aacsbr.c 65.2 KB
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/*
 * AAC Spectral Band Replication decoding functions
 * Copyright (c) 2008-2009 Robert Swain ( rob opendot cl )
 * Copyright (c) 2009-2010 Alex Converse <alex.converse@gmail.com>
 *
 * 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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 * AAC Spectral Band Replication decoding functions
 * @author Robert Swain ( rob opendot cl )
 */

#include "aac.h"
#include "sbr.h"
#include "aacsbr.h"
#include "aacsbrdata.h"
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#include "fft.h"
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#include "aacps.h"
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#include "sbrdsp.h"
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#include "libavutil/internal.h"
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#include "libavutil/libm.h"
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#include "libavutil/avassert.h"
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#include <stdint.h>
#include <float.h>
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#include <math.h>
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#define ENVELOPE_ADJUSTMENT_OFFSET 2
#define NOISE_FLOOR_OFFSET 6.0f

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#if ARCH_MIPS
#include "mips/aacsbr_mips.h"
#endif /* ARCH_MIPS */

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/**
 * SBR VLC tables
 */
enum {
    T_HUFFMAN_ENV_1_5DB,
    F_HUFFMAN_ENV_1_5DB,
    T_HUFFMAN_ENV_BAL_1_5DB,
    F_HUFFMAN_ENV_BAL_1_5DB,
    T_HUFFMAN_ENV_3_0DB,
    F_HUFFMAN_ENV_3_0DB,
    T_HUFFMAN_ENV_BAL_3_0DB,
    F_HUFFMAN_ENV_BAL_3_0DB,
    T_HUFFMAN_NOISE_3_0DB,
    T_HUFFMAN_NOISE_BAL_3_0DB,
};

/**
 * bs_frame_class - frame class of current SBR frame (14496-3 sp04 p98)
 */
enum {
    FIXFIX,
    FIXVAR,
    VARFIX,
    VARVAR,
};

enum {
    EXTENSION_ID_PS = 2,
};

static VLC vlc_sbr[10];
static const int8_t vlc_sbr_lav[10] =
    { 60, 60, 24, 24, 31, 31, 12, 12, 31, 12 };

#define SBR_INIT_VLC_STATIC(num, size) \
    INIT_VLC_STATIC(&vlc_sbr[num], 9, sbr_tmp[num].table_size / sbr_tmp[num].elem_size,     \
                    sbr_tmp[num].sbr_bits ,                      1,                      1, \
                    sbr_tmp[num].sbr_codes, sbr_tmp[num].elem_size, sbr_tmp[num].elem_size, \
                    size)

#define SBR_VLC_ROW(name) \
    { name ## _codes, name ## _bits, sizeof(name ## _codes), sizeof(name ## _codes[0]) }

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static void aacsbr_func_ptr_init(AACSBRContext *c);

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av_cold void ff_aac_sbr_init(void)
{
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    int n;
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    static const struct {
        const void *sbr_codes, *sbr_bits;
        const unsigned int table_size, elem_size;
    } sbr_tmp[] = {
        SBR_VLC_ROW(t_huffman_env_1_5dB),
        SBR_VLC_ROW(f_huffman_env_1_5dB),
        SBR_VLC_ROW(t_huffman_env_bal_1_5dB),
        SBR_VLC_ROW(f_huffman_env_bal_1_5dB),
        SBR_VLC_ROW(t_huffman_env_3_0dB),
        SBR_VLC_ROW(f_huffman_env_3_0dB),
        SBR_VLC_ROW(t_huffman_env_bal_3_0dB),
        SBR_VLC_ROW(f_huffman_env_bal_3_0dB),
        SBR_VLC_ROW(t_huffman_noise_3_0dB),
        SBR_VLC_ROW(t_huffman_noise_bal_3_0dB),
    };

    // SBR VLC table initialization
    SBR_INIT_VLC_STATIC(0, 1098);
    SBR_INIT_VLC_STATIC(1, 1092);
    SBR_INIT_VLC_STATIC(2, 768);
    SBR_INIT_VLC_STATIC(3, 1026);
    SBR_INIT_VLC_STATIC(4, 1058);
    SBR_INIT_VLC_STATIC(5, 1052);
    SBR_INIT_VLC_STATIC(6, 544);
    SBR_INIT_VLC_STATIC(7, 544);
    SBR_INIT_VLC_STATIC(8, 592);
    SBR_INIT_VLC_STATIC(9, 512);

    for (n = 1; n < 320; n++)
        sbr_qmf_window_us[320 + n] = sbr_qmf_window_us[320 - n];
    sbr_qmf_window_us[384] = -sbr_qmf_window_us[384];
    sbr_qmf_window_us[512] = -sbr_qmf_window_us[512];

    for (n = 0; n < 320; n++)
        sbr_qmf_window_ds[n] = sbr_qmf_window_us[2*n];
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    ff_ps_init();
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}

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/** Places SBR in pure upsampling mode. */
static void sbr_turnoff(SpectralBandReplication *sbr) {
    sbr->start = 0;
    // Init defults used in pure upsampling mode
    sbr->kx[1] = 32; //Typo in spec, kx' inits to 32
    sbr->m[1] = 0;
    // Reset values for first SBR header
    sbr->data[0].e_a[1] = sbr->data[1].e_a[1] = -1;
    memset(&sbr->spectrum_params, -1, sizeof(SpectrumParameters));
}

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av_cold void ff_aac_sbr_ctx_init(AACContext *ac, SpectralBandReplication *sbr)
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{
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    if(sbr->mdct.mdct_bits)
        return;
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    sbr->kx[0] = sbr->kx[1];
    sbr_turnoff(sbr);
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    sbr->data[0].synthesis_filterbank_samples_offset = SBR_SYNTHESIS_BUF_SIZE - (1280 - 128);
    sbr->data[1].synthesis_filterbank_samples_offset = SBR_SYNTHESIS_BUF_SIZE - (1280 - 128);
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    /* SBR requires samples to be scaled to +/-32768.0 to work correctly.
     * mdct scale factors are adjusted to scale up from +/-1.0 at analysis
     * and scale back down at synthesis. */
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    ff_mdct_init(&sbr->mdct,     7, 1, 1.0 / (64 * 32768.0));
    ff_mdct_init(&sbr->mdct_ana, 7, 1, -2.0 * 32768.0);
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    ff_ps_ctx_init(&sbr->ps);
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    ff_sbrdsp_init(&sbr->dsp);
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    aacsbr_func_ptr_init(&sbr->c);
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}

av_cold void ff_aac_sbr_ctx_close(SpectralBandReplication *sbr)
{
    ff_mdct_end(&sbr->mdct);
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    ff_mdct_end(&sbr->mdct_ana);
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}

static int qsort_comparison_function_int16(const void *a, const void *b)
{
    return *(const int16_t *)a - *(const int16_t *)b;
}

static inline int in_table_int16(const int16_t *table, int last_el, int16_t needle)
{
    int i;
    for (i = 0; i <= last_el; i++)
        if (table[i] == needle)
            return 1;
    return 0;
}

/// Limiter Frequency Band Table (14496-3 sp04 p198)
static void sbr_make_f_tablelim(SpectralBandReplication *sbr)
{
    int k;
    if (sbr->bs_limiter_bands > 0) {
        static const float bands_warped[3] = { 1.32715174233856803909f,   //2^(0.49/1.2)
                                               1.18509277094158210129f,   //2^(0.49/2)
                                               1.11987160404675912501f }; //2^(0.49/3)
        const float lim_bands_per_octave_warped = bands_warped[sbr->bs_limiter_bands - 1];
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        int16_t patch_borders[7];
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        uint16_t *in = sbr->f_tablelim + 1, *out = sbr->f_tablelim;

        patch_borders[0] = sbr->kx[1];
        for (k = 1; k <= sbr->num_patches; k++)
            patch_borders[k] = patch_borders[k-1] + sbr->patch_num_subbands[k-1];

        memcpy(sbr->f_tablelim, sbr->f_tablelow,
               (sbr->n[0] + 1) * sizeof(sbr->f_tablelow[0]));
        if (sbr->num_patches > 1)
            memcpy(sbr->f_tablelim + sbr->n[0] + 1, patch_borders + 1,
                   (sbr->num_patches - 1) * sizeof(patch_borders[0]));

        qsort(sbr->f_tablelim, sbr->num_patches + sbr->n[0],
              sizeof(sbr->f_tablelim[0]),
              qsort_comparison_function_int16);

        sbr->n_lim = sbr->n[0] + sbr->num_patches - 1;
        while (out < sbr->f_tablelim + sbr->n_lim) {
            if (*in >= *out * lim_bands_per_octave_warped) {
                *++out = *in++;
            } else if (*in == *out ||
                !in_table_int16(patch_borders, sbr->num_patches, *in)) {
                in++;
                sbr->n_lim--;
            } else if (!in_table_int16(patch_borders, sbr->num_patches, *out)) {
                *out = *in++;
                sbr->n_lim--;
            } else {
                *++out = *in++;
            }
        }
    } else {
        sbr->f_tablelim[0] = sbr->f_tablelow[0];
        sbr->f_tablelim[1] = sbr->f_tablelow[sbr->n[0]];
        sbr->n_lim = 1;
    }
}

static unsigned int read_sbr_header(SpectralBandReplication *sbr, GetBitContext *gb)
{
    unsigned int cnt = get_bits_count(gb);
    uint8_t bs_header_extra_1;
    uint8_t bs_header_extra_2;
    int old_bs_limiter_bands = sbr->bs_limiter_bands;
    SpectrumParameters old_spectrum_params;

    sbr->start = 1;

    // Save last spectrum parameters variables to compare to new ones
    memcpy(&old_spectrum_params, &sbr->spectrum_params, sizeof(SpectrumParameters));

    sbr->bs_amp_res_header              = get_bits1(gb);
    sbr->spectrum_params.bs_start_freq  = get_bits(gb, 4);
    sbr->spectrum_params.bs_stop_freq   = get_bits(gb, 4);
    sbr->spectrum_params.bs_xover_band  = get_bits(gb, 3);
                                          skip_bits(gb, 2); // bs_reserved

    bs_header_extra_1 = get_bits1(gb);
    bs_header_extra_2 = get_bits1(gb);

    if (bs_header_extra_1) {
        sbr->spectrum_params.bs_freq_scale  = get_bits(gb, 2);
        sbr->spectrum_params.bs_alter_scale = get_bits1(gb);
        sbr->spectrum_params.bs_noise_bands = get_bits(gb, 2);
    } else {
        sbr->spectrum_params.bs_freq_scale  = 2;
        sbr->spectrum_params.bs_alter_scale = 1;
        sbr->spectrum_params.bs_noise_bands = 2;
    }

    // Check if spectrum parameters changed
    if (memcmp(&old_spectrum_params, &sbr->spectrum_params, sizeof(SpectrumParameters)))
        sbr->reset = 1;

    if (bs_header_extra_2) {
        sbr->bs_limiter_bands  = get_bits(gb, 2);
        sbr->bs_limiter_gains  = get_bits(gb, 2);
        sbr->bs_interpol_freq  = get_bits1(gb);
        sbr->bs_smoothing_mode = get_bits1(gb);
    } else {
        sbr->bs_limiter_bands  = 2;
        sbr->bs_limiter_gains  = 2;
        sbr->bs_interpol_freq  = 1;
        sbr->bs_smoothing_mode = 1;
    }

    if (sbr->bs_limiter_bands != old_bs_limiter_bands && !sbr->reset)
        sbr_make_f_tablelim(sbr);

    return get_bits_count(gb) - cnt;
}

static int array_min_int16(const int16_t *array, int nel)
{
    int i, min = array[0];
    for (i = 1; i < nel; i++)
        min = FFMIN(array[i], min);
    return min;
}

static void make_bands(int16_t* bands, int start, int stop, int num_bands)
{
    int k, previous, present;
    float base, prod;

    base = powf((float)stop / start, 1.0f / num_bands);
    prod = start;
    previous = start;

    for (k = 0; k < num_bands-1; k++) {
        prod *= base;
        present  = lrintf(prod);
        bands[k] = present - previous;
        previous = present;
    }
    bands[num_bands-1] = stop - previous;
}

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static int check_n_master(AVCodecContext *avctx, int n_master, int bs_xover_band)
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{
    // Requirements (14496-3 sp04 p205)
    if (n_master <= 0) {
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        av_log(avctx, AV_LOG_ERROR, "Invalid n_master: %d\n", n_master);
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        return -1;
    }
    if (bs_xover_band >= n_master) {
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        av_log(avctx, AV_LOG_ERROR,
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               "Invalid bitstream, crossover band index beyond array bounds: %d\n",
               bs_xover_band);
        return -1;
    }
    return 0;
}

/// Master Frequency Band Table (14496-3 sp04 p194)
static int sbr_make_f_master(AACContext *ac, SpectralBandReplication *sbr,
                             SpectrumParameters *spectrum)
{
    unsigned int temp, max_qmf_subbands;
    unsigned int start_min, stop_min;
    int k;
    const int8_t *sbr_offset_ptr;
    int16_t stop_dk[13];

    if (sbr->sample_rate < 32000) {
        temp = 3000;
    } else if (sbr->sample_rate < 64000) {
        temp = 4000;
    } else
        temp = 5000;

    switch (sbr->sample_rate) {
    case 16000:
        sbr_offset_ptr = sbr_offset[0];
        break;
    case 22050:
        sbr_offset_ptr = sbr_offset[1];
        break;
    case 24000:
        sbr_offset_ptr = sbr_offset[2];
        break;
    case 32000:
        sbr_offset_ptr = sbr_offset[3];
        break;
    case 44100: case 48000: case 64000:
        sbr_offset_ptr = sbr_offset[4];
        break;
    case 88200: case 96000: case 128000: case 176400: case 192000:
        sbr_offset_ptr = sbr_offset[5];
        break;
    default:
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        av_log(ac->avctx, AV_LOG_ERROR,
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               "Unsupported sample rate for SBR: %d\n", sbr->sample_rate);
        return -1;
    }

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    start_min = ((temp << 7) + (sbr->sample_rate >> 1)) / sbr->sample_rate;
    stop_min  = ((temp << 8) + (sbr->sample_rate >> 1)) / sbr->sample_rate;

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    sbr->k[0] = start_min + sbr_offset_ptr[spectrum->bs_start_freq];

    if (spectrum->bs_stop_freq < 14) {
        sbr->k[2] = stop_min;
        make_bands(stop_dk, stop_min, 64, 13);
        qsort(stop_dk, 13, sizeof(stop_dk[0]), qsort_comparison_function_int16);
        for (k = 0; k < spectrum->bs_stop_freq; k++)
            sbr->k[2] += stop_dk[k];
    } else if (spectrum->bs_stop_freq == 14) {
        sbr->k[2] = 2*sbr->k[0];
    } else if (spectrum->bs_stop_freq == 15) {
        sbr->k[2] = 3*sbr->k[0];
    } else {
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        av_log(ac->avctx, AV_LOG_ERROR,
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               "Invalid bs_stop_freq: %d\n", spectrum->bs_stop_freq);
        return -1;
    }
    sbr->k[2] = FFMIN(64, sbr->k[2]);

    // Requirements (14496-3 sp04 p205)
    if (sbr->sample_rate <= 32000) {
        max_qmf_subbands = 48;
    } else if (sbr->sample_rate == 44100) {
        max_qmf_subbands = 35;
    } else if (sbr->sample_rate >= 48000)
        max_qmf_subbands = 32;
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    else
        av_assert0(0);
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    if (sbr->k[2] - sbr->k[0] > max_qmf_subbands) {
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        av_log(ac->avctx, AV_LOG_ERROR,
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               "Invalid bitstream, too many QMF subbands: %d\n", sbr->k[2] - sbr->k[0]);
        return -1;
    }

    if (!spectrum->bs_freq_scale) {
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        int dk, k2diff;
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        dk = spectrum->bs_alter_scale + 1;
        sbr->n_master = ((sbr->k[2] - sbr->k[0] + (dk&2)) >> dk) << 1;
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        if (check_n_master(ac->avctx, sbr->n_master, sbr->spectrum_params.bs_xover_band))
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            return -1;

        for (k = 1; k <= sbr->n_master; k++)
            sbr->f_master[k] = dk;

        k2diff = sbr->k[2] - sbr->k[0] - sbr->n_master * dk;
        if (k2diff < 0) {
            sbr->f_master[1]--;
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            sbr->f_master[2]-= (k2diff < -1);
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        } else if (k2diff) {
            sbr->f_master[sbr->n_master]++;
        }

        sbr->f_master[0] = sbr->k[0];
        for (k = 1; k <= sbr->n_master; k++)
            sbr->f_master[k] += sbr->f_master[k - 1];

    } else {
        int half_bands = 7 - spectrum->bs_freq_scale;      // bs_freq_scale  = {1,2,3}
        int two_regions, num_bands_0;
        int vdk0_max, vdk1_min;
        int16_t vk0[49];

        if (49 * sbr->k[2] > 110 * sbr->k[0]) {
            two_regions = 1;
            sbr->k[1] = 2 * sbr->k[0];
        } else {
            two_regions = 0;
            sbr->k[1] = sbr->k[2];
        }

        num_bands_0 = lrintf(half_bands * log2f(sbr->k[1] / (float)sbr->k[0])) * 2;

        if (num_bands_0 <= 0) { // Requirements (14496-3 sp04 p205)
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            av_log(ac->avctx, AV_LOG_ERROR, "Invalid num_bands_0: %d\n", num_bands_0);
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            return -1;
        }

        vk0[0] = 0;

        make_bands(vk0+1, sbr->k[0], sbr->k[1], num_bands_0);

        qsort(vk0 + 1, num_bands_0, sizeof(vk0[1]), qsort_comparison_function_int16);
        vdk0_max = vk0[num_bands_0];

        vk0[0] = sbr->k[0];
        for (k = 1; k <= num_bands_0; k++) {
            if (vk0[k] <= 0) { // Requirements (14496-3 sp04 p205)
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                av_log(ac->avctx, AV_LOG_ERROR, "Invalid vDk0[%d]: %d\n", k, vk0[k]);
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                return -1;
            }
            vk0[k] += vk0[k-1];
        }

        if (two_regions) {
            int16_t vk1[49];
            float invwarp = spectrum->bs_alter_scale ? 0.76923076923076923077f
                                                     : 1.0f; // bs_alter_scale = {0,1}
            int num_bands_1 = lrintf(half_bands * invwarp *
                                     log2f(sbr->k[2] / (float)sbr->k[1])) * 2;

            make_bands(vk1+1, sbr->k[1], sbr->k[2], num_bands_1);

            vdk1_min = array_min_int16(vk1 + 1, num_bands_1);

            if (vdk1_min < vdk0_max) {
                int change;
                qsort(vk1 + 1, num_bands_1, sizeof(vk1[1]), qsort_comparison_function_int16);
                change = FFMIN(vdk0_max - vk1[1], (vk1[num_bands_1] - vk1[1]) >> 1);
                vk1[1]           += change;
                vk1[num_bands_1] -= change;
            }

            qsort(vk1 + 1, num_bands_1, sizeof(vk1[1]), qsort_comparison_function_int16);

            vk1[0] = sbr->k[1];
            for (k = 1; k <= num_bands_1; k++) {
                if (vk1[k] <= 0) { // Requirements (14496-3 sp04 p205)
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                    av_log(ac->avctx, AV_LOG_ERROR, "Invalid vDk1[%d]: %d\n", k, vk1[k]);
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                    return -1;
                }
                vk1[k] += vk1[k-1];
            }

            sbr->n_master = num_bands_0 + num_bands_1;
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            if (check_n_master(ac->avctx, sbr->n_master, sbr->spectrum_params.bs_xover_band))
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                return -1;
            memcpy(&sbr->f_master[0],               vk0,
                   (num_bands_0 + 1) * sizeof(sbr->f_master[0]));
            memcpy(&sbr->f_master[num_bands_0 + 1], vk1 + 1,
                    num_bands_1      * sizeof(sbr->f_master[0]));

        } else {
            sbr->n_master = num_bands_0;
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            if (check_n_master(ac->avctx, sbr->n_master, sbr->spectrum_params.bs_xover_band))
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                return -1;
            memcpy(sbr->f_master, vk0, (num_bands_0 + 1) * sizeof(sbr->f_master[0]));
        }
    }

    return 0;
}

/// High Frequency Generation - Patch Construction (14496-3 sp04 p216 fig. 4.46)
static int sbr_hf_calc_npatches(AACContext *ac, SpectralBandReplication *sbr)
{
    int i, k, sb = 0;
    int msb = sbr->k[0];
    int usb = sbr->kx[1];
    int goal_sb = ((1000 << 11) + (sbr->sample_rate >> 1)) / sbr->sample_rate;

    sbr->num_patches = 0;

    if (goal_sb < sbr->kx[1] + sbr->m[1]) {
        for (k = 0; sbr->f_master[k] < goal_sb; k++) ;
    } else
        k = sbr->n_master;

    do {
        int odd = 0;
        for (i = k; i == k || sb > (sbr->k[0] - 1 + msb - odd); i--) {
            sb = sbr->f_master[i];
            odd = (sb + sbr->k[0]) & 1;
        }

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        // Requirements (14496-3 sp04 p205) sets the maximum number of patches to 5.
        // After this check the final number of patches can still be six which is
        // illegal however the Coding Technologies decoder check stream has a final
        // count of 6 patches
        if (sbr->num_patches > 5) {
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            av_log(ac->avctx, AV_LOG_ERROR, "Too many patches: %d\n", sbr->num_patches);
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            return -1;
        }

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        sbr->patch_num_subbands[sbr->num_patches]  = FFMAX(sb - usb, 0);
        sbr->patch_start_subband[sbr->num_patches] = sbr->k[0] - odd - sbr->patch_num_subbands[sbr->num_patches];

        if (sbr->patch_num_subbands[sbr->num_patches] > 0) {
            usb = sb;
            msb = sb;
            sbr->num_patches++;
        } else
            msb = sbr->kx[1];

        if (sbr->f_master[k] - sb < 3)
            k = sbr->n_master;
    } while (sb != sbr->kx[1] + sbr->m[1]);

565
    if (sbr->num_patches > 1 && sbr->patch_num_subbands[sbr->num_patches-1] < 3)
566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585
        sbr->num_patches--;

    return 0;
}

/// Derived Frequency Band Tables (14496-3 sp04 p197)
static int sbr_make_f_derived(AACContext *ac, SpectralBandReplication *sbr)
{
    int k, temp;

    sbr->n[1] = sbr->n_master - sbr->spectrum_params.bs_xover_band;
    sbr->n[0] = (sbr->n[1] + 1) >> 1;

    memcpy(sbr->f_tablehigh, &sbr->f_master[sbr->spectrum_params.bs_xover_band],
           (sbr->n[1] + 1) * sizeof(sbr->f_master[0]));
    sbr->m[1] = sbr->f_tablehigh[sbr->n[1]] - sbr->f_tablehigh[0];
    sbr->kx[1] = sbr->f_tablehigh[0];

    // Requirements (14496-3 sp04 p205)
    if (sbr->kx[1] + sbr->m[1] > 64) {
586
        av_log(ac->avctx, AV_LOG_ERROR,
587 588 589 590
               "Stop frequency border too high: %d\n", sbr->kx[1] + sbr->m[1]);
        return -1;
    }
    if (sbr->kx[1] > 32) {
591
        av_log(ac->avctx, AV_LOG_ERROR, "Start frequency border too high: %d\n", sbr->kx[1]);
592 593 594 595 596 597 598 599 600 601 602
        return -1;
    }

    sbr->f_tablelow[0] = sbr->f_tablehigh[0];
    temp = sbr->n[1] & 1;
    for (k = 1; k <= sbr->n[0]; k++)
        sbr->f_tablelow[k] = sbr->f_tablehigh[2 * k - temp];

    sbr->n_q = FFMAX(1, lrintf(sbr->spectrum_params.bs_noise_bands *
                               log2f(sbr->k[2] / (float)sbr->kx[1]))); // 0 <= bs_noise_bands <= 3
    if (sbr->n_q > 5) {
603
        av_log(ac->avctx, AV_LOG_ERROR, "Too many noise floor scale factors: %d\n", sbr->n_q);
604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642
        return -1;
    }

    sbr->f_tablenoise[0] = sbr->f_tablelow[0];
    temp = 0;
    for (k = 1; k <= sbr->n_q; k++) {
        temp += (sbr->n[0] - temp) / (sbr->n_q + 1 - k);
        sbr->f_tablenoise[k] = sbr->f_tablelow[temp];
    }

    if (sbr_hf_calc_npatches(ac, sbr) < 0)
        return -1;

    sbr_make_f_tablelim(sbr);

    sbr->data[0].f_indexnoise = 0;
    sbr->data[1].f_indexnoise = 0;

    return 0;
}

static av_always_inline void get_bits1_vector(GetBitContext *gb, uint8_t *vec,
                                              int elements)
{
    int i;
    for (i = 0; i < elements; i++) {
        vec[i] = get_bits1(gb);
    }
}

/** ceil(log2(index+1)) */
static const int8_t ceil_log2[] = {
    0, 1, 2, 2, 3, 3,
};

static int read_sbr_grid(AACContext *ac, SpectralBandReplication *sbr,
                         GetBitContext *gb, SBRData *ch_data)
{
    int i;
643
    unsigned bs_pointer = 0;
644 645 646
    // frameLengthFlag ? 15 : 16; 960 sample length frames unsupported; this value is numTimeSlots
    int abs_bord_trail = 16;
    int num_rel_lead, num_rel_trail;
647
    unsigned bs_num_env_old = ch_data->bs_num_env;
648

649
    ch_data->bs_freq_res[0] = ch_data->bs_freq_res[ch_data->bs_num_env];
650
    ch_data->bs_amp_res = sbr->bs_amp_res_header;
651
    ch_data->t_env_num_env_old = ch_data->t_env[bs_num_env_old];
652 653 654

    switch (ch_data->bs_frame_class = get_bits(gb, 2)) {
    case FIXFIX:
655 656
        ch_data->bs_num_env                 = 1 << get_bits(gb, 2);
        num_rel_lead                        = ch_data->bs_num_env - 1;
657
        if (ch_data->bs_num_env == 1)
658 659
            ch_data->bs_amp_res = 0;

660
        if (ch_data->bs_num_env > 4) {
661
            av_log(ac->avctx, AV_LOG_ERROR,
662
                   "Invalid bitstream, too many SBR envelopes in FIXFIX type SBR frame: %d\n",
663
                   ch_data->bs_num_env);
664 665 666
            return -1;
        }

667 668 669 670 671 672 673 674
        ch_data->t_env[0]                   = 0;
        ch_data->t_env[ch_data->bs_num_env] = abs_bord_trail;

        abs_bord_trail = (abs_bord_trail + (ch_data->bs_num_env >> 1)) /
                   ch_data->bs_num_env;
        for (i = 0; i < num_rel_lead; i++)
            ch_data->t_env[i + 1] = ch_data->t_env[i] + abs_bord_trail;

675
        ch_data->bs_freq_res[1] = get_bits1(gb);
676
        for (i = 1; i < ch_data->bs_num_env; i++)
677 678 679
            ch_data->bs_freq_res[i + 1] = ch_data->bs_freq_res[1];
        break;
    case FIXVAR:
680 681 682 683
        abs_bord_trail                     += get_bits(gb, 2);
        num_rel_trail                       = get_bits(gb, 2);
        ch_data->bs_num_env                 = num_rel_trail + 1;
        ch_data->t_env[0]                   = 0;
684
        ch_data->t_env[ch_data->bs_num_env] = abs_bord_trail;
685

686
        for (i = 0; i < num_rel_trail; i++)
687 688
            ch_data->t_env[ch_data->bs_num_env - 1 - i] =
                ch_data->t_env[ch_data->bs_num_env - i] - 2 * get_bits(gb, 2) - 2;
689

690
        bs_pointer = get_bits(gb, ceil_log2[ch_data->bs_num_env]);
691

692 693
        for (i = 0; i < ch_data->bs_num_env; i++)
            ch_data->bs_freq_res[ch_data->bs_num_env - i] = get_bits1(gb);
694 695
        break;
    case VARFIX:
696 697 698
        ch_data->t_env[0]                   = get_bits(gb, 2);
        num_rel_lead                        = get_bits(gb, 2);
        ch_data->bs_num_env                 = num_rel_lead + 1;
699
        ch_data->t_env[ch_data->bs_num_env] = abs_bord_trail;
700

701
        for (i = 0; i < num_rel_lead; i++)
702
            ch_data->t_env[i + 1] = ch_data->t_env[i] + 2 * get_bits(gb, 2) + 2;
703

704
        bs_pointer = get_bits(gb, ceil_log2[ch_data->bs_num_env]);
705

706
        get_bits1_vector(gb, ch_data->bs_freq_res + 1, ch_data->bs_num_env);
707 708
        break;
    case VARVAR:
709 710 711 712 713
        ch_data->t_env[0]                   = get_bits(gb, 2);
        abs_bord_trail                     += get_bits(gb, 2);
        num_rel_lead                        = get_bits(gb, 2);
        num_rel_trail                       = get_bits(gb, 2);
        ch_data->bs_num_env                 = num_rel_lead + num_rel_trail + 1;
714

715
        if (ch_data->bs_num_env > 5) {
716
            av_log(ac->avctx, AV_LOG_ERROR,
717
                   "Invalid bitstream, too many SBR envelopes in VARVAR type SBR frame: %d\n",
718
                   ch_data->bs_num_env);
719 720 721
            return -1;
        }

722 723
        ch_data->t_env[ch_data->bs_num_env] = abs_bord_trail;

724
        for (i = 0; i < num_rel_lead; i++)
725
            ch_data->t_env[i + 1] = ch_data->t_env[i] + 2 * get_bits(gb, 2) + 2;
726
        for (i = 0; i < num_rel_trail; i++)
727 728
            ch_data->t_env[ch_data->bs_num_env - 1 - i] =
                ch_data->t_env[ch_data->bs_num_env - i] - 2 * get_bits(gb, 2) - 2;
729

730
        bs_pointer = get_bits(gb, ceil_log2[ch_data->bs_num_env]);
731

732
        get_bits1_vector(gb, ch_data->bs_freq_res + 1, ch_data->bs_num_env);
733 734 735
        break;
    }

736
    if (bs_pointer > ch_data->bs_num_env + 1) {
737
        av_log(ac->avctx, AV_LOG_ERROR,
738
               "Invalid bitstream, bs_pointer points to a middle noise border outside the time borders table: %d\n",
739
               bs_pointer);
740 741 742
        return -1;
    }

743 744
    for (i = 1; i <= ch_data->bs_num_env; i++) {
        if (ch_data->t_env[i-1] > ch_data->t_env[i]) {
745
            av_log(ac->avctx, AV_LOG_ERROR, "Non monotone time borders\n");
746 747 748 749
            return -1;
        }
    }

750
    ch_data->bs_num_noise = (ch_data->bs_num_env > 1) + 1;
751

752
    ch_data->t_q[0]                     = ch_data->t_env[0];
753
    ch_data->t_q[ch_data->bs_num_noise] = ch_data->t_env[ch_data->bs_num_env];
754
    if (ch_data->bs_num_noise > 1) {
755 756
        unsigned int idx;
        if (ch_data->bs_frame_class == FIXFIX) {
757
            idx = ch_data->bs_num_env >> 1;
758
        } else if (ch_data->bs_frame_class & 1) { // FIXVAR or VARVAR
759
            idx = ch_data->bs_num_env - FFMAX((int)bs_pointer - 1, 1);
760
        } else { // VARFIX
761
            if (!bs_pointer)
762
                idx = 1;
763
            else if (bs_pointer == 1)
764
                idx = ch_data->bs_num_env - 1;
765
            else // bs_pointer > 1
766
                idx = bs_pointer - 1;
767 768
        }
        ch_data->t_q[1] = ch_data->t_env[idx];
769
    }
770

771
    ch_data->e_a[0] = -(ch_data->e_a[1] != bs_num_env_old); // l_APrev
772
    ch_data->e_a[1] = -1;
773
    if ((ch_data->bs_frame_class & 1) && bs_pointer) { // FIXVAR or VARVAR and bs_pointer != 0
774
        ch_data->e_a[1] = ch_data->bs_num_env + 1 - bs_pointer;
775 776
    } else if ((ch_data->bs_frame_class == 2) && (bs_pointer > 1)) // VARFIX and bs_pointer > 1
        ch_data->e_a[1] = bs_pointer - 1;
777

778 779 780 781 782
    return 0;
}

static void copy_sbr_grid(SBRData *dst, const SBRData *src) {
    //These variables are saved from the previous frame rather than copied
783
    dst->bs_freq_res[0]    = dst->bs_freq_res[dst->bs_num_env];
784
    dst->t_env_num_env_old = dst->t_env[dst->bs_num_env];
785
    dst->e_a[0]            = -(dst->e_a[1] != dst->bs_num_env);
786 787 788

    //These variables are read from the bitstream and therefore copied
    memcpy(dst->bs_freq_res+1, src->bs_freq_res+1, sizeof(dst->bs_freq_res)-sizeof(*dst->bs_freq_res));
789 790
    memcpy(dst->t_env,         src->t_env,         sizeof(dst->t_env));
    memcpy(dst->t_q,           src->t_q,           sizeof(dst->t_q));
791 792 793 794 795
    dst->bs_num_env        = src->bs_num_env;
    dst->bs_amp_res        = src->bs_amp_res;
    dst->bs_num_noise      = src->bs_num_noise;
    dst->bs_frame_class    = src->bs_frame_class;
    dst->e_a[1]            = src->e_a[1];
796 797 798 799 800 801
}

/// Read how the envelope and noise floor data is delta coded
static void read_sbr_dtdf(SpectralBandReplication *sbr, GetBitContext *gb,
                          SBRData *ch_data)
{
802
    get_bits1_vector(gb, ch_data->bs_df_env,   ch_data->bs_num_env);
803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856
    get_bits1_vector(gb, ch_data->bs_df_noise, ch_data->bs_num_noise);
}

/// Read inverse filtering data
static void read_sbr_invf(SpectralBandReplication *sbr, GetBitContext *gb,
                          SBRData *ch_data)
{
    int i;

    memcpy(ch_data->bs_invf_mode[1], ch_data->bs_invf_mode[0], 5 * sizeof(uint8_t));
    for (i = 0; i < sbr->n_q; i++)
        ch_data->bs_invf_mode[0][i] = get_bits(gb, 2);
}

static void read_sbr_envelope(SpectralBandReplication *sbr, GetBitContext *gb,
                              SBRData *ch_data, int ch)
{
    int bits;
    int i, j, k;
    VLC_TYPE (*t_huff)[2], (*f_huff)[2];
    int t_lav, f_lav;
    const int delta = (ch == 1 && sbr->bs_coupling == 1) + 1;
    const int odd = sbr->n[1] & 1;

    if (sbr->bs_coupling && ch) {
        if (ch_data->bs_amp_res) {
            bits   = 5;
            t_huff = vlc_sbr[T_HUFFMAN_ENV_BAL_3_0DB].table;
            t_lav  = vlc_sbr_lav[T_HUFFMAN_ENV_BAL_3_0DB];
            f_huff = vlc_sbr[F_HUFFMAN_ENV_BAL_3_0DB].table;
            f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_BAL_3_0DB];
        } else {
            bits   = 6;
            t_huff = vlc_sbr[T_HUFFMAN_ENV_BAL_1_5DB].table;
            t_lav  = vlc_sbr_lav[T_HUFFMAN_ENV_BAL_1_5DB];
            f_huff = vlc_sbr[F_HUFFMAN_ENV_BAL_1_5DB].table;
            f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_BAL_1_5DB];
        }
    } else {
        if (ch_data->bs_amp_res) {
            bits   = 6;
            t_huff = vlc_sbr[T_HUFFMAN_ENV_3_0DB].table;
            t_lav  = vlc_sbr_lav[T_HUFFMAN_ENV_3_0DB];
            f_huff = vlc_sbr[F_HUFFMAN_ENV_3_0DB].table;
            f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_3_0DB];
        } else {
            bits   = 7;
            t_huff = vlc_sbr[T_HUFFMAN_ENV_1_5DB].table;
            t_lav  = vlc_sbr_lav[T_HUFFMAN_ENV_1_5DB];
            f_huff = vlc_sbr[F_HUFFMAN_ENV_1_5DB].table;
            f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_1_5DB];
        }
    }

857
    for (i = 0; i < ch_data->bs_num_env; i++) {
858
        if (ch_data->bs_df_env[i]) {
859
            // bs_freq_res[0] == bs_freq_res[bs_num_env] from prev frame
860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881
            if (ch_data->bs_freq_res[i + 1] == ch_data->bs_freq_res[i]) {
                for (j = 0; j < sbr->n[ch_data->bs_freq_res[i + 1]]; j++)
                    ch_data->env_facs[i + 1][j] = ch_data->env_facs[i][j] + delta * (get_vlc2(gb, t_huff, 9, 3) - t_lav);
            } else if (ch_data->bs_freq_res[i + 1]) {
                for (j = 0; j < sbr->n[ch_data->bs_freq_res[i + 1]]; j++) {
                    k = (j + odd) >> 1; // find k such that f_tablelow[k] <= f_tablehigh[j] < f_tablelow[k + 1]
                    ch_data->env_facs[i + 1][j] = ch_data->env_facs[i][k] + delta * (get_vlc2(gb, t_huff, 9, 3) - t_lav);
                }
            } else {
                for (j = 0; j < sbr->n[ch_data->bs_freq_res[i + 1]]; j++) {
                    k = j ? 2*j - odd : 0; // find k such that f_tablehigh[k] == f_tablelow[j]
                    ch_data->env_facs[i + 1][j] = ch_data->env_facs[i][k] + delta * (get_vlc2(gb, t_huff, 9, 3) - t_lav);
                }
            }
        } else {
            ch_data->env_facs[i + 1][0] = delta * get_bits(gb, bits); // bs_env_start_value_balance
            for (j = 1; j < sbr->n[ch_data->bs_freq_res[i + 1]]; j++)
                ch_data->env_facs[i + 1][j] = ch_data->env_facs[i + 1][j - 1] + delta * (get_vlc2(gb, f_huff, 9, 3) - f_lav);
        }
    }

    //assign 0th elements of env_facs from last elements
882
    memcpy(ch_data->env_facs[0], ch_data->env_facs[ch_data->bs_num_env],
883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923
           sizeof(ch_data->env_facs[0]));
}

static void read_sbr_noise(SpectralBandReplication *sbr, GetBitContext *gb,
                           SBRData *ch_data, int ch)
{
    int i, j;
    VLC_TYPE (*t_huff)[2], (*f_huff)[2];
    int t_lav, f_lav;
    int delta = (ch == 1 && sbr->bs_coupling == 1) + 1;

    if (sbr->bs_coupling && ch) {
        t_huff = vlc_sbr[T_HUFFMAN_NOISE_BAL_3_0DB].table;
        t_lav  = vlc_sbr_lav[T_HUFFMAN_NOISE_BAL_3_0DB];
        f_huff = vlc_sbr[F_HUFFMAN_ENV_BAL_3_0DB].table;
        f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_BAL_3_0DB];
    } else {
        t_huff = vlc_sbr[T_HUFFMAN_NOISE_3_0DB].table;
        t_lav  = vlc_sbr_lav[T_HUFFMAN_NOISE_3_0DB];
        f_huff = vlc_sbr[F_HUFFMAN_ENV_3_0DB].table;
        f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_3_0DB];
    }

    for (i = 0; i < ch_data->bs_num_noise; i++) {
        if (ch_data->bs_df_noise[i]) {
            for (j = 0; j < sbr->n_q; j++)
                ch_data->noise_facs[i + 1][j] = ch_data->noise_facs[i][j] + delta * (get_vlc2(gb, t_huff, 9, 2) - t_lav);
        } else {
            ch_data->noise_facs[i + 1][0] = delta * get_bits(gb, 5); // bs_noise_start_value_balance or bs_noise_start_value_level
            for (j = 1; j < sbr->n_q; j++)
                ch_data->noise_facs[i + 1][j] = ch_data->noise_facs[i + 1][j - 1] + delta * (get_vlc2(gb, f_huff, 9, 3) - f_lav);
        }
    }

    //assign 0th elements of noise_facs from last elements
    memcpy(ch_data->noise_facs[0], ch_data->noise_facs[ch_data->bs_num_noise],
           sizeof(ch_data->noise_facs[0]));
}

static void read_sbr_extension(AACContext *ac, SpectralBandReplication *sbr,
                               GetBitContext *gb,
924
                               int bs_extension_id, int *num_bits_left)
925 926 927
{
    switch (bs_extension_id) {
    case EXTENSION_ID_PS:
928 929 930 931 932
        if (!ac->oc[1].m4ac.ps) {
            av_log(ac->avctx, AV_LOG_ERROR, "Parametric Stereo signaled to be not-present but was found in the bitstream.\n");
            skip_bits_long(gb, *num_bits_left); // bs_fill_bits
            *num_bits_left = 0;
        } else {
933 934
#if 1
            *num_bits_left -= ff_ps_read_data(ac->avctx, gb, &sbr->ps, *num_bits_left);
935
            ac->avctx->profile = FF_PROFILE_AAC_HE_V2;
936
#else
937
            avpriv_report_missing_feature(ac->avctx, "Parametric Stereo");
938 939
            skip_bits_long(gb, *num_bits_left); // bs_fill_bits
            *num_bits_left = 0;
940
#endif
941
        }
942 943
        break;
    default:
944 945
        // some files contain 0-padding
        if (bs_extension_id || *num_bits_left > 16 || show_bits(gb, *num_bits_left))
946
            avpriv_request_sample(ac->avctx, "Reserved SBR extensions");
947 948 949 950 951 952
        skip_bits_long(gb, *num_bits_left); // bs_fill_bits
        *num_bits_left = 0;
        break;
    }
}

953
static int read_sbr_single_channel_element(AACContext *ac,
954 955 956 957 958 959
                                            SpectralBandReplication *sbr,
                                            GetBitContext *gb)
{
    if (get_bits1(gb)) // bs_data_extra
        skip_bits(gb, 4); // bs_reserved

960 961
    if (read_sbr_grid(ac, sbr, gb, &sbr->data[0]))
        return -1;
962 963 964 965 966 967 968
    read_sbr_dtdf(sbr, gb, &sbr->data[0]);
    read_sbr_invf(sbr, gb, &sbr->data[0]);
    read_sbr_envelope(sbr, gb, &sbr->data[0], 0);
    read_sbr_noise(sbr, gb, &sbr->data[0], 0);

    if ((sbr->data[0].bs_add_harmonic_flag = get_bits1(gb)))
        get_bits1_vector(gb, sbr->data[0].bs_add_harmonic, sbr->n[1]);
969 970

    return 0;
971 972
}

973
static int read_sbr_channel_pair_element(AACContext *ac,
974 975 976 977 978 979 980
                                          SpectralBandReplication *sbr,
                                          GetBitContext *gb)
{
    if (get_bits1(gb))    // bs_data_extra
        skip_bits(gb, 8); // bs_reserved

    if ((sbr->bs_coupling = get_bits1(gb))) {
981 982
        if (read_sbr_grid(ac, sbr, gb, &sbr->data[0]))
            return -1;
983 984 985 986 987 988 989 990 991 992 993
        copy_sbr_grid(&sbr->data[1], &sbr->data[0]);
        read_sbr_dtdf(sbr, gb, &sbr->data[0]);
        read_sbr_dtdf(sbr, gb, &sbr->data[1]);
        read_sbr_invf(sbr, gb, &sbr->data[0]);
        memcpy(sbr->data[1].bs_invf_mode[1], sbr->data[1].bs_invf_mode[0], sizeof(sbr->data[1].bs_invf_mode[0]));
        memcpy(sbr->data[1].bs_invf_mode[0], sbr->data[0].bs_invf_mode[0], sizeof(sbr->data[1].bs_invf_mode[0]));
        read_sbr_envelope(sbr, gb, &sbr->data[0], 0);
        read_sbr_noise(sbr, gb, &sbr->data[0], 0);
        read_sbr_envelope(sbr, gb, &sbr->data[1], 1);
        read_sbr_noise(sbr, gb, &sbr->data[1], 1);
    } else {
994 995 996
        if (read_sbr_grid(ac, sbr, gb, &sbr->data[0]) ||
            read_sbr_grid(ac, sbr, gb, &sbr->data[1]))
            return -1;
997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010
        read_sbr_dtdf(sbr, gb, &sbr->data[0]);
        read_sbr_dtdf(sbr, gb, &sbr->data[1]);
        read_sbr_invf(sbr, gb, &sbr->data[0]);
        read_sbr_invf(sbr, gb, &sbr->data[1]);
        read_sbr_envelope(sbr, gb, &sbr->data[0], 0);
        read_sbr_envelope(sbr, gb, &sbr->data[1], 1);
        read_sbr_noise(sbr, gb, &sbr->data[0], 0);
        read_sbr_noise(sbr, gb, &sbr->data[1], 1);
    }

    if ((sbr->data[0].bs_add_harmonic_flag = get_bits1(gb)))
        get_bits1_vector(gb, sbr->data[0].bs_add_harmonic, sbr->n[1]);
    if ((sbr->data[1].bs_add_harmonic_flag = get_bits1(gb)))
        get_bits1_vector(gb, sbr->data[1].bs_add_harmonic, sbr->n[1]);
1011 1012

    return 0;
1013 1014 1015 1016 1017 1018 1019 1020
}

static unsigned int read_sbr_data(AACContext *ac, SpectralBandReplication *sbr,
                                  GetBitContext *gb, int id_aac)
{
    unsigned int cnt = get_bits_count(gb);

    if (id_aac == TYPE_SCE || id_aac == TYPE_CCE) {
1021
        if (read_sbr_single_channel_element(ac, sbr, gb)) {
1022
            sbr_turnoff(sbr);
1023 1024
            return get_bits_count(gb) - cnt;
        }
1025
    } else if (id_aac == TYPE_CPE) {
1026
        if (read_sbr_channel_pair_element(ac, sbr, gb)) {
1027
            sbr_turnoff(sbr);
1028 1029
            return get_bits_count(gb) - cnt;
        }
1030
    } else {
1031
        av_log(ac->avctx, AV_LOG_ERROR,
1032
            "Invalid bitstream - cannot apply SBR to element type %d\n", id_aac);
1033
        sbr_turnoff(sbr);
1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045
        return get_bits_count(gb) - cnt;
    }
    if (get_bits1(gb)) { // bs_extended_data
        int num_bits_left = get_bits(gb, 4); // bs_extension_size
        if (num_bits_left == 15)
            num_bits_left += get_bits(gb, 8); // bs_esc_count

        num_bits_left <<= 3;
        while (num_bits_left > 7) {
            num_bits_left -= 2;
            read_sbr_extension(ac, sbr, gb, get_bits(gb, 2), &num_bits_left); // bs_extension_id
        }
1046 1047 1048 1049 1050
        if (num_bits_left < 0) {
            av_log(ac->avctx, AV_LOG_ERROR, "SBR Extension over read.\n");
        }
        if (num_bits_left > 0)
            skip_bits(gb, num_bits_left);
1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062
    }

    return get_bits_count(gb) - cnt;
}

static void sbr_reset(AACContext *ac, SpectralBandReplication *sbr)
{
    int err;
    err = sbr_make_f_master(ac, sbr, &sbr->spectrum_params);
    if (err >= 0)
        err = sbr_make_f_derived(ac, sbr);
    if (err < 0) {
1063
        av_log(ac->avctx, AV_LOG_ERROR,
1064
               "SBR reset failed. Switching SBR to pure upsampling mode.\n");
1065
        sbr_turnoff(sbr);
1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087
    }
}

/**
 * Decode Spectral Band Replication extension data; reference: table 4.55.
 *
 * @param   crc flag indicating the presence of CRC checksum
 * @param   cnt length of TYPE_FIL syntactic element in bytes
 *
 * @return  Returns number of bytes consumed from the TYPE_FIL element.
 */
int ff_decode_sbr_extension(AACContext *ac, SpectralBandReplication *sbr,
                            GetBitContext *gb_host, int crc, int cnt, int id_aac)
{
    unsigned int num_sbr_bits = 0, num_align_bits;
    unsigned bytes_read;
    GetBitContext gbc = *gb_host, *gb = &gbc;
    skip_bits_long(gb_host, cnt*8 - 4);

    sbr->reset = 0;

    if (!sbr->sample_rate)
1088 1089 1090
        sbr->sample_rate = 2 * ac->oc[1].m4ac.sample_rate; //TODO use the nominal sample rate for arbitrary sample rate support
    if (!ac->oc[1].m4ac.ext_sample_rate)
        ac->oc[1].m4ac.ext_sample_rate = 2 * ac->oc[1].m4ac.sample_rate;
1091 1092 1093 1094 1095 1096 1097 1098 1099

    if (crc) {
        skip_bits(gb, 10); // bs_sbr_crc_bits; TODO - implement CRC check
        num_sbr_bits += 10;
    }

    //Save some state from the previous frame.
    sbr->kx[0] = sbr->kx[1];
    sbr->m[0] = sbr->m[1];
1100
    sbr->kx_and_m_pushed = 1;
1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115

    num_sbr_bits++;
    if (get_bits1(gb)) // bs_header_flag
        num_sbr_bits += read_sbr_header(sbr, gb);

    if (sbr->reset)
        sbr_reset(ac, sbr);

    if (sbr->start)
        num_sbr_bits  += read_sbr_data(ac, sbr, gb, id_aac);

    num_align_bits = ((cnt << 3) - 4 - num_sbr_bits) & 7;
    bytes_read = ((num_sbr_bits + num_align_bits + 4) >> 3);

    if (bytes_read > cnt) {
1116
        av_log(ac->avctx, AV_LOG_ERROR,
1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130
               "Expected to read %d SBR bytes actually read %d.\n", cnt, bytes_read);
    }
    return cnt;
}

/// Dequantization and stereo decoding (14496-3 sp04 p203)
static void sbr_dequant(SpectralBandReplication *sbr, int id_aac)
{
    int k, e;
    int ch;

    if (id_aac == TYPE_CPE && sbr->bs_coupling) {
        float alpha      = sbr->data[0].bs_amp_res ?  1.0f :  0.5f;
        float pan_offset = sbr->data[0].bs_amp_res ? 12.0f : 24.0f;
1131
        for (e = 1; e <= sbr->data[0].bs_num_env; e++) {
1132 1133 1134
            for (k = 0; k < sbr->n[sbr->data[0].bs_freq_res[e]]; k++) {
                float temp1 = exp2f(sbr->data[0].env_facs[e][k] * alpha + 7.0f);
                float temp2 = exp2f((pan_offset - sbr->data[1].env_facs[e][k]) * alpha);
1135 1136 1137 1138 1139 1140
                float fac;
                if (temp1 > 1E20) {
                    av_log(NULL, AV_LOG_ERROR, "envelope scalefactor overflow in dequant\n");
                    temp1 = 1;
                }
                fac   = temp1 / (1.0f + temp2);
1141 1142 1143 1144 1145 1146 1147 1148
                sbr->data[0].env_facs[e][k] = fac;
                sbr->data[1].env_facs[e][k] = fac * temp2;
            }
        }
        for (e = 1; e <= sbr->data[0].bs_num_noise; e++) {
            for (k = 0; k < sbr->n_q; k++) {
                float temp1 = exp2f(NOISE_FLOOR_OFFSET - sbr->data[0].noise_facs[e][k] + 1);
                float temp2 = exp2f(12 - sbr->data[1].noise_facs[e][k]);
1149 1150 1151 1152 1153 1154
                float fac;
                if (temp1 > 1E20) {
                    av_log(NULL, AV_LOG_ERROR, "envelope scalefactor overflow in dequant\n");
                    temp1 = 1;
                }
                fac = temp1 / (1.0f + temp2);
1155 1156 1157 1158 1159 1160 1161
                sbr->data[0].noise_facs[e][k] = fac;
                sbr->data[1].noise_facs[e][k] = fac * temp2;
            }
        }
    } else { // SCE or one non-coupled CPE
        for (ch = 0; ch < (id_aac == TYPE_CPE) + 1; ch++) {
            float alpha = sbr->data[ch].bs_amp_res ? 1.0f : 0.5f;
1162
            for (e = 1; e <= sbr->data[ch].bs_num_env; e++)
1163
                for (k = 0; k < sbr->n[sbr->data[ch].bs_freq_res[e]]; k++){
1164 1165
                    sbr->data[ch].env_facs[e][k] =
                        exp2f(alpha * sbr->data[ch].env_facs[e][k] + 6.0f);
1166 1167 1168 1169 1170 1171
                    if (sbr->data[ch].env_facs[e][k] > 1E20) {
                        av_log(NULL, AV_LOG_ERROR, "envelope scalefactor overflow in dequant\n");
                        sbr->data[ch].env_facs[e][k] = 1;
                    }
                }

1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185
            for (e = 1; e <= sbr->data[ch].bs_num_noise; e++)
                for (k = 0; k < sbr->n_q; k++)
                    sbr->data[ch].noise_facs[e][k] =
                        exp2f(NOISE_FLOOR_OFFSET - sbr->data[ch].noise_facs[e][k]);
        }
    }
}

/**
 * Analysis QMF Bank (14496-3 sp04 p206)
 *
 * @param   x       pointer to the beginning of the first sample window
 * @param   W       array of complex-valued samples split into subbands
 */
1186
#ifndef sbr_qmf_analysis
1187
static void sbr_qmf_analysis(AVFloatDSPContext *dsp, FFTContext *mdct,
1188
                             SBRDSPContext *sbrdsp, const float *in, float *x,
1189
                             float z[320], float W[2][32][32][2], int buf_idx)
1190
{
1191
    int i;
1192
    memcpy(x    , x+1024, (320-32)*sizeof(x[0]));
1193
    memcpy(x+288, in,         1024*sizeof(x[0]));
1194 1195 1196
    for (i = 0; i < 32; i++) { // numTimeSlots*RATE = 16*2 as 960 sample frames
                               // are not supported
        dsp->vector_fmul_reverse(z, sbr_qmf_window_ds, x, 320);
1197 1198
        sbrdsp->sum64x5(z);
        sbrdsp->qmf_pre_shuffle(z);
1199
        mdct->imdct_half(mdct, z, z+64);
1200
        sbrdsp->qmf_post_shuffle(W[buf_idx][i], z);
1201 1202 1203
        x += 32;
    }
}
1204
#endif
1205 1206 1207 1208 1209

/**
 * Synthesis QMF Bank (14496-3 sp04 p206) and Downsampled Synthesis QMF Bank
 * (14496-3 sp04 p206)
 */
1210
#ifndef sbr_qmf_synthesis
1211 1212
static void sbr_qmf_synthesis(FFTContext *mdct,
                              SBRDSPContext *sbrdsp, AVFloatDSPContext *dsp,
1213
                              float *out, float X[2][38][64],
1214
                              float mdct_buf[2][64],
1215
                              float *v0, int *v_off, const unsigned int div)
1216 1217 1218
{
    int i, n;
    const float *sbr_qmf_window = div ? sbr_qmf_window_ds : sbr_qmf_window_us;
1219
    const int step = 128 >> div;
1220 1221
    float *v;
    for (i = 0; i < 32; i++) {
1222
        if (*v_off < step) {
1223 1224
            int saved_samples = (1280 - 128) >> div;
            memcpy(&v0[SBR_SYNTHESIS_BUF_SIZE - saved_samples], v0, saved_samples * sizeof(float));
1225
            *v_off = SBR_SYNTHESIS_BUF_SIZE - saved_samples - step;
1226
        } else {
1227
            *v_off -= step;
1228 1229
        }
        v = v0 + *v_off;
1230 1231 1232 1233 1234
        if (div) {
            for (n = 0; n < 32; n++) {
                X[0][i][   n] = -X[0][i][n];
                X[0][i][32+n] =  X[1][i][31-n];
            }
1235
            mdct->imdct_half(mdct, mdct_buf[0], X[0][i]);
1236
            sbrdsp->qmf_deint_neg(v, mdct_buf[0]);
1237
        } else {
1238
            sbrdsp->neg_odd_64(X[1][i]);
1239 1240
            mdct->imdct_half(mdct, mdct_buf[0], X[0][i]);
            mdct->imdct_half(mdct, mdct_buf[1], X[1][i]);
1241
            sbrdsp->qmf_deint_bfly(v, mdct_buf[1], mdct_buf[0]);
1242
        }
1243
        dsp->vector_fmul    (out, v                , sbr_qmf_window                       , 64 >> div);
1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255
        dsp->vector_fmul_add(out, v + ( 192 >> div), sbr_qmf_window + ( 64 >> div), out   , 64 >> div);
        dsp->vector_fmul_add(out, v + ( 256 >> div), sbr_qmf_window + (128 >> div), out   , 64 >> div);
        dsp->vector_fmul_add(out, v + ( 448 >> div), sbr_qmf_window + (192 >> div), out   , 64 >> div);
        dsp->vector_fmul_add(out, v + ( 512 >> div), sbr_qmf_window + (256 >> div), out   , 64 >> div);
        dsp->vector_fmul_add(out, v + ( 704 >> div), sbr_qmf_window + (320 >> div), out   , 64 >> div);
        dsp->vector_fmul_add(out, v + ( 768 >> div), sbr_qmf_window + (384 >> div), out   , 64 >> div);
        dsp->vector_fmul_add(out, v + ( 960 >> div), sbr_qmf_window + (448 >> div), out   , 64 >> div);
        dsp->vector_fmul_add(out, v + (1024 >> div), sbr_qmf_window + (512 >> div), out   , 64 >> div);
        dsp->vector_fmul_add(out, v + (1216 >> div), sbr_qmf_window + (576 >> div), out   , 64 >> div);
        out += 64 >> div;
    }
}
1256
#endif
1257 1258 1259 1260 1261

/** High Frequency Generation (14496-3 sp04 p214+) and Inverse Filtering
 * (14496-3 sp04 p214)
 * Warning: This routine does not seem numerically stable.
 */
1262 1263
static void sbr_hf_inverse_filter(SBRDSPContext *dsp,
                                  float (*alpha0)[2], float (*alpha1)[2],
1264 1265 1266 1267
                                  const float X_low[32][40][2], int k0)
{
    int k;
    for (k = 0; k < k0; k++) {
1268 1269
        LOCAL_ALIGNED_16(float, phi, [3], [2][2]);
        float dk;
1270

1271
        dsp->autocorrelate(X_low[k], phi);
1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338

        dk =  phi[2][1][0] * phi[1][0][0] -
             (phi[1][1][0] * phi[1][1][0] + phi[1][1][1] * phi[1][1][1]) / 1.000001f;

        if (!dk) {
            alpha1[k][0] = 0;
            alpha1[k][1] = 0;
        } else {
            float temp_real, temp_im;
            temp_real = phi[0][0][0] * phi[1][1][0] -
                        phi[0][0][1] * phi[1][1][1] -
                        phi[0][1][0] * phi[1][0][0];
            temp_im   = phi[0][0][0] * phi[1][1][1] +
                        phi[0][0][1] * phi[1][1][0] -
                        phi[0][1][1] * phi[1][0][0];

            alpha1[k][0] = temp_real / dk;
            alpha1[k][1] = temp_im   / dk;
        }

        if (!phi[1][0][0]) {
            alpha0[k][0] = 0;
            alpha0[k][1] = 0;
        } else {
            float temp_real, temp_im;
            temp_real = phi[0][0][0] + alpha1[k][0] * phi[1][1][0] +
                                       alpha1[k][1] * phi[1][1][1];
            temp_im   = phi[0][0][1] + alpha1[k][1] * phi[1][1][0] -
                                       alpha1[k][0] * phi[1][1][1];

            alpha0[k][0] = -temp_real / phi[1][0][0];
            alpha0[k][1] = -temp_im   / phi[1][0][0];
        }

        if (alpha1[k][0] * alpha1[k][0] + alpha1[k][1] * alpha1[k][1] >= 16.0f ||
           alpha0[k][0] * alpha0[k][0] + alpha0[k][1] * alpha0[k][1] >= 16.0f) {
            alpha1[k][0] = 0;
            alpha1[k][1] = 0;
            alpha0[k][0] = 0;
            alpha0[k][1] = 0;
        }
    }
}

/// Chirp Factors (14496-3 sp04 p214)
static void sbr_chirp(SpectralBandReplication *sbr, SBRData *ch_data)
{
    int i;
    float new_bw;
    static const float bw_tab[] = { 0.0f, 0.75f, 0.9f, 0.98f };

    for (i = 0; i < sbr->n_q; i++) {
        if (ch_data->bs_invf_mode[0][i] + ch_data->bs_invf_mode[1][i] == 1) {
            new_bw = 0.6f;
        } else
            new_bw = bw_tab[ch_data->bs_invf_mode[0][i]];

        if (new_bw < ch_data->bw_array[i]) {
            new_bw = 0.75f    * new_bw + 0.25f    * ch_data->bw_array[i];
        } else
            new_bw = 0.90625f * new_bw + 0.09375f * ch_data->bw_array[i];
        ch_data->bw_array[i] = new_bw < 0.015625f ? 0.0f : new_bw;
    }
}

/// Generate the subband filtered lowband
static int sbr_lf_gen(AACContext *ac, SpectralBandReplication *sbr,
1339 1340
                      float X_low[32][40][2], const float W[2][32][32][2],
                      int buf_idx)
1341 1342 1343 1344 1345 1346 1347
{
    int i, k;
    const int t_HFGen = 8;
    const int i_f = 32;
    memset(X_low, 0, 32*sizeof(*X_low));
    for (k = 0; k < sbr->kx[1]; k++) {
        for (i = t_HFGen; i < i_f + t_HFGen; i++) {
1348 1349
            X_low[k][i][0] = W[buf_idx][i - t_HFGen][k][0];
            X_low[k][i][1] = W[buf_idx][i - t_HFGen][k][1];
1350 1351
        }
    }
1352
    buf_idx = 1-buf_idx;
1353 1354
    for (k = 0; k < sbr->kx[0]; k++) {
        for (i = 0; i < t_HFGen; i++) {
1355 1356
            X_low[k][i][0] = W[buf_idx][i + i_f - t_HFGen][k][0];
            X_low[k][i][1] = W[buf_idx][i + i_f - t_HFGen][k][1];
1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368
        }
    }
    return 0;
}

/// High Frequency Generator (14496-3 sp04 p215)
static int sbr_hf_gen(AACContext *ac, SpectralBandReplication *sbr,
                      float X_high[64][40][2], const float X_low[32][40][2],
                      const float (*alpha0)[2], const float (*alpha1)[2],
                      const float bw_array[5], const uint8_t *t_env,
                      int bs_num_env)
{
1369
    int j, x;
1370 1371 1372 1373 1374 1375 1376 1377 1378 1379
    int g = 0;
    int k = sbr->kx[1];
    for (j = 0; j < sbr->num_patches; j++) {
        for (x = 0; x < sbr->patch_num_subbands[j]; x++, k++) {
            const int p = sbr->patch_start_subband[j] + x;
            while (g <= sbr->n_q && k >= sbr->f_tablenoise[g])
                g++;
            g--;

            if (g < 0) {
1380
                av_log(ac->avctx, AV_LOG_ERROR,
1381 1382 1383 1384
                       "ERROR : no subband found for frequency %d\n", k);
                return -1;
            }

1385 1386 1387 1388
            sbr->dsp.hf_gen(X_high[k] + ENVELOPE_ADJUSTMENT_OFFSET,
                            X_low[p]  + ENVELOPE_ADJUSTMENT_OFFSET,
                            alpha0[p], alpha1[p], bw_array[g],
                            2 * t_env[0], 2 * t_env[bs_num_env]);
1389 1390 1391 1392 1393 1394 1395 1396 1397
        }
    }
    if (k < sbr->m[1] + sbr->kx[1])
        memset(X_high + k, 0, (sbr->m[1] + sbr->kx[1] - k) * sizeof(*X_high));

    return 0;
}

/// Generate the subband filtered lowband
1398
static int sbr_x_gen(SpectralBandReplication *sbr, float X[2][38][64],
1399 1400
                     const float Y0[38][64][2], const float Y1[38][64][2],
                     const float X_low[32][40][2], int ch)
1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413
{
    int k, i;
    const int i_f = 32;
    const int i_Temp = FFMAX(2*sbr->data[ch].t_env_num_env_old - i_f, 0);
    memset(X, 0, 2*sizeof(*X));
    for (k = 0; k < sbr->kx[0]; k++) {
        for (i = 0; i < i_Temp; i++) {
            X[0][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][0];
            X[1][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][1];
        }
    }
    for (; k < sbr->kx[0] + sbr->m[0]; k++) {
        for (i = 0; i < i_Temp; i++) {
1414 1415
            X[0][i][k] = Y0[i + i_f][k][0];
            X[1][i][k] = Y0[i + i_f][k][1];
1416 1417 1418 1419
        }
    }

    for (k = 0; k < sbr->kx[1]; k++) {
1420
        for (i = i_Temp; i < 38; i++) {
1421 1422 1423 1424 1425 1426
            X[0][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][0];
            X[1][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][1];
        }
    }
    for (; k < sbr->kx[1] + sbr->m[1]; k++) {
        for (i = i_Temp; i < i_f; i++) {
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            X[0][i][k] = Y1[i][k][0];
            X[1][i][k] = Y1[i][k][1];
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        }
    }
    return 0;
}

/** High Frequency Adjustment (14496-3 sp04 p217) and Mapping
 * (14496-3 sp04 p217)
 */
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static int sbr_mapping(AACContext *ac, SpectralBandReplication *sbr,
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                        SBRData *ch_data, int e_a[2])
{
    int e, i, m;

    memset(ch_data->s_indexmapped[1], 0, 7*sizeof(ch_data->s_indexmapped[1]));
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    for (e = 0; e < ch_data->bs_num_env; e++) {
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        const unsigned int ilim = sbr->n[ch_data->bs_freq_res[e + 1]];
        uint16_t *table = ch_data->bs_freq_res[e + 1] ? sbr->f_tablehigh : sbr->f_tablelow;
        int k;

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        if (sbr->kx[1] != table[0]) {
            av_log(ac->avctx, AV_LOG_ERROR, "kx != f_table{high,low}[0]. "
                   "Derived frequency tables were not regenerated.\n");
            sbr_turnoff(sbr);
            return AVERROR_BUG;
        }
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        for (i = 0; i < ilim; i++)
            for (m = table[i]; m < table[i + 1]; m++)
                sbr->e_origmapped[e][m - sbr->kx[1]] = ch_data->env_facs[e+1][i];

        // ch_data->bs_num_noise > 1 => 2 noise floors
        k = (ch_data->bs_num_noise > 1) && (ch_data->t_env[e] >= ch_data->t_q[1]);
        for (i = 0; i < sbr->n_q; i++)
            for (m = sbr->f_tablenoise[i]; m < sbr->f_tablenoise[i + 1]; m++)
                sbr->q_mapped[e][m - sbr->kx[1]] = ch_data->noise_facs[k+1][i];

        for (i = 0; i < sbr->n[1]; i++) {
            if (ch_data->bs_add_harmonic_flag) {
                const unsigned int m_midpoint =
                    (sbr->f_tablehigh[i] + sbr->f_tablehigh[i + 1]) >> 1;

                ch_data->s_indexmapped[e + 1][m_midpoint - sbr->kx[1]] = ch_data->bs_add_harmonic[i] *
                    (e >= e_a[1] || (ch_data->s_indexmapped[0][m_midpoint - sbr->kx[1]] == 1));
            }
        }

        for (i = 0; i < ilim; i++) {
            int additional_sinusoid_present = 0;
            for (m = table[i]; m < table[i + 1]; m++) {
                if (ch_data->s_indexmapped[e + 1][m - sbr->kx[1]]) {
                    additional_sinusoid_present = 1;
                    break;
                }
            }
            memset(&sbr->s_mapped[e][table[i] - sbr->kx[1]], additional_sinusoid_present,
                   (table[i + 1] - table[i]) * sizeof(sbr->s_mapped[e][0]));
        }
    }

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    memcpy(ch_data->s_indexmapped[0], ch_data->s_indexmapped[ch_data->bs_num_env], sizeof(ch_data->s_indexmapped[0]));
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    return 0;
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}

/// Estimation of current envelope (14496-3 sp04 p218)
static void sbr_env_estimate(float (*e_curr)[48], float X_high[64][40][2],
                             SpectralBandReplication *sbr, SBRData *ch_data)
{
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    int e, m;
    int kx1 = sbr->kx[1];
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    if (sbr->bs_interpol_freq) {
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        for (e = 0; e < ch_data->bs_num_env; e++) {
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            const float recip_env_size = 0.5f / (ch_data->t_env[e + 1] - ch_data->t_env[e]);
            int ilb = ch_data->t_env[e]     * 2 + ENVELOPE_ADJUSTMENT_OFFSET;
            int iub = ch_data->t_env[e + 1] * 2 + ENVELOPE_ADJUSTMENT_OFFSET;

            for (m = 0; m < sbr->m[1]; m++) {
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                float sum = sbr->dsp.sum_square(X_high[m+kx1] + ilb, iub - ilb);
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                e_curr[e][m] = sum * recip_env_size;
            }
        }
    } else {
        int k, p;

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        for (e = 0; e < ch_data->bs_num_env; e++) {
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            const int env_size = 2 * (ch_data->t_env[e + 1] - ch_data->t_env[e]);
            int ilb = ch_data->t_env[e]     * 2 + ENVELOPE_ADJUSTMENT_OFFSET;
            int iub = ch_data->t_env[e + 1] * 2 + ENVELOPE_ADJUSTMENT_OFFSET;
            const uint16_t *table = ch_data->bs_freq_res[e + 1] ? sbr->f_tablehigh : sbr->f_tablelow;

            for (p = 0; p < sbr->n[ch_data->bs_freq_res[e + 1]]; p++) {
                float sum = 0.0f;
                const int den = env_size * (table[p + 1] - table[p]);

                for (k = table[p]; k < table[p + 1]; k++) {
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                    sum += sbr->dsp.sum_square(X_high[k] + ilb, iub - ilb);
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                }
                sum /= den;
                for (k = table[p]; k < table[p + 1]; k++) {
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                    e_curr[e][k - kx1] = sum;
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                }
            }
        }
    }
}

/**
 * Calculation of levels of additional HF signal components (14496-3 sp04 p219)
 * and Calculation of gain (14496-3 sp04 p219)
 */
static void sbr_gain_calc(AACContext *ac, SpectralBandReplication *sbr,
                          SBRData *ch_data, const int e_a[2])
{
    int e, k, m;
    // max gain limits : -3dB, 0dB, 3dB, inf dB (limiter off)
    static const float limgain[4] = { 0.70795, 1.0, 1.41254, 10000000000 };

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    for (e = 0; e < ch_data->bs_num_env; e++) {
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        int delta = !((e == e_a[1]) || (e == e_a[0]));
        for (k = 0; k < sbr->n_lim; k++) {
            float gain_boost, gain_max;
            float sum[2] = { 0.0f, 0.0f };
            for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {
                const float temp = sbr->e_origmapped[e][m] / (1.0f + sbr->q_mapped[e][m]);
                sbr->q_m[e][m] = sqrtf(temp * sbr->q_mapped[e][m]);
                sbr->s_m[e][m] = sqrtf(temp * ch_data->s_indexmapped[e + 1][m]);
                if (!sbr->s_mapped[e][m]) {
                    sbr->gain[e][m] = sqrtf(sbr->e_origmapped[e][m] /
                                            ((1.0f + sbr->e_curr[e][m]) *
                                             (1.0f + sbr->q_mapped[e][m] * delta)));
                } else {
                    sbr->gain[e][m] = sqrtf(sbr->e_origmapped[e][m] * sbr->q_mapped[e][m] /
                                            ((1.0f + sbr->e_curr[e][m]) *
                                             (1.0f + sbr->q_mapped[e][m])));
                }
            }
            for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {
                sum[0] += sbr->e_origmapped[e][m];
                sum[1] += sbr->e_curr[e][m];
            }
            gain_max = limgain[sbr->bs_limiter_gains] * sqrtf((FLT_EPSILON + sum[0]) / (FLT_EPSILON + sum[1]));
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            gain_max = FFMIN(100000.f, gain_max);
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            for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {
                float q_m_max   = sbr->q_m[e][m] * gain_max / sbr->gain[e][m];
                sbr->q_m[e][m]  = FFMIN(sbr->q_m[e][m], q_m_max);
                sbr->gain[e][m] = FFMIN(sbr->gain[e][m], gain_max);
            }
            sum[0] = sum[1] = 0.0f;
            for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {
                sum[0] += sbr->e_origmapped[e][m];
                sum[1] += sbr->e_curr[e][m] * sbr->gain[e][m] * sbr->gain[e][m]
                          + sbr->s_m[e][m] * sbr->s_m[e][m]
                          + (delta && !sbr->s_m[e][m]) * sbr->q_m[e][m] * sbr->q_m[e][m];
            }
            gain_boost = sqrtf((FLT_EPSILON + sum[0]) / (FLT_EPSILON + sum[1]));
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            gain_boost = FFMIN(1.584893192f, gain_boost);
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            for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {
                sbr->gain[e][m] *= gain_boost;
                sbr->q_m[e][m]  *= gain_boost;
                sbr->s_m[e][m]  *= gain_boost;
            }
        }
    }
}

/// Assembling HF Signals (14496-3 sp04 p220)
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static void sbr_hf_assemble(float Y1[38][64][2],
                            const float X_high[64][40][2],
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                            SpectralBandReplication *sbr, SBRData *ch_data,
                            const int e_a[2])
{
    int e, i, j, m;
    const int h_SL = 4 * !sbr->bs_smoothing_mode;
    const int kx = sbr->kx[1];
    const int m_max = sbr->m[1];
    static const float h_smooth[5] = {
        0.33333333333333,
        0.30150283239582,
        0.21816949906249,
        0.11516383427084,
        0.03183050093751,
    };
    float (*g_temp)[48] = ch_data->g_temp, (*q_temp)[48] = ch_data->q_temp;
    int indexnoise = ch_data->f_indexnoise;
    int indexsine  = ch_data->f_indexsine;

    if (sbr->reset) {
        for (i = 0; i < h_SL; i++) {
            memcpy(g_temp[i + 2*ch_data->t_env[0]], sbr->gain[0], m_max * sizeof(sbr->gain[0][0]));
            memcpy(q_temp[i + 2*ch_data->t_env[0]], sbr->q_m[0],  m_max * sizeof(sbr->q_m[0][0]));
        }
    } else if (h_SL) {
        memcpy(g_temp[2*ch_data->t_env[0]], g_temp[2*ch_data->t_env_num_env_old], 4*sizeof(g_temp[0]));
        memcpy(q_temp[2*ch_data->t_env[0]], q_temp[2*ch_data->t_env_num_env_old], 4*sizeof(q_temp[0]));
    }

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    for (e = 0; e < ch_data->bs_num_env; e++) {
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        for (i = 2 * ch_data->t_env[e]; i < 2 * ch_data->t_env[e + 1]; i++) {
            memcpy(g_temp[h_SL + i], sbr->gain[e], m_max * sizeof(sbr->gain[0][0]));
            memcpy(q_temp[h_SL + i], sbr->q_m[e],  m_max * sizeof(sbr->q_m[0][0]));
        }
    }

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    for (e = 0; e < ch_data->bs_num_env; e++) {
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        for (i = 2 * ch_data->t_env[e]; i < 2 * ch_data->t_env[e + 1]; i++) {
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            LOCAL_ALIGNED_16(float, g_filt_tab, [48]);
            LOCAL_ALIGNED_16(float, q_filt_tab, [48]);
            float *g_filt, *q_filt;
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            if (h_SL && e != e_a[0] && e != e_a[1]) {
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                g_filt = g_filt_tab;
                q_filt = q_filt_tab;
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                for (m = 0; m < m_max; m++) {
                    const int idx1 = i + h_SL;
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                    g_filt[m] = 0.0f;
                    q_filt[m] = 0.0f;
                    for (j = 0; j <= h_SL; j++) {
                        g_filt[m] += g_temp[idx1 - j][m] * h_smooth[j];
                        q_filt[m] += q_temp[idx1 - j][m] * h_smooth[j];
                    }
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                }
            } else {
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                g_filt = g_temp[i + h_SL];
                q_filt = q_temp[i];
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            }

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            sbr->dsp.hf_g_filt(Y1[i] + kx, X_high + kx, g_filt, m_max,
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                               i + ENVELOPE_ADJUSTMENT_OFFSET);

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            if (e != e_a[0] && e != e_a[1]) {
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                sbr->dsp.hf_apply_noise[indexsine](Y1[i] + kx, sbr->s_m[e],
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                                                   q_filt, indexnoise,
                                                   kx, m_max);
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            } else {
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                int idx = indexsine&1;
                int A = (1-((indexsine+(kx & 1))&2));
                int B = (A^(-idx)) + idx;
                float *out = &Y1[i][kx][idx];
                float *in  = sbr->s_m[e];
                for (m = 0; m+1 < m_max; m+=2) {
                    out[2*m  ] += in[m  ] * A;
                    out[2*m+2] += in[m+1] * B;
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                }
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                if(m_max&1)
                    out[2*m  ] += in[m  ] * A;
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            }
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            indexnoise = (indexnoise + m_max) & 0x1ff;
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            indexsine = (indexsine + 1) & 3;
        }
    }
    ch_data->f_indexnoise = indexnoise;
    ch_data->f_indexsine  = indexsine;
}

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void ff_sbr_apply(AACContext *ac, SpectralBandReplication *sbr, int id_aac,
                  float* L, float* R)
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{
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    int downsampled = ac->oc[1].m4ac.ext_sample_rate < sbr->sample_rate;
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    int ch;
    int nch = (id_aac == TYPE_CPE) ? 2 : 1;
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    int err;
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    if (!sbr->kx_and_m_pushed) {
        sbr->kx[0] = sbr->kx[1];
        sbr->m[0] = sbr->m[1];
    } else {
        sbr->kx_and_m_pushed = 0;
    }
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    if (sbr->start) {
        sbr_dequant(sbr, id_aac);
    }
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    for (ch = 0; ch < nch; ch++) {
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        /* decode channel */
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        sbr_qmf_analysis(&ac->fdsp, &sbr->mdct_ana, &sbr->dsp, ch ? R : L, sbr->data[ch].analysis_filterbank_samples,
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                         (float*)sbr->qmf_filter_scratch,
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                         sbr->data[ch].W, sbr->data[ch].Ypos);
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        sbr->c.sbr_lf_gen(ac, sbr, sbr->X_low,
                          (const float (*)[32][32][2]) sbr->data[ch].W,
                          sbr->data[ch].Ypos);
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        sbr->data[ch].Ypos ^= 1;
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        if (sbr->start) {
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            sbr->c.sbr_hf_inverse_filter(&sbr->dsp, sbr->alpha0, sbr->alpha1,
                                         (const float (*)[40][2]) sbr->X_low, sbr->k[0]);
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            sbr_chirp(sbr, &sbr->data[ch]);
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            sbr_hf_gen(ac, sbr, sbr->X_high,
                       (const float (*)[40][2]) sbr->X_low,
                       (const float (*)[2]) sbr->alpha0,
                       (const float (*)[2]) sbr->alpha1,
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                       sbr->data[ch].bw_array, sbr->data[ch].t_env,
                       sbr->data[ch].bs_num_env);

            // hf_adj
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            err = sbr_mapping(ac, sbr, &sbr->data[ch], sbr->data[ch].e_a);
            if (!err) {
                sbr_env_estimate(sbr->e_curr, sbr->X_high, sbr, &sbr->data[ch]);
                sbr_gain_calc(ac, sbr, &sbr->data[ch], sbr->data[ch].e_a);
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                sbr->c.sbr_hf_assemble(sbr->data[ch].Y[sbr->data[ch].Ypos],
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                                (const float (*)[40][2]) sbr->X_high,
                                sbr, &sbr->data[ch],
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                                sbr->data[ch].e_a);
            }
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        }
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        /* synthesis */
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        sbr->c.sbr_x_gen(sbr, sbr->X[ch],
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                  (const float (*)[64][2]) sbr->data[ch].Y[1-sbr->data[ch].Ypos],
                  (const float (*)[64][2]) sbr->data[ch].Y[  sbr->data[ch].Ypos],
                  (const float (*)[40][2]) sbr->X_low, ch);
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    }
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    if (ac->oc[1].m4ac.ps == 1) {
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        if (sbr->ps.start) {
            ff_ps_apply(ac->avctx, &sbr->ps, sbr->X[0], sbr->X[1], sbr->kx[1] + sbr->m[1]);
        } else {
            memcpy(sbr->X[1], sbr->X[0], sizeof(sbr->X[0]));
        }
        nch = 2;
    }

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    sbr_qmf_synthesis(&sbr->mdct, &sbr->dsp, &ac->fdsp,
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                      L, sbr->X[0], sbr->qmf_filter_scratch,
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                      sbr->data[0].synthesis_filterbank_samples,
                      &sbr->data[0].synthesis_filterbank_samples_offset,
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                      downsampled);
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    if (nch == 2)
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        sbr_qmf_synthesis(&sbr->mdct, &sbr->dsp, &ac->fdsp,
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                          R, sbr->X[1], sbr->qmf_filter_scratch,
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                          sbr->data[1].synthesis_filterbank_samples,
                          &sbr->data[1].synthesis_filterbank_samples_offset,
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                          downsampled);
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}
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static void aacsbr_func_ptr_init(AACSBRContext *c)
{
    c->sbr_lf_gen            = sbr_lf_gen;
    c->sbr_hf_assemble       = sbr_hf_assemble;
    c->sbr_x_gen             = sbr_x_gen;
    c->sbr_hf_inverse_filter = sbr_hf_inverse_filter;

    if(ARCH_MIPS)
        ff_aacsbr_func_ptr_init_mips(c);
}