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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_ googlemail.com>

  4.  *

  5.  * This file is part of Libav.

  6.  *

  7.  * Libav 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.  * Libav 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 Libav; 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_ googlemail.com>

  26.  */

  27. 

  28. 

  29. //#define DEBUG

  30. 

  31. 

  32. #include "avcodec.h"

  33. #include "get_bits.h"

  34. #include "unary.h"

  35. #include "mpeg4audio.h"

  36. #include "bytestream.h"

  37. #include "bgmc.h"

  38. #include "dsputil.h"

  39. #include "libavutil/samplefmt.h"

  40. #include "libavutil/crc.h"

  41. 

  42. #include <stdint.h>

  43. 

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

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

  46.  *  by the encoder and stored in ALSSpecificConfig.

  47.  */

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

  49.     { {-52, 4}, {-29, 5}, {-31, 4}, { 19, 4}, {-16, 4},

  50.       { 12, 3}, { -7, 3}, {  9, 3}, { -5, 3}, {  6, 3},

  51.       { -4, 3}, {  3, 3}, { -3, 2}, {  3, 2}, { -2, 2},

  52.       {  3, 2}, { -1, 2}, {  2, 2}, { -1, 2}, {  2, 2} },

  53.     { {-58, 3}, {-42, 4}, {-46, 4}, { 37, 5}, {-36, 4},

  54.       { 29, 4}, {-29, 4}, { 25, 4}, {-23, 4}, { 20, 4},

  55.       {-17, 4}, { 16, 4}, {-12, 4}, { 12, 3}, {-10, 4},

  56.       {  7, 3}, { -4, 4}, {  3, 3}, { -1, 3}, {  1, 3} },

  57.     { {-59, 3}, {-45, 5}, {-50, 4}, { 38, 4}, {-39, 4},

  58.       { 32, 4}, {-30, 4}, { 25, 3}, {-23, 3}, { 20, 3},

  59.       {-20, 3}, { 16, 3}, {-13, 3}, { 10, 3}, { -7, 3},

  60.       {  3, 3}, {  0, 3}, { -1, 3}, {  2, 3}, { -1, 2} }

  61. };

  62. 

  63. 

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

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

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

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

  68.  */

  69. static const int16_t parcor_scaled_values[] = {

  70.     -1048544 / 32, -1048288 / 32, -1047776 / 32, -1047008 / 32,

  71.     -1045984 / 32, -1044704 / 32, -1043168 / 32, -1041376 / 32,

  72.     -1039328 / 32, -1037024 / 32, -1034464 / 32, -1031648 / 32,

  73.     -1028576 / 32, -1025248 / 32, -1021664 / 32, -1017824 / 32,

  74.     -1013728 / 32, -1009376 / 32, -1004768 / 32,  -999904 / 32,

  75.      -994784 / 32,  -989408 / 32,  -983776 / 32,  -977888 / 32,

  76.      -971744 / 32,  -965344 / 32,  -958688 / 32,  -951776 / 32,

  77.      -944608 / 32,  -937184 / 32,  -929504 / 32,  -921568 / 32,

  78.      -913376 / 32,  -904928 / 32,  -896224 / 32,  -887264 / 32,

  79.      -878048 / 32,  -868576 / 32,  -858848 / 32,  -848864 / 32,

  80.      -838624 / 32,  -828128 / 32,  -817376 / 32,  -806368 / 32,

  81.      -795104 / 32,  -783584 / 32,  -771808 / 32,  -759776 / 32,

  82.      -747488 / 32,  -734944 / 32,  -722144 / 32,  -709088 / 32,

  83.      -695776 / 32,  -682208 / 32,  -668384 / 32,  -654304 / 32,

  84.      -639968 / 32,  -625376 / 32,  -610528 / 32,  -595424 / 32,

  85.      -580064 / 32,  -564448 / 32,  -548576 / 32,  -532448 / 32,

  86.      -516064 / 32,  -499424 / 32,  -482528 / 32,  -465376 / 32,

  87.      -447968 / 32,  -430304 / 32,  -412384 / 32,  -394208 / 32,

  88.      -375776 / 32,  -357088 / 32,  -338144 / 32,  -318944 / 32,

  89.      -299488 / 32,  -279776 / 32,  -259808 / 32,  -239584 / 32,

  90.      -219104 / 32,  -198368 / 32,  -177376 / 32,  -156128 / 32,

  91.      -134624 / 32,  -112864 / 32,   -90848 / 32,   -68576 / 32,

  92.       -46048 / 32,   -23264 / 32,     -224 / 32,    23072 / 32,

  93.        46624 / 32,    70432 / 32,    94496 / 32,   118816 / 32,

  94.       143392 / 32,   168224 / 32,   193312 / 32,   218656 / 32,

  95.       244256 / 32,   270112 / 32,   296224 / 32,   322592 / 32,

  96.       349216 / 32,   376096 / 32,   403232 / 32,   430624 / 32,

  97.       458272 / 32,   486176 / 32,   514336 / 32,   542752 / 32,

  98.       571424 / 32,   600352 / 32,   629536 / 32,   658976 / 32,

  99.       688672 / 32,   718624 / 32,   748832 / 32,   779296 / 32,

  100.       810016 / 32,   840992 / 32,   872224 / 32,   903712 / 32,

  101.       935456 / 32,   967456 / 32,   999712 / 32,  1032224 / 32

  102. };

  103. 

  104. 

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

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

  107.  */

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

  109.     { 0,  8, 16,  24},

  110.     {32, 40, 48,  56},

  111.     {64, 70, 76,  82},

  112.     {88, 92, 96, 100}

  113. };

  114. 

  115. 

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

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

  118.  */

  119. static const int16_t mcc_weightings[] = {

  120.     204,  192,  179,  166,  153,  140,  128,  115,

  121.     102,   89,   76,   64,   51,   38,   25,   12,

  122.       0,  -12,  -25,  -38,  -51,  -64,  -76,  -89,

  123.    -102, -115, -128, -140, -153, -166, -179, -192

  124. };

  125. 

  126. 

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

  128.  */

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

  130.     { 74, 44, 25, 13,  7, 3},

  131.     { 68, 42, 24, 13,  7, 3},

  132.     { 58, 39, 23, 13,  7, 3},

  133.     {126, 70, 37, 19, 10, 5},

  134.     {132, 70, 37, 20, 10, 5},

  135.     {124, 70, 38, 20, 10, 5},

  136.     {120, 69, 37, 20, 11, 5},

  137.     {116, 67, 37, 20, 11, 5},

  138.     {108, 66, 36, 20, 10, 5},

  139.     {102, 62, 36, 20, 10, 5},

  140.     { 88, 58, 34, 19, 10, 5},

  141.     {162, 89, 49, 25, 13, 7},

  142.     {156, 87, 49, 26, 14, 7},

  143.     {150, 86, 47, 26, 14, 7},

  144.     {142, 84, 47, 26, 14, 7},

  145.     {131, 79, 46, 26, 14, 7}

  146. };

  147. 

  148. 

  149. enum RA_Flag {

  150.     RA_FLAG_NONE,

  151.     RA_FLAG_FRAMES,

  152.     RA_FLAG_HEADER

  153. };

  154. 

  155. 

  156. typedef struct {

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  179. } ALSSpecificConfig;

  180. 

  181. 

  182. typedef struct {

  183.     int stop_flag;

  184.     int master_channel;

  185.     int time_diff_flag;

  186.     int time_diff_sign;

  187.     int time_diff_index;

  188.     int weighting[6];

  189. } ALSChannelData;

  190. 

  191. 

  192. typedef struct {

  193.     AVCodecContext *avctx;

  194.     AVFrame frame;

  195.     ALSSpecificConfig sconf;

  196.     GetBitContext gb;

  197.     DSPContext dsp;

  198.     const AVCRC *crc_table;

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  229. } ALSDecContext;

  230. 

  231. 

  232. typedef struct {

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  248. } ALSBlockData;

  249. 

  250. 

  251. static av_cold void dprint_specific_config(ALSDecContext *ctx)

  252. {

  253. #ifdef DEBUG

  254.     AVCodecContext *avctx    = ctx->avctx;

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

  256. 

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  275. #endif

  276. }

  277. 

  278. 

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

  280.  */

  281. static av_cold int read_specific_config(ALSDecContext *ctx)

  282. {

  283.     GetBitContext gb;

  284.     uint64_t ht_size;

  285.     int i, config_offset;

  286.     MPEG4AudioConfig m4ac;

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

  288.     AVCodecContext *avctx    = ctx->avctx;

  289.     uint32_t als_id, header_size, trailer_size;

  290. 

  291.     init_get_bits(&gb, avctx->extradata, avctx->extradata_size * 8);

  292. 

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

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

  295. 

  296.     if (config_offset < 0)

  297.         return -1;

  298. 

  299.     skip_bits_long(&gb, config_offset);

  300. 

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

  302.         return -1;

  303. 

  304.     // read the fixed items

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

  306.     avctx->sample_rate          = m4ac.sample_rate;

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

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

  309.     avctx->channels             = m4ac.channels;

  310.     skip_bits(&gb, 16);      // number of channels already knwon

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  333. 

  334. 

  335.     // check for ALSSpecificConfig struct

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

  337.         return -1;

  338. 

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

  340. 

  341.     // read channel config

  342.     if (sconf->chan_config)

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

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

  345. 

  346. 

  347.     // read channel sorting

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

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

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

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

  352.             return -1;

  353. 

  354.         if (!(sconf->chan_pos = av_malloc(avctx->channels * sizeof(*sconf->chan_pos))))

  355.             return AVERROR(ENOMEM);

  356. 

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

  358.             sconf->chan_pos[i] = get_bits(&gb, chan_pos_bits);

  359. 

  360.         align_get_bits(&gb);

  361.         // TODO: use this to actually do channel sorting

  362.     } else {

  363.         sconf->chan_sort = 0;

  364.     }

  365. 

  366. 

  367.     // read fixed header and trailer sizes,

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

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

  370.         return -1;

  371. 

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

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

  374.     if (header_size  == 0xFFFFFFFF)

  375.         header_size  = 0;

  376.     if (trailer_size == 0xFFFFFFFF)

  377.         trailer_size = 0;

  378. 

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

  380. 

  381. 

  382.     // skip the header and trailer data

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

  384.         return -1;

  385. 

  386.     if (ht_size > INT32_MAX)

  387.         return -1;

  388. 

  389.     skip_bits_long(&gb, ht_size);

  390. 

  391. 

  392.     // initialize CRC calculation

  393.     if (sconf->crc_enabled) {

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

  395.             return -1;

  396. 

  397.         if (avctx->err_recognition & AV_EF_CRCCHECK) {

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

  399.             ctx->crc       = 0xFFFFFFFF;

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

  401.         } else

  402.             skip_bits_long(&gb, 32);

  403.     }

  404. 

  405. 

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

  407. 

  408.     dprint_specific_config(ctx);

  409. 

  410.     return 0;

  411. }

  412. 

  413. 

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

  415.  */

  416. static int check_specific_config(ALSDecContext *ctx)

  417. {

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

  419.     int error = 0;

  420. 

  421.     // report unsupported feature and set error value

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

  423.     {                                                   \

  424.         if (cond) {                                     \

  425.             av_log_missing_feature(ctx->avctx, str, 0); \

  426.             error = errval;                             \

  427.         }                                               \

  428.     }

  429. 

  430.     MISSING_ERR(sconf->floating,             "Floating point decoding",     -1);

  431.     MISSING_ERR(sconf->rlslms,               "Adaptive RLS-LMS prediction", -1);

  432.     MISSING_ERR(sconf->chan_sort,            "Channel sorting",              0);

  433. 

  434.     return error;

  435. }

  436. 

  437. 

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

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

  440.  */

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

  442.                           unsigned int div, unsigned int **div_blocks,

  443.                           unsigned int *num_blocks)

  444. {

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

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

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

  448.         n   *= 2;

  449.         div += 1;

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

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

  452.     } else {

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

  454.         // (bit implicitly not set)

  455.         **div_blocks = div;

  456.         (*div_blocks)++;

  457.         (*num_blocks)++;

  458.     }

  459. }

  460. 

  461. 

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

  463.  */

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

  465. {

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

  467.     int q   = get_unary(gb, 0, max);

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

  469. 

  470.     if (k > 1) {

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

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

  473.     } else if (!k) {

  474.         q >>= 1;

  475.     }

  476.     return r ? q : ~q;

  477. }

  478. 

  479. 

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

  481.  */

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

  483. {

  484.     int i, j;

  485. 

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

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

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

  489.         cof[i]  += tmp1;

  490.     }

  491.     if (i == j)

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

  493. 

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

  495. }

  496. 

  497. 

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

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

  500.  *  actual number of samples.

  501.  */

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

  503.                             uint32_t *bs_info)

  504. {

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

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

  507.     unsigned int *ptr_div_blocks = div_blocks;

  508.     unsigned int b;

  509. 

  510.     if (sconf->block_switching) {

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

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

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

  514.     }

  515. 

  516.     ctx->num_blocks = 0;

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

  518. 

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

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

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

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

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

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

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

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

  527.     // codec RM22 revision 2.

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

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

  530.     // of 14496-3.

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

  532.     // frame.

  533. 

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

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

  536. 

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

  538.         unsigned int remaining = ctx->cur_frame_length;

  539. 

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

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

  542.                 div_blocks[b] = remaining;

  543.                 ctx->num_blocks = b + 1;

  544.                 break;

  545.             }

  546. 

  547.             remaining -= div_blocks[b];

  548.         }

  549.     }

  550. }

  551. 

  552. 

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

  554.  */

  555. static void read_const_block_data(ALSDecContext *ctx, ALSBlockData *bd)

  556. {

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

  558.     AVCodecContext *avctx    = ctx->avctx;

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

  560. 

  561.     *bd->raw_samples = 0;

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

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

  564. 

  565.     // skip 5 reserved bits

  566.     skip_bits(gb, 5);

  567. 

  568.     if (*bd->const_block) {

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

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

  571.     }

  572. 

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

  574.     *bd->const_block = 1;

  575. }

  576. 

  577. 

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

  579.  */

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

  581. {

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

  583.     int32_t  val = *bd->raw_samples;

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

  585. 

  586.     // write raw samples into buffer

  587.     for (; smp; smp--)

  588.         *dst++ = val;

  589. }

  590. 

  591. 

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

  593.  */

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

  595. {

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

  597.     AVCodecContext *avctx    = ctx->avctx;

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

  599.     unsigned int k;

  600.     unsigned int s[8];

  601.     unsigned int sx[8];

  602.     unsigned int sub_blocks, log2_sub_blocks, sb_length;

  603.     unsigned int start      = 0;

  604.     unsigned int opt_order;

  605.     int          sb;

  606.     int32_t      *quant_cof = bd->quant_cof;

  607.     int32_t      *current_res;

  608. 

  609. 

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

  611.     *bd->const_block = 0;

  612. 

  613.     *bd->opt_order  = 1;

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

  615. 

  616.     opt_order       = *bd->opt_order;

  617. 

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

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

  620.         log2_sub_blocks = 0;

  621.     } else {

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

  623.             log2_sub_blocks = get_bits(gb, 2);

  624.         else

  625.             log2_sub_blocks = 2 * get_bits1(gb);

  626.     }

  627. 

  628.     sub_blocks = 1 << log2_sub_blocks;

  629. 

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

  631.     // block_length must be evenly divisible by sub_blocks

  632.     if (bd->block_length & (sub_blocks - 1)) {

  633.         av_log(avctx, AV_LOG_WARNING,

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

  635.         return -1;

  636.     }

  637. 

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

  639. 

  640.     if (sconf->bgmc) {

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

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

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

  644. 

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

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

  647.             s [k] >>= 4;

  648.         }

  649.     } else {

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

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

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

  653.     }

  654. 

  655.     if (get_bits1(gb))

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

  657. 

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

  659. 

  660. 

  661.     if (!sconf->rlslms) {

  662.         if (sconf->adapt_order) {

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

  664.                                                 2, sconf->max_order + 1));

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

  666.         } else {

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

  668.         }

  669. 

  670.         opt_order = *bd->opt_order;

  671. 

  672.         if (opt_order) {

  673.             int add_base;

  674. 

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

  676.                 add_base = 0x7F;

  677. 

  678.                 // read coefficient 0

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

  680. 

  681.                 // read coefficient 1

  682.                 if (opt_order > 1)

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

  684. 

  685.                 // read coefficients 2 to opt_order

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

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

  688.             } else {

  689.                 int k_max;

  690.                 add_base = 1;

  691. 

  692.                 // read coefficient 0 to 19

  693.                 k_max = FFMIN(opt_order, 20);

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

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

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

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

  698.                 }

  699. 

  700.                 // read coefficients 20 to 126

  701.                 k_max = FFMIN(opt_order, 127);

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

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

  704. 

  705.                 // read coefficients 127 to opt_order

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

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

  708. 

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

  710. 

  711.                 if (opt_order > 1)

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

  713.             }

  714. 

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

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

  717.         }

  718.     }

  719. 

  720.     // read LTP gain and lag values

  721.     if (sconf->long_term_prediction) {

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

  723. 

  724.         if (*bd->use_ltp) {

  725.             int r, c;

  726. 

  727.             bd->ltp_gain[0]   = decode_rice(gb, 1) << 3;

  728.             bd->ltp_gain[1]   = decode_rice(gb, 2) << 3;

  729. 

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

  731.             c                 = get_bits(gb, 2);

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

  733. 

  734.             bd->ltp_gain[3]   = decode_rice(gb, 2) << 3;

  735.             bd->ltp_gain[4]   = decode_rice(gb, 1) << 3;

  736. 

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

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

  739.         }

  740.     }

  741. 

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

  743.     if (bd->ra_block) {

  744.         if (opt_order)

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

  746.         if (opt_order > 1)

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

  748.         if (opt_order > 2)

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

  750. 

  751.         start = FFMIN(opt_order, 3);

  752.     }

  753. 

  754.     // read all residuals

  755.     if (sconf->bgmc) {

  756.         int          delta[8];

  757.         unsigned int k    [8];

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

  759.         unsigned int i;

  760. 

  761.         // read most significant bits

  762.         unsigned int high;

  763.         unsigned int low;

  764.         unsigned int value;

  765. 

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

  767. 

  768.         current_res = bd->raw_samples + start;

  769. 

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

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

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

  773. 

  774.             ff_bgmc_decode(gb, sb_length, current_res,

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

  776. 

  777.             current_res += sb_length;

  778.         }

  779. 

  780.         ff_bgmc_decode_end(gb);

  781. 

  782. 

  783.         // read least significant bits and tails

  784.         i = start;

  785.         current_res = bd->raw_samples + start;

  786. 

  787.         for (sb = 0; sb < sub_blocks; sb++, i = 0) {

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

  789.             unsigned int cur_k         = k[sb];

  790.             unsigned int cur_s         = s[sb];

  791. 

  792.             for (; i < sb_length; i++) {

  793.                 int32_t res = *current_res;

  794. 

  795.                 if (res == cur_tail_code) {

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

  797.                                           << (5 - delta[sb]);

  798. 

  799.                     res = decode_rice(gb, cur_s);

  800. 

  801.                     if (res >= 0) {

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

  803.                     } else {

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

  805.                     }

  806.                 } else {

  807.                     if (res > cur_tail_code)

  808.                         res--;

  809. 

  810.                     if (res & 1)

  811.                         res = -res;

  812. 

  813.                     res >>= 1;

  814. 

  815.                     if (cur_k) {

  816.                         res <<= cur_k;

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

  818.                     }

  819.                 }

  820. 

  821.                 *current_res++ = res;

  822.             }

  823.         }

  824.     } else {

  825.         current_res = bd->raw_samples + start;

  826. 

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

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

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

  830.      }

  831. 

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

  833.         align_get_bits(gb);

  834. 

  835.     return 0;

  836. }

  837. 

  838. 

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

  840.  */

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

  842. {

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

  844.     unsigned int block_length = bd->block_length;

  845.     unsigned int smp = 0;

  846.     unsigned int k;

  847.     int opt_order             = *bd->opt_order;

  848.     int sb;

  849.     int64_t y;

  850.     int32_t *quant_cof        = bd->quant_cof;

  851.     int32_t *lpc_cof          = bd->lpc_cof;

  852.     int32_t *raw_samples      = bd->raw_samples;

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

  854.     int32_t *lpc_cof_reversed = ctx->lpc_cof_reversed_buffer;

  855. 

  856.     // reverse long-term prediction

  857.     if (*bd->use_ltp) {

  858.         int ltp_smp;

  859. 

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

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

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

  863.             int end    = center + 3;

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

  865.             int base;

  866. 

  867.             y = 1 << 6;

  868. 

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

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

  871. 

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

  873.         }

  874.     }

  875. 

  876.     // reconstruct all samples from residuals

  877.     if (bd->ra_block) {

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

  879.             y = 1 << 19;

  880. 

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

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

  883. 

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

  885.             parcor_to_lpc(smp, quant_cof, lpc_cof);

  886.         }

  887.     } else {

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

  889.             parcor_to_lpc(k, quant_cof, lpc_cof);

  890. 

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

  892.         if (*bd->store_prev_samples)

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

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

  895. 

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

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

  898.             int32_t *left, *right;

  899. 

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

  901.                 left  = raw_samples;

  902.                 right = bd->raw_other;

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

  904.                 left  = bd->raw_other;

  905.                 right = raw_samples;

  906.             }

  907. 

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

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

  910.         }

  911. 

  912.         // reconstruct shifted signal

  913.         if (*bd->shift_lsbs)

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

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

  916.     }

  917. 

  918.     // reverse linear prediction coefficients for efficiency

  919.     lpc_cof = lpc_cof + opt_order;

  920. 

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

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

  923. 

  924.     // reconstruct raw samples

  925.     raw_samples = bd->raw_samples + smp;

  926.     lpc_cof     = lpc_cof_reversed + opt_order;

  927. 

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

  929.         y = 1 << 19;

  930. 

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

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

  933. 

  934.         *raw_samples -= y >> 20;

  935.     }

  936. 

  937.     raw_samples = bd->raw_samples;

  938. 

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

  940.     if (*bd->store_prev_samples)

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

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

  943. 

  944.     return 0;

  945. }

  946. 

  947. 

  948. /** Read the block data.

  949.  */

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

  951. {

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

  953. 

  954.     *bd->shift_lsbs = 0;

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

  956.     if (get_bits1(gb)) {

  957.         if (read_var_block_data(ctx, bd))

  958.             return -1;

  959.     } else {

  960.         read_const_block_data(ctx, bd);

  961.     }

  962. 

  963.     return 0;

  964. }

  965. 

  966. 

  967. /** Decode the block data.

  968.  */

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

  970. {

  971.     unsigned int smp;

  972. 

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

  974.     if (*bd->const_block)

  975.         decode_const_block_data(ctx, bd);

  976.     else if (decode_var_block_data(ctx, bd))

  977.         return -1;

  978. 

  979.     // TODO: read RLSLMS extension data

  980. 

  981.     if (*bd->shift_lsbs)

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

  983.             bd->raw_samples[smp] <<= *bd->shift_lsbs;

  984. 

  985.     return 0;

  986. }

  987. 

  988. 

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

  990.  */

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

  992. {

  993.     int ret;

  994. 

  995.     ret = read_block(ctx, bd);

  996. 

  997.     if (ret)

  998.         return ret;

  999. 

  1000.     ret = decode_block(ctx, bd);

  1001. 

  1002.     return ret;

  1003. }

  1004. 

  1005. 

  1006. /** Compute the number of samples left to decode for the current frame and

  1007.  *  sets these samples to zero.

  1008.  */

  1009. static void zero_remaining(unsigned int b, unsigned int b_max,

  1010.                            const unsigned int *div_blocks, int32_t *buf)

  1011. {

  1012.     unsigned int count = 0;

  1013. 

  1014.     for (; b < b_max; b++)

  1015.         count += div_blocks[b];

  1016. 

  1017.     if (count)

  1018.         memset(buf, 0, sizeof(*buf) * count);

  1019. }

  1020. 

  1021. 

  1022. /** Decode blocks independently.

  1023.  */

  1024. static int decode_blocks_ind(ALSDecContext *ctx, unsigned int ra_frame,

  1025.                              unsigned int c, const unsigned int *div_blocks,

  1026.                              unsigned int *js_blocks)

  1027. {

  1028.     unsigned int b;

  1029.     ALSBlockData bd = { 0 };

  1030. 

  1031.     bd.ra_block         = ra_frame;

  1032.     bd.const_block      = ctx->const_block;

  1033.     bd.shift_lsbs       = ctx->shift_lsbs;

  1034.     bd.opt_order        = ctx->opt_order;

  1035.     bd.store_prev_samples = ctx->store_prev_samples;

  1036.     bd.use_ltp          = ctx->use_ltp;

  1037.     bd.ltp_lag          = ctx->ltp_lag;

  1038.     bd.ltp_gain         = ctx->ltp_gain[0];

  1039.     bd.quant_cof        = ctx->quant_cof[0];

  1040.     bd.lpc_cof          = ctx->lpc_cof[0];

  1041.     bd.prev_raw_samples = ctx->prev_raw_samples;

  1042.     bd.raw_samples      = ctx->raw_samples[c];

  1043. 

  1044. 

  1045.     for (b = 0; b < ctx->num_blocks; b++) {

  1046.         bd.block_length     = div_blocks[b];

  1047. 

  1048.         if (read_decode_block(ctx, &bd)) {

  1049.             // damaged block, write zero for the rest of the frame

  1050.             zero_remaining(b, ctx->num_blocks, div_blocks, bd.raw_samples);

  1051.             return -1;

  1052.         }

  1053.         bd.raw_samples += div_blocks[b];

  1054.         bd.ra_block     = 0;

  1055.     }

  1056. 

  1057.     return 0;

  1058. }

  1059. 

  1060. 

  1061. /** Decode blocks dependently.

  1062.  */

  1063. static int decode_blocks(ALSDecContext *ctx, unsigned int ra_frame,

  1064.                          unsigned int c, const unsigned int *div_blocks,

  1065.                          unsigned int *js_blocks)

  1066. {

  1067.     ALSSpecificConfig *sconf = &ctx->sconf;

  1068.     unsigned int offset = 0;

  1069.     unsigned int b;

  1070.     ALSBlockData bd[2] = { { 0 } };

  1071. 

  1072.     bd[0].ra_block         = ra_frame;

  1073.     bd[0].const_block      = ctx->const_block;

  1074.     bd[0].shift_lsbs       = ctx->shift_lsbs;

  1075.     bd[0].opt_order        = ctx->opt_order;

  1076.     bd[0].store_prev_samples = ctx->store_prev_samples;

  1077.     bd[0].use_ltp          = ctx->use_ltp;

  1078.     bd[0].ltp_lag          = ctx->ltp_lag;

  1079.     bd[0].ltp_gain         = ctx->ltp_gain[0];

  1080.     bd[0].quant_cof        = ctx->quant_cof[0];

  1081.     bd[0].lpc_cof          = ctx->lpc_cof[0];

  1082.     bd[0].prev_raw_samples = ctx->prev_raw_samples;

  1083.     bd[0].js_blocks        = *js_blocks;

  1084. 

  1085.     bd[1].ra_block         = ra_frame;

  1086.     bd[1].const_block      = ctx->const_block;

  1087.     bd[1].shift_lsbs       = ctx->shift_lsbs;

  1088.     bd[1].opt_order        = ctx->opt_order;

  1089.     bd[1].store_prev_samples = ctx->store_prev_samples;

  1090.     bd[1].use_ltp          = ctx->use_ltp;

  1091.     bd[1].ltp_lag          = ctx->ltp_lag;

  1092.     bd[1].ltp_gain         = ctx->ltp_gain[0];

  1093.     bd[1].quant_cof        = ctx->quant_cof[0];

  1094.     bd[1].lpc_cof          = ctx->lpc_cof[0];

  1095.     bd[1].prev_raw_samples = ctx->prev_raw_samples;

  1096.     bd[1].js_blocks        = *(js_blocks + 1);

  1097. 

  1098.     // decode all blocks

  1099.     for (b = 0; b < ctx->num_blocks; b++) {

  1100.         unsigned int s;

  1101. 

  1102.         bd[0].block_length = div_blocks[b];

  1103.         bd[1].block_length = div_blocks[b];

  1104. 

  1105.         bd[0].raw_samples  = ctx->raw_samples[c    ] + offset;

  1106.         bd[1].raw_samples  = ctx->raw_samples[c + 1] + offset;

  1107. 

  1108.         bd[0].raw_other    = bd[1].raw_samples;

  1109.         bd[1].raw_other    = bd[0].raw_samples;

  1110. 

  1111.         if(read_decode_block(ctx, &bd[0]) || read_decode_block(ctx, &bd[1])) {

  1112.             // damaged block, write zero for the rest of the frame

  1113.             zero_remaining(b, ctx->num_blocks, div_blocks, bd[0].raw_samples);

  1114.             zero_remaining(b, ctx->num_blocks, div_blocks, bd[1].raw_samples);

  1115.             return -1;

  1116.         }

  1117. 

  1118.         // reconstruct joint-stereo blocks

  1119.         if (bd[0].js_blocks) {

  1120.             if (bd[1].js_blocks)

  1121.                 av_log(ctx->avctx, AV_LOG_WARNING, "Invalid channel pair!\n");

  1122. 

  1123.             for (s = 0; s < div_blocks[b]; s++)

  1124.                 bd[0].raw_samples[s] = bd[1].raw_samples[s] - bd[0].raw_samples[s];

  1125.         } else if (bd[1].js_blocks) {

  1126.             for (s = 0; s < div_blocks[b]; s++)

  1127.                 bd[1].raw_samples[s] = bd[1].raw_samples[s] + bd[0].raw_samples[s];

  1128.         }

  1129. 

  1130.         offset  += div_blocks[b];

  1131.         bd[0].ra_block = 0;

  1132.         bd[1].ra_block = 0;

  1133.     }

  1134. 

  1135.     // store carryover raw samples,

  1136.     // the others channel raw samples are stored by the calling function.

  1137.     memmove(ctx->raw_samples[c] - sconf->max_order,

  1138.             ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,

  1139.             sizeof(*ctx->raw_samples[c]) * sconf->max_order);

  1140. 

  1141.     return 0;

  1142. }

  1143. 

  1144. 

  1145. /** Read the channel data.

  1146.   */

  1147. static int read_channel_data(ALSDecContext *ctx, ALSChannelData *cd, int c)

  1148. {

  1149.     GetBitContext *gb       = &ctx->gb;

  1150.     ALSChannelData *current = cd;

  1151.     unsigned int channels   = ctx->avctx->channels;

  1152.     int entries             = 0;

  1153. 

  1154.     while (entries < channels && !(current->stop_flag = get_bits1(gb))) {

  1155.         current->master_channel = get_bits_long(gb, av_ceil_log2(channels));

  1156. 

  1157.         if (current->master_channel >= channels) {

  1158.             av_log(ctx->avctx, AV_LOG_ERROR, "Invalid master channel!\n");

  1159.             return -1;

  1160.         }

  1161. 

  1162.         if (current->master_channel != c) {

  1163.             current->time_diff_flag = get_bits1(gb);

  1164.             current->weighting[0]   = mcc_weightings[av_clip(decode_rice(gb, 1) + 16, 0, 32)];

  1165.             current->weighting[1]   = mcc_weightings[av_clip(decode_rice(gb, 2) + 14, 0, 32)];

  1166.             current->weighting[2]   = mcc_weightings[av_clip(decode_rice(gb, 1) + 16, 0, 32)];

  1167. 

  1168.             if (current->time_diff_flag) {

  1169.                 current->weighting[3] = mcc_weightings[av_clip(decode_rice(gb, 1) + 16, 0, 32)];

  1170.                 current->weighting[4] = mcc_weightings[av_clip(decode_rice(gb, 1) + 16, 0, 32)];

  1171.                 current->weighting[5] = mcc_weightings[av_clip(decode_rice(gb, 1) + 16, 0, 32)];

  1172. 

  1173.                 current->time_diff_sign  = get_bits1(gb);

  1174.                 current->time_diff_index = get_bits(gb, ctx->ltp_lag_length - 3) + 3;

  1175.             }

  1176.         }

  1177. 

  1178.         current++;

  1179.         entries++;

  1180.     }

  1181. 

  1182.     if (entries == channels) {

  1183.         av_log(ctx->avctx, AV_LOG_ERROR, "Damaged channel data!\n");

  1184.         return -1;

  1185.     }

  1186. 

  1187.     align_get_bits(gb);

  1188.     return 0;

  1189. }

  1190. 

  1191. 

  1192. /** Recursively reverts the inter-channel correlation for a block.

  1193.  */

  1194. static int revert_channel_correlation(ALSDecContext *ctx, ALSBlockData *bd,

  1195.                                        ALSChannelData **cd, int *reverted,

  1196.                                        unsigned int offset, int c)

  1197. {

  1198.     ALSChannelData *ch = cd[c];

  1199.     unsigned int   dep = 0;

  1200.     unsigned int channels = ctx->avctx->channels;

  1201. 

  1202.     if (reverted[c])

  1203.         return 0;

  1204. 

  1205.     reverted[c] = 1;

  1206. 

  1207.     while (dep < channels && !ch[dep].stop_flag) {

  1208.         revert_channel_correlation(ctx, bd, cd, reverted, offset,

  1209.                                    ch[dep].master_channel);

  1210. 

  1211.         dep++;

  1212.     }

  1213. 

  1214.     if (dep == channels) {

  1215.         av_log(ctx->avctx, AV_LOG_WARNING, "Invalid channel correlation!\n");

  1216.         return -1;

  1217.     }

  1218. 

  1219.     bd->const_block = ctx->const_block + c;

  1220.     bd->shift_lsbs  = ctx->shift_lsbs + c;

  1221.     bd->opt_order   = ctx->opt_order + c;

  1222.     bd->store_prev_samples = ctx->store_prev_samples + c;

  1223.     bd->use_ltp     = ctx->use_ltp + c;

  1224.     bd->ltp_lag     = ctx->ltp_lag + c;

  1225.     bd->ltp_gain    = ctx->ltp_gain[c];

  1226.     bd->lpc_cof     = ctx->lpc_cof[c];

  1227.     bd->quant_cof   = ctx->quant_cof[c];

  1228.     bd->raw_samples = ctx->raw_samples[c] + offset;

  1229. 

  1230.     dep = 0;

  1231.     while (!ch[dep].stop_flag) {

  1232.         unsigned int smp;

  1233.         unsigned int begin = 1;

  1234.         unsigned int end   = bd->block_length - 1;

  1235.         int64_t y;

  1236.         int32_t *master = ctx->raw_samples[ch[dep].master_channel] + offset;

  1237. 

  1238.         if (ch[dep].time_diff_flag) {

  1239.             int t = ch[dep].time_diff_index;

  1240. 

  1241.             if (ch[dep].time_diff_sign) {

  1242.                 t      = -t;

  1243.                 begin -= t;

  1244.             } else {

  1245.                 end   -= t;

  1246.             }

  1247. 

  1248.             for (smp = begin; smp < end; smp++) {

  1249.                 y  = (1 << 6) +

  1250.                      MUL64(ch[dep].weighting[0], master[smp - 1    ]) +

  1251.                      MUL64(ch[dep].weighting[1], master[smp        ]) +

  1252.                      MUL64(ch[dep].weighting[2], master[smp + 1    ]) +

  1253.                      MUL64(ch[dep].weighting[3], master[smp - 1 + t]) +

  1254.                      MUL64(ch[dep].weighting[4], master[smp     + t]) +

  1255.                      MUL64(ch[dep].weighting[5], master[smp + 1 + t]);

  1256. 

  1257.                 bd->raw_samples[smp] += y >> 7;

  1258.             }

  1259.         } else {

  1260.             for (smp = begin; smp < end; smp++) {

  1261.                 y  = (1 << 6) +

  1262.                      MUL64(ch[dep].weighting[0], master[smp - 1]) +

  1263.                      MUL64(ch[dep].weighting[1], master[smp    ]) +

  1264.                      MUL64(ch[dep].weighting[2], master[smp + 1]);

  1265. 

  1266.                 bd->raw_samples[smp] += y >> 7;

  1267.             }

  1268.         }

  1269. 

  1270.         dep++;

  1271.     }

  1272. 

  1273.     return 0;

  1274. }

  1275. 

  1276. 

  1277. /** Read the frame data.

  1278.  */

  1279. static int read_frame_data(ALSDecContext *ctx, unsigned int ra_frame)

  1280. {

  1281.     ALSSpecificConfig *sconf = &ctx->sconf;

  1282.     AVCodecContext *avctx    = ctx->avctx;

  1283.     GetBitContext *gb = &ctx->gb;

  1284.     unsigned int div_blocks[32];                ///< block sizes.

  1285.     unsigned int c;

  1286.     unsigned int js_blocks[2];

  1287. 

  1288.     uint32_t bs_info = 0;

  1289. 

  1290.     // skip the size of the ra unit if present in the frame

  1291.     if (sconf->ra_flag == RA_FLAG_FRAMES && ra_frame)

  1292.         skip_bits_long(gb, 32);

  1293. 

  1294.     if (sconf->mc_coding && sconf->joint_stereo) {

  1295.         ctx->js_switch = get_bits1(gb);

  1296.         align_get_bits(gb);

  1297.     }

  1298. 

  1299.     if (!sconf->mc_coding || ctx->js_switch) {

  1300.         int independent_bs = !sconf->joint_stereo;

  1301. 

  1302.         for (c = 0; c < avctx->channels; c++) {

  1303.             js_blocks[0] = 0;

  1304.             js_blocks[1] = 0;

  1305. 

  1306.             get_block_sizes(ctx, div_blocks, &bs_info);

  1307. 

  1308.             // if joint_stereo and block_switching is set, independent decoding

  1309.             // is signaled via the first bit of bs_info

  1310.             if (sconf->joint_stereo && sconf->block_switching)

  1311.                 if (bs_info >> 31)

  1312.                     independent_bs = 2;

  1313. 

  1314.             // if this is the last channel, it has to be decoded independently

  1315.             if (c == avctx->channels - 1)

  1316.                 independent_bs = 1;

  1317. 

  1318.             if (independent_bs) {

  1319.                 if (decode_blocks_ind(ctx, ra_frame, c, div_blocks, js_blocks))

  1320.                     return -1;

  1321. 

  1322.                 independent_bs--;

  1323.             } else {

  1324.                 if (decode_blocks(ctx, ra_frame, c, div_blocks, js_blocks))

  1325.                     return -1;

  1326. 

  1327.                 c++;

  1328.             }

  1329. 

  1330.             // store carryover raw samples

  1331.             memmove(ctx->raw_samples[c] - sconf->max_order,

  1332.                     ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,

  1333.                     sizeof(*ctx->raw_samples[c]) * sconf->max_order);

  1334.         }

  1335.     } else { // multi-channel coding

  1336.         ALSBlockData   bd = { 0 };

  1337.         int            b;

  1338.         int            *reverted_channels = ctx->reverted_channels;

  1339.         unsigned int   offset             = 0;

  1340. 

  1341.         for (c = 0; c < avctx->channels; c++)

  1342.             if (ctx->chan_data[c] < ctx->chan_data_buffer) {

  1343.                 av_log(ctx->avctx, AV_LOG_ERROR, "Invalid channel data!\n");

  1344.                 return -1;

  1345.             }

  1346. 

  1347.         memset(reverted_channels, 0, sizeof(*reverted_channels) * avctx->channels);

  1348. 

  1349.         bd.ra_block         = ra_frame;

  1350.         bd.prev_raw_samples = ctx->prev_raw_samples;

  1351. 

  1352.         get_block_sizes(ctx, div_blocks, &bs_info);

  1353. 

  1354.         for (b = 0; b < ctx->num_blocks; b++) {

  1355.             bd.block_length = div_blocks[b];

  1356. 

  1357.             for (c = 0; c < avctx->channels; c++) {

  1358.                 bd.const_block = ctx->const_block + c;

  1359.                 bd.shift_lsbs  = ctx->shift_lsbs + c;

  1360.                 bd.opt_order   = ctx->opt_order + c;

  1361.                 bd.store_prev_samples = ctx->store_prev_samples + c;

  1362.                 bd.use_ltp     = ctx->use_ltp + c;

  1363.                 bd.ltp_lag     = ctx->ltp_lag + c;

  1364.                 bd.ltp_gain    = ctx->ltp_gain[c];

  1365.                 bd.lpc_cof     = ctx->lpc_cof[c];

  1366.                 bd.quant_cof   = ctx->quant_cof[c];

  1367.                 bd.raw_samples = ctx->raw_samples[c] + offset;

  1368.                 bd.raw_other   = NULL;

  1369. 

  1370.                 read_block(ctx, &bd);

  1371.                 if (read_channel_data(ctx, ctx->chan_data[c], c))

  1372.                     return -1;

  1373.             }

  1374. 

  1375.             for (c = 0; c < avctx->channels; c++)

  1376.                 if (revert_channel_correlation(ctx, &bd, ctx->chan_data,

  1377.                                                reverted_channels, offset, c))

  1378.                     return -1;

  1379. 

  1380.             for (c = 0; c < avctx->channels; c++) {

  1381.                 bd.const_block = ctx->const_block + c;

  1382.                 bd.shift_lsbs  = ctx->shift_lsbs + c;

  1383.                 bd.opt_order   = ctx->opt_order + c;

  1384.                 bd.store_prev_samples = ctx->store_prev_samples + c;

  1385.                 bd.use_ltp     = ctx->use_ltp + c;

  1386.                 bd.ltp_lag     = ctx->ltp_lag + c;

  1387.                 bd.ltp_gain    = ctx->ltp_gain[c];

  1388.                 bd.lpc_cof     = ctx->lpc_cof[c];

  1389.                 bd.quant_cof   = ctx->quant_cof[c];

  1390.                 bd.raw_samples = ctx->raw_samples[c] + offset;

  1391.                 decode_block(ctx, &bd);

  1392.             }

  1393. 

  1394.             memset(reverted_channels, 0, avctx->channels * sizeof(*reverted_channels));

  1395.             offset      += div_blocks[b];

  1396.             bd.ra_block  = 0;

  1397.         }

  1398. 

  1399.         // store carryover raw samples

  1400.         for (c = 0; c < avctx->channels; c++)

  1401.             memmove(ctx->raw_samples[c] - sconf->max_order,

  1402.                     ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,

  1403.                     sizeof(*ctx->raw_samples[c]) * sconf->max_order);

  1404.     }

  1405. 

  1406.     // TODO: read_diff_float_data

  1407. 

  1408.     return 0;

  1409. }

  1410. 

  1411. 

  1412. /** Decode an ALS frame.

  1413.  */

  1414. static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr,

  1415.                         AVPacket *avpkt)

  1416. {

  1417.     ALSDecContext *ctx       = avctx->priv_data;

  1418.     ALSSpecificConfig *sconf = &ctx->sconf;

  1419.     const uint8_t *buffer    = avpkt->data;

  1420.     int buffer_size          = avpkt->size;

  1421.     int invalid_frame, ret;

  1422.     unsigned int c, sample, ra_frame, bytes_read, shift;

  1423. 

  1424.     init_get_bits(&ctx->gb, buffer, buffer_size * 8);

  1425. 

  1426.     // In the case that the distance between random access frames is set to zero

  1427.     // (sconf->ra_distance == 0) no frame is treated as a random access frame.

  1428.     // For the first frame, if prediction is used, all samples used from the

  1429.     // previous frame are assumed to be zero.

  1430.     ra_frame = sconf->ra_distance && !(ctx->frame_id % sconf->ra_distance);

  1431. 

  1432.     // the last frame to decode might have a different length

  1433.     if (sconf->samples != 0xFFFFFFFF)

  1434.         ctx->cur_frame_length = FFMIN(sconf->samples - ctx->frame_id * (uint64_t) sconf->frame_length,

  1435.                                       sconf->frame_length);

  1436.     else

  1437.         ctx->cur_frame_length = sconf->frame_length;

  1438. 

  1439.     // decode the frame data

  1440.     if ((invalid_frame = read_frame_data(ctx, ra_frame) < 0))

  1441.         av_log(ctx->avctx, AV_LOG_WARNING,

  1442.                "Reading frame data failed. Skipping RA unit.\n");

  1443. 

  1444.     ctx->frame_id++;

  1445. 

  1446.     /* get output buffer */

  1447.     ctx->frame.nb_samples = ctx->cur_frame_length;

  1448.     if ((ret = avctx->get_buffer(avctx, &ctx->frame)) < 0) {

  1449.         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");

  1450.         return ret;

  1451.     }

  1452. 

  1453.     // transform decoded frame into output format

  1454.     #define INTERLEAVE_OUTPUT(bps)                                 \

  1455.     {                                                              \

  1456.         int##bps##_t *dest = (int##bps##_t*)ctx->frame.data[0];    \

  1457.         shift = bps - ctx->avctx->bits_per_raw_sample;             \

  1458.         for (sample = 0; sample < ctx->cur_frame_length; sample++) \

  1459.             for (c = 0; c < avctx->channels; c++)                  \

  1460.                 *dest++ = ctx->raw_samples[c][sample] << shift;    \

  1461.     }

  1462. 

  1463.     if (ctx->avctx->bits_per_raw_sample <= 16) {

  1464.         INTERLEAVE_OUTPUT(16)

  1465.     } else {

  1466.         INTERLEAVE_OUTPUT(32)

  1467.     }

  1468. 

  1469.     // update CRC

  1470.     if (sconf->crc_enabled && (avctx->err_recognition & AV_EF_CRCCHECK)) {

  1471.         int swap = HAVE_BIGENDIAN != sconf->msb_first;

  1472. 

  1473.         if (ctx->avctx->bits_per_raw_sample == 24) {

  1474.             int32_t *src = (int32_t *)ctx->frame.data[0];

  1475. 

  1476.             for (sample = 0;

  1477.                  sample < ctx->cur_frame_length * avctx->channels;

  1478.                  sample++) {

  1479.                 int32_t v;

  1480. 

  1481.                 if (swap)

  1482.                     v = av_bswap32(src[sample]);

  1483.                 else

  1484.                     v = src[sample];

  1485.                 if (!HAVE_BIGENDIAN)

  1486.                     v >>= 8;

  1487. 

  1488.                 ctx->crc = av_crc(ctx->crc_table, ctx->crc, (uint8_t*)(&v), 3);

  1489.             }

  1490.         } else {

  1491.             uint8_t *crc_source;

  1492. 

  1493.             if (swap) {

  1494.                 if (ctx->avctx->bits_per_raw_sample <= 16) {

  1495.                     int16_t *src  = (int16_t*) ctx->frame.data[0];

  1496.                     int16_t *dest = (int16_t*) ctx->crc_buffer;

  1497.                     for (sample = 0;

  1498.                          sample < ctx->cur_frame_length * avctx->channels;

  1499.                          sample++)

  1500.                         *dest++ = av_bswap16(src[sample]);

  1501.                 } else {

  1502.                     ctx->dsp.bswap_buf((uint32_t*)ctx->crc_buffer,

  1503.                                        (uint32_t *)ctx->frame.data[0],

  1504.                                        ctx->cur_frame_length * avctx->channels);

  1505.                 }

  1506.                 crc_source = ctx->crc_buffer;

  1507.             } else {

  1508.                 crc_source = ctx->frame.data[0];

  1509.             }

  1510. 

  1511.             ctx->crc = av_crc(ctx->crc_table, ctx->crc, crc_source,

  1512.                               ctx->cur_frame_length * avctx->channels *

  1513.                               av_get_bytes_per_sample(avctx->sample_fmt));

  1514.         }

  1515. 

  1516. 

  1517.         // check CRC sums if this is the last frame

  1518.         if (ctx->cur_frame_length != sconf->frame_length &&

  1519.             ctx->crc_org != ctx->crc) {

  1520.             av_log(avctx, AV_LOG_ERROR, "CRC error.\n");

  1521.         }

  1522.     }

  1523. 

  1524.     *got_frame_ptr   = 1;

  1525.     *(AVFrame *)data = ctx->frame;

  1526. 

  1527. 

  1528.     bytes_read = invalid_frame ? buffer_size :

  1529.                                  (get_bits_count(&ctx->gb) + 7) >> 3;

  1530. 

  1531.     return bytes_read;

  1532. }

  1533. 

  1534. 

  1535. /** Uninitialize the ALS decoder.

  1536.  */

  1537. static av_cold int decode_end(AVCodecContext *avctx)

  1538. {

  1539.     ALSDecContext *ctx = avctx->priv_data;

  1540. 

  1541.     av_freep(&ctx->sconf.chan_pos);

  1542. 

  1543.     ff_bgmc_end(&ctx->bgmc_lut, &ctx->bgmc_lut_status);

  1544. 

  1545.     av_freep(&ctx->const_block);

  1546.     av_freep(&ctx->shift_lsbs);

  1547.     av_freep(&ctx->opt_order);

  1548.     av_freep(&ctx->store_prev_samples);

  1549.     av_freep(&ctx->use_ltp);

  1550.     av_freep(&ctx->ltp_lag);

  1551.     av_freep(&ctx->ltp_gain);

  1552.     av_freep(&ctx->ltp_gain_buffer);

  1553.     av_freep(&ctx->quant_cof);

  1554.     av_freep(&ctx->lpc_cof);

  1555.     av_freep(&ctx->quant_cof_buffer);

  1556.     av_freep(&ctx->lpc_cof_buffer);

  1557.     av_freep(&ctx->lpc_cof_reversed_buffer);

  1558.     av_freep(&ctx->prev_raw_samples);

  1559.     av_freep(&ctx->raw_samples);

  1560.     av_freep(&ctx->raw_buffer);

  1561.     av_freep(&ctx->chan_data);

  1562.     av_freep(&ctx->chan_data_buffer);

  1563.     av_freep(&ctx->reverted_channels);

  1564.     av_freep(&ctx->crc_buffer);

  1565. 

  1566.     return 0;

  1567. }

  1568. 

  1569. 

  1570. /** Initialize the ALS decoder.

  1571.  */

  1572. static av_cold int decode_init(AVCodecContext *avctx)

  1573. {

  1574.     unsigned int c;

  1575.     unsigned int channel_size;

  1576.     int num_buffers;

  1577.     ALSDecContext *ctx = avctx->priv_data;

  1578.     ALSSpecificConfig *sconf = &ctx->sconf;

  1579.     ctx->avctx = avctx;

  1580. 

  1581.     if (!avctx->extradata) {

  1582.         av_log(avctx, AV_LOG_ERROR, "Missing required ALS extradata.\n");

  1583.         return -1;

  1584.     }

  1585. 

  1586.     if (read_specific_config(ctx)) {

  1587.         av_log(avctx, AV_LOG_ERROR, "Reading ALSSpecificConfig failed.\n");

  1588.         decode_end(avctx);

  1589.         return -1;

  1590.     }

  1591. 

  1592.     if (check_specific_config(ctx)) {

  1593.         decode_end(avctx);

  1594.         return -1;

  1595.     }

  1596. 

  1597.     if (sconf->bgmc)

  1598.         ff_bgmc_init(avctx, &ctx->bgmc_lut, &ctx->bgmc_lut_status);

  1599. 

  1600.     if (sconf->floating) {

  1601.         avctx->sample_fmt          = AV_SAMPLE_FMT_FLT;

  1602.         avctx->bits_per_raw_sample = 32;

  1603.     } else {

  1604.         avctx->sample_fmt          = sconf->resolution > 1

  1605.                                      ? AV_SAMPLE_FMT_S32 : AV_SAMPLE_FMT_S16;

  1606.         avctx->bits_per_raw_sample = (sconf->resolution + 1) * 8;

  1607.     }

  1608. 

  1609.     // set maximum Rice parameter for progressive decoding based on resolution

  1610.     // This is not specified in 14496-3 but actually done by the reference

  1611.     // codec RM22 revision 2.

  1612.     ctx->s_max = sconf->resolution > 1 ? 31 : 15;

  1613. 

  1614.     // set lag value for long-term prediction

  1615.     ctx->ltp_lag_length = 8 + (avctx->sample_rate >=  96000) +

  1616.                               (avctx->sample_rate >= 192000);

  1617. 

  1618.     // allocate quantized parcor coefficient buffer

  1619.     num_buffers = sconf->mc_coding ? avctx->channels : 1;

  1620. 

  1621.     ctx->quant_cof        = av_malloc(sizeof(*ctx->quant_cof) * num_buffers);

  1622.     ctx->lpc_cof          = av_malloc(sizeof(*ctx->lpc_cof)   * num_buffers);

  1623.     ctx->quant_cof_buffer = av_malloc(sizeof(*ctx->quant_cof_buffer) *

  1624.                                       num_buffers * sconf->max_order);

  1625.     ctx->lpc_cof_buffer   = av_malloc(sizeof(*ctx->lpc_cof_buffer) *

  1626.                                       num_buffers * sconf->max_order);

  1627.     ctx->lpc_cof_reversed_buffer = av_malloc(sizeof(*ctx->lpc_cof_buffer) *

  1628.                                              sconf->max_order);

  1629. 

  1630.     if (!ctx->quant_cof              || !ctx->lpc_cof        ||

  1631.         !ctx->quant_cof_buffer       || !ctx->lpc_cof_buffer ||

  1632.         !ctx->lpc_cof_reversed_buffer) {

  1633.         av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");

  1634.         return AVERROR(ENOMEM);

  1635.     }

  1636. 

  1637.     // assign quantized parcor coefficient buffers

  1638.     for (c = 0; c < num_buffers; c++) {

  1639.         ctx->quant_cof[c] = ctx->quant_cof_buffer + c * sconf->max_order;

  1640.         ctx->lpc_cof[c]   = ctx->lpc_cof_buffer   + c * sconf->max_order;

  1641.     }

  1642. 

  1643.     // allocate and assign lag and gain data buffer for ltp mode

  1644.     ctx->const_block     = av_malloc (sizeof(*ctx->const_block) * num_buffers);

  1645.     ctx->shift_lsbs      = av_malloc (sizeof(*ctx->shift_lsbs)  * num_buffers);

  1646.     ctx->opt_order       = av_malloc (sizeof(*ctx->opt_order)   * num_buffers);

  1647.     ctx->store_prev_samples = av_malloc(sizeof(*ctx->store_prev_samples) * num_buffers);

  1648.     ctx->use_ltp         = av_mallocz(sizeof(*ctx->use_ltp)  * num_buffers);

  1649.     ctx->ltp_lag         = av_malloc (sizeof(*ctx->ltp_lag)  * num_buffers);

  1650.     ctx->ltp_gain        = av_malloc (sizeof(*ctx->ltp_gain) * num_buffers);

  1651.     ctx->ltp_gain_buffer = av_malloc (sizeof(*ctx->ltp_gain_buffer) *

  1652.                                       num_buffers * 5);

  1653. 

  1654.     if (!ctx->const_block || !ctx->shift_lsbs ||

  1655.         !ctx->opt_order || !ctx->store_prev_samples ||

  1656.         !ctx->use_ltp  || !ctx->ltp_lag ||

  1657.         !ctx->ltp_gain || !ctx->ltp_gain_buffer) {

  1658.         av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");

  1659.         decode_end(avctx);

  1660.         return AVERROR(ENOMEM);

  1661.     }

  1662. 

  1663.     for (c = 0; c < num_buffers; c++)

  1664.         ctx->ltp_gain[c] = ctx->ltp_gain_buffer + c * 5;

  1665. 

  1666.     // allocate and assign channel data buffer for mcc mode

  1667.     if (sconf->mc_coding) {

  1668.         ctx->chan_data_buffer  = av_malloc(sizeof(*ctx->chan_data_buffer) *

  1669.                                            num_buffers * num_buffers);

  1670.         ctx->chan_data         = av_malloc(sizeof(*ctx->chan_data) *

  1671.                                            num_buffers);

  1672.         ctx->reverted_channels = av_malloc(sizeof(*ctx->reverted_channels) *

  1673.                                            num_buffers);

  1674. 

  1675.         if (!ctx->chan_data_buffer || !ctx->chan_data || !ctx->reverted_channels) {

  1676.             av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");

  1677.             decode_end(avctx);

  1678.             return AVERROR(ENOMEM);

  1679.         }

  1680. 

  1681.         for (c = 0; c < num_buffers; c++)

  1682.             ctx->chan_data[c] = ctx->chan_data_buffer + c * num_buffers;

  1683.     } else {

  1684.         ctx->chan_data         = NULL;

  1685.         ctx->chan_data_buffer  = NULL;

  1686.         ctx->reverted_channels = NULL;

  1687.     }

  1688. 

  1689.     channel_size      = sconf->frame_length + sconf->max_order;

  1690. 

  1691.     ctx->prev_raw_samples = av_malloc (sizeof(*ctx->prev_raw_samples) * sconf->max_order);

  1692.     ctx->raw_buffer       = av_mallocz(sizeof(*ctx->     raw_buffer)  * avctx->channels * channel_size);

  1693.     ctx->raw_samples      = av_malloc (sizeof(*ctx->     raw_samples) * avctx->channels);

  1694. 

  1695.     // allocate previous raw sample buffer

  1696.     if (!ctx->prev_raw_samples || !ctx->raw_buffer|| !ctx->raw_samples) {

  1697.         av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");

  1698.         decode_end(avctx);

  1699.         return AVERROR(ENOMEM);

  1700.     }

  1701. 

  1702.     // assign raw samples buffers

  1703.     ctx->raw_samples[0] = ctx->raw_buffer + sconf->max_order;

  1704.     for (c = 1; c < avctx->channels; c++)

  1705.         ctx->raw_samples[c] = ctx->raw_samples[c - 1] + channel_size;

  1706. 

  1707.     // allocate crc buffer

  1708.     if (HAVE_BIGENDIAN != sconf->msb_first && sconf->crc_enabled &&

  1709.         (avctx->err_recognition & AV_EF_CRCCHECK)) {

  1710.         ctx->crc_buffer = av_malloc(sizeof(*ctx->crc_buffer) *

  1711.                                     ctx->cur_frame_length *

  1712.                                     avctx->channels *

  1713.                                     av_get_bytes_per_sample(avctx->sample_fmt));

  1714.         if (!ctx->crc_buffer) {

  1715.             av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");

  1716.             decode_end(avctx);

  1717.             return AVERROR(ENOMEM);

  1718.         }

  1719.     }

  1720. 

  1721.     ff_dsputil_init(&ctx->dsp, avctx);

  1722. 

  1723.     avcodec_get_frame_defaults(&ctx->frame);

  1724.     avctx->coded_frame = &ctx->frame;

  1725. 

  1726.     return 0;

  1727. }

  1728. 

  1729. 

  1730. /** Flush (reset) the frame ID after seeking.

  1731.  */

  1732. static av_cold void flush(AVCodecContext *avctx)

  1733. {

  1734.     ALSDecContext *ctx = avctx->priv_data;

  1735. 

  1736.     ctx->frame_id = 0;

  1737. }

  1738. 

  1739. 

  1740. AVCodec ff_als_decoder = {

  1741.     .name           = "als",

  1742.     .type           = AVMEDIA_TYPE_AUDIO,

  1743.     .id             = CODEC_ID_MP4ALS,

  1744.     .priv_data_size = sizeof(ALSDecContext),

  1745.     .init           = decode_init,

  1746.     .close          = decode_end,

  1747.     .decode         = decode_frame,

  1748.     .flush          = flush,

  1749.     .capabilities   = CODEC_CAP_SUBFRAMES | CODEC_CAP_DR1,

  1750.     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-4 Audio Lossless Coding (ALS)"),

  1751. };