alsdec.c 76.4 KB
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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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} 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_config(&m4ac, avctx->extradata,
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                                                 avctx->extradata_size * 8, 1);
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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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    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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485
/** 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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    int q   = get_unary(gb, 0, max);
    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--) {
        int tmp1 = ((MUL64(par[k], cof[j]) + (1 << 19)) >> 20);
        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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521 522
/** 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)) {
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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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        if (*bd->opt_order > bd->block_length) {
            *bd->opt_order = bd->block_length;
            av_log(avctx, AV_LOG_ERROR, "Predictor order too large.\n");
            return AVERROR_INVALIDDATA;
        }
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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) << 3;
            bd->ltp_gain[1]   = decode_rice(gb, 2) << 3;
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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) << 3;
            bd->ltp_gain[4]   = decode_rice(gb, 1) << 3;
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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
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    if (bd->ra_block) {
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        if (opt_order)
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            bd->raw_samples[0] = decode_rice(gb, avctx->bits_per_raw_sample - 4);
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        if (opt_order > 1)
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            bd->raw_samples[1] = decode_rice(gb, FFMIN(s[0] + 3, ctx->s_max));
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        if (opt_order > 2)
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            bd->raw_samples[2] = decode_rice(gb, FFMIN(s[0] + 1, ctx->s_max));
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        start = FFMIN(opt_order, 3);
    }

    // read all residuals
    if (sconf->bgmc) {
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        int          delta[8];
810
        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;

        ff_bgmc_decode_init(gb, &high, &low, &value);

        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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            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];

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            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) {
869
                        res  *= 1 << cur_k;
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                        res  |= get_bits_long(gb, cur_k);
                    }
                }

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                *current_res++ = res;
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            }
        }
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    } else {
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        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;
}


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/** 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;
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    int32_t *lpc_cof_reversed = ctx->lpc_cof_reversed_buffer;
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    // reverse long-term prediction
907
    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++)
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                y += MUL64(bd->ltp_gain[tab], raw_samples[base]);
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            raw_samples[ltp_smp] += y >> 7;
        }
    }

926
    // reconstruct all samples from residuals
927
    if (bd->ra_block) {
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        for (smp = 0; smp < opt_order; smp++) {
            y = 1 << 19;

            for (sb = 0; sb < smp; sb++)
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                y += MUL64(lpc_cof[sb], raw_samples[-(sb + 1)]);
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            *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
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        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)
947
        if (bd->js_blocks && bd->raw_other) {
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            int32_t *left, *right;

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            if (bd->raw_other > raw_samples) {  // D = R - L
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                left  = raw_samples;
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                right = bd->raw_other;
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            } 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
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        if (*bd->shift_lsbs)
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            for (sb = -1; sb >= -sconf->max_order; sb--)
965
                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;

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        for (sb = -opt_order; sb < 0; sb++)
            y += MUL64(lpc_cof[sb], raw_samples[sb]);
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984
        *raw_samples -= y >> 20;
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    }

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    raw_samples = bd->raw_samples;

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

    return 0;
}


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/** Read the block data.
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 */
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static int read_block(ALSDecContext *ctx, ALSBlockData *bd)
1001
{
1002
    int ret;
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    GetBitContext *gb        = &ctx->gb;
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    ALSSpecificConfig *sconf = &ctx->sconf;
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1006
    *bd->shift_lsbs = 0;
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    // read block type flag and read the samples accordingly
    if (get_bits1(gb)) {
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        ret = read_var_block_data(ctx, bd);
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    } else {
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        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;
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}
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1021
/** Decode the block data.
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 */
static int decode_block(ALSDecContext *ctx, ALSBlockData *bd)
{
    unsigned int smp;
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    int ret = 0;
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    // read block type flag and read the samples accordingly
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    if (*bd->const_block)
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        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

1039
    if (*bd->shift_lsbs)
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        for (smp = 0; smp < bd->block_length; smp++)
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            bd->raw_samples[smp] <<= *bd->shift_lsbs;
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    return 0;
}


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1047
/** 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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}


1060
/** 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)
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        count += div_blocks[b++];
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1071
    if (count)
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        memset(buf, 0, sizeof(*buf) * count);
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}


1076
/** Decode blocks independently.
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 */
static int decode_blocks_ind(ALSDecContext *ctx, unsigned int ra_frame,
                             unsigned int c, const unsigned int *div_blocks,
                             unsigned int *js_blocks)
{
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    int ret;
1083
    unsigned int b;
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    ALSBlockData bd = { 0 };
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    bd.ra_block         = ra_frame;
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    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;
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    bd.use_ltp          = ctx->use_ltp;
    bd.ltp_lag          = ctx->ltp_lag;
    bd.ltp_gain         = ctx->ltp_gain[0];
1094 1095
    bd.quant_cof        = ctx->quant_cof[0];
    bd.lpc_cof          = ctx->lpc_cof[0];
1096 1097 1098
    bd.prev_raw_samples = ctx->prev_raw_samples;
    bd.raw_samples      = ctx->raw_samples[c];

1099 1100

    for (b = 0; b < ctx->num_blocks; b++) {
1101 1102
        bd.block_length     = div_blocks[b];

1103
        if ((ret = read_decode_block(ctx, &bd)) < 0) {
1104
            // damaged block, write zero for the rest of the frame
1105
            zero_remaining(b, ctx->num_blocks, div_blocks, bd.raw_samples);
1106
            return ret;
1107
        }
1108 1109
        bd.raw_samples += div_blocks[b];
        bd.ra_block     = 0;
1110 1111 1112 1113 1114 1115
    }

    return 0;
}


1116
/** Decode blocks dependently.
1117 1118 1119 1120 1121 1122 1123 1124
 */
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;
1125
    int ret;
1126
    ALSBlockData bd[2] = { { 0 } };
1127 1128

    bd[0].ra_block         = ra_frame;
1129 1130 1131 1132
    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;
1133 1134 1135
    bd[0].use_ltp          = ctx->use_ltp;
    bd[0].ltp_lag          = ctx->ltp_lag;
    bd[0].ltp_gain         = ctx->ltp_gain[0];
1136 1137
    bd[0].quant_cof        = ctx->quant_cof[0];
    bd[0].lpc_cof          = ctx->lpc_cof[0];
1138 1139 1140 1141
    bd[0].prev_raw_samples = ctx->prev_raw_samples;
    bd[0].js_blocks        = *js_blocks;

    bd[1].ra_block         = ra_frame;
1142 1143 1144 1145
    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;
1146 1147 1148
    bd[1].use_ltp          = ctx->use_ltp;
    bd[1].ltp_lag          = ctx->ltp_lag;
    bd[1].ltp_gain         = ctx->ltp_gain[0];
1149 1150
    bd[1].quant_cof        = ctx->quant_cof[0];
    bd[1].lpc_cof          = ctx->lpc_cof[0];
1151 1152
    bd[1].prev_raw_samples = ctx->prev_raw_samples;
    bd[1].js_blocks        = *(js_blocks + 1);
1153 1154 1155 1156

    // decode all blocks
    for (b = 0; b < ctx->num_blocks; b++) {
        unsigned int s;
1157 1158 1159 1160 1161 1162 1163 1164 1165 1166

        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;

1167 1168 1169
        if ((ret = read_decode_block(ctx, &bd[0])) < 0 ||
            (ret = read_decode_block(ctx, &bd[1])) < 0)
            goto fail;
1170 1171

        // reconstruct joint-stereo blocks
1172 1173
        if (bd[0].js_blocks) {
            if (bd[1].js_blocks)
1174
                av_log(ctx->avctx, AV_LOG_WARNING, "Invalid channel pair.\n");
1175 1176

            for (s = 0; s < div_blocks[b]; s++)
1177 1178
                bd[0].raw_samples[s] = bd[1].raw_samples[s] - bd[0].raw_samples[s];
        } else if (bd[1].js_blocks) {
1179
            for (s = 0; s < div_blocks[b]; s++)
1180
                bd[1].raw_samples[s] = bd[1].raw_samples[s] + bd[0].raw_samples[s];
1181 1182 1183
        }

        offset  += div_blocks[b];
1184 1185
        bd[0].ra_block = 0;
        bd[1].ra_block = 0;
1186 1187 1188 1189 1190 1191 1192 1193 1194
    }

    // 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;
1195 1196 1197 1198 1199
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;
1200 1201
}

1202 1203 1204 1205 1206 1207
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];
}
1208

1209
/** Read the channel data.
1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221
  */
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) {
1222
            av_log(ctx->avctx, AV_LOG_ERROR, "Invalid master channel.\n");
1223
            return AVERROR_INVALIDDATA;
1224 1225 1226 1227
        }

        if (current->master_channel != c) {
            current->time_diff_flag = get_bits1(gb);
1228 1229 1230
            current->weighting[0]   = als_weighting(gb, 1, 16);
            current->weighting[1]   = als_weighting(gb, 2, 14);
            current->weighting[2]   = als_weighting(gb, 1, 16);
1231 1232

            if (current->time_diff_flag) {
1233 1234 1235
                current->weighting[3] = als_weighting(gb, 1, 16);
                current->weighting[4] = als_weighting(gb, 1, 16);
                current->weighting[5] = als_weighting(gb, 1, 16);
1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246

                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) {
1247
        av_log(ctx->avctx, AV_LOG_ERROR, "Damaged channel data.\n");
1248
        return AVERROR_INVALIDDATA;
1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264
    }

    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;
1265
    unsigned int channel_size = ctx->sconf.frame_length + ctx->sconf.max_order;
1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279

    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) {
1280
        av_log(ctx->avctx, AV_LOG_WARNING, "Invalid channel correlation.\n");
1281
        return AVERROR_INVALIDDATA;
1282 1283
    }

1284 1285 1286 1287
    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;
1288 1289 1290 1291 1292 1293 1294
    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;

1295
    for (dep = 0; !ch[dep].stop_flag; dep++) {
1296 1297 1298
        ptrdiff_t smp;
        ptrdiff_t begin = 1;
        ptrdiff_t end   = bd->block_length - 1;
1299 1300 1301
        int64_t y;
        int32_t *master = ctx->raw_samples[ch[dep].master_channel] + offset;

1302 1303 1304
        if (ch[dep].master_channel == c)
            continue;

1305 1306 1307 1308 1309
        if (ch[dep].time_diff_flag) {
            int t = ch[dep].time_diff_index;

            if (ch[dep].time_diff_sign) {
                t      = -t;
1310
                if (begin < t) {
1311
                    av_log(ctx->avctx, AV_LOG_ERROR, "begin %"PTRDIFF_SPECIFIER" smaller than time diff index %d.\n", begin, t);
1312 1313
                    return AVERROR_INVALIDDATA;
                }
1314 1315
                begin -= t;
            } else {
1316
                if (end < t) {
1317
                    av_log(ctx->avctx, AV_LOG_ERROR, "end %"PTRDIFF_SPECIFIER" smaller than time diff index %d.\n", end, t);
1318 1319
                    return AVERROR_INVALIDDATA;
                }
1320 1321 1322
                end   -= t;
            }

1323 1324 1325 1326 1327 1328 1329 1330 1331
            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;
            }

1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343
            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 {
1344 1345 1346 1347 1348 1349 1350 1351 1352 1353

            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;
            }

1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368
            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;
}


1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 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 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501
/** 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;

    // 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;
        }
    }

    mantissa = (unsigned int)(mantissa_temp >> cutoff_bit_count);

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

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

    return_val |= (a.exp + b.exp + bit_count - 47) << 23;
    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);
    }

    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) {
1502
                    av_log(ctx->avctx, AV_LOG_ERROR, "Error in MLZ decompression (%"PRId32", %d).\n", tmp_32, nchars);
1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528
                    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) {
1529
                        raw_mantissa[c][i] = get_bitsz(gb, nbits[i]);
1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544
                    }
                }
            } 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) {
1545
                    av_log(ctx->avctx, AV_LOG_ERROR, "Error in MLZ decompression (%"PRId32", %d).\n", tmp_32, nchars);
1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 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
                    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;
}


1601
/** Read the frame data.
1602 1603 1604 1605 1606 1607 1608 1609 1610 1611
 */
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;
1612
    int ret;
1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638

    // 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
1639
            if (c == avctx->channels - 1 || (c & 1))
1640 1641 1642
                independent_bs = 1;

            if (independent_bs) {
1643 1644 1645 1646
                ret = decode_blocks_ind(ctx, ra_frame, c,
                                        div_blocks, js_blocks);
                if (ret < 0)
                    return ret;
1647 1648
                independent_bs--;
            } else {
1649 1650 1651
                ret = decode_blocks(ctx, ra_frame, c, div_blocks, js_blocks);
                if (ret < 0)
                    return ret;
1652 1653 1654 1655 1656 1657 1658 1659 1660 1661

                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);
        }
    } else { // multi-channel coding
1662
        ALSBlockData   bd = { 0 };
1663
        int            b, ret;
1664 1665 1666 1667 1668
        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) {
1669
                av_log(ctx->avctx, AV_LOG_ERROR, "Invalid channel data.\n");
1670
                return AVERROR_INVALIDDATA;
1671 1672 1673 1674 1675 1676 1677
            }

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

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

1678 1679
        get_block_sizes(ctx, div_blocks, &bs_info);

1680 1681
        for (b = 0; b < ctx->num_blocks; b++) {
            bd.block_length = div_blocks[b];
1682 1683
            if (bd.block_length <= 0) {
                av_log(ctx->avctx, AV_LOG_WARNING,
1684 1685
                       "Invalid block length %u in channel data!\n",
                       bd.block_length);
1686 1687
                continue;
            }
1688 1689

            for (c = 0; c < avctx->channels; c++) {
1690 1691 1692 1693
                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;
1694 1695 1696 1697 1698 1699 1700 1701
                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;

1702 1703 1704 1705
                if ((ret = read_block(ctx, &bd)) < 0)
                    return ret;
                if ((ret = read_channel_data(ctx, ctx->chan_data[c], c)) < 0)
                    return ret;
1706 1707
            }

1708 1709 1710 1711 1712 1713
            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;
            }
1714
            for (c = 0; c < avctx->channels; c++) {
1715 1716 1717 1718
                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;
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;
1725

1726 1727
                if ((ret = decode_block(ctx, &bd)) < 0)
                    return ret;
1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739
            }

            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);
1740 1741
    }

1742 1743 1744
    if (sconf->floating) {
        read_diff_float_data(ctx, ra_frame);
    }
1745

1746 1747 1748 1749 1750
    if (get_bits_left(gb) < 0) {
        av_log(ctx->avctx, AV_LOG_ERROR, "Overread %d\n", -get_bits_left(gb));
        return AVERROR_INVALIDDATA;
    }

1751 1752 1753 1754
    return 0;
}


1755
/** Decode an ALS frame.
1756
 */
1757
static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr,
1758 1759 1760
                        AVPacket *avpkt)
{
    ALSDecContext *ctx       = avctx->priv_data;
1761
    AVFrame *frame           = data;
1762 1763 1764
    ALSSpecificConfig *sconf = &ctx->sconf;
    const uint8_t *buffer    = avpkt->data;
    int buffer_size          = avpkt->size;
1765
    int invalid_frame, ret;
1766 1767
    unsigned int c, sample, ra_frame, bytes_read, shift;

1768 1769
    if ((ret = init_get_bits8(&ctx->gb, buffer, buffer_size)) < 0)
        return ret;
1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784

    // 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;

    // decode the frame data
1785
    if ((invalid_frame = read_frame_data(ctx, ra_frame)) < 0)
1786 1787 1788 1789 1790
        av_log(ctx->avctx, AV_LOG_WARNING,
               "Reading frame data failed. Skipping RA unit.\n");

    ctx->frame_id++;

1791
    /* get output buffer */
1792
    frame->nb_samples = ctx->cur_frame_length;
1793
    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
1794
        return ret;
1795 1796

    // transform decoded frame into output format
1797 1798
    #define INTERLEAVE_OUTPUT(bps)                                                   \
    {                                                                                \
1799
        int##bps##_t *dest = (int##bps##_t*)frame->data[0];                          \
1800
        shift = bps - ctx->avctx->bits_per_raw_sample;                               \
1801
        if (!ctx->cs_switch) {                                                       \
1802 1803 1804
            for (sample = 0; sample < ctx->cur_frame_length; sample++)               \
                for (c = 0; c < avctx->channels; c++)                                \
                    *dest++ = ctx->raw_samples[c][sample] << shift;                  \
Paul B Mahol's avatar
Paul B Mahol committed
1805 1806 1807 1808 1809
        } else {                                                                     \
            for (sample = 0; sample < ctx->cur_frame_length; sample++)               \
                for (c = 0; c < avctx->channels; c++)                                \
                    *dest++ = ctx->raw_samples[sconf->chan_pos[c]][sample] << shift; \
        }                                                                            \
1810 1811 1812 1813 1814 1815 1816 1817
    }

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

1818
    // update CRC
1819
    if (sconf->crc_enabled && (avctx->err_recognition & (AV_EF_CRCCHECK|AV_EF_CAREFUL))) {
1820 1821 1822
        int swap = HAVE_BIGENDIAN != sconf->msb_first;

        if (ctx->avctx->bits_per_raw_sample == 24) {
1823
            int32_t *src = (int32_t *)frame->data[0];
1824 1825 1826 1827 1828 1829 1830

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

                if (swap)
1831
                    v = av_bswap32(src[sample]);
1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843
                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) {
1844
                    int16_t *src  = (int16_t*) frame->data[0];
1845 1846 1847 1848
                    int16_t *dest = (int16_t*) ctx->crc_buffer;
                    for (sample = 0;
                         sample < ctx->cur_frame_length * avctx->channels;
                         sample++)
1849
                        *dest++ = av_bswap16(src[sample]);
1850
                } else {
1851 1852 1853
                    ctx->bdsp.bswap_buf((uint32_t *) ctx->crc_buffer,
                                        (uint32_t *) frame->data[0],
                                        ctx->cur_frame_length * avctx->channels);
1854 1855 1856
                }
                crc_source = ctx->crc_buffer;
            } else {
1857
                crc_source = frame->data[0];
1858 1859
            }

1860 1861 1862
            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));
1863 1864 1865 1866 1867 1868
        }


        // check CRC sums if this is the last frame
        if (ctx->cur_frame_length != sconf->frame_length &&
            ctx->crc_org != ctx->crc) {
1869
            av_log(avctx, AV_LOG_ERROR, "CRC error.\n");
1870 1871
            if (avctx->err_recognition & AV_EF_EXPLODE)
                return AVERROR_INVALIDDATA;
1872 1873 1874
        }
    }

1875
    *got_frame_ptr = 1;
1876

1877 1878 1879 1880 1881 1882 1883
    bytes_read = invalid_frame ? buffer_size :
                                 (get_bits_count(&ctx->gb) + 7) >> 3;

    return bytes_read;
}


1884
/** Uninitialize the ALS decoder.
1885 1886 1887 1888
 */
static av_cold int decode_end(AVCodecContext *avctx)
{
    ALSDecContext *ctx = avctx->priv_data;
1889
    int i;
1890 1891 1892

    av_freep(&ctx->sconf.chan_pos);

1893 1894
    ff_bgmc_end(&ctx->bgmc_lut, &ctx->bgmc_lut_status);

1895 1896 1897 1898
    av_freep(&ctx->const_block);
    av_freep(&ctx->shift_lsbs);
    av_freep(&ctx->opt_order);
    av_freep(&ctx->store_prev_samples);
1899 1900 1901 1902
    av_freep(&ctx->use_ltp);
    av_freep(&ctx->ltp_lag);
    av_freep(&ctx->ltp_gain);
    av_freep(&ctx->ltp_gain_buffer);
1903 1904
    av_freep(&ctx->quant_cof);
    av_freep(&ctx->lpc_cof);
1905 1906
    av_freep(&ctx->quant_cof_buffer);
    av_freep(&ctx->lpc_cof_buffer);
1907
    av_freep(&ctx->lpc_cof_reversed_buffer);
1908 1909 1910
    av_freep(&ctx->prev_raw_samples);
    av_freep(&ctx->raw_samples);
    av_freep(&ctx->raw_buffer);
1911 1912 1913
    av_freep(&ctx->chan_data);
    av_freep(&ctx->chan_data_buffer);
    av_freep(&ctx->reverted_channels);
1914
    av_freep(&ctx->crc_buffer);
1915 1916 1917 1918
    if (ctx->mlz) {
        av_freep(&ctx->mlz->dict);
        av_freep(&ctx->mlz);
    }
1919 1920 1921 1922
    av_freep(&ctx->acf);
    av_freep(&ctx->last_acf_mantissa);
    av_freep(&ctx->shift_value);
    av_freep(&ctx->last_shift_value);
1923 1924 1925 1926 1927 1928
    if (ctx->raw_mantissa) {
        for (i = 0; i < avctx->channels; i++) {
            av_freep(&ctx->raw_mantissa[i]);
        }
        av_freep(&ctx->raw_mantissa);
    }
1929 1930
    av_freep(&ctx->larray);
    av_freep(&ctx->nbits);
1931 1932 1933 1934 1935

    return 0;
}


1936
/** Initialize the ALS decoder.
1937 1938 1939 1940 1941
 */
static av_cold int decode_init(AVCodecContext *avctx)
{
    unsigned int c;
    unsigned int channel_size;
1942
    int num_buffers, ret;
1943 1944 1945 1946 1947
    ALSDecContext *ctx = avctx->priv_data;
    ALSSpecificConfig *sconf = &ctx->sconf;
    ctx->avctx = avctx;

    if (!avctx->extradata) {
1948
        av_log(avctx, AV_LOG_ERROR, "Missing required ALS extradata.\n");
1949
        return AVERROR_INVALIDDATA;
1950 1951
    }

1952
    if ((ret = read_specific_config(ctx)) < 0) {
1953
        av_log(avctx, AV_LOG_ERROR, "Reading ALSSpecificConfig failed.\n");
1954
        goto fail;
1955 1956
    }

1957 1958
    if ((ret = check_specific_config(ctx)) < 0) {
        goto fail;
1959 1960
    }

1961 1962 1963 1964 1965
    if (sconf->bgmc) {
        ret = ff_bgmc_init(avctx, &ctx->bgmc_lut, &ctx->bgmc_lut_status);
        if (ret < 0)
            goto fail;
    }
1966
    if (sconf->floating) {
1967
        avctx->sample_fmt          = AV_SAMPLE_FMT_FLT;
1968 1969 1970
        avctx->bits_per_raw_sample = 32;
    } else {
        avctx->sample_fmt          = sconf->resolution > 1
1971
                                     ? AV_SAMPLE_FMT_S32 : AV_SAMPLE_FMT_S16;
1972
        avctx->bits_per_raw_sample = (sconf->resolution + 1) * 8;
1973 1974 1975 1976 1977 1978
        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;
        }
1979 1980
    }

1981 1982 1983 1984 1985
    // 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;

1986 1987 1988 1989
    // set lag value for long-term prediction
    ctx->ltp_lag_length = 8 + (avctx->sample_rate >=  96000) +
                              (avctx->sample_rate >= 192000);

1990 1991 1992
    // allocate quantized parcor coefficient buffer
    num_buffers = sconf->mc_coding ? avctx->channels : 1;

1993 1994 1995 1996 1997 1998 1999 2000
    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));
2001

2002 2003
    if (!ctx->quant_cof              || !ctx->lpc_cof        ||
        !ctx->quant_cof_buffer       || !ctx->lpc_cof_buffer ||
2004
        !ctx->lpc_cof_reversed_buffer) {
2005
        av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
2006 2007
        ret = AVERROR(ENOMEM);
        goto fail;
2008 2009 2010 2011 2012 2013 2014 2015
    }

    // 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;
    }

2016
    // allocate and assign lag and gain data buffer for ltp mode
2017 2018 2019 2020 2021 2022 2023 2024
    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));
2025

2026 2027 2028
    if (!ctx->const_block || !ctx->shift_lsbs ||
        !ctx->opt_order || !ctx->store_prev_samples ||
        !ctx->use_ltp  || !ctx->ltp_lag ||
2029
        !ctx->ltp_gain || !ctx->ltp_gain_buffer) {
2030
        av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
2031 2032
        ret = AVERROR(ENOMEM);
        goto fail;
2033 2034 2035 2036 2037
    }

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

2038 2039
    // allocate and assign channel data buffer for mcc mode
    if (sconf->mc_coding) {
2040
        ctx->chan_data_buffer  = av_mallocz_array(num_buffers * num_buffers,
2041
                                                 sizeof(*ctx->chan_data_buffer));
2042
        ctx->chan_data         = av_mallocz_array(num_buffers,
2043 2044 2045
                                                 sizeof(*ctx->chan_data));
        ctx->reverted_channels = av_malloc_array(num_buffers,
                                                 sizeof(*ctx->reverted_channels));
2046 2047

        if (!ctx->chan_data_buffer || !ctx->chan_data || !ctx->reverted_channels) {
2048
            av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
2049 2050
            ret = AVERROR(ENOMEM);
            goto fail;
2051 2052 2053
        }

        for (c = 0; c < num_buffers; c++)
2054
            ctx->chan_data[c] = ctx->chan_data_buffer + c * num_buffers;
2055 2056 2057 2058 2059 2060
    } else {
        ctx->chan_data         = NULL;
        ctx->chan_data_buffer  = NULL;
        ctx->reverted_channels = NULL;
    }

2061 2062
    channel_size      = sconf->frame_length + sconf->max_order;

2063 2064 2065
    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));
2066

2067 2068 2069 2070 2071
    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));
2072
        ctx->raw_mantissa      = av_mallocz_array(avctx->channels, sizeof(*ctx->raw_mantissa));
2073 2074 2075

        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));
2076
        ctx->mlz    = av_mallocz(sizeof(*ctx->mlz));
2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092

        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));
        }
    }

2093 2094
    // allocate previous raw sample buffer
    if (!ctx->prev_raw_samples || !ctx->raw_buffer|| !ctx->raw_samples) {
2095
        av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
2096 2097
        ret = AVERROR(ENOMEM);
        goto fail;
2098 2099 2100 2101 2102 2103 2104
    }

    // 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;

2105 2106
    // allocate crc buffer
    if (HAVE_BIGENDIAN != sconf->msb_first && sconf->crc_enabled &&
2107
        (avctx->err_recognition & (AV_EF_CRCCHECK|AV_EF_CAREFUL))) {
2108 2109 2110 2111
        ctx->crc_buffer = av_malloc_array(ctx->cur_frame_length *
                                          avctx->channels *
                                          av_get_bytes_per_sample(avctx->sample_fmt),
                                          sizeof(*ctx->crc_buffer));
2112
        if (!ctx->crc_buffer) {
2113
            av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
2114 2115
            ret = AVERROR(ENOMEM);
            goto fail;
2116 2117 2118
        }
    }

2119
    ff_bswapdsp_init(&ctx->bdsp);
2120

2121
    return 0;
2122 2123 2124 2125

fail:
    decode_end(avctx);
    return ret;
2126 2127 2128
}


2129
/** Flush (reset) the frame ID after seeking.
2130 2131 2132 2133 2134 2135 2136 2137 2138
 */
static av_cold void flush(AVCodecContext *avctx)
{
    ALSDecContext *ctx = avctx->priv_data;

    ctx->frame_id = 0;
}


2139
AVCodec ff_als_decoder = {
2140
    .name           = "als",
2141
    .long_name      = NULL_IF_CONFIG_SMALL("MPEG-4 Audio Lossless Coding (ALS)"),
2142
    .type           = AVMEDIA_TYPE_AUDIO,
2143
    .id             = AV_CODEC_ID_MP4ALS,
2144 2145 2146 2147
    .priv_data_size = sizeof(ALSDecContext),
    .init           = decode_init,
    .close          = decode_end,
    .decode         = decode_frame,
2148
    .flush          = flush,
2149
    .capabilities   = AV_CODEC_CAP_SUBFRAMES | AV_CODEC_CAP_DR1,
2150
};