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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.         int ret = ff_bgmc_decode_init(gb, &high, &low, &value);

  820.         if (ret < 0)

  821.             return ret;

  822. 

  823.         current_res = bd->raw_samples + start;

  824. 

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

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

  827. 

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

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

  830. 

  831.             if (k[sb] >= 32)

  832.                 return AVERROR_INVALIDDATA;

  833. 

  834.             ff_bgmc_decode(gb, sb_len, current_res,

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

  836. 

  837.             current_res += sb_len;

  838.         }

  839. 

  840.         ff_bgmc_decode_end(gb);

  841. 

  842. 

  843.         // read least significant bits and tails

  844.         current_res = bd->raw_samples + start;

  845. 

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

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

  848.             unsigned int cur_k         = k[sb];

  849.             unsigned int cur_s         = s[sb];

  850. 

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

  852.                 int32_t res = *current_res;

  853. 

  854.                 if (res == cur_tail_code) {

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

  856.                                           << (5 - delta[sb]);

  857. 

  858.                     res = decode_rice(gb, cur_s);

  859. 

  860.                     if (res >= 0) {

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

  862.                     } else {

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

  864.                     }

  865.                 } else {

  866.                     if (res > cur_tail_code)

  867.                         res--;

  868. 

  869.                     if (res & 1)

  870.                         res = -res;

  871. 

  872.                     res >>= 1;

  873. 

  874.                     if (cur_k) {

  875.                         res <<= cur_k;

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

  877.                     }

  878.                 }

  879. 

  880.                 *current_res++ = res;

  881.             }

  882.         }

  883.     } else {

  884.         current_res = bd->raw_samples + start;

  885. 

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

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

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

  889.      }

  890. 

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

  892.         align_get_bits(gb);

  893. 

  894.     return 0;

  895. }

  896. 

  897. 

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

  899.  */

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

  901. {

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

  903.     unsigned int block_length = bd->block_length;

  904.     unsigned int smp = 0;

  905.     unsigned int k;

  906.     int opt_order             = *bd->opt_order;

  907.     int sb;

  908.     int64_t y;

  909.     int32_t *quant_cof        = bd->quant_cof;

  910.     int32_t *lpc_cof          = bd->lpc_cof;

  911.     int32_t *raw_samples      = bd->raw_samples;

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

  913.     int32_t *lpc_cof_reversed = ctx->lpc_cof_reversed_buffer;

  914. 

  915.     // reverse long-term prediction

  916.     if (*bd->use_ltp) {

  917.         int ltp_smp;

  918. 

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

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

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

  922.             int end    = center + 3;

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

  924.             int base;

  925. 

  926.             y = 1 << 6;

  927. 

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

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

  930. 

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

  932.         }

  933.     }

  934. 

  935.     // reconstruct all samples from residuals

  936.     if (bd->ra_block) {

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

  938.             y = 1 << 19;

  939. 

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

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

  942. 

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

  944.             parcor_to_lpc(smp, quant_cof, lpc_cof);

  945.         }

  946.     } else {

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

  948.             parcor_to_lpc(k, quant_cof, lpc_cof);

  949. 

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

  951.         if (*bd->store_prev_samples)

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

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

  954. 

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

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

  957.             uint32_t *left, *right;

  958. 

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

  960.                 left  = raw_samples;

  961.                 right = bd->raw_other;

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

  963.                 left  = bd->raw_other;

  964.                 right = raw_samples;

  965.             }

  966. 

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

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

  969.         }

  970. 

  971.         // reconstruct shifted signal

  972.         if (*bd->shift_lsbs)

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

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

  975.     }

  976. 

  977.     // reverse linear prediction coefficients for efficiency

  978.     lpc_cof = lpc_cof + opt_order;

  979. 

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

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

  982. 

  983.     // reconstruct raw samples

  984.     raw_samples = bd->raw_samples + smp;

  985.     lpc_cof     = lpc_cof_reversed + opt_order;

  986. 

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

  988.         y = 1 << 19;

  989. 

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

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

  992. 

  993.         *raw_samples -= y >> 20;

  994.     }

  995. 

  996.     raw_samples = bd->raw_samples;

  997. 

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

  999.     if (*bd->store_prev_samples)

  1000.         memcpy(raw_samples - sconf->max_order, bd->prev_raw_samples,

  1001.                sizeof(*raw_samples) * sconf->max_order);

  1002. 

  1003.     return 0;

  1004. }

  1005. 

  1006. 

  1007. /** Read the block data.

  1008.  */

  1009. static int read_block(ALSDecContext *ctx, ALSBlockData *bd)

  1010. {

  1011.     int ret;

  1012.     GetBitContext *gb        = &ctx->gb;

  1013. 

  1014.     *bd->shift_lsbs = 0;

  1015.     // read block type flag and read the samples accordingly

  1016.     if (get_bits1(gb)) {

  1017.         ret = read_var_block_data(ctx, bd);

  1018.     } else {

  1019.         ret = read_const_block_data(ctx, bd);

  1020.     }

  1021. 

  1022.     return ret;

  1023. }

  1024. 

  1025. 

  1026. /** Decode the block data.

  1027.  */

  1028. static int decode_block(ALSDecContext *ctx, ALSBlockData *bd)

  1029. {

  1030.     unsigned int smp;

  1031.     int ret = 0;

  1032. 

  1033.     // read block type flag and read the samples accordingly

  1034.     if (*bd->const_block)

  1035.         decode_const_block_data(ctx, bd);

  1036.     else

  1037.         ret = decode_var_block_data(ctx, bd); // always return 0

  1038. 

  1039.     if (ret < 0)

  1040.         return ret;

  1041. 

  1042.     // TODO: read RLSLMS extension data

  1043. 

  1044.     if (*bd->shift_lsbs)

  1045.         for (smp = 0; smp < bd->block_length; smp++)

  1046.             bd->raw_samples[smp] = (unsigned)bd->raw_samples[smp] << *bd->shift_lsbs;

  1047. 

  1048.     return 0;

  1049. }

  1050. 

  1051. 

  1052. /** Read and decode block data successively.

  1053.  */

  1054. static int read_decode_block(ALSDecContext *ctx, ALSBlockData *bd)

  1055. {

  1056.     int ret;

  1057. 

  1058.     if ((ret = read_block(ctx, bd)) < 0)

  1059.         return ret;

  1060. 

  1061.     return decode_block(ctx, bd);

  1062. }

  1063. 

  1064. 

  1065. /** Compute the number of samples left to decode for the current frame and

  1066.  *  sets these samples to zero.

  1067.  */

  1068. static void zero_remaining(unsigned int b, unsigned int b_max,

  1069.                            const unsigned int *div_blocks, int32_t *buf)

  1070. {

  1071.     unsigned int count = 0;

  1072. 

  1073.     while (b < b_max)

  1074.         count += div_blocks[b++];

  1075. 

  1076.     if (count)

  1077.         memset(buf, 0, sizeof(*buf) * count);

  1078. }

  1079. 

  1080. 

  1081. /** Decode blocks independently.

  1082.  */

  1083. static int decode_blocks_ind(ALSDecContext *ctx, unsigned int ra_frame,

  1084.                              unsigned int c, const unsigned int *div_blocks,

  1085.                              unsigned int *js_blocks)

  1086. {

  1087.     int ret;

  1088.     unsigned int b;

  1089.     ALSBlockData bd = { 0 };

  1090. 

  1091.     bd.ra_block         = ra_frame;

  1092.     bd.const_block      = ctx->const_block;

  1093.     bd.shift_lsbs       = ctx->shift_lsbs;

  1094.     bd.opt_order        = ctx->opt_order;

  1095.     bd.store_prev_samples = ctx->store_prev_samples;

  1096.     bd.use_ltp          = ctx->use_ltp;

  1097.     bd.ltp_lag          = ctx->ltp_lag;

  1098.     bd.ltp_gain         = ctx->ltp_gain[0];

  1099.     bd.quant_cof        = ctx->quant_cof[0];

  1100.     bd.lpc_cof          = ctx->lpc_cof[0];

  1101.     bd.prev_raw_samples = ctx->prev_raw_samples;

  1102.     bd.raw_samples      = ctx->raw_samples[c];

  1103. 

  1104. 

  1105.     for (b = 0; b < ctx->num_blocks; b++) {

  1106.         bd.block_length     = div_blocks[b];

  1107. 

  1108.         if ((ret = read_decode_block(ctx, &bd)) < 0) {

  1109.             // damaged block, write zero for the rest of the frame

  1110.             zero_remaining(b, ctx->num_blocks, div_blocks, bd.raw_samples);

  1111.             return ret;

  1112.         }

  1113.         bd.raw_samples += div_blocks[b];

  1114.         bd.ra_block     = 0;

  1115.     }

  1116. 

  1117.     return 0;

  1118. }

  1119. 

  1120. 

  1121. /** Decode blocks dependently.

  1122.  */

  1123. static int decode_blocks(ALSDecContext *ctx, unsigned int ra_frame,

  1124.                          unsigned int c, const unsigned int *div_blocks,

  1125.                          unsigned int *js_blocks)

  1126. {

  1127.     ALSSpecificConfig *sconf = &ctx->sconf;

  1128.     unsigned int offset = 0;

  1129.     unsigned int b;

  1130.     int ret;

  1131.     ALSBlockData bd[2] = { { 0 } };

  1132. 

  1133.     bd[0].ra_block         = ra_frame;

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

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

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

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

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

  1139.     bd[0].ltp_lag          = ctx->ltp_lag;

  1140.     bd[0].ltp_gain         = ctx->ltp_gain[0];

  1141.     bd[0].quant_cof        = ctx->quant_cof[0];

  1142.     bd[0].lpc_cof          = ctx->lpc_cof[0];

  1143.     bd[0].prev_raw_samples = ctx->prev_raw_samples;

  1144.     bd[0].js_blocks        = *js_blocks;

  1145. 

  1146.     bd[1].ra_block         = ra_frame;

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

  1148.     bd[1].shift_lsbs       = ctx->shift_lsbs;

  1149.     bd[1].opt_order        = ctx->opt_order;

  1150.     bd[1].store_prev_samples = ctx->store_prev_samples;

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

  1152.     bd[1].ltp_lag          = ctx->ltp_lag;

  1153.     bd[1].ltp_gain         = ctx->ltp_gain[0];

  1154.     bd[1].quant_cof        = ctx->quant_cof[0];

  1155.     bd[1].lpc_cof          = ctx->lpc_cof[0];

  1156.     bd[1].prev_raw_samples = ctx->prev_raw_samples;

  1157.     bd[1].js_blocks        = *(js_blocks + 1);

  1158. 

  1159.     // decode all blocks

  1160.     for (b = 0; b < ctx->num_blocks; b++) {

  1161.         unsigned int s;

  1162. 

  1163.         bd[0].block_length = div_blocks[b];

  1164.         bd[1].block_length = div_blocks[b];

  1165. 

  1166.         bd[0].raw_samples  = ctx->raw_samples[c    ] + offset;

  1167.         bd[1].raw_samples  = ctx->raw_samples[c + 1] + offset;

  1168. 

  1169.         bd[0].raw_other    = bd[1].raw_samples;

  1170.         bd[1].raw_other    = bd[0].raw_samples;

  1171. 

  1172.         if ((ret = read_decode_block(ctx, &bd[0])) < 0 ||

  1173.             (ret = read_decode_block(ctx, &bd[1])) < 0)

  1174.             goto fail;

  1175. 

  1176.         // reconstruct joint-stereo blocks

  1177.         if (bd[0].js_blocks) {

  1178.             if (bd[1].js_blocks)

  1179.                 av_log(ctx->avctx, AV_LOG_WARNING, "Invalid channel pair.\n");

  1180. 

  1181.             for (s = 0; s < div_blocks[b]; s++)

  1182.                 bd[0].raw_samples[s] = bd[1].raw_samples[s] - (unsigned)bd[0].raw_samples[s];

  1183.         } else if (bd[1].js_blocks) {

  1184.             for (s = 0; s < div_blocks[b]; s++)

  1185.                 bd[1].raw_samples[s] = bd[1].raw_samples[s] + (unsigned)bd[0].raw_samples[s];

  1186.         }

  1187. 

  1188.         offset  += div_blocks[b];

  1189.         bd[0].ra_block = 0;

  1190.         bd[1].ra_block = 0;

  1191.     }

  1192. 

  1193.     // store carryover raw samples,

  1194.     // the others channel raw samples are stored by the calling function.

  1195.     memmove(ctx->raw_samples[c] - sconf->max_order,

  1196.             ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,

  1197.             sizeof(*ctx->raw_samples[c]) * sconf->max_order);

  1198. 

  1199.     return 0;

  1200. fail:

  1201.     // damaged block, write zero for the rest of the frame

  1202.     zero_remaining(b, ctx->num_blocks, div_blocks, bd[0].raw_samples);

  1203.     zero_remaining(b, ctx->num_blocks, div_blocks, bd[1].raw_samples);

  1204.     return ret;

  1205. }

  1206. 

  1207. static inline int als_weighting(GetBitContext *gb, int k, int off)

  1208. {

  1209.     int idx = av_clip(decode_rice(gb, k) + off,

  1210.                       0, FF_ARRAY_ELEMS(mcc_weightings) - 1);

  1211.     return mcc_weightings[idx];

  1212. }

  1213. 

  1214. /** Read the channel data.

  1215.   */

  1216. static int read_channel_data(ALSDecContext *ctx, ALSChannelData *cd, int c)

  1217. {

  1218.     GetBitContext *gb       = &ctx->gb;

  1219.     ALSChannelData *current = cd;

  1220.     unsigned int channels   = ctx->avctx->channels;

  1221.     int entries             = 0;

  1222. 

  1223.     while (entries < channels && !(current->stop_flag = get_bits1(gb))) {

  1224.         current->master_channel = get_bits_long(gb, av_ceil_log2(channels));

  1225. 

  1226.         if (current->master_channel >= channels) {

  1227.             av_log(ctx->avctx, AV_LOG_ERROR, "Invalid master channel.\n");

  1228.             return AVERROR_INVALIDDATA;

  1229.         }

  1230. 

  1231.         if (current->master_channel != c) {

  1232.             current->time_diff_flag = get_bits1(gb);

  1233.             current->weighting[0]   = als_weighting(gb, 1, 16);

  1234.             current->weighting[1]   = als_weighting(gb, 2, 14);

  1235.             current->weighting[2]   = als_weighting(gb, 1, 16);

  1236. 

  1237.             if (current->time_diff_flag) {

  1238.                 current->weighting[3] = als_weighting(gb, 1, 16);

  1239.                 current->weighting[4] = als_weighting(gb, 1, 16);

  1240.                 current->weighting[5] = als_weighting(gb, 1, 16);

  1241. 

  1242.                 current->time_diff_sign  = get_bits1(gb);

  1243.                 current->time_diff_index = get_bits(gb, ctx->ltp_lag_length - 3) + 3;

  1244.             }

  1245.         }

  1246. 

  1247.         current++;

  1248.         entries++;

  1249.     }

  1250. 

  1251.     if (entries == channels) {

  1252.         av_log(ctx->avctx, AV_LOG_ERROR, "Damaged channel data.\n");

  1253.         return AVERROR_INVALIDDATA;

  1254.     }

  1255. 

  1256.     align_get_bits(gb);

  1257.     return 0;

  1258. }

  1259. 

  1260. 

  1261. /** Recursively reverts the inter-channel correlation for a block.

  1262.  */

  1263. static int revert_channel_correlation(ALSDecContext *ctx, ALSBlockData *bd,

  1264.                                        ALSChannelData **cd, int *reverted,

  1265.                                        unsigned int offset, int c)

  1266. {

  1267.     ALSChannelData *ch = cd[c];

  1268.     unsigned int   dep = 0;

  1269.     unsigned int channels = ctx->avctx->channels;

  1270.     unsigned int channel_size = ctx->sconf.frame_length + ctx->sconf.max_order;

  1271. 

  1272.     if (reverted[c])

  1273.         return 0;

  1274. 

  1275.     reverted[c] = 1;

  1276. 

  1277.     while (dep < channels && !ch[dep].stop_flag) {

  1278.         revert_channel_correlation(ctx, bd, cd, reverted, offset,

  1279.                                    ch[dep].master_channel);

  1280. 

  1281.         dep++;

  1282.     }

  1283. 

  1284.     if (dep == channels) {

  1285.         av_log(ctx->avctx, AV_LOG_WARNING, "Invalid channel correlation.\n");

  1286.         return AVERROR_INVALIDDATA;

  1287.     }

  1288. 

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

  1290.     bd->shift_lsbs  = ctx->shift_lsbs + c;

  1291.     bd->opt_order   = ctx->opt_order + c;

  1292.     bd->store_prev_samples = ctx->store_prev_samples + c;

  1293.     bd->use_ltp     = ctx->use_ltp + c;

  1294.     bd->ltp_lag     = ctx->ltp_lag + c;

  1295.     bd->ltp_gain    = ctx->ltp_gain[c];

  1296.     bd->lpc_cof     = ctx->lpc_cof[c];

  1297.     bd->quant_cof   = ctx->quant_cof[c];

  1298.     bd->raw_samples = ctx->raw_samples[c] + offset;

  1299. 

  1300.     for (dep = 0; !ch[dep].stop_flag; dep++) {

  1301.         ptrdiff_t smp;

  1302.         ptrdiff_t begin = 1;

  1303.         ptrdiff_t end   = bd->block_length - 1;

  1304.         int64_t y;

  1305.         int32_t *master = ctx->raw_samples[ch[dep].master_channel] + offset;

  1306. 

  1307.         if (ch[dep].master_channel == c)

  1308.             continue;

  1309. 

  1310.         if (ch[dep].time_diff_flag) {

  1311.             int t = ch[dep].time_diff_index;

  1312. 

  1313.             if (ch[dep].time_diff_sign) {

  1314.                 t      = -t;

  1315.                 if (begin < t) {

  1316.                     av_log(ctx->avctx, AV_LOG_ERROR, "begin %td smaller than time diff index %d.\n", begin, t);

  1317.                     return AVERROR_INVALIDDATA;

  1318.                 }

  1319.                 begin -= t;

  1320.             } else {

  1321.                 if (end < t) {

  1322.                     av_log(ctx->avctx, AV_LOG_ERROR, "end %td smaller than time diff index %d.\n", end, t);

  1323.                     return AVERROR_INVALIDDATA;

  1324.                 }

  1325.                 end   -= t;

  1326.             }

  1327. 

  1328.             if (FFMIN(begin - 1, begin - 1 + t) < ctx->raw_buffer - master ||

  1329.                 FFMAX(end   + 1,   end + 1 + t) > ctx->raw_buffer + channels * channel_size - master) {

  1330.                 av_log(ctx->avctx, AV_LOG_ERROR,

  1331.                        "sample pointer range [%p, %p] not contained in raw_buffer [%p, %p].\n",

  1332.                        master + FFMIN(begin - 1, begin - 1 + t), master + FFMAX(end + 1,   end + 1 + t),

  1333.                        ctx->raw_buffer, ctx->raw_buffer + channels * channel_size);

  1334.                 return AVERROR_INVALIDDATA;

  1335.             }

  1336. 

  1337.             for (smp = begin; smp < end; smp++) {

  1338.                 y  = (1 << 6) +

  1339.                      MUL64(ch[dep].weighting[0], master[smp - 1    ]) +

  1340.                      MUL64(ch[dep].weighting[1], master[smp        ]) +

  1341.                      MUL64(ch[dep].weighting[2], master[smp + 1    ]) +

  1342.                      MUL64(ch[dep].weighting[3], master[smp - 1 + t]) +

  1343.                      MUL64(ch[dep].weighting[4], master[smp     + t]) +

  1344.                      MUL64(ch[dep].weighting[5], master[smp + 1 + t]);

  1345. 

  1346.                 bd->raw_samples[smp] += y >> 7;

  1347.             }

  1348.         } else {

  1349. 

  1350.             if (begin - 1 < ctx->raw_buffer - master ||

  1351.                 end   + 1 > ctx->raw_buffer + channels * channel_size - master) {

  1352.                 av_log(ctx->avctx, AV_LOG_ERROR,

  1353.                        "sample pointer range [%p, %p] not contained in raw_buffer [%p, %p].\n",

  1354.                        master + begin - 1, master + end + 1,

  1355.                        ctx->raw_buffer, ctx->raw_buffer + channels * channel_size);

  1356.                 return AVERROR_INVALIDDATA;

  1357.             }

  1358. 

  1359.             for (smp = begin; smp < end; smp++) {

  1360.                 y  = (1 << 6) +

  1361.                      MUL64(ch[dep].weighting[0], master[smp - 1]) +

  1362.                      MUL64(ch[dep].weighting[1], master[smp    ]) +

  1363.                      MUL64(ch[dep].weighting[2], master[smp + 1]);

  1364. 

  1365.                 bd->raw_samples[smp] += y >> 7;

  1366.             }

  1367.         }

  1368.     }

  1369. 

  1370.     return 0;

  1371. }

  1372. 

  1373. 

  1374. /** Read the frame data.

  1375.  */

  1376. static int read_frame_data(ALSDecContext *ctx, unsigned int ra_frame)

  1377. {

  1378.     ALSSpecificConfig *sconf = &ctx->sconf;

  1379.     AVCodecContext *avctx    = ctx->avctx;

  1380.     GetBitContext *gb = &ctx->gb;

  1381.     unsigned int div_blocks[32];                ///< block sizes.

  1382.     unsigned int c;

  1383.     unsigned int js_blocks[2];

  1384.     uint32_t bs_info = 0;

  1385.     int ret;

  1386. 

  1387.     // skip the size of the ra unit if present in the frame

  1388.     if (sconf->ra_flag == RA_FLAG_FRAMES && ra_frame)

  1389.         skip_bits_long(gb, 32);

  1390. 

  1391.     if (sconf->mc_coding && sconf->joint_stereo) {

  1392.         ctx->js_switch = get_bits1(gb);

  1393.         align_get_bits(gb);

  1394.     }

  1395. 

  1396.     if (!sconf->mc_coding || ctx->js_switch) {

  1397.         int independent_bs = !sconf->joint_stereo;

  1398. 

  1399.         for (c = 0; c < avctx->channels; c++) {

  1400.             js_blocks[0] = 0;

  1401.             js_blocks[1] = 0;

  1402. 

  1403.             get_block_sizes(ctx, div_blocks, &bs_info);

  1404. 

  1405.             // if joint_stereo and block_switching is set, independent decoding

  1406.             // is signaled via the first bit of bs_info

  1407.             if (sconf->joint_stereo && sconf->block_switching)

  1408.                 if (bs_info >> 31)

  1409.                     independent_bs = 2;

  1410. 

  1411.             // if this is the last channel, it has to be decoded independently

  1412.             if (c == avctx->channels - 1)

  1413.                 independent_bs = 1;

  1414. 

  1415.             if (independent_bs) {

  1416.                 ret = decode_blocks_ind(ctx, ra_frame, c,

  1417.                                         div_blocks, js_blocks);

  1418.                 if (ret < 0)

  1419.                     return ret;

  1420.                 independent_bs--;

  1421.             } else {

  1422.                 ret = decode_blocks(ctx, ra_frame, c, div_blocks, js_blocks);

  1423.                 if (ret < 0)

  1424.                     return ret;

  1425. 

  1426.                 c++;

  1427.             }

  1428. 

  1429.             // store carryover raw samples

  1430.             memmove(ctx->raw_samples[c] - sconf->max_order,

  1431.                     ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,

  1432.                     sizeof(*ctx->raw_samples[c]) * sconf->max_order);

  1433.         }

  1434.     } else { // multi-channel coding

  1435.         ALSBlockData   bd = { 0 };

  1436.         int            b, ret;

  1437.         int            *reverted_channels = ctx->reverted_channels;

  1438.         unsigned int   offset             = 0;

  1439. 

  1440.         for (c = 0; c < avctx->channels; c++)

  1441.             if (ctx->chan_data[c] < ctx->chan_data_buffer) {

  1442.                 av_log(ctx->avctx, AV_LOG_ERROR, "Invalid channel data.\n");

  1443.                 return AVERROR_INVALIDDATA;

  1444.             }

  1445. 

  1446.         memset(reverted_channels, 0, sizeof(*reverted_channels) * avctx->channels);

  1447. 

  1448.         bd.ra_block         = ra_frame;

  1449.         bd.prev_raw_samples = ctx->prev_raw_samples;

  1450. 

  1451.         get_block_sizes(ctx, div_blocks, &bs_info);

  1452. 

  1453.         for (b = 0; b < ctx->num_blocks; b++) {

  1454.             bd.block_length = div_blocks[b];

  1455.             if (bd.block_length <= 0) {

  1456.                 av_log(ctx->avctx, AV_LOG_WARNING,

  1457.                        "Invalid block length %u in channel data!\n",

  1458.                        bd.block_length);

  1459.                 continue;

  1460.             }

  1461. 

  1462.             for (c = 0; c < avctx->channels; c++) {

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

  1464.                 bd.shift_lsbs  = ctx->shift_lsbs + c;

  1465.                 bd.opt_order   = ctx->opt_order + c;

  1466.                 bd.store_prev_samples = ctx->store_prev_samples + c;

  1467.                 bd.use_ltp     = ctx->use_ltp + c;

  1468.                 bd.ltp_lag     = ctx->ltp_lag + c;

  1469.                 bd.ltp_gain    = ctx->ltp_gain[c];

  1470.                 bd.lpc_cof     = ctx->lpc_cof[c];

  1471.                 bd.quant_cof   = ctx->quant_cof[c];

  1472.                 bd.raw_samples = ctx->raw_samples[c] + offset;

  1473.                 bd.raw_other   = NULL;

  1474. 

  1475.                 if ((ret = read_block(ctx, &bd)) < 0)

  1476.                     return ret;

  1477.                 if ((ret = read_channel_data(ctx, ctx->chan_data[c], c)) < 0)

  1478.                     return ret;

  1479.             }

  1480. 

  1481.             for (c = 0; c < avctx->channels; c++) {

  1482.                 ret = revert_channel_correlation(ctx, &bd, ctx->chan_data,

  1483.                                                  reverted_channels, offset, c);

  1484.                 if (ret < 0)

  1485.                     return ret;

  1486.             }

  1487.             for (c = 0; c < avctx->channels; c++) {

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

  1489.                 bd.shift_lsbs  = ctx->shift_lsbs + c;

  1490.                 bd.opt_order   = ctx->opt_order + c;

  1491.                 bd.store_prev_samples = ctx->store_prev_samples + c;

  1492.                 bd.use_ltp     = ctx->use_ltp + c;

  1493.                 bd.ltp_lag     = ctx->ltp_lag + c;

  1494.                 bd.ltp_gain    = ctx->ltp_gain[c];

  1495.                 bd.lpc_cof     = ctx->lpc_cof[c];

  1496.                 bd.quant_cof   = ctx->quant_cof[c];

  1497.                 bd.raw_samples = ctx->raw_samples[c] + offset;

  1498. 

  1499.                 if ((ret = decode_block(ctx, &bd)) < 0)

  1500.                     return ret;

  1501.             }

  1502. 

  1503.             memset(reverted_channels, 0, avctx->channels * sizeof(*reverted_channels));

  1504.             offset      += div_blocks[b];

  1505.             bd.ra_block  = 0;

  1506.         }

  1507. 

  1508.         // store carryover raw samples

  1509.         for (c = 0; c < avctx->channels; c++)

  1510.             memmove(ctx->raw_samples[c] - sconf->max_order,

  1511.                     ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,

  1512.                     sizeof(*ctx->raw_samples[c]) * sconf->max_order);

  1513.     }

  1514. 

  1515.     // TODO: read_diff_float_data

  1516. 

  1517.     if (get_bits_left(gb) < 0) {

  1518.         av_log(ctx->avctx, AV_LOG_ERROR, "Overread %d\n", -get_bits_left(gb));

  1519.         return AVERROR_INVALIDDATA;

  1520.     }

  1521. 

  1522.     return 0;

  1523. }

  1524. 

  1525. 

  1526. /** Decode an ALS frame.

  1527.  */

  1528. static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr,

  1529.                         AVPacket *avpkt)

  1530. {

  1531.     ALSDecContext *ctx       = avctx->priv_data;

  1532.     AVFrame *frame           = data;

  1533.     ALSSpecificConfig *sconf = &ctx->sconf;

  1534.     const uint8_t *buffer    = avpkt->data;

  1535.     int buffer_size          = avpkt->size;

  1536.     int invalid_frame, ret;

  1537.     unsigned int c, sample, ra_frame, bytes_read, shift;

  1538. 

  1539.     if ((ret = init_get_bits8(&ctx->gb, buffer, buffer_size)) < 0)

  1540.         return ret;

  1541. 

  1542.     // In the case that the distance between random access frames is set to zero

  1543.     // (sconf->ra_distance == 0) no frame is treated as a random access frame.

  1544.     // For the first frame, if prediction is used, all samples used from the

  1545.     // previous frame are assumed to be zero.

  1546.     ra_frame = sconf->ra_distance && !(ctx->frame_id % sconf->ra_distance);

  1547. 

  1548.     // the last frame to decode might have a different length

  1549.     if (sconf->samples != 0xFFFFFFFF)

  1550.         ctx->cur_frame_length = FFMIN(sconf->samples - ctx->frame_id * (uint64_t) sconf->frame_length,

  1551.                                       sconf->frame_length);

  1552.     else

  1553.         ctx->cur_frame_length = sconf->frame_length;

  1554. 

  1555.     // decode the frame data

  1556.     if ((invalid_frame = read_frame_data(ctx, ra_frame)) < 0)

  1557.         av_log(ctx->avctx, AV_LOG_WARNING,

  1558.                "Reading frame data failed. Skipping RA unit.\n");

  1559. 

  1560.     ctx->frame_id++;

  1561. 

  1562.     /* get output buffer */

  1563.     frame->nb_samples = ctx->cur_frame_length;

  1564.     if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)

  1565.         return ret;

  1566. 

  1567.     // transform decoded frame into output format

  1568.     #define INTERLEAVE_OUTPUT(bps)                                                   \

  1569.     {                                                                                \

  1570.         int##bps##_t *dest = (int##bps##_t*)frame->data[0];                          \

  1571.         int channels = avctx->channels;                                              \

  1572.         int32_t **raw_samples = ctx->raw_samples;                                    \

  1573.         shift = bps - ctx->avctx->bits_per_raw_sample;                               \

  1574.         if (!ctx->cs_switch) {                                                       \

  1575.             for (sample = 0; sample < ctx->cur_frame_length; sample++)               \

  1576.                 for (c = 0; c < channels; c++)                                       \

  1577.                     *dest++ = raw_samples[c][sample] * (1U << shift);                \

  1578.         } else {                                                                     \

  1579.             for (sample = 0; sample < ctx->cur_frame_length; sample++)               \

  1580.                 for (c = 0; c < channels; c++)                                       \

  1581.                     *dest++ = raw_samples[sconf->chan_pos[c]][sample] * (1U << shift);\

  1582.         }                                                                            \

  1583.     }

  1584. 

  1585.     if (ctx->avctx->bits_per_raw_sample <= 16) {

  1586.         INTERLEAVE_OUTPUT(16)

  1587.     } else {

  1588.         INTERLEAVE_OUTPUT(32)

  1589.     }

  1590. 

  1591.     // update CRC

  1592.     if (sconf->crc_enabled && (avctx->err_recognition & (AV_EF_CRCCHECK|AV_EF_CAREFUL))) {

  1593.         int swap = HAVE_BIGENDIAN != sconf->msb_first;

  1594. 

  1595.         if (ctx->avctx->bits_per_raw_sample == 24) {

  1596.             int32_t *src = (int32_t *)frame->data[0];

  1597. 

  1598.             for (sample = 0;

  1599.                  sample < ctx->cur_frame_length * avctx->channels;

  1600.                  sample++) {

  1601.                 int32_t v;

  1602. 

  1603.                 if (swap)

  1604.                     v = av_bswap32(src[sample]);

  1605.                 else

  1606.                     v = src[sample];

  1607.                 if (!HAVE_BIGENDIAN)

  1608.                     v >>= 8;

  1609. 

  1610.                 ctx->crc = av_crc(ctx->crc_table, ctx->crc, (uint8_t*)(&v), 3);

  1611.             }

  1612.         } else {

  1613.             uint8_t *crc_source;

  1614. 

  1615.             if (swap) {

  1616.                 if (ctx->avctx->bits_per_raw_sample <= 16) {

  1617.                     int16_t *src  = (int16_t*) frame->data[0];

  1618.                     int16_t *dest = (int16_t*) ctx->crc_buffer;

  1619.                     for (sample = 0;

  1620.                          sample < ctx->cur_frame_length * avctx->channels;

  1621.                          sample++)

  1622.                         *dest++ = av_bswap16(src[sample]);

  1623.                 } else {

  1624.                     ctx->bdsp.bswap_buf((uint32_t *) ctx->crc_buffer,

  1625.                                         (uint32_t *) frame->data[0],

  1626.                                         ctx->cur_frame_length * avctx->channels);

  1627.                 }

  1628.                 crc_source = ctx->crc_buffer;

  1629.             } else {

  1630.                 crc_source = frame->data[0];

  1631.             }

  1632. 

  1633.             ctx->crc = av_crc(ctx->crc_table, ctx->crc, crc_source,

  1634.                               ctx->cur_frame_length * avctx->channels *

  1635.                               av_get_bytes_per_sample(avctx->sample_fmt));

  1636.         }

  1637. 

  1638. 

  1639.         // check CRC sums if this is the last frame

  1640.         if (ctx->cur_frame_length != sconf->frame_length &&

  1641.             ctx->crc_org != ctx->crc) {

  1642.             av_log(avctx, AV_LOG_ERROR, "CRC error.\n");

  1643.             if (avctx->err_recognition & AV_EF_EXPLODE)

  1644.                 return AVERROR_INVALIDDATA;

  1645.         }

  1646.     }

  1647. 

  1648.     *got_frame_ptr = 1;

  1649. 

  1650.     bytes_read = invalid_frame ? buffer_size :

  1651.                                  (get_bits_count(&ctx->gb) + 7) >> 3;

  1652. 

  1653.     return bytes_read;

  1654. }

  1655. 

  1656. 

  1657. /** Uninitialize the ALS decoder.

  1658.  */

  1659. static av_cold int decode_end(AVCodecContext *avctx)

  1660. {

  1661.     ALSDecContext *ctx = avctx->priv_data;

  1662. 

  1663.     av_freep(&ctx->sconf.chan_pos);

  1664. 

  1665.     ff_bgmc_end(&ctx->bgmc_lut, &ctx->bgmc_lut_status);

  1666. 

  1667.     av_freep(&ctx->const_block);

  1668.     av_freep(&ctx->shift_lsbs);

  1669.     av_freep(&ctx->opt_order);

  1670.     av_freep(&ctx->store_prev_samples);

  1671.     av_freep(&ctx->use_ltp);

  1672.     av_freep(&ctx->ltp_lag);

  1673.     av_freep(&ctx->ltp_gain);

  1674.     av_freep(&ctx->ltp_gain_buffer);

  1675.     av_freep(&ctx->quant_cof);

  1676.     av_freep(&ctx->lpc_cof);

  1677.     av_freep(&ctx->quant_cof_buffer);

  1678.     av_freep(&ctx->lpc_cof_buffer);

  1679.     av_freep(&ctx->lpc_cof_reversed_buffer);

  1680.     av_freep(&ctx->prev_raw_samples);

  1681.     av_freep(&ctx->raw_samples);

  1682.     av_freep(&ctx->raw_buffer);

  1683.     av_freep(&ctx->chan_data);

  1684.     av_freep(&ctx->chan_data_buffer);

  1685.     av_freep(&ctx->reverted_channels);

  1686.     av_freep(&ctx->crc_buffer);

  1687. 

  1688.     return 0;

  1689. }

  1690. 

  1691. 

  1692. /** Initialize the ALS decoder.

  1693.  */

  1694. static av_cold int decode_init(AVCodecContext *avctx)

  1695. {

  1696.     unsigned int c;

  1697.     unsigned int channel_size;

  1698.     int num_buffers, ret;

  1699.     ALSDecContext *ctx = avctx->priv_data;

  1700.     ALSSpecificConfig *sconf = &ctx->sconf;

  1701.     ctx->avctx = avctx;

  1702. 

  1703.     if (!avctx->extradata) {

  1704.         av_log(avctx, AV_LOG_ERROR, "Missing required ALS extradata.\n");

  1705.         return AVERROR_INVALIDDATA;

  1706.     }

  1707. 

  1708.     if ((ret = read_specific_config(ctx)) < 0) {

  1709.         av_log(avctx, AV_LOG_ERROR, "Reading ALSSpecificConfig failed.\n");

  1710.         goto fail;

  1711.     }

  1712. 

  1713.     if ((ret = check_specific_config(ctx)) < 0) {

  1714.         goto fail;

  1715.     }

  1716. 

  1717.     if (sconf->bgmc) {

  1718.         ret = ff_bgmc_init(avctx, &ctx->bgmc_lut, &ctx->bgmc_lut_status);

  1719.         if (ret < 0)

  1720.             goto fail;

  1721.     }

  1722.     if (sconf->floating) {

  1723.         avctx->sample_fmt          = AV_SAMPLE_FMT_FLT;

  1724.         avctx->bits_per_raw_sample = 32;

  1725.     } else {

  1726.         avctx->sample_fmt          = sconf->resolution > 1

  1727.                                      ? AV_SAMPLE_FMT_S32 : AV_SAMPLE_FMT_S16;

  1728.         avctx->bits_per_raw_sample = (sconf->resolution + 1) * 8;

  1729.         if (avctx->bits_per_raw_sample > 32) {

  1730.             av_log(avctx, AV_LOG_ERROR, "Bits per raw sample %d larger than 32.\n",

  1731.                    avctx->bits_per_raw_sample);

  1732.             ret = AVERROR_INVALIDDATA;

  1733.             goto fail;

  1734.         }

  1735.     }

  1736. 

  1737.     // set maximum Rice parameter for progressive decoding based on resolution

  1738.     // This is not specified in 14496-3 but actually done by the reference

  1739.     // codec RM22 revision 2.

  1740.     ctx->s_max = sconf->resolution > 1 ? 31 : 15;

  1741. 

  1742.     // set lag value for long-term prediction

  1743.     ctx->ltp_lag_length = 8 + (avctx->sample_rate >=  96000) +

  1744.                               (avctx->sample_rate >= 192000);

  1745. 

  1746.     // allocate quantized parcor coefficient buffer

  1747.     num_buffers = sconf->mc_coding ? avctx->channels : 1;

  1748.     if (num_buffers * (uint64_t)num_buffers > INT_MAX) // protect chan_data_buffer allocation

  1749.         return AVERROR_INVALIDDATA;

  1750. 

  1751.     ctx->quant_cof        = av_malloc_array(num_buffers, sizeof(*ctx->quant_cof));

  1752.     ctx->lpc_cof          = av_malloc_array(num_buffers, sizeof(*ctx->lpc_cof));

  1753.     ctx->quant_cof_buffer = av_malloc_array(num_buffers * sconf->max_order,

  1754.                                             sizeof(*ctx->quant_cof_buffer));

  1755.     ctx->lpc_cof_buffer   = av_malloc_array(num_buffers * sconf->max_order,

  1756.                                             sizeof(*ctx->lpc_cof_buffer));

  1757.     ctx->lpc_cof_reversed_buffer = av_malloc_array(sconf->max_order,

  1758.                                                    sizeof(*ctx->lpc_cof_buffer));

  1759. 

  1760.     if (!ctx->quant_cof              || !ctx->lpc_cof        ||

  1761.         !ctx->quant_cof_buffer       || !ctx->lpc_cof_buffer ||

  1762.         !ctx->lpc_cof_reversed_buffer) {

  1763.         av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");

  1764.         ret = AVERROR(ENOMEM);

  1765.         goto fail;

  1766.     }

  1767. 

  1768.     // assign quantized parcor coefficient buffers

  1769.     for (c = 0; c < num_buffers; c++) {

  1770.         ctx->quant_cof[c] = ctx->quant_cof_buffer + c * sconf->max_order;

  1771.         ctx->lpc_cof[c]   = ctx->lpc_cof_buffer   + c * sconf->max_order;

  1772.     }

  1773. 

  1774.     // allocate and assign lag and gain data buffer for ltp mode

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

  1776.     ctx->shift_lsbs      = av_malloc_array(num_buffers, sizeof(*ctx->shift_lsbs));

  1777.     ctx->opt_order       = av_malloc_array(num_buffers, sizeof(*ctx->opt_order));

  1778.     ctx->store_prev_samples = av_malloc_array(num_buffers, sizeof(*ctx->store_prev_samples));

  1779.     ctx->use_ltp         = av_mallocz_array(num_buffers, sizeof(*ctx->use_ltp));

  1780.     ctx->ltp_lag         = av_malloc_array(num_buffers, sizeof(*ctx->ltp_lag));

  1781.     ctx->ltp_gain        = av_malloc_array(num_buffers, sizeof(*ctx->ltp_gain));

  1782.     ctx->ltp_gain_buffer = av_malloc_array(num_buffers * 5, sizeof(*ctx->ltp_gain_buffer));

  1783. 

  1784.     if (!ctx->const_block || !ctx->shift_lsbs ||

  1785.         !ctx->opt_order || !ctx->store_prev_samples ||

  1786.         !ctx->use_ltp  || !ctx->ltp_lag ||

  1787.         !ctx->ltp_gain || !ctx->ltp_gain_buffer) {

  1788.         av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");

  1789.         ret = AVERROR(ENOMEM);

  1790.         goto fail;

  1791.     }

  1792. 

  1793.     for (c = 0; c < num_buffers; c++)

  1794.         ctx->ltp_gain[c] = ctx->ltp_gain_buffer + c * 5;

  1795. 

  1796.     // allocate and assign channel data buffer for mcc mode

  1797.     if (sconf->mc_coding) {

  1798.         ctx->chan_data_buffer  = av_mallocz_array(num_buffers * num_buffers,

  1799.                                                  sizeof(*ctx->chan_data_buffer));

  1800.         ctx->chan_data         = av_mallocz_array(num_buffers,

  1801.                                                  sizeof(*ctx->chan_data));

  1802.         ctx->reverted_channels = av_malloc_array(num_buffers,

  1803.                                                  sizeof(*ctx->reverted_channels));

  1804. 

  1805.         if (!ctx->chan_data_buffer || !ctx->chan_data || !ctx->reverted_channels) {

  1806.             av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");

  1807.             ret = AVERROR(ENOMEM);

  1808.             goto fail;

  1809.         }

  1810. 

  1811.         for (c = 0; c < num_buffers; c++)

  1812.             ctx->chan_data[c] = ctx->chan_data_buffer + c * num_buffers;

  1813.     } else {

  1814.         ctx->chan_data         = NULL;

  1815.         ctx->chan_data_buffer  = NULL;

  1816.         ctx->reverted_channels = NULL;

  1817.     }

  1818. 

  1819.     channel_size      = sconf->frame_length + sconf->max_order;

  1820. 

  1821.     ctx->prev_raw_samples = av_malloc_array(sconf->max_order, sizeof(*ctx->prev_raw_samples));

  1822.     ctx->raw_buffer       = av_mallocz_array(avctx->channels * channel_size, sizeof(*ctx->raw_buffer));

  1823.     ctx->raw_samples      = av_malloc_array(avctx->channels, sizeof(*ctx->raw_samples));

  1824. 

  1825.     // allocate previous raw sample buffer

  1826.     if (!ctx->prev_raw_samples || !ctx->raw_buffer|| !ctx->raw_samples) {

  1827.         av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");

  1828.         ret = AVERROR(ENOMEM);

  1829.         goto fail;

  1830.     }

  1831. 

  1832.     // assign raw samples buffers

  1833.     ctx->raw_samples[0] = ctx->raw_buffer + sconf->max_order;

  1834.     for (c = 1; c < avctx->channels; c++)

  1835.         ctx->raw_samples[c] = ctx->raw_samples[c - 1] + channel_size;

  1836. 

  1837.     // allocate crc buffer

  1838.     if (HAVE_BIGENDIAN != sconf->msb_first && sconf->crc_enabled &&

  1839.         (avctx->err_recognition & (AV_EF_CRCCHECK|AV_EF_CAREFUL))) {

  1840.         ctx->crc_buffer = av_malloc_array(ctx->cur_frame_length *

  1841.                                           avctx->channels *

  1842.                                           av_get_bytes_per_sample(avctx->sample_fmt),

  1843.                                           sizeof(*ctx->crc_buffer));

  1844.         if (!ctx->crc_buffer) {

  1845.             av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");

  1846.             ret = AVERROR(ENOMEM);

  1847.             goto fail;

  1848.         }

  1849.     }

  1850. 

  1851.     ff_bswapdsp_init(&ctx->bdsp);

  1852. 

  1853.     return 0;

  1854. 

  1855. fail:

  1856.     return ret;

  1857. }

  1858. 

  1859. 

  1860. /** Flush (reset) the frame ID after seeking.

  1861.  */

  1862. static av_cold void flush(AVCodecContext *avctx)

  1863. {

  1864.     ALSDecContext *ctx = avctx->priv_data;

  1865. 

  1866.     ctx->frame_id = 0;

  1867. }

  1868. 

  1869. 

  1870. AVCodec ff_als_decoder = {

  1871.     .name           = "als",

  1872.     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-4 Audio Lossless Coding (ALS)"),

  1873.     .type           = AVMEDIA_TYPE_AUDIO,

  1874.     .id             = AV_CODEC_ID_MP4ALS,

  1875.     .priv_data_size = sizeof(ALSDecContext),

  1876.     .init           = decode_init,

  1877.     .close          = decode_end,

  1878.     .decode         = decode_frame,

  1879.     .flush          = flush,

  1880.     .capabilities   = AV_CODEC_CAP_SUBFRAMES | AV_CODEC_CAP_DR1,

  1881.     .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,

  1882. };