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FFmpeg/libavcodec/alsdec.c

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  1. /*

  2.  * MPEG-4 ALS decoder

  3.  * Copyright (c) 2009 Thilo Borgmann <thilo.borgmann _at_ mail.de>

  4.  *

  5.  * This file is part of FFmpeg.

  6.  *

  7.  * FFmpeg is free software; you can redistribute it and/or

  8.  * modify it under the terms of the GNU Lesser General Public

  9.  * License as published by the Free Software Foundation; either

  10.  * version 2.1 of the License, or (at your option) any later version.

  11.  *

  12.  * FFmpeg is distributed in the hope that it will be useful,

  13.  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  14.  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

  15.  * Lesser General Public License for more details.

  16.  *

  17.  * You should have received a copy of the GNU Lesser General Public

  18.  * License along with FFmpeg; if not, write to the Free Software

  19.  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

  20.  */

  21. 

  22. /**

  23.  * @file

  24.  * MPEG-4 ALS decoder

  25.  * @author Thilo Borgmann <thilo.borgmann _at_ mail.de>

  26.  */

  27. 

  28. #include <inttypes.h>

  29. 

  30. #include "avcodec.h"

  31. #include "get_bits.h"

  32. #include "unary.h"

  33. #include "mpeg4audio.h"

  34. #include "bytestream.h"

  35. #include "bgmc.h"

  36. #include "bswapdsp.h"

  37. #include "internal.h"

  38. #include "libavutil/samplefmt.h"

  39. #include "libavutil/crc.h"

  40. 

  41. #include <stdint.h>

  42. 

  43. /** Rice parameters and corresponding index offsets for decoding the

  44.  *  indices of scaled PARCOR values. The table chosen is set globally

  45.  *  by the encoder and stored in ALSSpecificConfig.

  46.  */

  47. static const int8_t parcor_rice_table[3][20][2] = {

  48.     { {-52, 4}, {-29, 5}, {-31, 4}, { 19, 4}, {-16, 4},

  49.       { 12, 3}, { -7, 3}, {  9, 3}, { -5, 3}, {  6, 3},

  50.       { -4, 3}, {  3, 3}, { -3, 2}, {  3, 2}, { -2, 2},

  51.       {  3, 2}, { -1, 2}, {  2, 2}, { -1, 2}, {  2, 2} },

  52.     { {-58, 3}, {-42, 4}, {-46, 4}, { 37, 5}, {-36, 4},

  53.       { 29, 4}, {-29, 4}, { 25, 4}, {-23, 4}, { 20, 4},

  54.       {-17, 4}, { 16, 4}, {-12, 4}, { 12, 3}, {-10, 4},

  55.       {  7, 3}, { -4, 4}, {  3, 3}, { -1, 3}, {  1, 3} },

  56.     { {-59, 3}, {-45, 5}, {-50, 4}, { 38, 4}, {-39, 4},

  57.       { 32, 4}, {-30, 4}, { 25, 3}, {-23, 3}, { 20, 3},

  58.       {-20, 3}, { 16, 3}, {-13, 3}, { 10, 3}, { -7, 3},

  59.       {  3, 3}, {  0, 3}, { -1, 3}, {  2, 3}, { -1, 2} }

  60. };

  61. 

  62. 

  63. /** Scaled PARCOR values used for the first two PARCOR coefficients.

  64.  *  To be indexed by the Rice coded indices.

  65.  *  Generated by: parcor_scaled_values[i] = 32 + ((i * (i+1)) << 7) - (1 << 20)

  66.  *  Actual values are divided by 32 in order to be stored in 16 bits.

  67.  */

  68. static const int16_t parcor_scaled_values[] = {

  69.     -1048544 / 32, -1048288 / 32, -1047776 / 32, -1047008 / 32,

  70.     -1045984 / 32, -1044704 / 32, -1043168 / 32, -1041376 / 32,

  71.     -1039328 / 32, -1037024 / 32, -1034464 / 32, -1031648 / 32,

  72.     -1028576 / 32, -1025248 / 32, -1021664 / 32, -1017824 / 32,

  73.     -1013728 / 32, -1009376 / 32, -1004768 / 32,  -999904 / 32,

  74.      -994784 / 32,  -989408 / 32,  -983776 / 32,  -977888 / 32,

  75.      -971744 / 32,  -965344 / 32,  -958688 / 32,  -951776 / 32,

  76.      -944608 / 32,  -937184 / 32,  -929504 / 32,  -921568 / 32,

  77.      -913376 / 32,  -904928 / 32,  -896224 / 32,  -887264 / 32,

  78.      -878048 / 32,  -868576 / 32,  -858848 / 32,  -848864 / 32,

  79.      -838624 / 32,  -828128 / 32,  -817376 / 32,  -806368 / 32,

  80.      -795104 / 32,  -783584 / 32,  -771808 / 32,  -759776 / 32,

  81.      -747488 / 32,  -734944 / 32,  -722144 / 32,  -709088 / 32,

  82.      -695776 / 32,  -682208 / 32,  -668384 / 32,  -654304 / 32,

  83.      -639968 / 32,  -625376 / 32,  -610528 / 32,  -595424 / 32,

  84.      -580064 / 32,  -564448 / 32,  -548576 / 32,  -532448 / 32,

  85.      -516064 / 32,  -499424 / 32,  -482528 / 32,  -465376 / 32,

  86.      -447968 / 32,  -430304 / 32,  -412384 / 32,  -394208 / 32,

  87.      -375776 / 32,  -357088 / 32,  -338144 / 32,  -318944 / 32,

  88.      -299488 / 32,  -279776 / 32,  -259808 / 32,  -239584 / 32,

  89.      -219104 / 32,  -198368 / 32,  -177376 / 32,  -156128 / 32,

  90.      -134624 / 32,  -112864 / 32,   -90848 / 32,   -68576 / 32,

  91.       -46048 / 32,   -23264 / 32,     -224 / 32,    23072 / 32,

  92.        46624 / 32,    70432 / 32,    94496 / 32,   118816 / 32,

  93.       143392 / 32,   168224 / 32,   193312 / 32,   218656 / 32,

  94.       244256 / 32,   270112 / 32,   296224 / 32,   322592 / 32,

  95.       349216 / 32,   376096 / 32,   403232 / 32,   430624 / 32,

  96.       458272 / 32,   486176 / 32,   514336 / 32,   542752 / 32,

  97.       571424 / 32,   600352 / 32,   629536 / 32,   658976 / 32,

  98.       688672 / 32,   718624 / 32,   748832 / 32,   779296 / 32,

  99.       810016 / 32,   840992 / 32,   872224 / 32,   903712 / 32,

  100.       935456 / 32,   967456 / 32,   999712 / 32,  1032224 / 32

  101. };

  102. 

  103. 

  104. /** Gain values of p(0) for long-term prediction.

  105.  *  To be indexed by the Rice coded indices.

  106.  */

  107. static const uint8_t ltp_gain_values [4][4] = {

  108.     { 0,  8, 16,  24},

  109.     {32, 40, 48,  56},

  110.     {64, 70, 76,  82},

  111.     {88, 92, 96, 100}

  112. };

  113. 

  114. 

  115. /** Inter-channel weighting factors for multi-channel correlation.

  116.  *  To be indexed by the Rice coded indices.

  117.  */

  118. static const int16_t mcc_weightings[] = {

  119.     204,  192,  179,  166,  153,  140,  128,  115,

  120.     102,   89,   76,   64,   51,   38,   25,   12,

  121.       0,  -12,  -25,  -38,  -51,  -64,  -76,  -89,

  122.    -102, -115, -128, -140, -153, -166, -179, -192

  123. };

  124. 

  125. 

  126. /** Tail codes used in arithmetic coding using block Gilbert-Moore codes.

  127.  */

  128. static const uint8_t tail_code[16][6] = {

  129.     { 74, 44, 25, 13,  7, 3},

  130.     { 68, 42, 24, 13,  7, 3},

  131.     { 58, 39, 23, 13,  7, 3},

  132.     {126, 70, 37, 19, 10, 5},

  133.     {132, 70, 37, 20, 10, 5},

  134.     {124, 70, 38, 20, 10, 5},

  135.     {120, 69, 37, 20, 11, 5},

  136.     {116, 67, 37, 20, 11, 5},

  137.     {108, 66, 36, 20, 10, 5},

  138.     {102, 62, 36, 20, 10, 5},

  139.     { 88, 58, 34, 19, 10, 5},

  140.     {162, 89, 49, 25, 13, 7},

  141.     {156, 87, 49, 26, 14, 7},

  142.     {150, 86, 47, 26, 14, 7},

  143.     {142, 84, 47, 26, 14, 7},

  144.     {131, 79, 46, 26, 14, 7}

  145. };

  146. 

  147. 

  148. enum RA_Flag {

  149.     RA_FLAG_NONE,

  150.     RA_FLAG_FRAMES,

  151.     RA_FLAG_HEADER

  152. };

  153. 

  154. 

  155. typedef struct ALSSpecificConfig {

  156.     uint32_t samples;         ///< number of samples, 0xFFFFFFFF if unknown

  157.     int resolution;           ///< 000 = 8-bit; 001 = 16-bit; 010 = 24-bit; 011 = 32-bit

  158.     int floating;             ///< 1 = IEEE 32-bit floating-point, 0 = integer

  159.     int msb_first;            ///< 1 = original CRC calculated on big-endian system, 0 = little-endian

  160.     int frame_length;         ///< frame length for each frame (last frame may differ)

  161.     int ra_distance;          ///< distance between RA frames (in frames, 0...255)

  162.     enum RA_Flag ra_flag;     ///< indicates where the size of ra units is stored

  163.     int adapt_order;          ///< adaptive order: 1 = on, 0 = off

  164.     int coef_table;           ///< table index of Rice code parameters

  165.     int long_term_prediction; ///< long term prediction (LTP): 1 = on, 0 = off

  166.     int max_order;            ///< maximum prediction order (0..1023)

  167.     int block_switching;      ///< number of block switching levels

  168.     int bgmc;                 ///< "Block Gilbert-Moore Code": 1 = on, 0 = off (Rice coding only)

  169.     int sb_part;              ///< sub-block partition

  170.     int joint_stereo;         ///< joint stereo: 1 = on, 0 = off

  171.     int mc_coding;            ///< extended inter-channel coding (multi channel coding): 1 = on, 0 = off

  172.     int chan_config;          ///< indicates that a chan_config_info field is present

  173.     int chan_sort;            ///< channel rearrangement: 1 = on, 0 = off

  174.     int rlslms;               ///< use "Recursive Least Square-Least Mean Square" predictor: 1 = on, 0 = off

  175.     int chan_config_info;     ///< mapping of channels to loudspeaker locations. Unused until setting channel configuration is implemented.

  176.     int *chan_pos;            ///< original channel positions

  177.     int crc_enabled;          ///< enable Cyclic Redundancy Checksum

  178. } ALSSpecificConfig;

  179. 

  180. 

  181. typedef struct ALSChannelData {

  182.     int stop_flag;

  183.     int master_channel;

  184.     int time_diff_flag;

  185.     int time_diff_sign;

  186.     int time_diff_index;

  187.     int weighting[6];

  188. } ALSChannelData;

  189. 

  190. 

  191. typedef struct ALSDecContext {

  192.     AVCodecContext *avctx;

  193.     ALSSpecificConfig sconf;

  194.     GetBitContext gb;

  195.     BswapDSPContext bdsp;

  196.     const AVCRC *crc_table;

  197.     uint32_t crc_org;               ///< CRC value of the original input data

  198.     uint32_t crc;                   ///< CRC value calculated from decoded data

  199.     unsigned int cur_frame_length;  ///< length of the current frame to decode

  200.     unsigned int frame_id;          ///< the frame ID / number of the current frame

  201.     unsigned int js_switch;         ///< if true, joint-stereo decoding is enforced

  202.     unsigned int cs_switch;         ///< if true, channel rearrangement is done

  203.     unsigned int num_blocks;        ///< number of blocks used in the current frame

  204.     unsigned int s_max;             ///< maximum Rice parameter allowed in entropy coding

  205.     uint8_t *bgmc_lut;              ///< pointer at lookup tables used for BGMC

  206.     int *bgmc_lut_status;           ///< pointer at lookup table status flags used for BGMC

  207.     int ltp_lag_length;             ///< number of bits used for ltp lag value

  208.     int *const_block;               ///< contains const_block flags for all channels

  209.     unsigned int *shift_lsbs;       ///< contains shift_lsbs flags for all channels

  210.     unsigned int *opt_order;        ///< contains opt_order flags for all channels

  211.     int *store_prev_samples;        ///< contains store_prev_samples flags for all channels

  212.     int *use_ltp;                   ///< contains use_ltp flags for all channels

  213.     int *ltp_lag;                   ///< contains ltp lag values for all channels

  214.     int **ltp_gain;                 ///< gain values for ltp 5-tap filter for a channel

  215.     int *ltp_gain_buffer;           ///< contains all gain values for ltp 5-tap filter

  216.     int32_t **quant_cof;            ///< quantized parcor coefficients for a channel

  217.     int32_t *quant_cof_buffer;      ///< contains all quantized parcor coefficients

  218.     int32_t **lpc_cof;              ///< coefficients of the direct form prediction filter for a channel

  219.     int32_t *lpc_cof_buffer;        ///< contains all coefficients of the direct form prediction filter

  220.     int32_t *lpc_cof_reversed_buffer; ///< temporary buffer to set up a reversed versio of lpc_cof_buffer

  221.     ALSChannelData **chan_data;     ///< channel data for multi-channel correlation

  222.     ALSChannelData *chan_data_buffer; ///< contains channel data for all channels

  223.     int *reverted_channels;         ///< stores a flag for each reverted channel

  224.     int32_t *prev_raw_samples;      ///< contains unshifted raw samples from the previous block

  225.     int32_t **raw_samples;          ///< decoded raw samples for each channel

  226.     int32_t *raw_buffer;            ///< contains all decoded raw samples including carryover samples

  227.     uint8_t *crc_buffer;            ///< buffer of byte order corrected samples used for CRC check

  228. } ALSDecContext;

  229. 

  230. 

  231. typedef struct ALSBlockData {

  232.     unsigned int block_length;      ///< number of samples within the block

  233.     unsigned int ra_block;          ///< if true, this is a random access block

  234.     int          *const_block;      ///< if true, this is a constant value block

  235.     int          js_blocks;         ///< true if this block contains a difference signal

  236.     unsigned int *shift_lsbs;       ///< shift of values for this block

  237.     unsigned int *opt_order;        ///< prediction order of this block

  238.     int          *store_prev_samples;///< if true, carryover samples have to be stored

  239.     int          *use_ltp;          ///< if true, long-term prediction is used

  240.     int          *ltp_lag;          ///< lag value for long-term prediction

  241.     int          *ltp_gain;         ///< gain values for ltp 5-tap filter

  242.     int32_t      *quant_cof;        ///< quantized parcor coefficients

  243.     int32_t      *lpc_cof;          ///< coefficients of the direct form prediction

  244.     int32_t      *raw_samples;      ///< decoded raw samples / residuals for this block

  245.     int32_t      *prev_raw_samples; ///< contains unshifted raw samples from the previous block

  246.     int32_t      *raw_other;        ///< decoded raw samples of the other channel of a channel pair

  247. } ALSBlockData;

  248. 

  249. 

  250. static av_cold void dprint_specific_config(ALSDecContext *ctx)

  251. {

  252. #ifdef DEBUG

  253.     AVCodecContext *avctx    = ctx->avctx;

  254.     ALSSpecificConfig *sconf = &ctx->sconf;

  255. 

  256.     ff_dlog(avctx, "resolution = %i\n",           sconf->resolution);

  257.     ff_dlog(avctx, "floating = %i\n",             sconf->floating);

  258.     ff_dlog(avctx, "frame_length = %i\n",         sconf->frame_length);

  259.     ff_dlog(avctx, "ra_distance = %i\n",          sconf->ra_distance);

  260.     ff_dlog(avctx, "ra_flag = %i\n",              sconf->ra_flag);

  261.     ff_dlog(avctx, "adapt_order = %i\n",          sconf->adapt_order);

  262.     ff_dlog(avctx, "coef_table = %i\n",           sconf->coef_table);

  263.     ff_dlog(avctx, "long_term_prediction = %i\n", sconf->long_term_prediction);

  264.     ff_dlog(avctx, "max_order = %i\n",            sconf->max_order);

  265.     ff_dlog(avctx, "block_switching = %i\n",      sconf->block_switching);

  266.     ff_dlog(avctx, "bgmc = %i\n",                 sconf->bgmc);

  267.     ff_dlog(avctx, "sb_part = %i\n",              sconf->sb_part);

  268.     ff_dlog(avctx, "joint_stereo = %i\n",         sconf->joint_stereo);

  269.     ff_dlog(avctx, "mc_coding = %i\n",            sconf->mc_coding);

  270.     ff_dlog(avctx, "chan_config = %i\n",          sconf->chan_config);

  271.     ff_dlog(avctx, "chan_sort = %i\n",            sconf->chan_sort);

  272.     ff_dlog(avctx, "RLSLMS = %i\n",               sconf->rlslms);

  273.     ff_dlog(avctx, "chan_config_info = %i\n",     sconf->chan_config_info);

  274. #endif

  275. }

  276. 

  277. 

  278. /** Read an ALSSpecificConfig from a buffer into the output struct.

  279.  */

  280. static av_cold int read_specific_config(ALSDecContext *ctx)

  281. {

  282.     GetBitContext gb;

  283.     uint64_t ht_size;

  284.     int i, config_offset;

  285.     MPEG4AudioConfig m4ac = {0};

  286.     ALSSpecificConfig *sconf = &ctx->sconf;

  287.     AVCodecContext *avctx    = ctx->avctx;

  288.     uint32_t als_id, header_size, trailer_size;

  289.     int ret;

  290. 

  291.     if ((ret = init_get_bits8(&gb, avctx->extradata, avctx->extradata_size)) < 0)

  292.         return ret;

  293. 

  294.     config_offset = avpriv_mpeg4audio_get_config(&m4ac, avctx->extradata,

  295.                                                  avctx->extradata_size * 8, 1);

  296. 

  297.     if (config_offset < 0)

  298.         return AVERROR_INVALIDDATA;

  299. 

  300.     skip_bits_long(&gb, config_offset);

  301. 

  302.     if (get_bits_left(&gb) < (30 << 3))

  303.         return AVERROR_INVALIDDATA;

  304. 

  305.     // read the fixed items

  306.     als_id                      = get_bits_long(&gb, 32);

  307.     avctx->sample_rate          = m4ac.sample_rate;

  308.     skip_bits_long(&gb, 32); // sample rate already known

  309.     sconf->samples              = get_bits_long(&gb, 32);

  310.     avctx->channels             = m4ac.channels;

  311.     skip_bits(&gb, 16);      // number of channels already known

  312.     skip_bits(&gb, 3);       // skip file_type

  313.     sconf->resolution           = get_bits(&gb, 3);

  314.     sconf->floating             = get_bits1(&gb);

  315.     sconf->msb_first            = get_bits1(&gb);

  316.     sconf->frame_length         = get_bits(&gb, 16) + 1;

  317.     sconf->ra_distance          = get_bits(&gb, 8);

  318.     sconf->ra_flag              = get_bits(&gb, 2);

  319.     sconf->adapt_order          = get_bits1(&gb);

  320.     sconf->coef_table           = get_bits(&gb, 2);

  321.     sconf->long_term_prediction = get_bits1(&gb);

  322.     sconf->max_order            = get_bits(&gb, 10);

  323.     sconf->block_switching      = get_bits(&gb, 2);

  324.     sconf->bgmc                 = get_bits1(&gb);

  325.     sconf->sb_part              = get_bits1(&gb);

  326.     sconf->joint_stereo         = get_bits1(&gb);

  327.     sconf->mc_coding            = get_bits1(&gb);

  328.     sconf->chan_config          = get_bits1(&gb);

  329.     sconf->chan_sort            = get_bits1(&gb);

  330.     sconf->crc_enabled          = get_bits1(&gb);

  331.     sconf->rlslms               = get_bits1(&gb);

  332.     skip_bits(&gb, 5);       // skip 5 reserved bits

  333.     skip_bits1(&gb);         // skip aux_data_enabled

  334. 

  335. 

  336.     // check for ALSSpecificConfig struct

  337.     if (als_id != MKBETAG('A','L','S','\0'))

  338.         return AVERROR_INVALIDDATA;

  339. 

  340.     if (avctx->channels > FF_SANE_NB_CHANNELS) {

  341.         avpriv_request_sample(avctx, "Huge number of channels\n");

  342.         return AVERROR_PATCHWELCOME;

  343.     }

  344. 

  345.     ctx->cur_frame_length = sconf->frame_length;

  346. 

  347.     // read channel config

  348.     if (sconf->chan_config)

  349.         sconf->chan_config_info = get_bits(&gb, 16);

  350.     // TODO: use this to set avctx->channel_layout

  351. 

  352. 

  353.     // read channel sorting

  354.     if (sconf->chan_sort && avctx->channels > 1) {

  355.         int chan_pos_bits = av_ceil_log2(avctx->channels);

  356.         int bits_needed  = avctx->channels * chan_pos_bits + 7;

  357.         if (get_bits_left(&gb) < bits_needed)

  358.             return AVERROR_INVALIDDATA;

  359. 

  360.         if (!(sconf->chan_pos = av_malloc_array(avctx->channels, sizeof(*sconf->chan_pos))))

  361.             return AVERROR(ENOMEM);

  362. 

  363.         ctx->cs_switch = 1;

  364. 

  365.         for (i = 0; i < avctx->channels; i++) {

  366.             sconf->chan_pos[i] = -1;

  367.         }

  368. 

  369.         for (i = 0; i < avctx->channels; i++) {

  370.             int idx;

  371. 

  372.             idx = get_bits(&gb, chan_pos_bits);

  373.             if (idx >= avctx->channels || sconf->chan_pos[idx] != -1) {

  374.                 av_log(avctx, AV_LOG_WARNING, "Invalid channel reordering.\n");

  375.                 ctx->cs_switch = 0;

  376.                 break;

  377.             }

  378.             sconf->chan_pos[idx] = i;

  379.         }

  380. 

  381.         align_get_bits(&gb);

  382.     }

  383. 

  384. 

  385.     // read fixed header and trailer sizes,

  386.     // if size = 0xFFFFFFFF then there is no data field!

  387.     if (get_bits_left(&gb) < 64)

  388.         return AVERROR_INVALIDDATA;

  389. 

  390.     header_size  = get_bits_long(&gb, 32);

  391.     trailer_size = get_bits_long(&gb, 32);

  392.     if (header_size  == 0xFFFFFFFF)

  393.         header_size  = 0;

  394.     if (trailer_size == 0xFFFFFFFF)

  395.         trailer_size = 0;

  396. 

  397.     ht_size = ((int64_t)(header_size) + (int64_t)(trailer_size)) << 3;

  398. 

  399. 

  400.     // skip the header and trailer data

  401.     if (get_bits_left(&gb) < ht_size)

  402.         return AVERROR_INVALIDDATA;

  403. 

  404.     if (ht_size > INT32_MAX)

  405.         return AVERROR_PATCHWELCOME;

  406. 

  407.     skip_bits_long(&gb, ht_size);

  408. 

  409. 

  410.     // initialize CRC calculation

  411.     if (sconf->crc_enabled) {

  412.         if (get_bits_left(&gb) < 32)

  413.             return AVERROR_INVALIDDATA;

  414. 

  415.         if (avctx->err_recognition & (AV_EF_CRCCHECK|AV_EF_CAREFUL)) {

  416.             ctx->crc_table = av_crc_get_table(AV_CRC_32_IEEE_LE);

  417.             ctx->crc       = 0xFFFFFFFF;

  418.             ctx->crc_org   = ~get_bits_long(&gb, 32);

  419.         } else

  420.             skip_bits_long(&gb, 32);

  421.     }

  422. 

  423. 

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

  425. 

  426.     dprint_specific_config(ctx);

  427. 

  428.     return 0;

  429. }

  430. 

  431. 

  432. /** Check the ALSSpecificConfig for unsupported features.

  433.  */

  434. static int check_specific_config(ALSDecContext *ctx)

  435. {

  436.     ALSSpecificConfig *sconf = &ctx->sconf;

  437.     int error = 0;

  438. 

  439.     // report unsupported feature and set error value

  440.     #define MISSING_ERR(cond, str, errval)              \

  441.     {                                                   \

  442.         if (cond) {                                     \

  443.             avpriv_report_missing_feature(ctx->avctx,   \

  444.                                           str);         \

  445.             error = errval;                             \

  446.         }                                               \

  447.     }

  448. 

  449.     MISSING_ERR(sconf->floating,  "Floating point decoding",     AVERROR_PATCHWELCOME);

  450.     MISSING_ERR(sconf->rlslms,    "Adaptive RLS-LMS prediction", AVERROR_PATCHWELCOME);

  451. 

  452.     return error;

  453. }

  454. 

  455. 

  456. /** Parse the bs_info field to extract the block partitioning used in

  457.  *  block switching mode, refer to ISO/IEC 14496-3, section 11.6.2.

  458.  */

  459. static void parse_bs_info(const uint32_t bs_info, unsigned int n,

  460.                           unsigned int div, unsigned int **div_blocks,

  461.                           unsigned int *num_blocks)

  462. {

  463.     if (n < 31 && ((bs_info << n) & 0x40000000)) {

  464.         // if the level is valid and the investigated bit n is set

  465.         // then recursively check both children at bits (2n+1) and (2n+2)

  466.         n   *= 2;

  467.         div += 1;

  468.         parse_bs_info(bs_info, n + 1, div, div_blocks, num_blocks);

  469.         parse_bs_info(bs_info, n + 2, div, div_blocks, num_blocks);

  470.     } else {

  471.         // else the bit is not set or the last level has been reached

  472.         // (bit implicitly not set)

  473.         **div_blocks = div;

  474.         (*div_blocks)++;

  475.         (*num_blocks)++;

  476.     }

  477. }

  478. 

  479. 

  480. /** Read and decode a Rice codeword.

  481.  */

  482. static int32_t decode_rice(GetBitContext *gb, unsigned int k)

  483. {

  484.     int max = get_bits_left(gb) - k;

  485.     unsigned q = get_unary(gb, 0, max);

  486.     int r   = k ? get_bits1(gb) : !(q & 1);

  487. 

  488.     if (k > 1) {

  489.         q <<= (k - 1);

  490.         q  += get_bits_long(gb, k - 1);

  491.     } else if (!k) {

  492.         q >>= 1;

  493.     }

  494.     return r ? q : ~q;

  495. }

  496. 

  497. 

  498. /** Convert PARCOR coefficient k to direct filter coefficient.

  499.  */

  500. static void parcor_to_lpc(unsigned int k, const int32_t *par, int32_t *cof)

  501. {

  502.     int i, j;

  503. 

  504.     for (i = 0, j = k - 1; i < j; i++, j--) {

  505.         unsigned tmp1 = ((MUL64(par[k], cof[j]) + (1 << 19)) >> 20);

  506.         cof[j]  += ((MUL64(par[k], cof[i]) + (1 << 19)) >> 20);

  507.         cof[i]  += tmp1;

  508.     }

  509.     if (i == j)

  510.         cof[i] += ((MUL64(par[k], cof[j]) + (1 << 19)) >> 20);

  511. 

  512.     cof[k] = par[k];

  513. }

  514. 

  515. 

  516. /** Read block switching field if necessary and set actual block sizes.

  517.  *  Also assure that the block sizes of the last frame correspond to the

  518.  *  actual number of samples.

  519.  */

  520. static void get_block_sizes(ALSDecContext *ctx, unsigned int *div_blocks,

  521.                             uint32_t *bs_info)

  522. {

  523.     ALSSpecificConfig *sconf     = &ctx->sconf;

  524.     GetBitContext *gb            = &ctx->gb;

  525.     unsigned int *ptr_div_blocks = div_blocks;

  526.     unsigned int b;

  527. 

  528.     if (sconf->block_switching) {

  529.         unsigned int bs_info_len = 1 << (sconf->block_switching + 2);

  530.         *bs_info = get_bits_long(gb, bs_info_len);

  531.         *bs_info <<= (32 - bs_info_len);

  532.     }

  533. 

  534.     ctx->num_blocks = 0;

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

  536. 

  537.     // The last frame may have an overdetermined block structure given in

  538.     // the bitstream. In that case the defined block structure would need

  539.     // more samples than available to be consistent.

  540.     // The block structure is actually used but the block sizes are adapted

  541.     // to fit the actual number of available samples.

  542.     // Example: 5 samples, 2nd level block sizes: 2 2 2 2.

  543.     // This results in the actual block sizes:    2 2 1 0.

  544.     // This is not specified in 14496-3 but actually done by the reference

  545.     // codec RM22 revision 2.

  546.     // This appears to happen in case of an odd number of samples in the last

  547.     // frame which is actually not allowed by the block length switching part

  548.     // of 14496-3.

  549.     // The ALS conformance files feature an odd number of samples in the last

  550.     // frame.

  551. 

  552.     for (b = 0; b < ctx->num_blocks; b++)

  553.         div_blocks[b] = ctx->sconf.frame_length >> div_blocks[b];

  554. 

  555.     if (ctx->cur_frame_length != ctx->sconf.frame_length) {

  556.         unsigned int remaining = ctx->cur_frame_length;

  557. 

  558.         for (b = 0; b < ctx->num_blocks; b++) {

  559.             if (remaining <= div_blocks[b]) {

  560.                 div_blocks[b] = remaining;

  561.                 ctx->num_blocks = b + 1;

  562.                 break;

  563.             }

  564. 

  565.             remaining -= div_blocks[b];

  566.         }

  567.     }

  568. }

  569. 

  570. 

  571. /** Read the block data for a constant block

  572.  */

  573. static int read_const_block_data(ALSDecContext *ctx, ALSBlockData *bd)

  574. {

  575.     ALSSpecificConfig *sconf = &ctx->sconf;

  576.     AVCodecContext *avctx    = ctx->avctx;

  577.     GetBitContext *gb        = &ctx->gb;

  578. 

  579.     if (bd->block_length <= 0)

  580.         return AVERROR_INVALIDDATA;

  581. 

  582.     *bd->raw_samples = 0;

  583.     *bd->const_block = get_bits1(gb);    // 1 = constant value, 0 = zero block (silence)

  584.     bd->js_blocks    = get_bits1(gb);

  585. 

  586.     // skip 5 reserved bits

  587.     skip_bits(gb, 5);

  588. 

  589.     if (*bd->const_block) {

  590.         unsigned int const_val_bits = sconf->floating ? 24 : avctx->bits_per_raw_sample;

  591.         *bd->raw_samples = get_sbits_long(gb, const_val_bits);

  592.     }

  593. 

  594.     // ensure constant block decoding by reusing this field

  595.     *bd->const_block = 1;

  596. 

  597.     return 0;

  598. }

  599. 

  600. 

  601. /** Decode the block data for a constant block

  602.  */

  603. static void decode_const_block_data(ALSDecContext *ctx, ALSBlockData *bd)

  604. {

  605.     int      smp = bd->block_length - 1;

  606.     int32_t  val = *bd->raw_samples;

  607.     int32_t *dst = bd->raw_samples + 1;

  608. 

  609.     // write raw samples into buffer

  610.     for (; smp; smp--)

  611.         *dst++ = val;

  612. }

  613. 

  614. 

  615. /** Read the block data for a non-constant block

  616.  */

  617. static int read_var_block_data(ALSDecContext *ctx, ALSBlockData *bd)

  618. {

  619.     ALSSpecificConfig *sconf = &ctx->sconf;

  620.     AVCodecContext *avctx    = ctx->avctx;

  621.     GetBitContext *gb        = &ctx->gb;

  622.     unsigned int k;

  623.     unsigned int s[8];

  624.     unsigned int sx[8];

  625.     unsigned int sub_blocks, log2_sub_blocks, sb_length;

  626.     unsigned int start      = 0;

  627.     unsigned int opt_order;

  628.     int          sb;

  629.     int32_t      *quant_cof = bd->quant_cof;

  630.     int32_t      *current_res;

  631. 

  632. 

  633.     // ensure variable block decoding by reusing this field

  634.     *bd->const_block = 0;

  635. 

  636.     *bd->opt_order  = 1;

  637.     bd->js_blocks   = get_bits1(gb);

  638. 

  639.     opt_order       = *bd->opt_order;

  640. 

  641.     // determine the number of subblocks for entropy decoding

  642.     if (!sconf->bgmc && !sconf->sb_part) {

  643.         log2_sub_blocks = 0;

  644.     } else {

  645.         if (sconf->bgmc && sconf->sb_part)

  646.             log2_sub_blocks = get_bits(gb, 2);

  647.         else

  648.             log2_sub_blocks = 2 * get_bits1(gb);

  649.     }

  650. 

  651.     sub_blocks = 1 << log2_sub_blocks;

  652. 

  653.     // do not continue in case of a damaged stream since

  654.     // block_length must be evenly divisible by sub_blocks

  655.     if (bd->block_length & (sub_blocks - 1) || bd->block_length <= 0) {

  656.         av_log(avctx, AV_LOG_WARNING,

  657.                "Block length is not evenly divisible by the number of subblocks.\n");

  658.         return AVERROR_INVALIDDATA;

  659.     }

  660. 

  661.     sb_length = bd->block_length >> log2_sub_blocks;

  662. 

  663.     if (sconf->bgmc) {

  664.         s[0] = get_bits(gb, 8 + (sconf->resolution > 1));

  665.         for (k = 1; k < sub_blocks; k++)

  666.             s[k] = s[k - 1] + decode_rice(gb, 2);

  667. 

  668.         for (k = 0; k < sub_blocks; k++) {

  669.             sx[k]   = s[k] & 0x0F;

  670.             s [k] >>= 4;

  671.         }

  672.     } else {

  673.         s[0] = get_bits(gb, 4 + (sconf->resolution > 1));

  674.         for (k = 1; k < sub_blocks; k++)

  675.             s[k] = s[k - 1] + decode_rice(gb, 0);

  676.     }

  677.     for (k = 1; k < sub_blocks; k++)

  678.         if (s[k] > 32) {

  679.             av_log(avctx, AV_LOG_ERROR, "k invalid for rice code.\n");

  680.             return AVERROR_INVALIDDATA;

  681.         }

  682. 

  683.     if (get_bits1(gb))

  684.         *bd->shift_lsbs = get_bits(gb, 4) + 1;

  685. 

  686.     *bd->store_prev_samples = (bd->js_blocks && bd->raw_other) || *bd->shift_lsbs;

  687. 

  688. 

  689.     if (!sconf->rlslms) {

  690.         if (sconf->adapt_order && sconf->max_order) {

  691.             int opt_order_length = av_ceil_log2(av_clip((bd->block_length >> 3) - 1,

  692.                                                 2, sconf->max_order + 1));

  693.             *bd->opt_order       = get_bits(gb, opt_order_length);

  694.             if (*bd->opt_order > sconf->max_order) {

  695.                 *bd->opt_order = sconf->max_order;

  696.                 av_log(avctx, AV_LOG_ERROR, "Predictor order too large.\n");

  697.                 return AVERROR_INVALIDDATA;

  698.             }

  699.         } else {

  700.             *bd->opt_order = sconf->max_order;

  701.         }

  702.         if (*bd->opt_order > bd->block_length) {

  703.             *bd->opt_order = bd->block_length;

  704.             av_log(avctx, AV_LOG_ERROR, "Predictor order too large.\n");

  705.             return AVERROR_INVALIDDATA;

  706.         }

  707.         opt_order = *bd->opt_order;

  708. 

  709.         if (opt_order) {

  710.             int add_base;

  711. 

  712.             if (sconf->coef_table == 3) {

  713.                 add_base = 0x7F;

  714. 

  715.                 // read coefficient 0

  716.                 quant_cof[0] = 32 * parcor_scaled_values[get_bits(gb, 7)];

  717. 

  718.                 // read coefficient 1

  719.                 if (opt_order > 1)

  720.                     quant_cof[1] = -32 * parcor_scaled_values[get_bits(gb, 7)];

  721. 

  722.                 // read coefficients 2 to opt_order

  723.                 for (k = 2; k < opt_order; k++)

  724.                     quant_cof[k] = get_bits(gb, 7);

  725.             } else {

  726.                 int k_max;

  727.                 add_base = 1;

  728. 

  729.                 // read coefficient 0 to 19

  730.                 k_max = FFMIN(opt_order, 20);

  731.                 for (k = 0; k < k_max; k++) {

  732.                     int rice_param = parcor_rice_table[sconf->coef_table][k][1];

  733.                     int offset     = parcor_rice_table[sconf->coef_table][k][0];

  734.                     quant_cof[k] = decode_rice(gb, rice_param) + offset;

  735.                     if (quant_cof[k] < -64 || quant_cof[k] > 63) {

  736.                         av_log(avctx, AV_LOG_ERROR,

  737.                                "quant_cof %"PRIu32" is out of range.\n",

  738.                                quant_cof[k]);

  739.                         return AVERROR_INVALIDDATA;

  740.                     }

  741.                 }

  742. 

  743.                 // read coefficients 20 to 126

  744.                 k_max = FFMIN(opt_order, 127);

  745.                 for (; k < k_max; k++)

  746.                     quant_cof[k] = decode_rice(gb, 2) + (k & 1);

  747. 

  748.                 // read coefficients 127 to opt_order

  749.                 for (; k < opt_order; k++)

  750.                     quant_cof[k] = decode_rice(gb, 1);

  751. 

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

  753. 

  754.                 if (opt_order > 1)

  755.                     quant_cof[1] = -32 * parcor_scaled_values[quant_cof[1] + 64];

  756.             }

  757. 

  758.             for (k = 2; k < opt_order; k++)

  759.                 quant_cof[k] = (quant_cof[k] << 14) + (add_base << 13);

  760.         }

  761.     }

  762. 

  763.     // read LTP gain and lag values

  764.     if (sconf->long_term_prediction) {

  765.         *bd->use_ltp = get_bits1(gb);

  766. 

  767.         if (*bd->use_ltp) {

  768.             int r, c;

  769. 

  770.             bd->ltp_gain[0]   = decode_rice(gb, 1) * 8;

  771.             bd->ltp_gain[1]   = decode_rice(gb, 2) * 8;

  772. 

  773.             r                 = get_unary(gb, 0, 4);

  774.             c                 = get_bits(gb, 2);

  775.             if (r >= 4) {

  776.                 av_log(avctx, AV_LOG_ERROR, "r overflow\n");

  777.                 return AVERROR_INVALIDDATA;

  778.             }

  779. 

  780.             bd->ltp_gain[2]   = ltp_gain_values[r][c];

  781. 

  782.             bd->ltp_gain[3]   = decode_rice(gb, 2) * 8;

  783.             bd->ltp_gain[4]   = decode_rice(gb, 1) * 8;

  784. 

  785.             *bd->ltp_lag      = get_bits(gb, ctx->ltp_lag_length);

  786.             *bd->ltp_lag     += FFMAX(4, opt_order + 1);

  787.         }

  788.     }

  789. 

  790.     // read first value and residuals in case of a random access block

  791.     if (bd->ra_block) {

  792.         start = FFMIN(opt_order, 3);

  793.         av_assert0(sb_length <= sconf->frame_length);

  794.         if (sb_length <= start) {

  795.             // opt_order or sb_length may be corrupted, either way this is unsupported and not well defined in the specification

  796.             av_log(avctx, AV_LOG_ERROR, "Sub block length smaller or equal start\n");

  797.             return AVERROR_PATCHWELCOME;

  798.         }

  799. 

  800.         if (opt_order)

  801.             bd->raw_samples[0] = decode_rice(gb, avctx->bits_per_raw_sample - 4);

  802.         if (opt_order > 1)

  803.             bd->raw_samples[1] = decode_rice(gb, FFMIN(s[0] + 3, ctx->s_max));

  804.         if (opt_order > 2)

  805.             bd->raw_samples[2] = decode_rice(gb, FFMIN(s[0] + 1, ctx->s_max));

  806.     }

  807. 

  808.     // read all residuals

  809.     if (sconf->bgmc) {

  810.         int          delta[8];

  811.         unsigned int k    [8];

  812.         unsigned int b = av_clip((av_ceil_log2(bd->block_length) - 3) >> 1, 0, 5);

  813. 

  814.         // read most significant bits

  815.         unsigned int high;

  816.         unsigned int low;

  817.         unsigned int value;

  818. 

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

  820. 

  821.         current_res = bd->raw_samples + start;

  822. 

  823.         for (sb = 0; sb < sub_blocks; sb++) {

  824.             unsigned int sb_len  = sb_length - (sb ? 0 : start);

  825. 

  826.             k    [sb] = s[sb] > b ? s[sb] - b : 0;

  827.             delta[sb] = 5 - s[sb] + k[sb];

  828. 

  829.             ff_bgmc_decode(gb, sb_len, current_res,

  830.                         delta[sb], sx[sb], &high, &low, &value, ctx->bgmc_lut, ctx->bgmc_lut_status);

  831. 

  832.             current_res += sb_len;

  833.         }

  834. 

  835.         ff_bgmc_decode_end(gb);

  836. 

  837. 

  838.         // read least significant bits and tails

  839.         current_res = bd->raw_samples + start;

  840. 

  841.         for (sb = 0; sb < sub_blocks; sb++, start = 0) {

  842.             unsigned int cur_tail_code = tail_code[sx[sb]][delta[sb]];

  843.             unsigned int cur_k         = k[sb];

  844.             unsigned int cur_s         = s[sb];

  845. 

  846.             for (; start < sb_length; start++) {

  847.                 int32_t res = *current_res;

  848. 

  849.                 if (res == cur_tail_code) {

  850.                     unsigned int max_msb =   (2 + (sx[sb] > 2) + (sx[sb] > 10))

  851.                                           << (5 - delta[sb]);

  852. 

  853.                     res = decode_rice(gb, cur_s);

  854. 

  855.                     if (res >= 0) {

  856.                         res += (max_msb    ) << cur_k;

  857.                     } else {

  858.                         res -= (max_msb - 1) << cur_k;

  859.                     }

  860.                 } else {

  861.                     if (res > cur_tail_code)

  862.                         res--;

  863. 

  864.                     if (res & 1)

  865.                         res = -res;

  866. 

  867.                     res >>= 1;

  868. 

  869.                     if (cur_k) {

  870.                         res <<= cur_k;

  871.                         res  |= get_bits_long(gb, cur_k);

  872.                     }

  873.                 }

  874. 

  875.                 *current_res++ = res;

  876.             }

  877.         }

  878.     } else {

  879.         current_res = bd->raw_samples + start;

  880. 

  881.         for (sb = 0; sb < sub_blocks; sb++, start = 0)

  882.             for (; start < sb_length; start++)

  883.                 *current_res++ = decode_rice(gb, s[sb]);

  884.      }

  885. 

  886.     if (!sconf->mc_coding || ctx->js_switch)

  887.         align_get_bits(gb);

  888. 

  889.     return 0;

  890. }

  891. 

  892. 

  893. /** Decode the block data for a non-constant block

  894.  */

  895. static int decode_var_block_data(ALSDecContext *ctx, ALSBlockData *bd)

  896. {

  897.     ALSSpecificConfig *sconf = &ctx->sconf;

  898.     unsigned int block_length = bd->block_length;

  899.     unsigned int smp = 0;

  900.     unsigned int k;

  901.     int opt_order             = *bd->opt_order;

  902.     int sb;

  903.     int64_t y;

  904.     int32_t *quant_cof        = bd->quant_cof;

  905.     int32_t *lpc_cof          = bd->lpc_cof;

  906.     int32_t *raw_samples      = bd->raw_samples;

  907.     int32_t *raw_samples_end  = bd->raw_samples + bd->block_length;

  908.     int32_t *lpc_cof_reversed = ctx->lpc_cof_reversed_buffer;

  909. 

  910.     // reverse long-term prediction

  911.     if (*bd->use_ltp) {

  912.         int ltp_smp;

  913. 

  914.         for (ltp_smp = FFMAX(*bd->ltp_lag - 2, 0); ltp_smp < block_length; ltp_smp++) {

  915.             int center = ltp_smp - *bd->ltp_lag;

  916.             int begin  = FFMAX(0, center - 2);

  917.             int end    = center + 3;

  918.             int tab    = 5 - (end - begin);

  919.             int base;

  920. 

  921.             y = 1 << 6;

  922. 

  923.             for (base = begin; base < end; base++, tab++)

  924.                 y += (uint64_t)MUL64(bd->ltp_gain[tab], raw_samples[base]);

  925. 

  926.             raw_samples[ltp_smp] += y >> 7;

  927.         }

  928.     }

  929. 

  930.     // reconstruct all samples from residuals

  931.     if (bd->ra_block) {

  932.         for (smp = 0; smp < opt_order; smp++) {

  933.             y = 1 << 19;

  934. 

  935.             for (sb = 0; sb < smp; sb++)

  936.                 y += (uint64_t)MUL64(lpc_cof[sb], raw_samples[-(sb + 1)]);

  937. 

  938.             *raw_samples++ -= y >> 20;

  939.             parcor_to_lpc(smp, quant_cof, lpc_cof);

  940.         }

  941.     } else {

  942.         for (k = 0; k < opt_order; k++)

  943.             parcor_to_lpc(k, quant_cof, lpc_cof);

  944. 

  945.         // store previous samples in case that they have to be altered

  946.         if (*bd->store_prev_samples)

  947.             memcpy(bd->prev_raw_samples, raw_samples - sconf->max_order,

  948.                    sizeof(*bd->prev_raw_samples) * sconf->max_order);

  949. 

  950.         // reconstruct difference signal for prediction (joint-stereo)

  951.         if (bd->js_blocks && bd->raw_other) {

  952.             int32_t *left, *right;

  953. 

  954.             if (bd->raw_other > raw_samples) {  // D = R - L

  955.                 left  = raw_samples;

  956.                 right = bd->raw_other;

  957.             } else {                                // D = R - L

  958.                 left  = bd->raw_other;

  959.                 right = raw_samples;

  960.             }

  961. 

  962.             for (sb = -1; sb >= -sconf->max_order; sb--)

  963.                 raw_samples[sb] = right[sb] - left[sb];

  964.         }

  965. 

  966.         // reconstruct shifted signal

  967.         if (*bd->shift_lsbs)

  968.             for (sb = -1; sb >= -sconf->max_order; sb--)

  969.                 raw_samples[sb] >>= *bd->shift_lsbs;

  970.     }

  971. 

  972.     // reverse linear prediction coefficients for efficiency

  973.     lpc_cof = lpc_cof + opt_order;

  974. 

  975.     for (sb = 0; sb < opt_order; sb++)

  976.         lpc_cof_reversed[sb] = lpc_cof[-(sb + 1)];

  977. 

  978.     // reconstruct raw samples

  979.     raw_samples = bd->raw_samples + smp;

  980.     lpc_cof     = lpc_cof_reversed + opt_order;

  981. 

  982.     for (; raw_samples < raw_samples_end; raw_samples++) {

  983.         y = 1 << 19;

  984. 

  985.         for (sb = -opt_order; sb < 0; sb++)

  986.             y += (uint64_t)MUL64(lpc_cof[sb], raw_samples[sb]);

  987. 

  988.         *raw_samples -= y >> 20;

  989.     }

  990. 

  991.     raw_samples = bd->raw_samples;

  992. 

  993.     // restore previous samples in case that they have been altered

  994.     if (*bd->store_prev_samples)

  995.         memcpy(raw_samples - sconf->max_order, bd->prev_raw_samples,

  996.                sizeof(*raw_samples) * sconf->max_order);

  997. 

  998.     return 0;

  999. }

  1000. 

  1001. 

  1002. /** Read the block data.

  1003.  */

  1004. static int read_block(ALSDecContext *ctx, ALSBlockData *bd)

  1005. {

  1006.     int ret;

  1007.     GetBitContext *gb        = &ctx->gb;

  1008. 

  1009.     *bd->shift_lsbs = 0;

  1010.     // read block type flag and read the samples accordingly

  1011.     if (get_bits1(gb)) {

  1012.         ret = read_var_block_data(ctx, bd);

  1013.     } else {

  1014.         ret = read_const_block_data(ctx, bd);

  1015.     }

  1016. 

  1017.     return ret;

  1018. }

  1019. 

  1020. 

  1021. /** Decode the block data.

  1022.  */

  1023. static int decode_block(ALSDecContext *ctx, ALSBlockData *bd)

  1024. {

  1025.     unsigned int smp;

  1026.     int ret = 0;

  1027. 

  1028.     // read block type flag and read the samples accordingly

  1029.     if (*bd->const_block)

  1030.         decode_const_block_data(ctx, bd);

  1031.     else

  1032.         ret = decode_var_block_data(ctx, bd); // always return 0

  1033. 

  1034.     if (ret < 0)

  1035.         return ret;

  1036. 

  1037.     // TODO: read RLSLMS extension data

  1038. 

  1039.     if (*bd->shift_lsbs)

  1040.         for (smp = 0; smp < bd->block_length; smp++)

  1041.             bd->raw_samples[smp] = (unsigned)bd->raw_samples[smp] << *bd->shift_lsbs;

  1042. 

  1043.     return 0;

  1044. }

  1045. 

  1046. 

  1047. /** Read and decode block data successively.

  1048.  */

  1049. static int read_decode_block(ALSDecContext *ctx, ALSBlockData *bd)

  1050. {

  1051.     int ret;

  1052. 

  1053.     if ((ret = read_block(ctx, bd)) < 0)

  1054.         return ret;

  1055. 

  1056.     return decode_block(ctx, bd);

  1057. }

  1058. 

  1059. 

  1060. /** Compute the number of samples left to decode for the current frame and

  1061.  *  sets these samples to zero.

  1062.  */

  1063. static void zero_remaining(unsigned int b, unsigned int b_max,

  1064.                            const unsigned int *div_blocks, int32_t *buf)

  1065. {

  1066.     unsigned int count = 0;

  1067. 

  1068.     while (b < b_max)

  1069.         count += div_blocks[b++];

  1070. 

  1071.     if (count)

  1072.         memset(buf, 0, sizeof(*buf) * count);

  1073. }

  1074. 

  1075. 

  1076. /** Decode blocks independently.

  1077.  */

  1078. static int decode_blocks_ind(ALSDecContext *ctx, unsigned int ra_frame,

  1079.                              unsigned int c, const unsigned int *div_blocks,

  1080.                              unsigned int *js_blocks)

  1081. {

  1082.     int ret;

  1083.     unsigned int b;

  1084.     ALSBlockData bd = { 0 };

  1085. 

  1086.     bd.ra_block         = ra_frame;

  1087.     bd.const_block      = ctx->const_block;

  1088.     bd.shift_lsbs       = ctx->shift_lsbs;

  1089.     bd.opt_order        = ctx->opt_order;

  1090.     bd.store_prev_samples = ctx->store_prev_samples;

  1091.     bd.use_ltp          = ctx->use_ltp;

  1092.     bd.ltp_lag          = ctx->ltp_lag;

  1093.     bd.ltp_gain         = ctx->ltp_gain[0];

  1094.     bd.quant_cof        = ctx->quant_cof[0];

  1095.     bd.lpc_cof          = ctx->lpc_cof[0];

  1096.     bd.prev_raw_samples = ctx->prev_raw_samples;

  1097.     bd.raw_samples      = ctx->raw_samples[c];

  1098. 

  1099. 

  1100.     for (b = 0; b < ctx->num_blocks; b++) {

  1101.         bd.block_length     = div_blocks[b];

  1102. 

  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.         bd.raw_samples += div_blocks[b];

  1109.         bd.ra_block     = 0;

  1110.     }

  1111. 

  1112.     return 0;

  1113. }

  1114. 

  1115. 

  1116. /** Decode blocks dependently.

  1117.  */

  1118. static int decode_blocks(ALSDecContext *ctx, unsigned int ra_frame,

  1119.                          unsigned int c, const unsigned int *div_blocks,

  1120.                          unsigned int *js_blocks)

  1121. {

  1122.     ALSSpecificConfig *sconf = &ctx->sconf;

  1123.     unsigned int offset = 0;

  1124.     unsigned int b;

  1125.     int ret;

  1126.     ALSBlockData bd[2] = { { 0 } };

  1127. 

  1128.     bd[0].ra_block         = ra_frame;

  1129.     bd[0].const_block      = ctx->const_block;

  1130.     bd[0].shift_lsbs       = ctx->shift_lsbs;

  1131.     bd[0].opt_order        = ctx->opt_order;

  1132.     bd[0].store_prev_samples = ctx->store_prev_samples;

  1133.     bd[0].use_ltp          = ctx->use_ltp;

  1134.     bd[0].ltp_lag          = ctx->ltp_lag;

  1135.     bd[0].ltp_gain         = ctx->ltp_gain[0];

  1136.     bd[0].quant_cof        = ctx->quant_cof[0];

  1137.     bd[0].lpc_cof          = ctx->lpc_cof[0];

  1138.     bd[0].prev_raw_samples = ctx->prev_raw_samples;

  1139.     bd[0].js_blocks        = *js_blocks;

  1140. 

  1141.     bd[1].ra_block         = ra_frame;

  1142.     bd[1].const_block      = ctx->const_block;

  1143.     bd[1].shift_lsbs       = ctx->shift_lsbs;

  1144.     bd[1].opt_order        = ctx->opt_order;

  1145.     bd[1].store_prev_samples = ctx->store_prev_samples;

  1146.     bd[1].use_ltp          = ctx->use_ltp;

  1147.     bd[1].ltp_lag          = ctx->ltp_lag;

  1148.     bd[1].ltp_gain         = ctx->ltp_gain[0];

  1149.     bd[1].quant_cof        = ctx->quant_cof[0];

  1150.     bd[1].lpc_cof          = ctx->lpc_cof[0];

  1151.     bd[1].prev_raw_samples = ctx->prev_raw_samples;

  1152.     bd[1].js_blocks        = *(js_blocks + 1);

  1153. 

  1154.     // decode all blocks

  1155.     for (b = 0; b < ctx->num_blocks; b++) {

  1156.         unsigned int s;

  1157. 

  1158.         bd[0].block_length = div_blocks[b];

  1159.         bd[1].block_length = div_blocks[b];

  1160. 

  1161.         bd[0].raw_samples  = ctx->raw_samples[c    ] + offset;

  1162.         bd[1].raw_samples  = ctx->raw_samples[c + 1] + offset;

  1163. 

  1164.         bd[0].raw_other    = bd[1].raw_samples;

  1165.         bd[1].raw_other    = bd[0].raw_samples;

  1166. 

  1167.         if ((ret = read_decode_block(ctx, &bd[0])) < 0 ||

  1168.             (ret = read_decode_block(ctx, &bd[1])) < 0)

  1169.             goto fail;

  1170. 

  1171.         // reconstruct joint-stereo blocks

  1172.         if (bd[0].js_blocks) {

  1173.             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.                 bd[0].raw_samples[s] = bd[1].raw_samples[s] - (unsigned)bd[0].raw_samples[s];

  1178.         } 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] + (unsigned)bd[0].raw_samples[s];

  1181.         }

  1182. 

  1183.         offset  += div_blocks[b];

  1184.         bd[0].ra_block = 0;

  1185.         bd[1].ra_block = 0;

  1186.     }

  1187. 

  1188.     // store carryover raw samples,

  1189.     // the others channel raw samples are stored by the calling function.

  1190.     memmove(ctx->raw_samples[c] - sconf->max_order,

  1191.             ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,

  1192.             sizeof(*ctx->raw_samples[c]) * sconf->max_order);

  1193. 

  1194.     return 0;

  1195. fail:

  1196.     // damaged block, write zero for the rest of the frame

  1197.     zero_remaining(b, ctx->num_blocks, div_blocks, bd[0].raw_samples);

  1198.     zero_remaining(b, ctx->num_blocks, div_blocks, bd[1].raw_samples);

  1199.     return ret;

  1200. }

  1201. 

  1202. static inline int als_weighting(GetBitContext *gb, int k, int off)

  1203. {

  1204.     int idx = av_clip(decode_rice(gb, k) + off,

  1205.                       0, FF_ARRAY_ELEMS(mcc_weightings) - 1);

  1206.     return mcc_weightings[idx];

  1207. }

  1208. 

  1209. /** Read the channel data.

  1210.   */

  1211. static int read_channel_data(ALSDecContext *ctx, ALSChannelData *cd, int c)

  1212. {

  1213.     GetBitContext *gb       = &ctx->gb;

  1214.     ALSChannelData *current = cd;

  1215.     unsigned int channels   = ctx->avctx->channels;

  1216.     int entries             = 0;

  1217. 

  1218.     while (entries < channels && !(current->stop_flag = get_bits1(gb))) {

  1219.         current->master_channel = get_bits_long(gb, av_ceil_log2(channels));

  1220. 

  1221.         if (current->master_channel >= channels) {

  1222.             av_log(ctx->avctx, AV_LOG_ERROR, "Invalid master channel.\n");

  1223.             return AVERROR_INVALIDDATA;

  1224.         }

  1225. 

  1226.         if (current->master_channel != c) {

  1227.             current->time_diff_flag = get_bits1(gb);

  1228.             current->weighting[0]   = als_weighting(gb, 1, 16);

  1229.             current->weighting[1]   = als_weighting(gb, 2, 14);

  1230.             current->weighting[2]   = als_weighting(gb, 1, 16);

  1231. 

  1232.             if (current->time_diff_flag) {

  1233.                 current->weighting[3] = als_weighting(gb, 1, 16);

  1234.                 current->weighting[4] = als_weighting(gb, 1, 16);

  1235.                 current->weighting[5] = als_weighting(gb, 1, 16);

  1236. 

  1237.                 current->time_diff_sign  = get_bits1(gb);

  1238.                 current->time_diff_index = get_bits(gb, ctx->ltp_lag_length - 3) + 3;

  1239.             }

  1240.         }

  1241. 

  1242.         current++;

  1243.         entries++;

  1244.     }

  1245. 

  1246.     if (entries == channels) {

  1247.         av_log(ctx->avctx, AV_LOG_ERROR, "Damaged channel data.\n");

  1248.         return AVERROR_INVALIDDATA;

  1249.     }

  1250. 

  1251.     align_get_bits(gb);

  1252.     return 0;

  1253. }

  1254. 

  1255. 

  1256. /** Recursively reverts the inter-channel correlation for a block.

  1257.  */

  1258. static int revert_channel_correlation(ALSDecContext *ctx, ALSBlockData *bd,

  1259.                                        ALSChannelData **cd, int *reverted,

  1260.                                        unsigned int offset, int c)

  1261. {

  1262.     ALSChannelData *ch = cd[c];

  1263.     unsigned int   dep = 0;

  1264.     unsigned int channels = ctx->avctx->channels;

  1265.     unsigned int channel_size = ctx->sconf.frame_length + ctx->sconf.max_order;

  1266. 

  1267.     if (reverted[c])

  1268.         return 0;

  1269. 

  1270.     reverted[c] = 1;

  1271. 

  1272.     while (dep < channels && !ch[dep].stop_flag) {

  1273.         revert_channel_correlation(ctx, bd, cd, reverted, offset,

  1274.                                    ch[dep].master_channel);

  1275. 

  1276.         dep++;

  1277.     }

  1278. 

  1279.     if (dep == channels) {

  1280.         av_log(ctx->avctx, AV_LOG_WARNING, "Invalid channel correlation.\n");

  1281.         return AVERROR_INVALIDDATA;

  1282.     }

  1283. 

  1284.     bd->const_block = ctx->const_block + c;

  1285.     bd->shift_lsbs  = ctx->shift_lsbs + c;

  1286.     bd->opt_order   = ctx->opt_order + c;

  1287.     bd->store_prev_samples = ctx->store_prev_samples + c;

  1288.     bd->use_ltp     = ctx->use_ltp + c;

  1289.     bd->ltp_lag     = ctx->ltp_lag + c;

  1290.     bd->ltp_gain    = ctx->ltp_gain[c];

  1291.     bd->lpc_cof     = ctx->lpc_cof[c];

  1292.     bd->quant_cof   = ctx->quant_cof[c];

  1293.     bd->raw_samples = ctx->raw_samples[c] + offset;

  1294. 

  1295.     for (dep = 0; !ch[dep].stop_flag; dep++) {

  1296.         ptrdiff_t smp;

  1297.         ptrdiff_t begin = 1;

  1298.         ptrdiff_t end   = bd->block_length - 1;

  1299.         int64_t y;

  1300.         int32_t *master = ctx->raw_samples[ch[dep].master_channel] + offset;

  1301. 

  1302.         if (ch[dep].master_channel == c)

  1303.             continue;

  1304. 

  1305.         if (ch[dep].time_diff_flag) {

  1306.             int t = ch[dep].time_diff_index;

  1307. 

  1308.             if (ch[dep].time_diff_sign) {

  1309.                 t      = -t;

  1310.                 if (begin < t) {

  1311.                     av_log(ctx->avctx, AV_LOG_ERROR, "begin %td smaller than time diff index %d.\n", begin, t);

  1312.                     return AVERROR_INVALIDDATA;

  1313.                 }

  1314.                 begin -= t;

  1315.             } else {

  1316.                 if (end < t) {

  1317.                     av_log(ctx->avctx, AV_LOG_ERROR, "end %td smaller than time diff index %d.\n", end, t);

  1318.                     return AVERROR_INVALIDDATA;

  1319.                 }

  1320.                 end   -= t;

  1321.             }

  1322. 

  1323.             if (FFMIN(begin - 1, begin - 1 + t) < ctx->raw_buffer - master ||

  1324.                 FFMAX(end   + 1,   end + 1 + t) > ctx->raw_buffer + channels * channel_size - master) {

  1325.                 av_log(ctx->avctx, AV_LOG_ERROR,

  1326.                        "sample pointer range [%p, %p] not contained in raw_buffer [%p, %p].\n",

  1327.                        master + FFMIN(begin - 1, begin - 1 + t), master + FFMAX(end + 1,   end + 1 + t),

  1328.                        ctx->raw_buffer, ctx->raw_buffer + channels * channel_size);

  1329.                 return AVERROR_INVALIDDATA;

  1330.             }

  1331. 

  1332.             for (smp = begin; smp < end; smp++) {

  1333.                 y  = (1 << 6) +

  1334.                      MUL64(ch[dep].weighting[0], master[smp - 1    ]) +

  1335.                      MUL64(ch[dep].weighting[1], master[smp        ]) +

  1336.                      MUL64(ch[dep].weighting[2], master[smp + 1    ]) +

  1337.                      MUL64(ch[dep].weighting[3], master[smp - 1 + t]) +

  1338.                      MUL64(ch[dep].weighting[4], master[smp     + t]) +

  1339.                      MUL64(ch[dep].weighting[5], master[smp + 1 + t]);

  1340. 

  1341.                 bd->raw_samples[smp] += y >> 7;

  1342.             }

  1343.         } else {

  1344. 

  1345.             if (begin - 1 < ctx->raw_buffer - master ||

  1346.                 end   + 1 > ctx->raw_buffer + channels * channel_size - master) {

  1347.                 av_log(ctx->avctx, AV_LOG_ERROR,

  1348.                        "sample pointer range [%p, %p] not contained in raw_buffer [%p, %p].\n",

  1349.                        master + begin - 1, master + end + 1,

  1350.                        ctx->raw_buffer, ctx->raw_buffer + channels * channel_size);

  1351.                 return AVERROR_INVALIDDATA;

  1352.             }

  1353. 

  1354.             for (smp = begin; smp < end; smp++) {

  1355.                 y  = (1 << 6) +

  1356.                      MUL64(ch[dep].weighting[0], master[smp - 1]) +

  1357.                      MUL64(ch[dep].weighting[1], master[smp    ]) +

  1358.                      MUL64(ch[dep].weighting[2], master[smp + 1]);

  1359. 

  1360.                 bd->raw_samples[smp] += y >> 7;

  1361.             }

  1362.         }

  1363.     }

  1364. 

  1365.     return 0;

  1366. }

  1367. 

  1368. 

  1369. /** Read the frame data.

  1370.  */

  1371. static int read_frame_data(ALSDecContext *ctx, unsigned int ra_frame)

  1372. {

  1373.     ALSSpecificConfig *sconf = &ctx->sconf;

  1374.     AVCodecContext *avctx    = ctx->avctx;

  1375.     GetBitContext *gb = &ctx->gb;

  1376.     unsigned int div_blocks[32];                ///< block sizes.

  1377.     unsigned int c;

  1378.     unsigned int js_blocks[2];

  1379.     uint32_t bs_info = 0;

  1380.     int ret;

  1381. 

  1382.     // skip the size of the ra unit if present in the frame

  1383.     if (sconf->ra_flag == RA_FLAG_FRAMES && ra_frame)

  1384.         skip_bits_long(gb, 32);

  1385. 

  1386.     if (sconf->mc_coding && sconf->joint_stereo) {

  1387.         ctx->js_switch = get_bits1(gb);

  1388.         align_get_bits(gb);

  1389.     }

  1390. 

  1391.     if (!sconf->mc_coding || ctx->js_switch) {

  1392.         int independent_bs = !sconf->joint_stereo;

  1393. 

  1394.         for (c = 0; c < avctx->channels; c++) {

  1395.             js_blocks[0] = 0;

  1396.             js_blocks[1] = 0;

  1397. 

  1398.             get_block_sizes(ctx, div_blocks, &bs_info);

  1399. 

  1400.             // if joint_stereo and block_switching is set, independent decoding

  1401.             // is signaled via the first bit of bs_info

  1402.             if (sconf->joint_stereo && sconf->block_switching)

  1403.                 if (bs_info >> 31)

  1404.                     independent_bs = 2;

  1405. 

  1406.             // if this is the last channel, it has to be decoded independently

  1407.             if (c == avctx->channels - 1)

  1408.                 independent_bs = 1;

  1409. 

  1410.             if (independent_bs) {

  1411.                 ret = decode_blocks_ind(ctx, ra_frame, c,

  1412.                                         div_blocks, js_blocks);

  1413.                 if (ret < 0)

  1414.                     return ret;

  1415.                 independent_bs--;

  1416.             } else {

  1417.                 ret = decode_blocks(ctx, ra_frame, c, div_blocks, js_blocks);

  1418.                 if (ret < 0)

  1419.                     return ret;

  1420. 

  1421.                 c++;

  1422.             }

  1423. 

  1424.             // store carryover raw samples

  1425.             memmove(ctx->raw_samples[c] - sconf->max_order,

  1426.                     ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,

  1427.                     sizeof(*ctx->raw_samples[c]) * sconf->max_order);

  1428.         }

  1429.     } else { // multi-channel coding

  1430.         ALSBlockData   bd = { 0 };

  1431.         int            b, ret;

  1432.         int            *reverted_channels = ctx->reverted_channels;

  1433.         unsigned int   offset             = 0;

  1434. 

  1435.         for (c = 0; c < avctx->channels; c++)

  1436.             if (ctx->chan_data[c] < ctx->chan_data_buffer) {

  1437.                 av_log(ctx->avctx, AV_LOG_ERROR, "Invalid channel data.\n");

  1438.                 return AVERROR_INVALIDDATA;

  1439.             }

  1440. 

  1441.         memset(reverted_channels, 0, sizeof(*reverted_channels) * avctx->channels);

  1442. 

  1443.         bd.ra_block         = ra_frame;

  1444.         bd.prev_raw_samples = ctx->prev_raw_samples;

  1445. 

  1446.         get_block_sizes(ctx, div_blocks, &bs_info);

  1447. 

  1448.         for (b = 0; b < ctx->num_blocks; b++) {

  1449.             bd.block_length = div_blocks[b];

  1450.             if (bd.block_length <= 0) {

  1451.                 av_log(ctx->avctx, AV_LOG_WARNING,

  1452.                        "Invalid block length %u in channel data!\n",

  1453.                        bd.block_length);

  1454.                 continue;

  1455.             }

  1456. 

  1457.             for (c = 0; c < avctx->channels; c++) {

  1458.                 bd.const_block = ctx->const_block + c;

  1459.                 bd.shift_lsbs  = ctx->shift_lsbs + c;

  1460.                 bd.opt_order   = ctx->opt_order + c;

  1461.                 bd.store_prev_samples = ctx->store_prev_samples + c;

  1462.                 bd.use_ltp     = ctx->use_ltp + c;

  1463.                 bd.ltp_lag     = ctx->ltp_lag + c;

  1464.                 bd.ltp_gain    = ctx->ltp_gain[c];

  1465.                 bd.lpc_cof     = ctx->lpc_cof[c];

  1466.                 bd.quant_cof   = ctx->quant_cof[c];

  1467.                 bd.raw_samples = ctx->raw_samples[c] + offset;

  1468.                 bd.raw_other   = NULL;

  1469. 

  1470.                 if ((ret = read_block(ctx, &bd)) < 0)

  1471.                     return ret;

  1472.                 if ((ret = read_channel_data(ctx, ctx->chan_data[c], c)) < 0)

  1473.                     return ret;

  1474.             }

  1475. 

  1476.             for (c = 0; c < avctx->channels; c++) {

  1477.                 ret = revert_channel_correlation(ctx, &bd, ctx->chan_data,

  1478.                                                  reverted_channels, offset, c);

  1479.                 if (ret < 0)

  1480.                     return ret;

  1481.             }

  1482.             for (c = 0; c < avctx->channels; c++) {

  1483.                 bd.const_block = ctx->const_block + c;

  1484.                 bd.shift_lsbs  = ctx->shift_lsbs + c;

  1485.                 bd.opt_order   = ctx->opt_order + c;

  1486.                 bd.store_prev_samples = ctx->store_prev_samples + c;

  1487.                 bd.use_ltp     = ctx->use_ltp + c;

  1488.                 bd.ltp_lag     = ctx->ltp_lag + c;

  1489.                 bd.ltp_gain    = ctx->ltp_gain[c];

  1490.                 bd.lpc_cof     = ctx->lpc_cof[c];

  1491.                 bd.quant_cof   = ctx->quant_cof[c];

  1492.                 bd.raw_samples = ctx->raw_samples[c] + offset;

  1493. 

  1494.                 if ((ret = decode_block(ctx, &bd)) < 0)

  1495.                     return ret;

  1496.             }

  1497. 

  1498.             memset(reverted_channels, 0, avctx->channels * sizeof(*reverted_channels));

  1499.             offset      += div_blocks[b];

  1500.             bd.ra_block  = 0;

  1501.         }

  1502. 

  1503.         // store carryover raw samples

  1504.         for (c = 0; c < avctx->channels; c++)

  1505.             memmove(ctx->raw_samples[c] - sconf->max_order,

  1506.                     ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,

  1507.                     sizeof(*ctx->raw_samples[c]) * sconf->max_order);

  1508.     }

  1509. 

  1510.     // TODO: read_diff_float_data

  1511. 

  1512.     if (get_bits_left(gb) < 0) {

  1513.         av_log(ctx->avctx, AV_LOG_ERROR, "Overread %d\n", -get_bits_left(gb));

  1514.         return AVERROR_INVALIDDATA;

  1515.     }

  1516. 

  1517.     return 0;

  1518. }

  1519. 

  1520. 

  1521. /** Decode an ALS frame.

  1522.  */

  1523. static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr,

  1524.                         AVPacket *avpkt)

  1525. {

  1526.     ALSDecContext *ctx       = avctx->priv_data;

  1527.     AVFrame *frame           = data;

  1528.     ALSSpecificConfig *sconf = &ctx->sconf;

  1529.     const uint8_t *buffer    = avpkt->data;

  1530.     int buffer_size          = avpkt->size;

  1531.     int invalid_frame, ret;

  1532.     unsigned int c, sample, ra_frame, bytes_read, shift;

  1533. 

  1534.     if ((ret = init_get_bits8(&ctx->gb, buffer, buffer_size)) < 0)

  1535.         return ret;

  1536. 

  1537.     // In the case that the distance between random access frames is set to zero

  1538.     // (sconf->ra_distance == 0) no frame is treated as a random access frame.

  1539.     // For the first frame, if prediction is used, all samples used from the

  1540.     // previous frame are assumed to be zero.

  1541.     ra_frame = sconf->ra_distance && !(ctx->frame_id % sconf->ra_distance);

  1542. 

  1543.     // the last frame to decode might have a different length

  1544.     if (sconf->samples != 0xFFFFFFFF)

  1545.         ctx->cur_frame_length = FFMIN(sconf->samples - ctx->frame_id * (uint64_t) sconf->frame_length,

  1546.                                       sconf->frame_length);

  1547.     else

  1548.         ctx->cur_frame_length = sconf->frame_length;

  1549. 

  1550.     // decode the frame data

  1551.     if ((invalid_frame = read_frame_data(ctx, ra_frame)) < 0)

  1552.         av_log(ctx->avctx, AV_LOG_WARNING,

  1553.                "Reading frame data failed. Skipping RA unit.\n");

  1554. 

  1555.     ctx->frame_id++;

  1556. 

  1557.     /* get output buffer */

  1558.     frame->nb_samples = ctx->cur_frame_length;

  1559.     if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)

  1560.         return ret;

  1561. 

  1562.     // transform decoded frame into output format

  1563.     #define INTERLEAVE_OUTPUT(bps)                                                   \

  1564.     {                                                                                \

  1565.         int##bps##_t *dest = (int##bps##_t*)frame->data[0];                          \

  1566.         shift = bps - ctx->avctx->bits_per_raw_sample;                               \

  1567.         if (!ctx->cs_switch) {                                                       \

  1568.             for (sample = 0; sample < ctx->cur_frame_length; sample++)               \

  1569.                 for (c = 0; c < avctx->channels; c++)                                \

  1570.                     *dest++ = ctx->raw_samples[c][sample] * (1U << shift);            \

  1571.         } else {                                                                     \

  1572.             for (sample = 0; sample < ctx->cur_frame_length; sample++)               \

  1573.                 for (c = 0; c < avctx->channels; c++)                                \

  1574.                     *dest++ = ctx->raw_samples[sconf->chan_pos[c]][sample] * (1U << shift); \

  1575.         }                                                                            \

  1576.     }

  1577. 

  1578.     if (ctx->avctx->bits_per_raw_sample <= 16) {

  1579.         INTERLEAVE_OUTPUT(16)

  1580.     } else {

  1581.         INTERLEAVE_OUTPUT(32)

  1582.     }

  1583. 

  1584.     // update CRC

  1585.     if (sconf->crc_enabled && (avctx->err_recognition & (AV_EF_CRCCHECK|AV_EF_CAREFUL))) {

  1586.         int swap = HAVE_BIGENDIAN != sconf->msb_first;

  1587. 

  1588.         if (ctx->avctx->bits_per_raw_sample == 24) {

  1589.             int32_t *src = (int32_t *)frame->data[0];

  1590. 

  1591.             for (sample = 0;

  1592.                  sample < ctx->cur_frame_length * avctx->channels;

  1593.                  sample++) {

  1594.                 int32_t v;

  1595. 

  1596.                 if (swap)

  1597.                     v = av_bswap32(src[sample]);

  1598.                 else

  1599.                     v = src[sample];

  1600.                 if (!HAVE_BIGENDIAN)

  1601.                     v >>= 8;

  1602. 

  1603.                 ctx->crc = av_crc(ctx->crc_table, ctx->crc, (uint8_t*)(&v), 3);

  1604.             }

  1605.         } else {

  1606.             uint8_t *crc_source;

  1607. 

  1608.             if (swap) {

  1609.                 if (ctx->avctx->bits_per_raw_sample <= 16) {

  1610.                     int16_t *src  = (int16_t*) frame->data[0];

  1611.                     int16_t *dest = (int16_t*) ctx->crc_buffer;

  1612.                     for (sample = 0;

  1613.                          sample < ctx->cur_frame_length * avctx->channels;

  1614.                          sample++)

  1615.                         *dest++ = av_bswap16(src[sample]);

  1616.                 } else {

  1617.                     ctx->bdsp.bswap_buf((uint32_t *) ctx->crc_buffer,

  1618.                                         (uint32_t *) frame->data[0],

  1619.                                         ctx->cur_frame_length * avctx->channels);

  1620.                 }

  1621.                 crc_source = ctx->crc_buffer;

  1622.             } else {

  1623.                 crc_source = frame->data[0];

  1624.             }

  1625. 

  1626.             ctx->crc = av_crc(ctx->crc_table, ctx->crc, crc_source,

  1627.                               ctx->cur_frame_length * avctx->channels *

  1628.                               av_get_bytes_per_sample(avctx->sample_fmt));

  1629.         }

  1630. 

  1631. 

  1632.         // check CRC sums if this is the last frame

  1633.         if (ctx->cur_frame_length != sconf->frame_length &&

  1634.             ctx->crc_org != ctx->crc) {

  1635.             av_log(avctx, AV_LOG_ERROR, "CRC error.\n");

  1636.             if (avctx->err_recognition & AV_EF_EXPLODE)

  1637.                 return AVERROR_INVALIDDATA;

  1638.         }

  1639.     }

  1640. 

  1641.     *got_frame_ptr = 1;

  1642. 

  1643.     bytes_read = invalid_frame ? buffer_size :

  1644.                                  (get_bits_count(&ctx->gb) + 7) >> 3;

  1645. 

  1646.     return bytes_read;

  1647. }

  1648. 

  1649. 

  1650. /** Uninitialize the ALS decoder.

  1651.  */

  1652. static av_cold int decode_end(AVCodecContext *avctx)

  1653. {

  1654.     ALSDecContext *ctx = avctx->priv_data;

  1655. 

  1656.     av_freep(&ctx->sconf.chan_pos);

  1657. 

  1658.     ff_bgmc_end(&ctx->bgmc_lut, &ctx->bgmc_lut_status);

  1659. 

  1660.     av_freep(&ctx->const_block);

  1661.     av_freep(&ctx->shift_lsbs);

  1662.     av_freep(&ctx->opt_order);

  1663.     av_freep(&ctx->store_prev_samples);

  1664.     av_freep(&ctx->use_ltp);

  1665.     av_freep(&ctx->ltp_lag);

  1666.     av_freep(&ctx->ltp_gain);

  1667.     av_freep(&ctx->ltp_gain_buffer);

  1668.     av_freep(&ctx->quant_cof);

  1669.     av_freep(&ctx->lpc_cof);

  1670.     av_freep(&ctx->quant_cof_buffer);

  1671.     av_freep(&ctx->lpc_cof_buffer);

  1672.     av_freep(&ctx->lpc_cof_reversed_buffer);

  1673.     av_freep(&ctx->prev_raw_samples);

  1674.     av_freep(&ctx->raw_samples);

  1675.     av_freep(&ctx->raw_buffer);

  1676.     av_freep(&ctx->chan_data);

  1677.     av_freep(&ctx->chan_data_buffer);

  1678.     av_freep(&ctx->reverted_channels);

  1679.     av_freep(&ctx->crc_buffer);

  1680. 

  1681.     return 0;

  1682. }

  1683. 

  1684. 

  1685. /** Initialize the ALS decoder.

  1686.  */

  1687. static av_cold int decode_init(AVCodecContext *avctx)

  1688. {

  1689.     unsigned int c;

  1690.     unsigned int channel_size;

  1691.     int num_buffers, ret;

  1692.     ALSDecContext *ctx = avctx->priv_data;

  1693.     ALSSpecificConfig *sconf = &ctx->sconf;

  1694.     ctx->avctx = avctx;

  1695. 

  1696.     if (!avctx->extradata) {

  1697.         av_log(avctx, AV_LOG_ERROR, "Missing required ALS extradata.\n");

  1698.         return AVERROR_INVALIDDATA;

  1699.     }

  1700. 

  1701.     if ((ret = read_specific_config(ctx)) < 0) {

  1702.         av_log(avctx, AV_LOG_ERROR, "Reading ALSSpecificConfig failed.\n");

  1703.         goto fail;

  1704.     }

  1705. 

  1706.     if ((ret = check_specific_config(ctx)) < 0) {

  1707.         goto fail;

  1708.     }

  1709. 

  1710.     if (sconf->bgmc) {

  1711.         ret = ff_bgmc_init(avctx, &ctx->bgmc_lut, &ctx->bgmc_lut_status);

  1712.         if (ret < 0)

  1713.             goto fail;

  1714.     }

  1715.     if (sconf->floating) {

  1716.         avctx->sample_fmt          = AV_SAMPLE_FMT_FLT;

  1717.         avctx->bits_per_raw_sample = 32;

  1718.     } else {

  1719.         avctx->sample_fmt          = sconf->resolution > 1

  1720.                                      ? AV_SAMPLE_FMT_S32 : AV_SAMPLE_FMT_S16;

  1721.         avctx->bits_per_raw_sample = (sconf->resolution + 1) * 8;

  1722.         if (avctx->bits_per_raw_sample > 32) {

  1723.             av_log(avctx, AV_LOG_ERROR, "Bits per raw sample %d larger than 32.\n",

  1724.                    avctx->bits_per_raw_sample);

  1725.             ret = AVERROR_INVALIDDATA;

  1726.             goto fail;

  1727.         }

  1728.     }

  1729. 

  1730.     // set maximum Rice parameter for progressive decoding based on resolution

  1731.     // This is not specified in 14496-3 but actually done by the reference

  1732.     // codec RM22 revision 2.

  1733.     ctx->s_max = sconf->resolution > 1 ? 31 : 15;

  1734. 

  1735.     // set lag value for long-term prediction

  1736.     ctx->ltp_lag_length = 8 + (avctx->sample_rate >=  96000) +

  1737.                               (avctx->sample_rate >= 192000);

  1738. 

  1739.     // allocate quantized parcor coefficient buffer

  1740.     num_buffers = sconf->mc_coding ? avctx->channels : 1;

  1741.     if (num_buffers * (uint64_t)num_buffers > INT_MAX) // protect chan_data_buffer allocation

  1742.         return AVERROR_INVALIDDATA;

  1743. 

  1744.     ctx->quant_cof        = av_malloc_array(num_buffers, sizeof(*ctx->quant_cof));

  1745.     ctx->lpc_cof          = av_malloc_array(num_buffers, sizeof(*ctx->lpc_cof));

  1746.     ctx->quant_cof_buffer = av_malloc_array(num_buffers * sconf->max_order,

  1747.                                             sizeof(*ctx->quant_cof_buffer));

  1748.     ctx->lpc_cof_buffer   = av_malloc_array(num_buffers * sconf->max_order,

  1749.                                             sizeof(*ctx->lpc_cof_buffer));

  1750.     ctx->lpc_cof_reversed_buffer = av_malloc_array(sconf->max_order,

  1751.                                                    sizeof(*ctx->lpc_cof_buffer));

  1752. 

  1753.     if (!ctx->quant_cof              || !ctx->lpc_cof        ||

  1754.         !ctx->quant_cof_buffer       || !ctx->lpc_cof_buffer ||

  1755.         !ctx->lpc_cof_reversed_buffer) {

  1756.         av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");

  1757.         ret = AVERROR(ENOMEM);

  1758.         goto fail;

  1759.     }

  1760. 

  1761.     // assign quantized parcor coefficient buffers

  1762.     for (c = 0; c < num_buffers; c++) {

  1763.         ctx->quant_cof[c] = ctx->quant_cof_buffer + c * sconf->max_order;

  1764.         ctx->lpc_cof[c]   = ctx->lpc_cof_buffer   + c * sconf->max_order;

  1765.     }

  1766. 

  1767.     // allocate and assign lag and gain data buffer for ltp mode

  1768.     ctx->const_block     = av_malloc_array(num_buffers, sizeof(*ctx->const_block));

  1769.     ctx->shift_lsbs      = av_malloc_array(num_buffers, sizeof(*ctx->shift_lsbs));

  1770.     ctx->opt_order       = av_malloc_array(num_buffers, sizeof(*ctx->opt_order));

  1771.     ctx->store_prev_samples = av_malloc_array(num_buffers, sizeof(*ctx->store_prev_samples));

  1772.     ctx->use_ltp         = av_mallocz_array(num_buffers, sizeof(*ctx->use_ltp));

  1773.     ctx->ltp_lag         = av_malloc_array(num_buffers, sizeof(*ctx->ltp_lag));

  1774.     ctx->ltp_gain        = av_malloc_array(num_buffers, sizeof(*ctx->ltp_gain));

  1775.     ctx->ltp_gain_buffer = av_malloc_array(num_buffers * 5, sizeof(*ctx->ltp_gain_buffer));

  1776. 

  1777.     if (!ctx->const_block || !ctx->shift_lsbs ||

  1778.         !ctx->opt_order || !ctx->store_prev_samples ||

  1779.         !ctx->use_ltp  || !ctx->ltp_lag ||

  1780.         !ctx->ltp_gain || !ctx->ltp_gain_buffer) {

  1781.         av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");

  1782.         ret = AVERROR(ENOMEM);

  1783.         goto fail;

  1784.     }

  1785. 

  1786.     for (c = 0; c < num_buffers; c++)

  1787.         ctx->ltp_gain[c] = ctx->ltp_gain_buffer + c * 5;

  1788. 

  1789.     // allocate and assign channel data buffer for mcc mode

  1790.     if (sconf->mc_coding) {

  1791.         ctx->chan_data_buffer  = av_mallocz_array(num_buffers * num_buffers,

  1792.                                                  sizeof(*ctx->chan_data_buffer));

  1793.         ctx->chan_data         = av_mallocz_array(num_buffers,

  1794.                                                  sizeof(*ctx->chan_data));

  1795.         ctx->reverted_channels = av_malloc_array(num_buffers,

  1796.                                                  sizeof(*ctx->reverted_channels));

  1797. 

  1798.         if (!ctx->chan_data_buffer || !ctx->chan_data || !ctx->reverted_channels) {

  1799.             av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");

  1800.             ret = AVERROR(ENOMEM);

  1801.             goto fail;

  1802.         }

  1803. 

  1804.         for (c = 0; c < num_buffers; c++)

  1805.             ctx->chan_data[c] = ctx->chan_data_buffer + c * num_buffers;

  1806.     } else {

  1807.         ctx->chan_data         = NULL;

  1808.         ctx->chan_data_buffer  = NULL;

  1809.         ctx->reverted_channels = NULL;

  1810.     }

  1811. 

  1812.     channel_size      = sconf->frame_length + sconf->max_order;

  1813. 

  1814.     ctx->prev_raw_samples = av_malloc_array(sconf->max_order, sizeof(*ctx->prev_raw_samples));

  1815.     ctx->raw_buffer       = av_mallocz_array(avctx->channels * channel_size, sizeof(*ctx->raw_buffer));

  1816.     ctx->raw_samples      = av_malloc_array(avctx->channels, sizeof(*ctx->raw_samples));

  1817. 

  1818.     // allocate previous raw sample buffer

  1819.     if (!ctx->prev_raw_samples || !ctx->raw_buffer|| !ctx->raw_samples) {

  1820.         av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");

  1821.         ret = AVERROR(ENOMEM);

  1822.         goto fail;

  1823.     }

  1824. 

  1825.     // assign raw samples buffers

  1826.     ctx->raw_samples[0] = ctx->raw_buffer + sconf->max_order;

  1827.     for (c = 1; c < avctx->channels; c++)

  1828.         ctx->raw_samples[c] = ctx->raw_samples[c - 1] + channel_size;

  1829. 

  1830.     // allocate crc buffer

  1831.     if (HAVE_BIGENDIAN != sconf->msb_first && sconf->crc_enabled &&

  1832.         (avctx->err_recognition & (AV_EF_CRCCHECK|AV_EF_CAREFUL))) {

  1833.         ctx->crc_buffer = av_malloc_array(ctx->cur_frame_length *

  1834.                                           avctx->channels *

  1835.                                           av_get_bytes_per_sample(avctx->sample_fmt),

  1836.                                           sizeof(*ctx->crc_buffer));

  1837.         if (!ctx->crc_buffer) {

  1838.             av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");

  1839.             ret = AVERROR(ENOMEM);

  1840.             goto fail;

  1841.         }

  1842.     }

  1843. 

  1844.     ff_bswapdsp_init(&ctx->bdsp);

  1845. 

  1846.     return 0;

  1847. 

  1848. fail:

  1849.     return ret;

  1850. }

  1851. 

  1852. 

  1853. /** Flush (reset) the frame ID after seeking.

  1854.  */

  1855. static av_cold void flush(AVCodecContext *avctx)

  1856. {

  1857.     ALSDecContext *ctx = avctx->priv_data;

  1858. 

  1859.     ctx->frame_id = 0;

  1860. }

  1861. 

  1862. 

  1863. AVCodec ff_als_decoder = {

  1864.     .name           = "als",

  1865.     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-4 Audio Lossless Coding (ALS)"),

  1866.     .type           = AVMEDIA_TYPE_AUDIO,

  1867.     .id             = AV_CODEC_ID_MP4ALS,

  1868.     .priv_data_size = sizeof(ALSDecContext),

  1869.     .init           = decode_init,

  1870.     .close          = decode_end,

  1871.     .decode         = decode_frame,

  1872.     .flush          = flush,

  1873.     .capabilities   = AV_CODEC_CAP_SUBFRAMES | AV_CODEC_CAP_DR1,

  1874.     .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,

  1875. };