 70, 38, 20, 10, 5},
    {120, 69, 37, 20, 11, 5},
    {116, 67, 37, 20, 11, 5},
    {108, 66, 36, 20, 10, 5},
    {102, 62, 36, 20, 10, 5},
    { 88, 58, 34, 19, 10, 5},
    {162, 89, 49, 25, 13, 7},
    {156, 87, 49, 26, 14, 7},
    {150, 86, 47, 26, 14, 7},
    {142, 84, 47, 26, 14, 7},
    {131, 79, 46, 26, 14, 7}
};


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enum RA_Flag {
    RA_FLAG_NONE,
    RA_FLAG_FRAMES,
    RA_FLAG_HEADER
};


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typedef struct ALSSpecificConfig {
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    uint32_t samples;         ///< number of samples, 0xFFFFFFFF if unknown
    int resolution;           ///< 000 = 8-bit; 001 = 16-bit; 010 = 24-bit; 011 = 32-bit
    int floating;             ///< 1 = IEEE 32-bit floating-point, 0 = integer
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    int msb_first;            ///< 1 = original CRC calculated on big-endian system, 0 = little-endian
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    int frame_length;         ///< frame length for each frame (last frame may differ)
    int ra_distance;          ///< distance between RA frames (in frames, 0...255)
    enum RA_Flag ra_flag;     ///< indicates where the size of ra units is stored
    int adapt_order;          ///< adaptive order: 1 = on, 0 = off
    int coef_table;           ///< table index of Rice code parameters
    int long_term_prediction; ///< long term prediction (LTP): 1 = on, 0 = off
    int max_order;            ///< maximum prediction order (0..1023)
    int block_switching;      ///< number of block switching levels
    int bgmc;                 ///< "Block Gilbert-Moore Code": 1 = on, 0 = off (Rice coding only)
    int sb_part;              ///< sub-block partition
    int joint_stereo;         ///< joint stereo: 1 = on, 0 = off
    int mc_coding;            ///< extended inter-channel coding (multi channel coding): 1 = on, 0 = off
    int chan_config;          ///< indicates that a chan_config_info field is present
    int chan_sort;            ///< channel rearrangement: 1 = on, 0 = off
    int rlslms;               ///< use "Recursive Least Square-Least Mean Square" predictor: 1 = on, 0 = off
    int chan_config_info;     ///< mapping of channels to loudspeaker locations. Unused until setting channel configuration is implemented.
    int *chan_pos;            ///< original channel positions
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    int crc_enabled;          ///< enable Cyclic Redundancy Checksum
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} ALSSpecificConfig;


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typedef struct ALSChannelData {
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    int stop_flag;
    int master_channel;
    int time_diff_flag;
    int time_diff_sign;
    int time_diff_index;
    int weighting[6];
} ALSChannelData;


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typedef struct ALSDecContext {
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    AVCodecContext *avctx;
    ALSSpecificConfig sconf;
    GetBitContext gb;
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    BswapDSPContext bdsp;
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    const AVCRC *crc_table;
    uint32_t crc_org;               ///< CRC value of the original input data
    uint32_t crc;                   ///< CRC value calculated from decoded data
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    unsigned int cur_frame_length;  ///< length of the current frame to decode
    unsigned int frame_id;          ///< the frame ID / number of the current frame
    unsigned int js_switch;         ///< if true, joint-stereo decoding is enforced
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    unsigned int cs_switch;         ///< if true, channel rearrangement is done
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    unsigned int num_blocks;        ///< number of blocks used in the current frame
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    unsigned int s_max;             ///< maximum Rice parameter allowed in entropy coding
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    uint8_t *bgmc_lut;              ///< pointer at lookup tables used for BGMC
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    int *bgmc_lut_status;           ///< pointer at lookup table status flags used for BGMC
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    int ltp_lag_length;             ///< number of bits used for ltp lag value
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    int *const_block;               ///< contains const_block flags for all channels
    unsigned int *shift_lsbs;       ///< contains shift_lsbs flags for all channels
    unsigned int *opt_order;        ///< contains opt_order flags for all channels
    int *store_prev_samples;        ///< contains store_prev_samples flags for all channels
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    int *use_ltp;                   ///< contains use_ltp flags for all channels
    int *ltp_lag;                   ///< contains ltp lag values for all channels
    int **ltp_gain;                 ///< gain values for ltp 5-tap filter for a channel
    int *ltp_gain_buffer;           ///< contains all gain values for ltp 5-tap filter
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    int32_t **quant_cof;            ///< quantized parcor coefficients for a channel
    int32_t *quant_cof_buffer;      ///< contains all quantized parcor coefficients
    int32_t **lpc_cof;              ///< coefficients of the direct form prediction filter for a channel
    int32_t *lpc_cof_buffer;        ///< contains all coefficients of the direct form prediction filter
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    int32_t *lpc_cof_reversed_buffer; ///< temporary buffer to set up a reversed versio of lpc_cof_buffer
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    ALSChannelData **chan_data;     ///< channel data for multi-channel correlation
    ALSChannelData *chan_data_buffer; ///< contains channel data for all channels
    int *reverted_channels;         ///< stores a flag for each reverted channel
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    int32_t *prev_raw_samples;      ///< contains unshifted raw samples from the previous block
    int32_t **raw_samples;          ///< decoded raw samples for each channel
    int32_t *raw_buffer;            ///< contains all decoded raw samples including carryover samples
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    uint8_t *crc_buffer;            ///< buffer of byte order corrected samples used for CRC check
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    MLZ* mlz;                       ///< masked lz decompression structure
    SoftFloat_IEEE754 *acf;         ///< contains common multiplier for all channels
    int *last_acf_mantissa;         ///< contains the last acf mantissa data of common multiplier for all channels
    int *shift_value;               ///< value by which the binary point is to be shifted for all channels
    int *last_shift_value;          ///< contains last shift value for all channels
    int **raw_mantissa;             ///< decoded mantissa bits of the difference signal
    unsigned char *larray;          ///< buffer to store the output of masked lz decompression
    int *nbits;                     ///< contains the number of bits to read for masked lz decompression for all samples
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    int highest_decoded_channel;
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} ALSDecContext;


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typedef struct ALSBlockData {
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    unsigned int block_length;      ///< number of samples within the block
    unsigned int ra_block;          ///< if true, this is a random access block
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    int          *const_block;      ///< if true, this is a constant value block
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    int          js_blocks;         ///< true if this block contains a difference signal
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    unsigned int *shift_lsbs;       ///< shift of values for this block
    unsigned int *opt_order;        ///< prediction order of this block
    int          *store_prev_samples;///< if true, carryover samples have to be stored
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    int          *use_ltp;          ///< if true, long-term prediction is used
    int          *ltp_lag;          ///< lag value for long-term prediction
    int          *ltp_gain;         ///< gain values for ltp 5-tap filter
    int32_t      *quant_cof;        ///< quantized parcor coefficients
    int32_t      *lpc_cof;          ///< coefficients of the direct form prediction
    int32_t      *raw_samples;      ///< decoded raw samples / residuals for this block
    int32_t      *prev_raw_samples; ///< contains unshifted raw samples from the previous block
    int32_t      *raw_other;        ///< decoded raw samples of the other channel of a channel pair
} ALSBlockData;


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static av_cold void dprint_specific_config(ALSDecContext *ctx)
{
#ifdef DEBUG
    AVCodecContext *avctx    = ctx->avctx;
    ALSSpecificConfig *sconf = &ctx->sconf;

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    ff_dlog(avctx, "resolution = %i\n",           sconf->resolution);
    ff_dlog(avctx, "floating = %i\n",             sconf->floating);
    ff_dlog(avctx, "frame_length = %i\n",         sconf->frame_length);
    ff_dlog(avctx, "ra_distance = %i\n",          sconf->ra_distance);
    ff_dlog(avctx, "ra_flag = %i\n",              sconf->ra_flag);
    ff_dlog(avctx, "adapt_order = %i\n",          sconf->adapt_order);
    ff_dlog(avctx, "coef_table = %i\n",           sconf->coef_table);
    ff_dlog(avctx, "long_term_prediction = %i\n", sconf->long_term_prediction);
    ff_dlog(avctx, "max_order = %i\n",            sconf->max_order);
    ff_dlog(avctx, "block_switching = %i\n",      sconf->block_switching);
    ff_dlog(avctx, "bgmc = %i\n",                 sconf->bgmc);
    ff_dlog(avctx, "sb_part = %i\n",              sconf->sb_part);
    ff_dlog(avctx, "joint_stereo = %i\n",         sconf->joint_stereo);
    ff_dlog(avctx, "mc_coding = %i\n",            sconf->mc_coding);
    ff_dlog(avctx, "chan_config = %i\n",          sconf->chan_config);
    ff_dlog(avctx, "chan_sort = %i\n",            sconf->chan_sort);
    ff_dlog(avctx, "RLSLMS = %i\n",               sconf->rlslms);
    ff_dlog(avctx, "chan_config_info = %i\n",     sconf->chan_config_info);
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#endif
}


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/** Read an ALSSpecificConfig from a buffer into the output struct.
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 */
static av_cold int read_specific_config(ALSDecContext *ctx)
{
    GetBitContext gb;
    uint64_t ht_size;
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    int i, config_offset;
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    MPEG4AudioConfig m4ac = {0};
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    ALSSpecificConfig *sconf = &ctx->sconf;
    AVCodecContext *avctx    = ctx->avctx;
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    uint32_t als_id, header_size, trailer_size;
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    int ret;
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    if ((ret = init_get_bits8(&gb, avctx->extradata, avctx->extradata_size)) < 0)
        return ret;
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    config_offset = avpriv_mpeg4audio_get_config2(&m4ac, avctx->extradata,
                                                  avctx->extradata_size, 1, avctx);
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    if (config_offset < 0)
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        return AVERROR_INVALIDDATA;
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    skip_bits_long(&gb, config_offset);

    if (get_bits_left(&gb) < (30 << 3))
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        return AVERROR_INVALIDDATA;
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    // read the fixed items
    als_id                      = get_bits_long(&gb, 32);
    avctx->sample_rate          = m4ac.sample_rate;
    skip_bits_long(&gb, 32); // sample rate already known
    sconf->samples              = get_bits_long(&gb, 32);
    avctx->channels             = m4ac.channels;
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    skip_bits(&gb, 16);      // number of channels already known
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    skip_bits(&gb, 3);       // skip file_type
    sconf->resolution           = get_bits(&gb, 3);
    sconf->floating             = get_bits1(&gb);
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    sconf->msb_first            = get_bits1(&gb);
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    sconf->frame_length         = get_bits(&gb, 16) + 1;
    sconf->ra_distance          = get_bits(&gb, 8);
    sconf->ra_flag              = get_bits(&gb, 2);
    sconf->adapt_order          = get_bits1(&gb);
    sconf->coef_table           = get_bits(&gb, 2);
    sconf->long_term_prediction = get_bits1(&gb);
    sconf->max_order            = get_bits(&gb, 10);
    sconf->block_switching      = get_bits(&gb, 2);
    sconf->bgmc                 = get_bits1(&gb);
    sconf->sb_part              = get_bits1(&gb);
    sconf->joint_stereo         = get_bits1(&gb);
    sconf->mc_coding            = get_bits1(&gb);
    sconf->chan_config          = get_bits1(&gb);
    sconf->chan_sort            = get_bits1(&gb);
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    sconf->crc_enabled          = get_bits1(&gb);
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    sconf->rlslms               = get_bits1(&gb);
    skip_bits(&gb, 5);       // skip 5 reserved bits
    skip_bits1(&gb);         // skip aux_data_enabled


    // check for ALSSpecificConfig struct
    if (als_id != MKBETAG('A','L','S','\0'))
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        return AVERROR_INVALIDDATA;
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    if (avctx->channels > FF_SANE_NB_CHANNELS) {
        avpriv_request_sample(avctx, "Huge number of channels\n");
        return AVERROR_PATCHWELCOME;
    }

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    ctx->cur_frame_length = sconf->frame_length;

    // read channel config
    if (sconf->chan_config)
        sconf->chan_config_info = get_bits(&gb, 16);
    // TODO: use this to set avctx->channel_layout


    // read channel sorting
    if (sconf->chan_sort && avctx->channels > 1) {
        int chan_pos_bits = av_ceil_log2(avctx->channels);
        int bits_needed  = avctx->channels * chan_pos_bits + 7;
        if (get_bits_left(&gb) < bits_needed)
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            return AVERROR_INVALIDDATA;
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        if (!(sconf->chan_pos = av_malloc_array(avctx->channels, sizeof(*sconf->chan_pos))))
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            return AVERROR(ENOMEM);

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        ctx->cs_switch = 1;

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        for (i = 0; i < avctx->channels; i++) {
            sconf->chan_pos[i] = -1;
        }

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        for (i = 0; i < avctx->channels; i++) {
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            int idx;

            idx = get_bits(&gb, chan_pos_bits);
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            if (idx >= avctx->channels || sconf->chan_pos[idx] != -1) {
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                av_log(avctx, AV_LOG_WARNING, "Invalid channel reordering.\n");
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                ctx->cs_switch = 0;
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                break;
            }
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            sconf->chan_pos[idx] = i;
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        }
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        align_get_bits(&gb);
    }


    // read fixed header and trailer sizes,
    // if size = 0xFFFFFFFF then there is no data field!
    if (get_bits_left(&gb) < 64)
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        return AVERROR_INVALIDDATA;
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    header_size  = get_bits_long(&gb, 32);
    trailer_size = get_bits_long(&gb, 32);
    if (header_size  == 0xFFFFFFFF)
        header_size  = 0;
    if (trailer_size == 0xFFFFFFFF)
        trailer_size = 0;
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    ht_size = ((int64_t)(header_size) + (int64_t)(trailer_size)) << 3;
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    // skip the header and trailer data
    if (get_bits_left(&gb) < ht_size)
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        return AVERROR_INVALIDDATA;
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    if (ht_size > INT32_MAX)
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        return AVERROR_PATCHWELCOME;
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    skip_bits_long(&gb, ht_size);


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    // initialize CRC calculation
    if (sconf->crc_enabled) {
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        if (get_bits_left(&gb) < 32)
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            return AVERROR_INVALIDDATA;
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        if (avctx->err_recognition & (AV_EF_CRCCHECK|AV_EF_CAREFUL)) {
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            ctx->crc_table = av_crc_get_table(AV_CRC_32_IEEE_LE);
            ctx->crc       = 0xFFFFFFFF;
            ctx->crc_org   = ~get_bits_long(&gb, 32);
        } else
            skip_bits_long(&gb, 32);
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    }


    // no need to read the rest of ALSSpecificConfig (ra_unit_size & aux data)

    dprint_specific_config(ctx);

    return 0;
}


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/** Check the ALSSpecificConfig for unsupported features.
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 */
static int check_specific_config(ALSDecContext *ctx)
{
    ALSSpecificConfig *sconf = &ctx->sconf;
    int error = 0;

    // report unsupported feature and set error value
    #define MISSING_ERR(cond, str, errval)              \
    {                                                   \
        if (cond) {                                     \
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            avpriv_report_missing_feature(ctx->avctx,   \
                                          str);         \
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            error = errval;                             \
        }                                               \
    }

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    MISSING_ERR(sconf->rlslms,    "Adaptive RLS-LMS prediction", AVERROR_PATCHWELCOME);
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    return error;
}


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/** Parse the bs_info field to extract the block partitioning used in
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 *  block switching mode, refer to ISO/IEC 14496-3, section 11.6.2.
 */
static void parse_bs_info(const uint32_t bs_info, unsigned int n,
                          unsigned int div, unsigned int **div_blocks,
                          unsigned int *num_blocks)
{
    if (n < 31 && ((bs_info << n) & 0x40000000)) {
        // if the level is valid and the investigated bit n is set
        // then recursively check both children at bits (2n+1) and (2n+2)
        n   *= 2;
        div += 1;
        parse_bs_info(bs_info, n + 1, div, div_blocks, num_blocks);
        parse_bs_info(bs_info, n + 2, div, div_blocks, num_blocks);
    } else {
        // else the bit is not set or the last level has been reached
        // (bit implicitly not set)
        **div_blocks = div;
        (*div_blocks)++;
        (*num_blocks)++;
    }
}


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491
/** Read and decode a Rice codeword.
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 */
static int32_t decode_rice(GetBitContext *gb, unsigned int k)
{
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    int max = get_bits_left(gb) - k;
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    unsigned q = get_unary(gb, 0, max);
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    int r   = k ? get_bits1(gb) : !(q & 1);

    if (k > 1) {
        q <<= (k - 1);
        q  += get_bits_long(gb, k - 1);
    } else if (!k) {
        q >>= 1;
    }
    return r ? q : ~q;
}


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/** Convert PARCOR coefficient k to direct filter coefficient.
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 */
static void parcor_to_lpc(unsigned int k, const int32_t *par, int32_t *cof)
{
    int i, j;

    for (i = 0, j = k - 1; i < j; i++, j--) {
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        unsigned tmp1 = ((MUL64(par[k], cof[j]) + (1 << 19)) >> 20);
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        cof[j]  += ((MUL64(par[k], cof[i]) + (1 << 19)) >> 20);
        cof[i]  += tmp1;
    }
    if (i == j)
        cof[i] += ((MUL64(par[k], cof[j]) + (1 << 19)) >> 20);

    cof[k] = par[k];
}


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Måns Rullgård committed
527 528
/** Read block switching field if necessary and set actual block sizes.
 *  Also assure that the block sizes of the last frame correspond to the
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 *  actual number of samples.
 */
static void get_block_sizes(ALSDecContext *ctx, unsigned int *div_blocks,
                            uint32_t *bs_info)
{
    ALSSpecificConfig *sconf     = &ctx->sconf;
    GetBitContext *gb            = &ctx->gb;
    unsigned int *ptr_div_blocks = div_blocks;
    unsigned int b;

    if (sconf->block_switching) {
        unsigned int bs_info_len = 1 << (sconf->block_switching + 2);
        *bs_info = get_bits_long(gb, bs_info_len);
        *bs_info <<= (32 - bs_info_len);
    }

    ctx->num_blocks = 0;
    parse_bs_info(*bs_info, 0, 0, &ptr_div_blocks, &ctx->num_blocks);

    // The last frame may have an overdetermined block structure given in
    // the bitstream. In that case the defined block structure would need
    // more samples than available to be consistent.
    // The block structure is actually used but the block sizes are adapted
    // to fit the actual number of available samples.
    // Example: 5 samples, 2nd level block sizes: 2 2 2 2.
    // This results in the actual block sizes:    2 2 1 0.
    // This is not specified in 14496-3 but actually done by the reference
    // codec RM22 revision 2.
    // This appears to happen in case of an odd number of samples in the last
    // frame which is actually not allowed by the block length switching part
    // of 14496-3.
    // The ALS conformance files feature an odd number of samples in the last
    // frame.

    for (b = 0; b < ctx->num_blocks; b++)
        div_blocks[b] = ctx->sconf.frame_length >> div_blocks[b];

    if (ctx->cur_frame_length != ctx->sconf.frame_length) {
        unsigned int remaining = ctx->cur_frame_length;

        for (b = 0; b < ctx->num_blocks; b++) {
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            if (remaining <= div_blocks[b]) {
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                div_blocks[b] = remaining;
                ctx->num_blocks = b + 1;
                break;
            }

            remaining -= div_blocks[b];
        }
    }
}


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/** Read the block data for a constant block
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 */
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static int read_const_block_data(ALSDecContext *ctx, ALSBlockData *bd)
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{
    ALSSpecificConfig *sconf = &ctx->sconf;
    AVCodecContext *avctx    = ctx->avctx;
    GetBitContext *gb        = &ctx->gb;

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    if (bd->block_length <= 0)
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        return AVERROR_INVALIDDATA;
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    *bd->raw_samples = 0;
    *bd->const_block = get_bits1(gb);    // 1 = constant value, 0 = zero block (silence)
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    bd->js_blocks    = get_bits1(gb);
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    // skip 5 reserved bits
    skip_bits(gb, 5);

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    if (*bd->const_block) {
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        unsigned int const_val_bits = sconf->floating ? 24 : avctx->bits_per_raw_sample;
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        *bd->raw_samples = get_sbits_long(gb, const_val_bits);
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    }

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    // ensure constant block decoding by reusing this field
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    *bd->const_block = 1;
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    return 0;
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}


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/** Decode the block data for a constant block
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 */
static void decode_const_block_data(ALSDecContext *ctx, ALSBlockData *bd)
{
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    int      smp = bd->block_length - 1;
    int32_t  val = *bd->raw_samples;
    int32_t *dst = bd->raw_samples + 1;
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    // write raw samples into buffer
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    for (; smp; smp--)
        *dst++ = val;
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}


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/** Read the block data for a non-constant block
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 */
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static int read_var_block_data(ALSDecContext *ctx, ALSBlockData *bd)
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{
    ALSSpecificConfig *sconf = &ctx->sconf;
    AVCodecContext *avctx    = ctx->avctx;
    GetBitContext *gb        = &ctx->gb;
    unsigned int k;
    unsigned int s[8];
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    unsigned int sx[8];
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    unsigned int sub_blocks, log2_sub_blocks, sb_length;
    unsigned int start      = 0;
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    unsigned int opt_order;
    int          sb;
    int32_t      *quant_cof = bd->quant_cof;
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    int32_t      *current_res;
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    // ensure variable block decoding by reusing this field
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    *bd->const_block = 0;
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    *bd->opt_order  = 1;
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    bd->js_blocks   = get_bits1(gb);

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    opt_order       = *bd->opt_order;
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    // determine the number of subblocks for entropy decoding
    if (!sconf->bgmc && !sconf->sb_part) {
        log2_sub_blocks = 0;
    } else {
        if (sconf->bgmc && sconf->sb_part)
            log2_sub_blocks = get_bits(gb, 2);
        else
            log2_sub_blocks = 2 * get_bits1(gb);
    }

    sub_blocks = 1 << log2_sub_blocks;

    // do not continue in case of a damaged stream since
    // block_length must be evenly divisible by sub_blocks
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    if (bd->block_length & (sub_blocks - 1) || bd->block_length <= 0) {
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        av_log(avctx, AV_LOG_WARNING,
               "Block length is not evenly divisible by the number of subblocks.\n");
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        return AVERROR_INVALIDDATA;
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    }

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    sb_length = bd->block_length >> log2_sub_blocks;
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    if (sconf->bgmc) {
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        s[0] = get_bits(gb, 8 + (sconf->resolution > 1));
        for (k = 1; k < sub_blocks; k++)
            s[k] = s[k - 1] + decode_rice(gb, 2);

        for (k = 0; k < sub_blocks; k++) {
            sx[k]   = s[k] & 0x0F;
            s [k] >>= 4;
        }
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    } else {
        s[0] = get_bits(gb, 4 + (sconf->resolution > 1));
        for (k = 1; k < sub_blocks; k++)
            s[k] = s[k - 1] + decode_rice(gb, 0);
    }
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    for (k = 1; k < sub_blocks; k++)
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        if (s[k] > 32) {
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            av_log(avctx, AV_LOG_ERROR, "k invalid for rice code.\n");
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            return AVERROR_INVALIDDATA;
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        }
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    if (get_bits1(gb))
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        *bd->shift_lsbs = get_bits(gb, 4) + 1;
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    *bd->store_prev_samples = (bd->js_blocks && bd->raw_other) || *bd->shift_lsbs;
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    if (!sconf->rlslms) {
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        if (sconf->adapt_order && sconf->max_order) {
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            int opt_order_length = av_ceil_log2(av_clip((bd->block_length >> 3) - 1,
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                                                2, sconf->max_order + 1));
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            *bd->opt_order       = get_bits(gb, opt_order_length);
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            if (*bd->opt_order > sconf->max_order) {
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                *bd->opt_order = sconf->max_order;
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                av_log(avctx, AV_LOG_ERROR, "Predictor order too large.\n");
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                return AVERROR_INVALIDDATA;
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            }
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        } else {
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            *bd->opt_order = sconf->max_order;
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        }
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        opt_order = *bd->opt_order;
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        if (opt_order) {
            int add_base;

            if (sconf->coef_table == 3) {
                add_base = 0x7F;

                // read coefficient 0
                quant_cof[0] = 32 * parcor_scaled_values[get_bits(gb, 7)];

                // read coefficient 1
                if (opt_order > 1)
                    quant_cof[1] = -32 * parcor_scaled_values[get_bits(gb, 7)];

                // read coefficients 2 to opt_order
                for (k = 2; k < opt_order; k++)
                    quant_cof[k] = get_bits(gb, 7);
            } else {
                int k_max;
                add_base = 1;

                // read coefficient 0 to 19
                k_max = FFMIN(opt_order, 20);
                for (k = 0; k < k_max; k++) {
                    int rice_param = parcor_rice_table[sconf->coef_table][k][1];
                    int offset     = parcor_rice_table[sconf->coef_table][k][0];
                    quant_cof[k] = decode_rice(gb, rice_param) + offset;
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                    if (quant_cof[k] < -64 || quant_cof[k] > 63) {
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                        av_log(avctx, AV_LOG_ERROR,
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                               "quant_cof %"PRId32" is out of range.\n",
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                               quant_cof[k]);
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                        return AVERROR_INVALIDDATA;
                    }
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                }

                // read coefficients 20 to 126
                k_max = FFMIN(opt_order, 127);
                for (; k < k_max; k++)
                    quant_cof[k] = decode_rice(gb, 2) + (k & 1);

                // read coefficients 127 to opt_order
                for (; k < opt_order; k++)
                    quant_cof[k] = decode_rice(gb, 1);

                quant_cof[0] = 32 * parcor_scaled_values[quant_cof[0] + 64];

                if (opt_order > 1)
                    quant_cof[1] = -32 * parcor_scaled_values[quant_cof[1] + 64];
            }

            for (k = 2; k < opt_order; k++)
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                quant_cof[k] = (quant_cof[k] * (1 << 14)) + (add_base << 13);
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        }
    }

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    // read LTP gain and lag values
    if (sconf->long_term_prediction) {
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        *bd->use_ltp = get_bits1(gb);
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        if (*bd->use_ltp) {
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            int r, c;

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            bd->ltp_gain[0]   = decode_rice(gb, 1) * 8;
            bd->ltp_gain[1]   = decode_rice(gb, 2) * 8;
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            r                 = get_unary(gb, 0, 4);
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            c                 = get_bits(gb, 2);
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            if (r >= 4) {
                av_log(avctx, AV_LOG_ERROR, "r overflow\n");
                return AVERROR_INVALIDDATA;
            }

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            bd->ltp_gain[2]   = ltp_gain_values[r][c];
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            bd->ltp_gain[3]   = decode_rice(gb, 2) * 8;
            bd->ltp_gain[4]   = decode_rice(gb, 1) * 8;
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            *bd->ltp_lag      = get_bits(gb, ctx->ltp_lag_length);
            *bd->ltp_lag     += FFMAX(4, opt_order + 1);
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        }
    }
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    // read first value and residuals in case of a random access block
797
    if (bd->ra_block) {
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        start = FFMIN(opt_order, 3);
        av_assert0(sb_length <= sconf->frame_length);
        if (sb_length <= start) {
            // opt_order or sb_length may be corrupted, either way this is unsupported and not well defined in the specification
            av_log(avctx, AV_LOG_ERROR, "Sub block length smaller or equal start\n");
            return AVERROR_PATCHWELCOME;
        }

806
        if (opt_order)
807
            bd->raw_samples[0] = decode_rice(gb, avctx->bits_per_raw_sample - 4);
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        if (opt_order > 1)
809
            bd->raw_samples[1] = decode_rice(gb, FFMIN(s[0] + 3, ctx->s_max));
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        if (opt_order > 2)
811
            bd->raw_samples[2] = decode_rice(gb, FFMIN(s[0] + 1, ctx->s_max));
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    }

    // read all residuals
    if (sconf->bgmc) {
816
        int          delta[8];
817
        unsigned int k    [8];
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        unsigned int b = av_clip((av_ceil_log2(bd->block_length) - 3) >> 1, 0, 5);

        // read most significant bits
        unsigned int high;
        unsigned int low;
        unsigned int value;

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        int ret = ff_bgmc_decode_init(gb, &high, &low, &value);
        if (ret < 0)
            return ret;
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        current_res = bd->raw_samples + start;

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        for (sb = 0; sb < sub_blocks; sb++) {
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            unsigned int sb_len  = sb_length - (sb ? 0 : start);

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            k    [sb] = s[sb] > b ? s[sb] - b : 0;
            delta[sb] = 5 - s[sb] + k[sb];

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            if (k[sb] >= 32)
                return AVERROR_INVALIDDATA;

840
            ff_bgmc_decode(gb, sb_len, current_res,
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                        delta[sb], sx[sb], &high, &low, &value, ctx->bgmc_lut, ctx->bgmc_lut_status);

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            current_res += sb_len;
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        }

        ff_bgmc_decode_end(gb);


        // read least significant bits and tails
        current_res = bd->raw_samples + start;

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        for (sb = 0; sb < sub_blocks; sb++, start = 0) {
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            unsigned int cur_tail_code = tail_code[sx[sb]][delta[sb]];
            unsigned int cur_k         = k[sb];
            unsigned int cur_s         = s[sb];

857
            for (; start < sb_length; start++) {
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                int32_t res = *current_res;

                if (res == cur_tail_code) {
                    unsigned int max_msb =   (2 + (sx[sb] > 2) + (sx[sb] > 10))
                                          << (5 - delta[sb]);

                    res = decode_rice(gb, cur_s);

                    if (res >= 0) {
                        res += (max_msb    ) << cur_k;
                    } else {
                        res -= (max_msb - 1) << cur_k;
                    }
                } else {
                    if (res > cur_tail_code)
                        res--;

                    if (res & 1)
                        res = -res;

                    res >>= 1;

                    if (cur_k) {
881
                        res  *= 1U << cur_k;
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                        res  |= get_bits_long(gb, cur_k);
                    }
                }

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                *current_res++ = res;
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            }
        }
889
    } else {
890
        current_res = bd->raw_samples + start;
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        for (sb = 0; sb < sub_blocks; sb++, start = 0)
            for (; start < sb_length; start++)
                *current_res++ = decode_rice(gb, s[sb]);
     }

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    return 0;
}


901
/** Decode the block data for a non-constant block
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 */
static int decode_var_block_data(ALSDecContext *ctx, ALSBlockData *bd)
{
    ALSSpecificConfig *sconf = &ctx->sconf;
    unsigned int block_length = bd->block_length;
    unsigned int smp = 0;
    unsigned int k;
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    int opt_order             = *bd->opt_order;
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    int sb;
    int64_t y;
    int32_t *quant_cof        = bd->quant_cof;
    int32_t *lpc_cof          = bd->lpc_cof;
    int32_t *raw_samples      = bd->raw_samples;
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    int32_t *raw_samples_end  = bd->raw_samples + bd->block_length;
916
    int32_t *lpc_cof_reversed = ctx->lpc_cof_reversed_buffer;
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918
    // reverse long-term prediction
919
    if (*bd->use_ltp) {
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        int ltp_smp;

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        for (ltp_smp = FFMAX(*bd->ltp_lag - 2, 0); ltp_smp < block_length; ltp_smp++) {
            int center = ltp_smp - *bd->ltp_lag;
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            int begin  = FFMAX(0, center - 2);
            int end    = center + 3;
            int tab    = 5 - (end - begin);
            int base;

            y = 1 << 6;

            for (base = begin; base < end; base++, tab++)
932
                y += (uint64_t)MUL64(bd->ltp_gain[tab], raw_samples[base]);
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            raw_samples[ltp_smp] += y >> 7;
        }
    }

938
    // reconstruct all samples from residuals
939
    if (bd->ra_block) {
940
        for (smp = 0; smp < FFMIN(opt_order, block_length); smp++) {
941 942 943
            y = 1 << 19;

            for (sb = 0; sb < smp; sb++)
944
                y += (uint64_t)MUL64(lpc_cof[sb], raw_samples[-(sb + 1)]);
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946
            *raw_samples++ -= y >> 20;
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            parcor_to_lpc(smp, quant_cof, lpc_cof);
        }
    } else {
        for (k = 0; k < opt_order; k++)
            parcor_to_lpc(k, quant_cof, lpc_cof);

        // store previous samples in case that they have to be altered
954
        if (*bd->store_prev_samples)
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            memcpy(bd->prev_raw_samples, raw_samples - sconf->max_order,
                   sizeof(*bd->prev_raw_samples) * sconf->max_order);
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        // reconstruct difference signal for prediction (joint-stereo)
959
        if (bd->js_blocks && bd->raw_other) {
960
            uint32_t *left, *right;
961

962
            if (bd->raw_other > raw_samples) {  // D = R - L
963
                left  = raw_samples;
964
                right = bd->raw_other;
965
            } else {                                // D = R - L
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                left  = bd->raw_other;
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                right = raw_samples;
            }

            for (sb = -1; sb >= -sconf->max_order; sb--)
                raw_samples[sb] = right[sb] - left[sb];
        }

        // reconstruct shifted signal
975
        if (*bd->shift_lsbs)
976
            for (sb = -1; sb >= -sconf->max_order; sb--)
977
                raw_samples[sb] >>= *bd->shift_lsbs;
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    }

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    // reverse linear prediction coefficients for efficiency
    lpc_cof = lpc_cof + opt_order;

    for (sb = 0; sb < opt_order; sb++)
        lpc_cof_reversed[sb] = lpc_cof[-(sb + 1)];

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    // reconstruct raw samples
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    raw_samples = bd->raw_samples + smp;
    lpc_cof     = lpc_cof_reversed + opt_order;

    for (; raw_samples < raw_samples_end; raw_samples++) {
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        y = 1 << 19;

993
        for (sb = -opt_order; sb < 0; sb++)
994
            y += (uint64_t)MUL64(lpc_cof[sb], raw_samples[sb]);
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996
        *raw_samples -= y >> 20;
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    }

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    raw_samples = bd->raw_samples;

1001
    // restore previous samples in case that they have been altered
1002
    if (*bd->store_prev_samples)
1003
        memcpy(raw_samples - sconf->max_order, bd->prev_raw_samples,
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               sizeof(*raw_samples) * sconf->max_order);

    return 0;
}


1010
/** Read the block data.
1011
 */
1012
static int read_block(ALSDecContext *ctx, ALSBlockData *bd)
1013
{
1014
    int ret;
1015
    GetBitContext *gb        = &ctx->gb;
1016
    ALSSpecificConfig *sconf = &ctx->sconf;
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1018
    *bd->shift_lsbs = 0;
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    // read block type flag and read the samples accordingly
    if (get_bits1(gb)) {
1021
        ret = read_var_block_data(ctx, bd);
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    } else {
1023
        ret = read_const_block_data(ctx, bd);
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    }

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    if (!sconf->mc_coding || ctx->js_switch)
        align_get_bits(gb);

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    return ret;
1030
}
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1033
/** Decode the block data.
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 */
static int decode_block(ALSDecContext *ctx, ALSBlockData *bd)
{
    unsigned int smp;
1038
    int ret = 0;
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    // read block type flag and read the samples accordingly
1041
    if (*bd->const_block)
1042
        decode_const_block_data(ctx, bd);
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    else
        ret = decode_var_block_data(ctx, bd); // always return 0

    if (ret < 0)
        return ret;
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    // TODO: read RLSLMS extension data

1051
    if (*bd->shift_lsbs)
1052
        for (smp = 0; smp < bd->block_length; smp++)
1053
            bd->raw_samples[smp] = (unsigned)bd->raw_samples[smp] << *bd->shift_lsbs;
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    return 0;
}


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Måns Rullgård committed
1059
/** Read and decode block data successively.
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 */
static int read_decode_block(ALSDecContext *ctx, ALSBlockData *bd)
{
    int ret;

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    if ((ret = read_block(ctx, bd)) < 0)
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        return ret;

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    return decode_block(ctx, bd);
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}


1072
/** Compute the number of samples left to decode for the current frame and
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 *  sets these samples to zero.
 */
static void zero_remaining(unsigned int b, unsigned int b_max,
                           const unsigned int *div_blocks, int32_t *buf)
{
    unsigned int count = 0;

    while (b < b_max)
1081
        count += div_blocks[b++];
1082

1083
    if (count)
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1084
        memset(buf, 0, sizeof(*buf) * count);
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}


1088
/** Decode blocks independently.
1089 1090 1091 1092 1093
 */
static int decode_blocks_ind(ALSDecContext *ctx, unsigned int ra_frame,
                             unsigned int c, const unsigned int *div_blocks,
                             unsigned int *js_blocks)
{
1094
    int ret;
1095
    unsigned int b;
1096
    ALSBlockData bd = { 0 };
1097 1098

    bd.ra_block         = ra_frame;
1099 1100 1101 1102
    bd.const_block      = ctx->const_block;
    bd.shift_lsbs       = ctx->shift_lsbs;
    bd.opt_order        = ctx->opt_order;
    bd.store_prev_samples = ctx->store_prev_samples;
1103 1104 1105
    bd.use_ltp          = ctx->use_ltp;
    bd.ltp_lag          = ctx->ltp_lag;
    bd.ltp_gain         = ctx->ltp_gain[0];
1106 1107
    bd.quant_cof        = ctx->quant_cof[0];
    bd.lpc_cof          = ctx->lpc_cof[0];
1108 1109 1110
    bd.prev_raw_samples = ctx->prev_raw_samples;
    bd.raw_samples      = ctx->raw_samples[c];

1111 1112

    for (b = 0; b < ctx->num_blocks; b++) {
1113 1114
        bd.block_length     = div_blocks[b];

1115
        if ((ret = read_decode_block(ctx, &bd)) < 0) {
1116
            // damaged block, write zero for the rest of the frame
1117
            zero_remaining(b, ctx->num_blocks, div_blocks, bd.raw_samples);
1118
            return ret;
1119
        }
1120 1121
        bd.raw_samples += div_blocks[b];
        bd.ra_block     = 0;
1122 1123 1124 1125 1126 1127
    }

    return 0;
}


1128
/** Decode blocks dependently.
1129 1130 1131 1132 1133 1134 1135 1136
 */
static int decode_blocks(ALSDecContext *ctx, unsigned int ra_frame,
                         unsigned int c, const unsigned int *div_blocks,
                         unsigned int *js_blocks)
{
    ALSSpecificConfig *sconf = &ctx->sconf;
    unsigned int offset = 0;
    unsigned int b;
1137
    int ret;
1138
    ALSBlockData bd[2] = { { 0 } };
1139 1140

    bd[0].ra_block         = ra_frame;
1141 1142 1143 1144
    bd[0].const_block      = ctx->const_block;
    bd[0].shift_lsbs       = ctx->shift_lsbs;
    bd[0].opt_order        = ctx->opt_order;
    bd[0].store_prev_samples = ctx->store_prev_samples;
1145 1146 1147
    bd[0].use_ltp          = ctx->use_ltp;
    bd[0].ltp_lag          = ctx->ltp_lag;
    bd[0].ltp_gain         = ctx->ltp_gain[0];
1148 1149
    bd[0].quant_cof        = ctx->quant_cof[0];
    bd[0].lpc_cof          = ctx->lpc_cof[0];
1150 1151 1152 1153
    bd[0].prev_raw_samples = ctx->prev_raw_samples;
    bd[0].js_blocks        = *js_blocks;

    bd[1].ra_block         = ra_frame;
1154 1155 1156 1157
    bd[1].const_block      = ctx->const_block;
    bd[1].shift_lsbs       = ctx->shift_lsbs;
    bd[1].opt_order        = ctx->opt_order;
    bd[1].store_prev_samples = ctx->store_prev_samples;
1158 1159 1160
    bd[1].use_ltp          = ctx->use_ltp;
    bd[1].ltp_lag          = ctx->ltp_lag;
    bd[1].ltp_gain         = ctx->ltp_gain[0];
1161 1162
    bd[1].quant_cof        = ctx->quant_cof[0];
    bd[1].lpc_cof          = ctx->lpc_cof[0];
1163 1164
    bd[1].prev_raw_samples = ctx->prev_raw_samples;
    bd[1].js_blocks        = *(js_blocks + 1);
1165 1166 1167 1168

    // decode all blocks
    for (b = 0; b < ctx->num_blocks; b++) {
        unsigned int s;
1169 1170 1171 1172 1173 1174 1175 1176 1177 1178

        bd[0].block_length = div_blocks[b];
        bd[1].block_length = div_blocks[b];

        bd[0].raw_samples  = ctx->raw_samples[c    ] + offset;
        bd[1].raw_samples  = ctx->raw_samples[c + 1] + offset;

        bd[0].raw_other    = bd[1].raw_samples;
        bd[1].raw_other    = bd[0].raw_samples;

1179 1180 1181
        if ((ret = read_decode_block(ctx, &bd[0])) < 0 ||
            (ret = read_decode_block(ctx, &bd[1])) < 0)
            goto fail;
1182 1183

        // reconstruct joint-stereo blocks
1184 1185
        if (bd[0].js_blocks) {
            if (bd[1].js_blocks)
1186
                av_log(ctx->avctx, AV_LOG_WARNING, "Invalid channel pair.\n");
1187 1188

            for (s = 0; s < div_blocks[b]; s++)
1189
                bd[0].raw_samples[s] = bd[1].raw_samples[s] - (unsigned)bd[0].raw_samples[s];
1190
        } else if (bd[1].js_blocks) {
1191
            for (s = 0; s < div_blocks[b]; s++)
1192
                bd[1].raw_samples[s] = bd[1].raw_samples[s] + (unsigned)bd[0].raw_samples[s];
1193 1194 1195
        }

        offset  += div_blocks[b];
1196 1197
        bd[0].ra_block = 0;
        bd[1].ra_block = 0;
1198 1199 1200 1201 1202 1203 1204 1205 1206
    }

    // store carryover raw samples,
    // the others channel raw samples are stored by the calling function.
    memmove(ctx->raw_samples[c] - sconf->max_order,
            ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,
            sizeof(*ctx->raw_samples[c]) * sconf->max_order);

    return 0;
1207 1208 1209 1210 1211
fail:
    // damaged block, write zero for the rest of the frame
    zero_remaining(b, ctx->num_blocks, div_blocks, bd[0].raw_samples);
    zero_remaining(b, ctx->num_blocks, div_blocks, bd[1].raw_samples);
    return ret;
1212 1213
}

1214 1215 1216 1217 1218 1219
static inline int als_weighting(GetBitContext *gb, int k, int off)
{
    int idx = av_clip(decode_rice(gb, k) + off,
                      0, FF_ARRAY_ELEMS(mcc_weightings) - 1);
    return mcc_weightings[idx];
}
1220

1221
/** Read the channel data.
1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233
  */
static int read_channel_data(ALSDecContext *ctx, ALSChannelData *cd, int c)
{
    GetBitContext *gb       = &ctx->gb;
    ALSChannelData *current = cd;
    unsigned int channels   = ctx->avctx->channels;
    int entries             = 0;

    while (entries < channels && !(current->stop_flag = get_bits1(gb))) {
        current->master_channel = get_bits_long(gb, av_ceil_log2(channels));

        if (current->master_channel >= channels) {
1234
            av_log(ctx->avctx, AV_LOG_ERROR, "Invalid master channel.\n");
1235
            return AVERROR_INVALIDDATA;
1236 1237 1238 1239
        }

        if (current->master_channel != c) {
            current->time_diff_flag = get_bits1(gb);
1240 1241 1242
            current->weighting[0]   = als_weighting(gb, 1, 16);
            current->weighting[1]   = als_weighting(gb, 2, 14);
            current->weighting[2]   = als_weighting(gb, 1, 16);
1243 1244

            if (current->time_diff_flag) {
1245 1246 1247
                current->weighting[3] = als_weighting(gb, 1, 16);
                current->weighting[4] = als_weighting(gb, 1, 16);
                current->weighting[5] = als_weighting(gb, 1, 16);
1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258

                current->time_diff_sign  = get_bits1(gb);
                current->time_diff_index = get_bits(gb, ctx->ltp_lag_length - 3) + 3;
            }
        }

        current++;
        entries++;
    }

    if (entries == channels) {
1259
        av_log(ctx->avctx, AV_LOG_ERROR, "Damaged channel data.\n");
1260
        return AVERROR_INVALIDDATA;
1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276
    }

    align_get_bits(gb);
    return 0;
}


/** Recursively reverts the inter-channel correlation for a block.
 */
static int revert_channel_correlation(ALSDecContext *ctx, ALSBlockData *bd,
                                       ALSChannelData **cd, int *reverted,
                                       unsigned int offset, int c)
{
    ALSChannelData *ch = cd[c];
    unsigned int   dep = 0;
    unsigned int channels = ctx->avctx->channels;
1277
    unsigned int channel_size = ctx->sconf.frame_length + ctx->sconf.max_order;
1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291

    if (reverted[c])
        return 0;

    reverted[c] = 1;

    while (dep < channels && !ch[dep].stop_flag) {
        revert_channel_correlation(ctx, bd, cd, reverted, offset,
                                   ch[dep].master_channel);

        dep++;
    }

    if (dep == channels) {
1292
        av_log(ctx->avctx, AV_LOG_WARNING, "Invalid channel correlation.\n");
1293
        return AVERROR_INVALIDDATA;
1294 1295
    }

1296 1297 1298 1299
    bd->const_block = ctx->const_block + c;
    bd->shift_lsbs  = ctx->shift_lsbs + c;
    bd->opt_order   = ctx->opt_order + c;
    bd->store_prev_samples = ctx->store_prev_samples + c;
1300 1301 1302 1303 1304 1305 1306
    bd->use_ltp     = ctx->use_ltp + c;
    bd->ltp_lag     = ctx->ltp_lag + c;
    bd->ltp_gain    = ctx->ltp_gain[c];
    bd->lpc_cof     = ctx->lpc_cof[c];
    bd->quant_cof   = ctx->quant_cof[c];
    bd->raw_samples = ctx->raw_samples[c] + offset;

1307
    for (dep = 0; !ch[dep].stop_flag; dep++) {
1308 1309 1310
        ptrdiff_t smp;
        ptrdiff_t begin = 1;
        ptrdiff_t end   = bd->block_length - 1;
1311 1312 1313
        int64_t y;
        int32_t *master = ctx->raw_samples[ch[dep].master_channel] + offset;

1314 1315 1316
        if (ch[dep].master_channel == c)
            continue;

1317 1318 1319 1320 1321
        if (ch[dep].time_diff_flag) {
            int t = ch[dep].time_diff_index;

            if (ch[dep].time_diff_sign) {
                t      = -t;
1322
                if (begin < t) {
1323
                    av_log(ctx->avctx, AV_LOG_ERROR, "begin %"PTRDIFF_SPECIFIER" smaller than time diff index %d.\n", begin, t);
1324 1325
                    return AVERROR_INVALIDDATA;
                }
1326 1327
                begin -= t;
            } else {
1328
                if (end < t) {
1329
                    av_log(ctx->avctx, AV_LOG_ERROR, "end %"PTRDIFF_SPECIFIER" smaller than time diff index %d.\n", end, t);
1330 1331
                    return AVERROR_INVALIDDATA;
                }
1332 1333 1334
                end   -= t;
            }

1335 1336 1337 1338 1339 1340 1341 1342 1343
            if (FFMIN(begin - 1, begin - 1 + t) < ctx->raw_buffer - master ||
                FFMAX(end   + 1,   end + 1 + t) > ctx->raw_buffer + channels * channel_size - master) {
                av_log(ctx->avctx, AV_LOG_ERROR,
                       "sample pointer range [%p, %p] not contained in raw_buffer [%p, %p].\n",
                       master + FFMIN(begin - 1, begin - 1 + t), master + FFMAX(end + 1,   end + 1 + t),
                       ctx->raw_buffer, ctx->raw_buffer + channels * channel_size);
                return AVERROR_INVALIDDATA;
            }

1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355
            for (smp = begin; smp < end; smp++) {
                y  = (1 << 6) +
                     MUL64(ch[dep].weighting[0], master[smp - 1    ]) +
                     MUL64(ch[dep].weighting[1], master[smp        ]) +
                     MUL64(ch[dep].weighting[2], master[smp + 1    ]) +
                     MUL64(ch[dep].weighting[3], master[smp - 1 + t]) +
                     MUL64(ch[dep].weighting[4], master[smp     + t]) +
                     MUL64(ch[dep].weighting[5], master[smp + 1 + t]);

                bd->raw_samples[smp] += y >> 7;
            }
        } else {
1356 1357 1358 1359 1360 1361 1362 1363 1364 1365

            if (begin - 1 < ctx->raw_buffer - master ||
                end   + 1 > ctx->raw_buffer + channels * channel_size - master) {
                av_log(ctx->avctx, AV_LOG_ERROR,
                       "sample pointer range [%p, %p] not contained in raw_buffer [%p, %p].\n",
                       master + begin - 1, master + end + 1,
                       ctx->raw_buffer, ctx->raw_buffer + channels * channel_size);
                return AVERROR_INVALIDDATA;
            }

1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380
            for (smp = begin; smp < end; smp++) {
                y  = (1 << 6) +
                     MUL64(ch[dep].weighting[0], master[smp - 1]) +
                     MUL64(ch[dep].weighting[1], master[smp    ]) +
                     MUL64(ch[dep].weighting[2], master[smp + 1]);

                bd->raw_samples[smp] += y >> 7;
            }
        }
    }

    return 0;
}


1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398
/** multiply two softfloats and handle the rounding off
 */
static SoftFloat_IEEE754 multiply(SoftFloat_IEEE754 a, SoftFloat_IEEE754 b) {
    uint64_t mantissa_temp;
    uint64_t mask_64;
    int cutoff_bit_count;
    unsigned char last_2_bits;
    unsigned int mantissa;
    int32_t sign;
    uint32_t return_val = 0;
    int bit_count       = 48;

    sign = a.sign ^ b.sign;

    // Multiply mantissa bits in a 64-bit register
    mantissa_temp = (uint64_t)a.mant * (uint64_t)b.mant;
    mask_64       = (uint64_t)0x1 << 47;

1399 1400 1401
    if (!mantissa_temp)
        return FLOAT_0;

1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417
    // Count the valid bit count
    while (!(mantissa_temp & mask_64) && mask_64) {
        bit_count--;
        mask_64 >>= 1;
    }

    // Round off
    cutoff_bit_count = bit_count - 24;
    if (cutoff_bit_count > 0) {
        last_2_bits = (unsigned char)(((unsigned int)mantissa_temp >> (cutoff_bit_count - 1)) & 0x3 );
        if ((last_2_bits == 0x3) || ((last_2_bits == 0x1) && ((unsigned int)mantissa_temp & ((0x1UL << (cutoff_bit_count - 1)) - 1)))) {
            // Need to round up
            mantissa_temp += (uint64_t)0x1 << cutoff_bit_count;
        }
    }

1418 1419 1420 1421 1422
    if (cutoff_bit_count >= 0) {
        mantissa = (unsigned int)(mantissa_temp >> cutoff_bit_count);
    } else {
        mantissa = (unsigned int)(mantissa_temp <<-cutoff_bit_count);
    }
1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433

    // Need one more shift?
    if (mantissa & 0x01000000ul) {
        bit_count++;
        mantissa >>= 1;
    }

    if (!sign) {
        return_val = 0x80000000U;
    }

1434
    return_val |= ((unsigned)av_clip(a.exp + b.exp + bit_count - 47, -126, 127) << 23) & 0x7F800000;
1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478
    return_val |= mantissa;
    return av_bits2sf_ieee754(return_val);
}


/** Read and decode the floating point sample data
 */
static int read_diff_float_data(ALSDecContext *ctx, unsigned int ra_frame) {
    AVCodecContext *avctx   = ctx->avctx;
    GetBitContext *gb       = &ctx->gb;
    SoftFloat_IEEE754 *acf  = ctx->acf;
    int *shift_value        = ctx->shift_value;
    int *last_shift_value   = ctx->last_shift_value;
    int *last_acf_mantissa  = ctx->last_acf_mantissa;
    int **raw_mantissa      = ctx->raw_mantissa;
    int *nbits              = ctx->nbits;
    unsigned char *larray   = ctx->larray;
    int frame_length        = ctx->cur_frame_length;
    SoftFloat_IEEE754 scale = av_int2sf_ieee754(0x1u, 23);
    unsigned int partA_flag;
    unsigned int highest_byte;
    unsigned int shift_amp;
    uint32_t tmp_32;
    int use_acf;
    int nchars;
    int i;
    int c;
    long k;
    long nbits_aligned;
    unsigned long acc;
    unsigned long j;
    uint32_t sign;
    uint32_t e;
    uint32_t mantissa;

    skip_bits_long(gb, 32); //num_bytes_diff_float
    use_acf = get_bits1(gb);

    if (ra_frame) {
        memset(last_acf_mantissa, 0, avctx->channels * sizeof(*last_acf_mantissa));
        memset(last_shift_value,  0, avctx->channels * sizeof(*last_shift_value) );
        ff_mlz_flush_dict(ctx->mlz);
    }

1479 1480 1481
    if (avctx->channels * 8 > get_bits_left(gb))
        return AVERROR_INVALIDDATA;

1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523
    for (c = 0; c < avctx->channels; ++c) {
        if (use_acf) {
            //acf_flag
            if (get_bits1(gb)) {
                tmp_32 = get_bits(gb, 23);
                last_acf_mantissa[c] = tmp_32;
            } else {
                tmp_32 = last_acf_mantissa[c];
            }
            acf[c] = av_bits2sf_ieee754(tmp_32);
        } else {
            acf[c] = FLOAT_1;
        }

        highest_byte = get_bits(gb, 2);
        partA_flag   = get_bits1(gb);
        shift_amp    = get_bits1(gb);

        if (shift_amp) {
            shift_value[c] = get_bits(gb, 8);
            last_shift_value[c] = shift_value[c];
        } else {
            shift_value[c] = last_shift_value[c];
        }

        if (partA_flag) {
            if (!get_bits1(gb)) { //uncompressed
                for (i = 0; i < frame_length; ++i) {
                    if (ctx->raw_samples[c][i] == 0) {
                        ctx->raw_mantissa[c][i] = get_bits_long(gb, 32);
                    }
                }
            } else { //compressed
                nchars = 0;
                for (i = 0; i < frame_length; ++i) {
                    if (ctx->raw_samples[c][i] == 0) {
                        nchars += 4;
                    }
                }

                tmp_32 = ff_mlz_decompression(ctx->mlz, gb, nchars, larray);
                if(tmp_32 != nchars) {
1524
                    av_log(ctx->avctx, AV_LOG_ERROR, "Error in MLZ decompression (%"PRId32", %d).\n", tmp_32, nchars);
1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550
                    return AVERROR_INVALIDDATA;
                }

                for (i = 0; i < frame_length; ++i) {
                    ctx->raw_mantissa[c][i] = AV_RB32(larray);
                }
            }
        }

        //decode part B
        if (highest_byte) {
            for (i = 0; i < frame_length; ++i) {
                if (ctx->raw_samples[c][i] != 0) {
                    //The following logic is taken from Tabel 14.45 and 14.46 from the ISO spec
                    if (av_cmp_sf_ieee754(acf[c], FLOAT_1)) {
                        nbits[i] = 23 - av_log2(abs(ctx->raw_samples[c][i]));
                    } else {
                        nbits[i] = 23;
                    }
                    nbits[i] = FFMIN(nbits[i], highest_byte*8);
                }
            }

            if (!get_bits1(gb)) { //uncompressed
                for (i = 0; i < frame_length; ++i) {
                    if (ctx->raw_samples[c][i] != 0) {
1551
                        raw_mantissa[c][i] = get_bitsz(gb, nbits[i]);
1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566
                    }
                }
            } else { //compressed
                nchars = 0;
                for (i = 0; i < frame_length; ++i) {
                    if (ctx->raw_samples[c][i]) {
                        nchars += (int) nbits[i] / 8;
                        if (nbits[i] & 7) {
                            ++nchars;
                        }
                    }
                }

                tmp_32 = ff_mlz_decompression(ctx->mlz, gb, nchars, larray);
                if(tmp_32 != nchars) {
1567
                    av_log(ctx->avctx, AV_LOG_ERROR, "Error in MLZ decompression (%"PRId32", %d).\n", tmp_32, nchars);
1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622
                    return AVERROR_INVALIDDATA;
                }

                j = 0;
                for (i = 0; i < frame_length; ++i) {
                    if (ctx->raw_samples[c][i]) {
                        if (nbits[i] & 7) {
                            nbits_aligned = 8 * ((unsigned int)(nbits[i] / 8) + 1);
                        } else {
                            nbits_aligned = nbits[i];
                        }
                        acc = 0;
                        for (k = 0; k < nbits_aligned/8; ++k) {
                            acc = (acc << 8) + larray[j++];
                        }
                        acc >>= (nbits_aligned - nbits[i]);
                        raw_mantissa[c][i] = acc;
                    }
                }
            }
        }

        for (i = 0; i < frame_length; ++i) {
            SoftFloat_IEEE754 pcm_sf = av_int2sf_ieee754(ctx->raw_samples[c][i], 0);
            pcm_sf = av_div_sf_ieee754(pcm_sf, scale);

            if (ctx->raw_samples[c][i] != 0) {
                if (!av_cmp_sf_ieee754(acf[c], FLOAT_1)) {
                    pcm_sf = multiply(acf[c], pcm_sf);
                }

                sign = pcm_sf.sign;
                e = pcm_sf.exp;
                mantissa = (pcm_sf.mant | 0x800000) + raw_mantissa[c][i];

                while(mantissa >= 0x1000000) {
                    e++;
                    mantissa >>= 1;
                }

                if (mantissa) e += (shift_value[c] - 127);
                mantissa &= 0x007fffffUL;

                tmp_32 = (sign << 31) | ((e + EXP_BIAS) << 23) | (mantissa);
                ctx->raw_samples[c][i] = tmp_32;
            } else {
                ctx->raw_samples[c][i] = raw_mantissa[c][i] & 0x007fffffUL;
            }
        }
        align_get_bits(gb);
    }
    return 0;
}


1623
/** Read the frame data.
1624 1625 1626 1627 1628 1629 1630 1631 1632 1633
 */
static int read_frame_data(ALSDecContext *ctx, unsigned int ra_frame)
{
    ALSSpecificConfig *sconf = &ctx->sconf;
    AVCodecContext *avctx    = ctx->avctx;
    GetBitContext *gb = &ctx->gb;
    unsigned int div_blocks[32];                ///< block sizes.
    unsigned int c;
    unsigned int js_blocks[2];
    uint32_t bs_info = 0;
1634
    int ret;
1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660

    // skip the size of the ra unit if present in the frame
    if (sconf->ra_flag == RA_FLAG_FRAMES && ra_frame)
        skip_bits_long(gb, 32);

    if (sconf->mc_coding && sconf->joint_stereo) {
        ctx->js_switch = get_bits1(gb);
        align_get_bits(gb);
    }

    if (!sconf->mc_coding || ctx->js_switch) {
        int independent_bs = !sconf->joint_stereo;

        for (c = 0; c < avctx->channels; c++) {
            js_blocks[0] = 0;
            js_blocks[1] = 0;

            get_block_sizes(ctx, div_blocks, &bs_info);

            // if joint_stereo and block_switching is set, independent decoding
            // is signaled via the first bit of bs_info
            if (sconf->joint_stereo && sconf->block_switching)
                if (bs_info >> 31)
                    independent_bs = 2;

            // if this is the last channel, it has to be decoded independently
1661
            if (c == avctx->channels - 1 || (c & 1))
1662 1663 1664
                independent_bs = 1;

            if (independent_bs) {
1665 1666 1667 1668
                ret = decode_blocks_ind(ctx, ra_frame, c,
                                        div_blocks, js_blocks);
                if (ret < 0)
                    return ret;
1669 1670
                independent_bs--;
            } else {
1671 1672 1673
                ret = decode_blocks(ctx, ra_frame, c, div_blocks, js_blocks);
                if (ret < 0)
                    return ret;
1674 1675 1676 1677 1678 1679 1680 1681

                c++;
            }

            // store carryover raw samples
            memmove(ctx->raw_samples[c] - sconf->max_order,
                    ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,
                    sizeof(*ctx->raw_samples[c]) * sconf->max_order);
1682
            ctx->highest_decoded_channel = c;
1683 1684
        }
    } else { // multi-channel coding
1685
        ALSBlockData   bd = { 0 };
1686
        int            b, ret;
1687 1688 1689 1690 1691
        int            *reverted_channels = ctx->reverted_channels;
        unsigned int   offset             = 0;

        for (c = 0; c < avctx->channels; c++)
            if (ctx->chan_data[c] < ctx->chan_data_buffer) {
1692
                av_log(ctx->avctx, AV_LOG_ERROR, "Invalid channel data.\n");
1693
                return AVERROR_INVALIDDATA;
1694 1695 1696 1697 1698 1699 1700
            }

        memset(reverted_channels, 0, sizeof(*reverted_channels) * avctx->channels);

        bd.ra_block         = ra_frame;
        bd.prev_raw_samples = ctx->prev_raw_samples;

1701 1702
        get_block_sizes(ctx, div_blocks, &bs_info);

1703 1704
        for (b = 0; b < ctx->num_blocks; b++) {
            bd.block_length = div_blocks[b];
1705 1706
            if (bd.block_length <= 0) {
                av_log(ctx->avctx, AV_LOG_WARNING,
1707 1708
                       "Invalid block length %u in channel data!\n",
                       bd.block_length);
1709 1710
                continue;
            }
1711 1712

            for (c = 0; c < avctx->channels; c++) {
1713 1714 1715 1716
                bd.const_block = ctx->const_block + c;
                bd.shift_lsbs  = ctx->shift_lsbs + c;
                bd.opt_order   = ctx->opt_order + c;
                bd.store_prev_samples = ctx->store_prev_samples + c;
1717 1718 1719 1720 1721 1722 1723 1724
                bd.use_ltp     = ctx->use_ltp + c;
                bd.ltp_lag     = ctx->ltp_lag + c;
                bd.ltp_gain    = ctx->ltp_gain[c];
                bd.lpc_cof     = ctx->lpc_cof[c];
                bd.quant_cof   = ctx->quant_cof[c];
                bd.raw_samples = ctx->raw_samples[c] + offset;
                bd.raw_other   = NULL;

1725 1726 1727 1728
                if ((ret = read_block(ctx, &bd)) < 0)
                    return ret;
                if ((ret = read_channel_data(ctx, ctx->chan_data[c], c)) < 0)
                    return ret;
1729 1730
            }

1731 1732 1733 1734 1735 1736
            for (c = 0; c < avctx->channels; c++) {
                ret = revert_channel_correlation(ctx, &bd, ctx->chan_data,
                                                 reverted_channels, offset, c);
                if (ret < 0)
                    return ret;
            }
1737
            for (c = 0; c < avctx->channels; c++) {
1738 1739 1740 1741
                bd.const_block = ctx->const_block + c;
                bd.shift_lsbs  = ctx->shift_lsbs + c;
                bd.opt_order   = ctx->opt_order + c;
                bd.store_prev_samples = ctx->store_prev_samples + c;
1742 1743 1744 1745 1746 1747
                bd.use_ltp     = ctx->use_ltp + c;
                bd.ltp_lag     = ctx->ltp_lag + c;
                bd.ltp_gain    = ctx->ltp_gain[c];
                bd.lpc_cof     = ctx->lpc_cof[c];
                bd.quant_cof   = ctx->quant_cof[c];
                bd.raw_samples = ctx->raw_samples[c] + offset;
1748

1749 1750
                if ((ret = decode_block(ctx, &bd)) < 0)
                    return ret;
1751 1752

                ctx->highest_decoded_channel = FFMAX(ctx->highest_decoded_channel, c);
1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764
            }

            memset(reverted_channels, 0, avctx->channels * sizeof(*reverted_channels));
            offset      += div_blocks[b];
            bd.ra_block  = 0;
        }

        // store carryover raw samples
        for (c = 0; c < avctx->channels; c++)
            memmove(ctx->raw_samples[c] - sconf->max_order,
                    ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,
                    sizeof(*ctx->raw_samples[c]) * sconf->max_order);
1765 1766
    }

1767 1768 1769
    if (sconf->floating) {
        read_diff_float_data(ctx, ra_frame);
    }
1770

1771 1772 1773 1774 1775
    if (get_bits_left(gb) < 0) {
        av_log(ctx->avctx, AV_LOG_ERROR, "Overread %d\n", -get_bits_left(gb));
        return AVERROR_INVALIDDATA;
    }

1776 1777 1778 1779
    return 0;
}


1780
/** Decode an ALS frame.
1781
 */
1782
static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr,
1783 1784 1785
                        AVPacket *avpkt)
{
    ALSDecContext *ctx       = avctx->priv_data;
1786
    AVFrame *frame           = data;
1787 1788 1789
    ALSSpecificConfig *sconf = &ctx->sconf;
    const uint8_t *buffer    = avpkt->data;
    int buffer_size          = avpkt->size;
1790
    int invalid_frame, ret;
1791 1792
    unsigned int c, sample, ra_frame, bytes_read, shift;

1793 1794
    if ((ret = init_get_bits8(&ctx->gb, buffer, buffer_size)) < 0)
        return ret;
1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808

    // In the case that the distance between random access frames is set to zero
    // (sconf->ra_distance == 0) no frame is treated as a random access frame.
    // For the first frame, if prediction is used, all samples used from the
    // previous frame are assumed to be zero.
    ra_frame = sconf->ra_distance && !(ctx->frame_id % sconf->ra_distance);

    // the last frame to decode might have a different length
    if (sconf->samples != 0xFFFFFFFF)
        ctx->cur_frame_length = FFMIN(sconf->samples - ctx->frame_id * (uint64_t) sconf->frame_length,
                                      sconf->frame_length);
    else
        ctx->cur_frame_length = sconf->frame_length;

1809
    ctx->highest_decoded_channel = 0;
1810
    // decode the frame data
1811
    if ((invalid_frame = read_frame_data(ctx, ra_frame)) < 0)
1812 1813 1814
        av_log(ctx->avctx, AV_LOG_WARNING,
               "Reading frame data failed. Skipping RA unit.\n");

1815 1816 1817
    if (ctx->highest_decoded_channel == 0)
        return AVERROR_INVALIDDATA;

1818 1819
    ctx->frame_id++;

1820
    /* get output buffer */
1821
    frame->nb_samples = ctx->cur_frame_length;
1822
    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
1823
        return ret;
1824 1825

    // transform decoded frame into output format
1826 1827
    #define INTERLEAVE_OUTPUT(bps)                                                   \
    {                                                                                \
1828
        int##bps##_t *dest = (int##bps##_t*)frame->data[0];                          \
1829
        int channels = avctx->channels;                                              \
1830 1831
        int32_t *raw_samples = ctx->raw_samples[0];                                  \
        int raw_step = channels > 1 ? ctx->raw_samples[1] - raw_samples : 1;         \
1832
        shift = bps - ctx->avctx->bits_per_raw_sample;                               \
1833
        if (!ctx->cs_switch) {                                                       \
1834
            for (sample = 0; sample < ctx->cur_frame_length; sample++)               \
1835
                for (c = 0; c < channels; c++)                                       \
1836
                    *dest++ = raw_samples[c*raw_step + sample] * (1U << shift);      \
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Paul B Mahol committed
1837 1838
        } else {                                                                     \
            for (sample = 0; sample < ctx->cur_frame_length; sample++)               \
1839
                for (c = 0; c < channels; c++)                                       \
1840
                    *dest++ = raw_samples[sconf->chan_pos[c]*raw_step + sample] * (1U << shift);\
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Paul B Mahol committed
1841
        }                                                                            \
1842 1843 1844 1845 1846 1847 1848 1849
    }

    if (ctx->avctx->bits_per_raw_sample <= 16) {
        INTERLEAVE_OUTPUT(16)
    } else {
        INTERLEAVE_OUTPUT(32)
    }

1850
    // update CRC
1851
    if (sconf->crc_enabled && (avctx->err_recognition & (AV_EF_CRCCHECK|AV_EF_CAREFUL))) {
1852 1853 1854
        int swap = HAVE_BIGENDIAN != sconf->msb_first;

        if (ctx->avctx->bits_per_raw_sample == 24) {
1855
            int32_t *src = (int32_t *)frame->data[0];
1856 1857 1858 1859 1860 1861 1862

            for (sample = 0;
                 sample < ctx->cur_frame_length * avctx->channels;
                 sample++) {
                int32_t v;

                if (swap)
1863
                    v = av_bswap32(src[sample]);
1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875
                else
                    v = src[sample];
                if (!HAVE_BIGENDIAN)
                    v >>= 8;

                ctx->crc = av_crc(ctx->crc_table, ctx->crc, (uint8_t*)(&v), 3);
            }
        } else {
            uint8_t *crc_source;

            if (swap) {
                if (ctx->avctx->bits_per_raw_sample <= 16) {
1876
                    int16_t *src  = (int16_t*) frame->data[0];
1877 1878 1879 1880
                    int16_t *dest = (int16_t*) ctx->crc_buffer;
                    for (sample = 0;
                         sample < ctx->cur_frame_length * avctx->channels;
                         sample++)
1881
                        *dest++ = av_bswap16(src[sample]);
1882
                } else {
1883 1884 1885
                    ctx->bdsp.bswap_buf((uint32_t *) ctx->crc_buffer,
                                        (uint32_t *) frame->data[0],
                                        ctx->cur_frame_length * avctx->channels);
1886 1887 1888
                }
                crc_source = ctx->crc_buffer;
            } else {
1889
                crc_source = frame->data[0];
1890 1891
            }

1892 1893 1894
            ctx->crc = av_crc(ctx->crc_table, ctx->crc, crc_source,
                              ctx->cur_frame_length * avctx->channels *
                              av_get_bytes_per_sample(avctx->sample_fmt));
1895 1896 1897 1898 1899 1900
        }


        // check CRC sums if this is the last frame
        if (ctx->cur_frame_length != sconf->frame_length &&
            ctx->crc_org != ctx->crc) {
1901
            av_log(avctx, AV_LOG_ERROR, "CRC error.\n");
1902 1903
            if (avctx->err_recognition & AV_EF_EXPLODE)
                return AVERROR_INVALIDDATA;
1904 1905 1906
        }
    }

1907
    *got_frame_ptr = 1;
1908

1909 1910 1911 1912 1913 1914 1915
    bytes_read = invalid_frame ? buffer_size :
                                 (get_bits_count(&ctx->gb) + 7) >> 3;

    return bytes_read;
}


1916
/** Uninitialize the ALS decoder.
1917 1918 1919 1920
 */
static av_cold int decode_end(AVCodecContext *avctx)
{
    ALSDecContext *ctx = avctx->priv_data;
1921
    int i;
1922 1923 1924

    av_freep(&ctx->sconf.chan_pos);

1925 1926
    ff_bgmc_end(&ctx->bgmc_lut, &ctx->bgmc_lut_status);

1927 1928 1929 1930
    av_freep(&ctx->const_block);
    av_freep(&ctx->shift_lsbs);
    av_freep(&ctx->opt_order);
    av_freep(&ctx->store_prev_samples);
1931 1932 1933 1934
    av_freep(&ctx->use_ltp);
    av_freep(&ctx->ltp_lag);
    av_freep(&ctx->ltp_gain);
    av_freep(&ctx->ltp_gain_buffer);
1935 1936
    av_freep(&ctx->quant_cof);
    av_freep(&ctx->lpc_cof);
1937 1938
    av_freep(&ctx->quant_cof_buffer);
    av_freep(&ctx->lpc_cof_buffer);
1939
    av_freep(&ctx->lpc_cof_reversed_buffer);
1940 1941 1942
    av_freep(&ctx->prev_raw_samples);
    av_freep(&ctx->raw_samples);
    av_freep(&ctx->raw_buffer);
1943 1944 1945
    av_freep(&ctx->chan_data);
    av_freep(&ctx->chan_data_buffer);
    av_freep(&ctx->reverted_channels);
1946
    av_freep(&ctx->crc_buffer);
1947 1948 1949 1950
    if (ctx->mlz) {
        av_freep(&ctx->mlz->dict);
        av_freep(&ctx->mlz);
    }
1951 1952 1953 1954
    av_freep(&ctx->acf);
    av_freep(&ctx->last_acf_mantissa);
    av_freep(&ctx->shift_value);
    av_freep(&ctx->last_shift_value);
1955 1956 1957 1958 1959 1960
    if (ctx->raw_mantissa) {
        for (i = 0; i < avctx->channels; i++) {
            av_freep(&ctx->raw_mantissa[i]);
        }
        av_freep(&ctx->raw_mantissa);
    }
1961 1962
    av_freep(&ctx->larray);
    av_freep(&ctx->nbits);
1963 1964 1965 1966 1967

    return 0;
}


1968
/** Initialize the ALS decoder.
1969 1970 1971 1972 1973
 */
static av_cold int decode_init(AVCodecContext *avctx)
{
    unsigned int c;
    unsigned int channel_size;
1974
    int num_buffers, ret;
1975 1976 1977 1978 1979
    ALSDecContext *ctx = avctx->priv_data;
    ALSSpecificConfig *sconf = &ctx->sconf;
    ctx->avctx = avctx;

    if (!avctx->extradata) {
1980
        av_log(avctx, AV_LOG_ERROR, "Missing required ALS extradata.\n");
1981
        return AVERROR_INVALIDDATA;
1982 1983
    }

1984
    if ((ret = read_specific_config(ctx)) < 0) {
1985
        av_log(avctx, AV_LOG_ERROR, "Reading ALSSpecificConfig failed.\n");
1986
        goto fail;
1987 1988
    }

1989 1990
    if ((ret = check_specific_config(ctx)) < 0) {
        goto fail;
1991 1992
    }

1993 1994 1995 1996 1997
    if (sconf->bgmc) {
        ret = ff_bgmc_init(avctx, &ctx->bgmc_lut, &ctx->bgmc_lut_status);
        if (ret < 0)
            goto fail;
    }
1998
    if (sconf->floating) {
1999
        avctx->sample_fmt          = AV_SAMPLE_FMT_FLT;
2000 2001 2002
        avctx->bits_per_raw_sample = 32;
    } else {
        avctx->sample_fmt          = sconf->resolution > 1
2003
                                     ? AV_SAMPLE_FMT_S32 : AV_SAMPLE_FMT_S16;
2004
        avctx->bits_per_raw_sample = (sconf->resolution + 1) * 8;
2005 2006 2007 2008 2009 2010
        if (avctx->bits_per_raw_sample > 32) {
            av_log(avctx, AV_LOG_ERROR, "Bits per raw sample %d larger than 32.\n",
                   avctx->bits_per_raw_sample);
            ret = AVERROR_INVALIDDATA;
            goto fail;
        }
2011 2012
    }

2013 2014 2015 2016 2017
    // set maximum Rice parameter for progressive decoding based on resolution
    // This is not specified in 14496-3 but actually done by the reference
    // codec RM22 revision 2.
    ctx->s_max = sconf->resolution > 1 ? 31 : 15;

2018 2019 2020 2021
    // set lag value for long-term prediction
    ctx->ltp_lag_length = 8 + (avctx->sample_rate >=  96000) +
                              (avctx->sample_rate >= 192000);

2022 2023
    // allocate quantized parcor coefficient buffer
    num_buffers = sconf->mc_coding ? avctx->channels : 1;
2024 2025
    if (num_buffers * (uint64_t)num_buffers > INT_MAX) // protect chan_data_buffer allocation
        return AVERROR_INVALIDDATA;
2026

2027 2028 2029 2030 2031 2032 2033 2034
    ctx->quant_cof        = av_malloc_array(num_buffers, sizeof(*ctx->quant_cof));
    ctx->lpc_cof          = av_malloc_array(num_buffers, sizeof(*ctx->lpc_cof));
    ctx->quant_cof_buffer = av_malloc_array(num_buffers * sconf->max_order,
                                            sizeof(*ctx->quant_cof_buffer));
    ctx->lpc_cof_buffer   = av_malloc_array(num_buffers * sconf->max_order,
                                            sizeof(*ctx->lpc_cof_buffer));
    ctx->lpc_cof_reversed_buffer = av_malloc_array(sconf->max_order,
                                                   sizeof(*ctx->lpc_cof_buffer));
2035

2036 2037
    if (!ctx->quant_cof              || !ctx->lpc_cof        ||
        !ctx->quant_cof_buffer       || !ctx->lpc_cof_buffer ||
2038
        !ctx->lpc_cof_reversed_buffer) {
2039
        av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
2040 2041
        ret = AVERROR(ENOMEM);
        goto fail;
2042 2043 2044 2045 2046 2047 2048 2049
    }

    // assign quantized parcor coefficient buffers
    for (c = 0; c < num_buffers; c++) {
        ctx->quant_cof[c] = ctx->quant_cof_buffer + c * sconf->max_order;
        ctx->lpc_cof[c]   = ctx->lpc_cof_buffer   + c * sconf->max_order;
    }

2050
    // allocate and assign lag and gain data buffer for ltp mode
2051 2052 2053 2054 2055 2056 2057 2058
    ctx->const_block     = av_malloc_array(num_buffers, sizeof(*ctx->const_block));
    ctx->shift_lsbs      = av_malloc_array(num_buffers, sizeof(*ctx->shift_lsbs));
    ctx->opt_order       = av_malloc_array(num_buffers, sizeof(*ctx->opt_order));
    ctx->store_prev_samples = av_malloc_array(num_buffers, sizeof(*ctx->store_prev_samples));
    ctx->use_ltp         = av_mallocz_array(num_buffers, sizeof(*ctx->use_ltp));
    ctx->ltp_lag         = av_malloc_array(num_buffers, sizeof(*ctx->ltp_lag));
    ctx->ltp_gain        = av_malloc_array(num_buffers, sizeof(*ctx->ltp_gain));
    ctx->ltp_gain_buffer = av_malloc_array(num_buffers * 5, sizeof(*ctx->ltp_gain_buffer));
2059

2060 2061 2062
    if (!ctx->const_block || !ctx->shift_lsbs ||
        !ctx->opt_order || !ctx->store_prev_samples ||
        !ctx->use_ltp  || !ctx->ltp_lag ||
2063
        !ctx->ltp_gain || !ctx->ltp_gain_buffer) {
2064
        av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
2065 2066
        ret = AVERROR(ENOMEM);
        goto fail;
2067 2068 2069 2070 2071
    }

    for (c = 0; c < num_buffers; c++)
        ctx->ltp_gain[c] = ctx->ltp_gain_buffer + c * 5;

2072 2073
    // allocate and assign channel data buffer for mcc mode
    if (sconf->mc_coding) {
2074
        ctx->chan_data_buffer  = av_mallocz_array(num_buffers * num_buffers,
2075
                                                 sizeof(*ctx->chan_data_buffer));
2076
        ctx->chan_data         = av_mallocz_array(num_buffers,
2077 2078 2079
                                                 sizeof(*ctx->chan_data));
        ctx->reverted_channels = av_malloc_array(num_buffers,
                                                 sizeof(*ctx->reverted_channels));
2080 2081

        if (!ctx->chan_data_buffer || !ctx->chan_data || !ctx->reverted_channels) {
2082
            av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
2083 2084
            ret = AVERROR(ENOMEM);
            goto fail;
2085 2086 2087
        }

        for (c = 0; c < num_buffers; c++)
2088
            ctx->chan_data[c] = ctx->chan_data_buffer + c * num_buffers;
2089 2090 2091 2092 2093 2094
    } else {
        ctx->chan_data         = NULL;
        ctx->chan_data_buffer  = NULL;
        ctx->reverted_channels = NULL;
    }

2095 2096
    channel_size      = sconf->frame_length + sconf->max_order;

2097 2098 2099
    ctx->prev_raw_samples = av_malloc_array(sconf->max_order, sizeof(*ctx->prev_raw_samples));
    ctx->raw_buffer       = av_mallocz_array(avctx->channels * channel_size, sizeof(*ctx->raw_buffer));
    ctx->raw_samples      = av_malloc_array(avctx->channels, sizeof(*ctx->raw_samples));
2100

2101 2102 2103 2104 2105
    if (sconf->floating) {
        ctx->acf               = av_malloc_array(avctx->channels, sizeof(*ctx->acf));
        ctx->shift_value       = av_malloc_array(avctx->channels, sizeof(*ctx->shift_value));
        ctx->last_shift_value  = av_malloc_array(avctx->channels, sizeof(*ctx->last_shift_value));
        ctx->last_acf_mantissa = av_malloc_array(avctx->channels, sizeof(*ctx->last_acf_mantissa));
2106
        ctx->raw_mantissa      = av_mallocz_array(avctx->channels, sizeof(*ctx->raw_mantissa));
2107 2108 2109

        ctx->larray = av_malloc_array(ctx->cur_frame_length * 4, sizeof(*ctx->larray));
        ctx->nbits  = av_malloc_array(ctx->cur_frame_length, sizeof(*ctx->nbits));
2110
        ctx->mlz    = av_mallocz(sizeof(*ctx->mlz));
2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126

        if (!ctx->mlz || !ctx->acf || !ctx->shift_value || !ctx->last_shift_value
            || !ctx->last_acf_mantissa || !ctx->raw_mantissa) {
            av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
            ret = AVERROR(ENOMEM);
            goto fail;
        }

        ff_mlz_init_dict(avctx, ctx->mlz);
        ff_mlz_flush_dict(ctx->mlz);

        for (c = 0; c < avctx->channels; ++c) {
            ctx->raw_mantissa[c] = av_mallocz_array(ctx->cur_frame_length, sizeof(**ctx->raw_mantissa));
        }
    }

2127 2128
    // allocate previous raw sample buffer
    if (!ctx->prev_raw_samples || !ctx->raw_buffer|| !ctx->raw_samples) {
2129
        av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
2130 2131
        ret = AVERROR(ENOMEM);
        goto fail;
2132 2133 2134 2135 2136 2137 2138
    }

    // assign raw samples buffers
    ctx->raw_samples[0] = ctx->raw_buffer + sconf->max_order;
    for (c = 1; c < avctx->channels; c++)
        ctx->raw_samples[c] = ctx->raw_samples[c - 1] + channel_size;

2139 2140
    // allocate crc buffer
    if (HAVE_BIGENDIAN != sconf->msb_first && sconf->crc_enabled &&
2141
        (avctx->err_recognition & (AV_EF_CRCCHECK|AV_EF_CAREFUL))) {
2142 2143 2144 2145
        ctx->crc_buffer = av_malloc_array(ctx->cur_frame_length *
                                          avctx->channels *
                                          av_get_bytes_per_sample(avctx->sample_fmt),
                                          sizeof(*ctx->crc_buffer));
2146
        if (!ctx->crc_buffer) {
2147
            av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
2148 2149
            ret = AVERROR(ENOMEM);
            goto fail;
2150 2151 2152
        }
    }

2153
    ff_bswapdsp_init(&ctx->bdsp);
2154

2155
    return 0;
2156 2157 2158

fail:
    return ret;
2159 2160 2161
}


2162
/** Flush (reset) the frame ID after seeking.
2163 2164 2165 2166 2167 2168 2169 2170 2171
 */
static av_cold void flush(AVCodecContext *avctx)
{
    ALSDecContext *ctx = avctx->priv_data;

    ctx->frame_id = 0;
}


2172
AVCodec ff_als_decoder = {
2173
    .name           = "als",
2174
    .long_name      = NULL_IF_CONFIG_SMALL("MPEG-4 Audio Lossless Coding (ALS)"),
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    .type           = AVMEDIA_TYPE_AUDIO,
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    .id             = AV_CODEC_ID_MP4ALS,
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    .priv_data_size = sizeof(ALSDecContext),
    .init           = decode_init,
    .close          = decode_end,
    .decode         = decode_frame,
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    .flush          = flush,
2182
    .capabilities   = AV_CODEC_CAP_SUBFRAMES | AV_CODEC_CAP_DR1,
2183
    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,
2184
};