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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 "mlz.h"

  39. #include "libavutil/samplefmt.h"

  40. #include "libavutil/crc.h"

  41. #include "libavutil/softfloat_ieee754.h"

  42. #include "libavutil/intfloat.h"

  43. #include "libavutil/intreadwrite.h"

  44. 

  45. #include <stdint.h>

  46. 

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

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

  49.  *  by the encoder and stored in ALSSpecificConfig.

  50.  */

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

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

  53.       { 12, 3}, { -7, 3}, {  9, 3}, { -5, 3}, {  6, 3},

  54.       { -4, 3}, {  3, 3}, { -3, 2}, {  3, 2}, { -2, 2},

  55.       {  3, 2}, { -1, 2}, {  2, 2}, { -1, 2}, {  2, 2} },

  56.     { {-58, 3}, {-42, 4}, {-46, 4}, { 37, 5}, {-36, 4},

  57.       { 29, 4}, {-29, 4}, { 25, 4}, {-23, 4}, { 20, 4},

  58.       {-17, 4}, { 16, 4}, {-12, 4}, { 12, 3}, {-10, 4},

  59.       {  7, 3}, { -4, 4}, {  3, 3}, { -1, 3}, {  1, 3} },

  60.     { {-59, 3}, {-45, 5}, {-50, 4}, { 38, 4}, {-39, 4},

  61.       { 32, 4}, {-30, 4}, { 25, 3}, {-23, 3}, { 20, 3},

  62.       {-20, 3}, { 16, 3}, {-13, 3}, { 10, 3}, { -7, 3},

  63.       {  3, 3}, {  0, 3}, { -1, 3}, {  2, 3}, { -1, 2} }

  64. };

  65. 

  66. 

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

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

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

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

  71.  */

  72. static const int16_t parcor_scaled_values[] = {

  73.     -1048544 / 32, -1048288 / 32, -1047776 / 32, -1047008 / 32,

  74.     -1045984 / 32, -1044704 / 32, -1043168 / 32, -1041376 / 32,

  75.     -1039328 / 32, -1037024 / 32, -1034464 / 32, -1031648 / 32,

  76.     -1028576 / 32, -1025248 / 32, -1021664 / 32, -1017824 / 32,

  77.     -1013728 / 32, -1009376 / 32, -1004768 / 32,  -999904 / 32,

  78.      -994784 / 32,  -989408 / 32,  -983776 / 32,  -977888 / 32,

  79.      -971744 / 32,  -965344 / 32,  -958688 / 32,  -951776 / 32,

  80.      -944608 / 32,  -937184 / 32,  -929504 / 32,  -921568 / 32,

  81.      -913376 / 32,  -904928 / 32,  -896224 / 32,  -887264 / 32,

  82.      -878048 / 32,  -868576 / 32,  -858848 / 32,  -848864 / 32,

  83.      -838624 / 32,  -828128 / 32,  -817376 / 32,  -806368 / 32,

  84.      -795104 / 32,  -783584 / 32,  -771808 / 32,  -759776 / 32,

  85.      -747488 / 32,  -734944 / 32,  -722144 / 32,  -709088 / 32,

  86.      -695776 / 32,  -682208 / 32,  -668384 / 32,  -654304 / 32,

  87.      -639968 / 32,  -625376 / 32,  -610528 / 32,  -595424 / 32,

  88.      -580064 / 32,  -564448 / 32,  -548576 / 32,  -532448 / 32,

  89.      -516064 / 32,  -499424 / 32,  -482528 / 32,  -465376 / 32,

  90.      -447968 / 32,  -430304 / 32,  -412384 / 32,  -394208 / 32,

  91.      -375776 / 32,  -357088 / 32,  -338144 / 32,  -318944 / 32,

  92.      -299488 / 32,  -279776 / 32,  -259808 / 32,  -239584 / 32,

  93.      -219104 / 32,  -198368 / 32,  -177376 / 32,  -156128 / 32,

  94.      -134624 / 32,  -112864 / 32,   -90848 / 32,   -68576 / 32,

  95.       -46048 / 32,   -23264 / 32,     -224 / 32,    23072 / 32,

  96.        46624 / 32,    70432 / 32,    94496 / 32,   118816 / 32,

  97.       143392 / 32,   168224 / 32,   193312 / 32,   218656 / 32,

  98.       244256 / 32,   270112 / 32,   296224 / 32,   322592 / 32,

  99.       349216 / 32,   376096 / 32,   403232 / 32,   430624 / 32,

  100.       458272 / 32,   486176 / 32,   514336 / 32,   542752 / 32,

  101.       571424 / 32,   600352 / 32,   629536 / 32,   658976 / 32,

  102.       688672 / 32,   718624 / 32,   748832 / 32,   779296 / 32,

  103.       810016 / 32,   840992 / 32,   872224 / 32,   903712 / 32,

  104.       935456 / 32,   967456 / 32,   999712 / 32,  1032224 / 32

  105. };

  106. 

  107. 

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

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

  110.  */

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

  112.     { 0,  8, 16,  24},

  113.     {32, 40, 48,  56},

  114.     {64, 70, 76,  82},

  115.     {88, 92, 96, 100}

  116. };

  117. 

  118. 

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

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

  121.  */

  122. static const int16_t mcc_weightings[] = {

  123.     204,  192,  179,  166,  153,  140,  128,  115,

  124.     102,   89,   76,   64,   51,   38,   25,   12,

  125.       0,  -12,  -25,  -38,  -51,  -64,  -76,  -89,

  126.    -102, -115, -128, -140, -153, -166, -179, -192

  127. };

  128. 

  129. 

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

  131.  */

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

  133.     { 74, 44, 25, 13,  7, 3},

  134.     { 68, 42, 24, 13,  7, 3},

  135.     { 58, 39, 23, 13,  7, 3},

  136.     {126, 70, 37, 19, 10, 5},

  137.     {132, 70, 37, 20, 10, 5},

  138.     {124, 70, 38, 20, 10, 5},

  139.     {120, 69, 37, 20, 11, 5},

  140.     {116, 67, 37, 20, 11, 5},

  141.     {108, 66, 36, 20, 10, 5},

  142.     {102, 62, 36, 20, 10, 5},

  143.     { 88, 58, 34, 19, 10, 5},

  144.     {162, 89, 49, 25, 13, 7},

  145.     {156, 87, 49, 26, 14, 7},

  146.     {150, 86, 47, 26, 14, 7},

  147.     {142, 84, 47, 26, 14, 7},

  148.     {131, 79, 46, 26, 14, 7}

  149. };

  150. 

  151. 

  152. enum RA_Flag {

  153.     RA_FLAG_NONE,

  154.     RA_FLAG_FRAMES,

  155.     RA_FLAG_HEADER

  156. };

  157. 

  158. 

  159. typedef struct ALSSpecificConfig {

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  182. } ALSSpecificConfig;

  183. 

  184. 

  185. typedef struct ALSChannelData {

  186.     int stop_flag;

  187.     int master_channel;

  188.     int time_diff_flag;

  189.     int time_diff_sign;

  190.     int time_diff_index;

  191.     int weighting[6];

  192. } ALSChannelData;

  193. 

  194. 

  195. typedef struct ALSDecContext {

  196.     AVCodecContext *avctx;

  197.     ALSSpecificConfig sconf;

  198.     GetBitContext gb;

  199.     BswapDSPContext bdsp;

  200.     const AVCRC *crc_table;

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  232.     MLZ* mlz;                       ///< masked lz decompression structure

  233.     SoftFloat_IEEE754 *acf;         ///< contains common multiplier for all channels

  234.     int *last_acf_mantissa;         ///< contains the last acf mantissa data of common multiplier for all channels

  235.     int *shift_value;               ///< value by which the binary point is to be shifted for all channels

  236.     int *last_shift_value;          ///< contains last shift value for all channels

  237.     int **raw_mantissa;             ///< decoded mantissa bits of the difference signal

  238.     unsigned char *larray;          ///< buffer to store the output of masked lz decompression

  239.     int *nbits;                     ///< contains the number of bits to read for masked lz decompression for all samples

  240. } ALSDecContext;

  241. 

  242. 

  243. typedef struct ALSBlockData {

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  259. } ALSBlockData;

  260. 

  261. 

  262. static av_cold void dprint_specific_config(ALSDecContext *ctx)

  263. {

  264. #ifdef DEBUG

  265.     AVCodecContext *avctx    = ctx->avctx;

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

  267. 

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  286. #endif

  287. }

  288. 

  289. 

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

  291.  */

  292. static av_cold int read_specific_config(ALSDecContext *ctx)

  293. {

  294.     GetBitContext gb;

  295.     uint64_t ht_size;

  296.     int i, config_offset;

  297.     MPEG4AudioConfig m4ac = {0};

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

  299.     AVCodecContext *avctx    = ctx->avctx;

  300.     uint32_t als_id, header_size, trailer_size;

  301.     int ret;

  302. 

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

  304.         return ret;

  305. 

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

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

  308. 

  309.     if (config_offset < 0)

  310.         return AVERROR_INVALIDDATA;

  311. 

  312.     skip_bits_long(&gb, config_offset);

  313. 

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

  315.         return AVERROR_INVALIDDATA;

  316. 

  317.     // read the fixed items

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

  319.     avctx->sample_rate          = m4ac.sample_rate;

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

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

  322.     avctx->channels             = m4ac.channels;

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  346. 

  347. 

  348.     // check for ALSSpecificConfig struct

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

  350.         return AVERROR_INVALIDDATA;

  351. 

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

  353. 

  354.     // read channel config

  355.     if (sconf->chan_config)

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

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

  358. 

  359. 

  360.     // read channel sorting

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

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

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

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

  365.             return AVERROR_INVALIDDATA;

  366. 

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

  368.             return AVERROR(ENOMEM);

  369. 

  370.         ctx->cs_switch = 1;

  371. 

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

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

  374.         }

  375. 

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

  377.             int idx;

  378. 

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

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

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

  382.                 ctx->cs_switch = 0;

  383.                 break;

  384.             }

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

  386.         }

  387. 

  388.         align_get_bits(&gb);

  389.     }

  390. 

  391. 

  392.     // read fixed header and trailer sizes,

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

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

  395.         return AVERROR_INVALIDDATA;

  396. 

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

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

  399.     if (header_size  == 0xFFFFFFFF)

  400.         header_size  = 0;

  401.     if (trailer_size == 0xFFFFFFFF)

  402.         trailer_size = 0;

  403. 

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

  405. 

  406. 

  407.     // skip the header and trailer data

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

  409.         return AVERROR_INVALIDDATA;

  410. 

  411.     if (ht_size > INT32_MAX)

  412.         return AVERROR_PATCHWELCOME;

  413. 

  414.     skip_bits_long(&gb, ht_size);

  415. 

  416. 

  417.     // initialize CRC calculation

  418.     if (sconf->crc_enabled) {

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

  420.             return AVERROR_INVALIDDATA;

  421. 

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

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

  424.             ctx->crc       = 0xFFFFFFFF;

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

  426.         } else

  427.             skip_bits_long(&gb, 32);

  428.     }

  429. 

  430. 

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

  432. 

  433.     dprint_specific_config(ctx);

  434. 

  435.     return 0;

  436. }

  437. 

  438. 

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

  440.  */

  441. static int check_specific_config(ALSDecContext *ctx)

  442. {

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

  444.     int error = 0;

  445. 

  446.     // report unsupported feature and set error value

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

  448.     {                                                   \

  449.         if (cond) {                                     \

  450.             avpriv_report_missing_feature(ctx->avctx,   \

  451.                                           str);         \

  452.             error = errval;                             \

  453.         }                                               \

  454.     }

  455. 

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

  457. 

  458.     return error;

  459. }

  460. 

  461. 

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

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

  464.  */

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

  466.                           unsigned int div, unsigned int **div_blocks,

  467.                           unsigned int *num_blocks)

  468. {

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

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

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

  472.         n   *= 2;

  473.         div += 1;

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

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

  476.     } else {

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

  478.         // (bit implicitly not set)

  479.         **div_blocks = div;

  480.         (*div_blocks)++;

  481.         (*num_blocks)++;

  482.     }

  483. }

  484. 

  485. 

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

  487.  */

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

  489. {

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

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

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

  493. 

  494.     if (k > 1) {

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

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

  497.     } else if (!k) {

  498.         q >>= 1;

  499.     }

  500.     return r ? q : ~q;

  501. }

  502. 

  503. 

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

  505.  */

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

  507. {

  508.     int i, j;

  509. 

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

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

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

  513.         cof[i]  += tmp1;

  514.     }

  515.     if (i == j)

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

  517. 

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

  519. }

  520. 

  521. 

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

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

  524.  *  actual number of samples.

  525.  */

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

  527.                             uint32_t *bs_info)

  528. {

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

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

  531.     unsigned int *ptr_div_blocks = div_blocks;

  532.     unsigned int b;

  533. 

  534.     if (sconf->block_switching) {

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

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

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

  538.     }

  539. 

  540.     ctx->num_blocks = 0;

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

  542. 

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

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

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

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

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

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

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

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

  551.     // codec RM22 revision 2.

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

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

  554.     // of 14496-3.

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

  556.     // frame.

  557. 

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

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

  560. 

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

  562.         unsigned int remaining = ctx->cur_frame_length;

  563. 

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

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

  566.                 div_blocks[b] = remaining;

  567.                 ctx->num_blocks = b + 1;

  568.                 break;

  569.             }

  570. 

  571.             remaining -= div_blocks[b];

  572.         }

  573.     }

  574. }

  575. 

  576. 

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

  578.  */

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

  580. {

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

  582.     AVCodecContext *avctx    = ctx->avctx;

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

  584. 

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

  586.         return AVERROR_INVALIDDATA;

  587. 

  588.     *bd->raw_samples = 0;

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

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

  591. 

  592.     // skip 5 reserved bits

  593.     skip_bits(gb, 5);

  594. 

  595.     if (*bd->const_block) {

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

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

  598.     }

  599. 

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

  601.     *bd->const_block = 1;

  602. 

  603.     return 0;

  604. }

  605. 

  606. 

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

  608.  */

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

  610. {

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

  612.     int32_t  val = *bd->raw_samples;

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

  614. 

  615.     // write raw samples into buffer

  616.     for (; smp; smp--)

  617.         *dst++ = val;

  618. }

  619. 

  620. 

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

  622.  */

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

  624. {

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

  626.     AVCodecContext *avctx    = ctx->avctx;

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

  628.     unsigned int k;

  629.     unsigned int s[8];

  630.     unsigned int sx[8];

  631.     unsigned int sub_blocks, log2_sub_blocks, sb_length;

  632.     unsigned int start      = 0;

  633.     unsigned int opt_order;

  634.     int          sb;

  635.     int32_t      *quant_cof = bd->quant_cof;

  636.     int32_t      *current_res;

  637. 

  638. 

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

  640.     *bd->const_block = 0;

  641. 

  642.     *bd->opt_order  = 1;

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

  644. 

  645.     opt_order       = *bd->opt_order;

  646. 

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

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

  649.         log2_sub_blocks = 0;

  650.     } else {

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

  652.             log2_sub_blocks = get_bits(gb, 2);

  653.         else

  654.             log2_sub_blocks = 2 * get_bits1(gb);

  655.     }

  656. 

  657.     sub_blocks = 1 << log2_sub_blocks;

  658. 

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

  660.     // block_length must be evenly divisible by sub_blocks

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

  662.         av_log(avctx, AV_LOG_WARNING,

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

  664.         return AVERROR_INVALIDDATA;

  665.     }

  666. 

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

  668. 

  669.     if (sconf->bgmc) {

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

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

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

  673. 

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

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

  676.             s [k] >>= 4;

  677.         }

  678.     } else {

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

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

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

  682.     }

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

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

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

  686.             return AVERROR_INVALIDDATA;

  687.         }

  688. 

  689.     if (get_bits1(gb))

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

  691. 

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

  693. 

  694. 

  695.     if (!sconf->rlslms) {

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

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

  698.                                                 2, sconf->max_order + 1));

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

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

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

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

  703.                 return AVERROR_INVALIDDATA;

  704.             }

  705.         } else {

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

  707.         }

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

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

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

  711.             return AVERROR_INVALIDDATA;

  712.         }

  713.         opt_order = *bd->opt_order;

  714. 

  715.         if (opt_order) {

  716.             int add_base;

  717. 

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

  719.                 add_base = 0x7F;

  720. 

  721.                 // read coefficient 0

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

  723. 

  724.                 // read coefficient 1

  725.                 if (opt_order > 1)

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

  727. 

  728.                 // read coefficients 2 to opt_order

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

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

  731.             } else {

  732.                 int k_max;

  733.                 add_base = 1;

  734. 

  735.                 // read coefficient 0 to 19

  736.                 k_max = FFMIN(opt_order, 20);

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

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

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

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

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

  742.                         av_log(avctx, AV_LOG_ERROR,

  743.                                "quant_cof %"PRId32" is out of range.\n",

  744.                                quant_cof[k]);

  745.                         return AVERROR_INVALIDDATA;

  746.                     }

  747.                 }

  748. 

  749.                 // read coefficients 20 to 126

  750.                 k_max = FFMIN(opt_order, 127);

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

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

  753. 

  754.                 // read coefficients 127 to opt_order

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

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

  757. 

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

  759. 

  760.                 if (opt_order > 1)

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

  762.             }

  763. 

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

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

  766.         }

  767.     }

  768. 

  769.     // read LTP gain and lag values

  770.     if (sconf->long_term_prediction) {

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

  772. 

  773.         if (*bd->use_ltp) {

  774.             int r, c;

  775. 

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

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

  778. 

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

  780.             c                 = get_bits(gb, 2);

  781.             if (r >= 4) {

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

  783.                 return AVERROR_INVALIDDATA;

  784.             }

  785. 

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

  787. 

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

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

  790. 

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

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

  793.         }

  794.     }

  795. 

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

  797.     if (bd->ra_block) {

  798.         if (opt_order)

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

  800.         if (opt_order > 1)

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

  802.         if (opt_order > 2)

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

  804. 

  805.         start = FFMIN(opt_order, 3);

  806.     }

  807. 

  808.     // read all residuals

  809.     if (sconf->bgmc) {

  810.         int          delta[8];

  811.         unsigned int k    [8];

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

  813. 

  814.         // read most significant bits

  815.         unsigned int high;

  816.         unsigned int low;

  817.         unsigned int value;

  818. 

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

  820. 

  821.         current_res = bd->raw_samples + start;

  822. 

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

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

  825. 

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

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

  828. 

  829.             ff_bgmc_decode(gb, sb_len, current_res,

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

  831. 

  832.             current_res += sb_len;

  833.         }

  834. 

  835.         ff_bgmc_decode_end(gb);

  836. 

  837. 

  838.         // read least significant bits and tails

  839.         current_res = bd->raw_samples + start;

  840. 

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

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

  843.             unsigned int cur_k         = k[sb];

  844.             unsigned int cur_s         = s[sb];

  845. 

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

  847.                 int32_t res = *current_res;

  848. 

  849.                 if (res == cur_tail_code) {

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

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

  852. 

  853.                     res = decode_rice(gb, cur_s);

  854. 

  855.                     if (res >= 0) {

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

  857.                     } else {

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

  859.                     }

  860.                 } else {

  861.                     if (res > cur_tail_code)

  862.                         res--;

  863. 

  864.                     if (res & 1)

  865.                         res = -res;

  866. 

  867.                     res >>= 1;

  868. 

  869.                     if (cur_k) {

  870.                         res <<= cur_k;

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

  872.                     }

  873.                 }

  874. 

  875.                 *current_res++ = res;

  876.             }

  877.         }

  878.     } else {

  879.         current_res = bd->raw_samples + start;

  880. 

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

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

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

  884.      }

  885. 

  886.     return 0;

  887. }

  888. 

  889. 

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

  891.  */

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

  893. {

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

  895.     unsigned int block_length = bd->block_length;

  896.     unsigned int smp = 0;

  897.     unsigned int k;

  898.     int opt_order             = *bd->opt_order;

  899.     int sb;

  900.     int64_t y;

  901.     int32_t *quant_cof        = bd->quant_cof;

  902.     int32_t *lpc_cof          = bd->lpc_cof;

  903.     int32_t *raw_samples      = bd->raw_samples;

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

  905.     int32_t *lpc_cof_reversed = ctx->lpc_cof_reversed_buffer;

  906. 

  907.     // reverse long-term prediction

  908.     if (*bd->use_ltp) {

  909.         int ltp_smp;

  910. 

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

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

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

  914.             int end    = center + 3;

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

  916.             int base;

  917. 

  918.             y = 1 << 6;

  919. 

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

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

  922. 

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

  924.         }

  925.     }

  926. 

  927.     // reconstruct all samples from residuals

  928.     if (bd->ra_block) {

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

  930.             y = 1 << 19;

  931. 

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

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

  934. 

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

  936.             parcor_to_lpc(smp, quant_cof, lpc_cof);

  937.         }

  938.     } else {

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

  940.             parcor_to_lpc(k, quant_cof, lpc_cof);

  941. 

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

  943.         if (*bd->store_prev_samples)

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

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

  946. 

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

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

  949.             int32_t *left, *right;

  950. 

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

  952.                 left  = raw_samples;

  953.                 right = bd->raw_other;

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

  955.                 left  = bd->raw_other;

  956.                 right = raw_samples;

  957.             }

  958. 

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

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

  961.         }

  962. 

  963.         // reconstruct shifted signal

  964.         if (*bd->shift_lsbs)

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

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

  967.     }

  968. 

  969.     // reverse linear prediction coefficients for efficiency

  970.     lpc_cof = lpc_cof + opt_order;

  971. 

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

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

  974. 

  975.     // reconstruct raw samples

  976.     raw_samples = bd->raw_samples + smp;

  977.     lpc_cof     = lpc_cof_reversed + opt_order;

  978. 

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

  980.         y = 1 << 19;

  981. 

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

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

  984. 

  985.         *raw_samples -= y >> 20;

  986.     }

  987. 

  988.     raw_samples = bd->raw_samples;

  989. 

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

  991.     if (*bd->store_prev_samples)

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

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

  994. 

  995.     return 0;

  996. }

  997. 

  998. 

  999. /** Read the block data.

  1000.  */

  1001. static int read_block(ALSDecContext *ctx, ALSBlockData *bd)

  1002. {

  1003.     int ret;

  1004.     GetBitContext *gb        = &ctx->gb;

  1005.     ALSSpecificConfig *sconf = &ctx->sconf;

  1006. 

  1007.     *bd->shift_lsbs = 0;

  1008.     // read block type flag and read the samples accordingly

  1009.     if (get_bits1(gb)) {

  1010.         ret = read_var_block_data(ctx, bd);

  1011.     } else {

  1012.         ret = read_const_block_data(ctx, bd);

  1013.     }

  1014. 

  1015.     if (!sconf->mc_coding || ctx->js_switch)

  1016.         align_get_bits(gb);

  1017. 

  1018.     return ret;

  1019. }

  1020. 

  1021. 

  1022. /** Decode the block data.

  1023.  */

  1024. static int decode_block(ALSDecContext *ctx, ALSBlockData *bd)

  1025. {

  1026.     unsigned int smp;

  1027.     int ret = 0;

  1028. 

  1029.     // read block type flag and read the samples accordingly

  1030.     if (*bd->const_block)

  1031.         decode_const_block_data(ctx, bd);

  1032.     else

  1033.         ret = decode_var_block_data(ctx, bd); // always return 0

  1034. 

  1035.     if (ret < 0)

  1036.         return ret;

  1037. 

  1038.     // TODO: read RLSLMS extension data

  1039. 

  1040.     if (*bd->shift_lsbs)

  1041.         for (smp = 0; smp < bd->block_length; smp++)

  1042.             bd->raw_samples[smp] = (unsigned)bd->raw_samples[smp] << *bd->shift_lsbs;

  1043. 

  1044.     return 0;

  1045. }

  1046. 

  1047. 

  1048. /** Read and decode block data successively.

  1049.  */

  1050. static int read_decode_block(ALSDecContext *ctx, ALSBlockData *bd)

  1051. {

  1052.     int ret;

  1053. 

  1054.     if ((ret = read_block(ctx, bd)) < 0)

  1055.         return ret;

  1056. 

  1057.     return decode_block(ctx, bd);

  1058. }

  1059. 

  1060. 

  1061. /** Compute the number of samples left to decode for the current frame and

  1062.  *  sets these samples to zero.

  1063.  */

  1064. static void zero_remaining(unsigned int b, unsigned int b_max,

  1065.                            const unsigned int *div_blocks, int32_t *buf)

  1066. {

  1067.     unsigned int count = 0;

  1068. 

  1069.     while (b < b_max)

  1070.         count += div_blocks[b++];

  1071. 

  1072.     if (count)

  1073.         memset(buf, 0, sizeof(*buf) * count);

  1074. }

  1075. 

  1076. 

  1077. /** Decode blocks independently.

  1078.  */

  1079. static int decode_blocks_ind(ALSDecContext *ctx, unsigned int ra_frame,

  1080.                              unsigned int c, const unsigned int *div_blocks,

  1081.                              unsigned int *js_blocks)

  1082. {

  1083.     int ret;

  1084.     unsigned int b;

  1085.     ALSBlockData bd = { 0 };

  1086. 

  1087.     bd.ra_block         = ra_frame;

  1088.     bd.const_block      = ctx->const_block;

  1089.     bd.shift_lsbs       = ctx->shift_lsbs;

  1090.     bd.opt_order        = ctx->opt_order;

  1091.     bd.store_prev_samples = ctx->store_prev_samples;

  1092.     bd.use_ltp          = ctx->use_ltp;

  1093.     bd.ltp_lag          = ctx->ltp_lag;

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

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

  1096.     bd.lpc_cof          = ctx->lpc_cof[0];

  1097.     bd.prev_raw_samples = ctx->prev_raw_samples;

  1098.     bd.raw_samples      = ctx->raw_samples[c];

  1099. 

  1100. 

  1101.     for (b = 0; b < ctx->num_blocks; b++) {

  1102.         bd.block_length     = div_blocks[b];

  1103. 

  1104.         if ((ret = read_decode_block(ctx, &bd)) < 0) {

  1105.             // damaged block, write zero for the rest of the frame

  1106.             zero_remaining(b, ctx->num_blocks, div_blocks, bd.raw_samples);

  1107.             return ret;

  1108.         }

  1109.         bd.raw_samples += div_blocks[b];

  1110.         bd.ra_block     = 0;

  1111.     }

  1112. 

  1113.     return 0;

  1114. }

  1115. 

  1116. 

  1117. /** Decode blocks dependently.

  1118.  */

  1119. static int decode_blocks(ALSDecContext *ctx, unsigned int ra_frame,

  1120.                          unsigned int c, const unsigned int *div_blocks,

  1121.                          unsigned int *js_blocks)

  1122. {

  1123.     ALSSpecificConfig *sconf = &ctx->sconf;

  1124.     unsigned int offset = 0;

  1125.     unsigned int b;

  1126.     int ret;

  1127.     ALSBlockData bd[2] = { { 0 } };

  1128. 

  1129.     bd[0].ra_block         = ra_frame;

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

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

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

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

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

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

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

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

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

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

  1140.     bd[0].js_blocks        = *js_blocks;

  1141. 

  1142.     bd[1].ra_block         = ra_frame;

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

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

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

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

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

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

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

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

  1151.     bd[1].lpc_cof          = ctx->lpc_cof[0];

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

  1153.     bd[1].js_blocks        = *(js_blocks + 1);

  1154. 

  1155.     // decode all blocks

  1156.     for (b = 0; b < ctx->num_blocks; b++) {

  1157.         unsigned int s;

  1158. 

  1159.         bd[0].block_length = div_blocks[b];

  1160.         bd[1].block_length = div_blocks[b];

  1161. 

  1162.         bd[0].raw_samples  = ctx->raw_samples[c    ] + offset;

  1163.         bd[1].raw_samples  = ctx->raw_samples[c + 1] + offset;

  1164. 

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

  1166.         bd[1].raw_other    = bd[0].raw_samples;

  1167. 

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

  1169.             (ret = read_decode_block(ctx, &bd[1])) < 0)

  1170.             goto fail;

  1171. 

  1172.         // reconstruct joint-stereo blocks

  1173.         if (bd[0].js_blocks) {

  1174.             if (bd[1].js_blocks)

  1175.                 av_log(ctx->avctx, AV_LOG_WARNING, "Invalid channel pair.\n");

  1176. 

  1177.             for (s = 0; s < div_blocks[b]; s++)

  1178.                 bd[0].raw_samples[s] = bd[1].raw_samples[s] - bd[0].raw_samples[s];

  1179.         } else if (bd[1].js_blocks) {

  1180.             for (s = 0; s < div_blocks[b]; s++)

  1181.                 bd[1].raw_samples[s] = bd[1].raw_samples[s] + bd[0].raw_samples[s];

  1182.         }

  1183. 

  1184.         offset  += div_blocks[b];

  1185.         bd[0].ra_block = 0;

  1186.         bd[1].ra_block = 0;

  1187.     }

  1188. 

  1189.     // store carryover raw samples,

  1190.     // the others channel raw samples are stored by the calling function.

  1191.     memmove(ctx->raw_samples[c] - sconf->max_order,

  1192.             ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,

  1193.             sizeof(*ctx->raw_samples[c]) * sconf->max_order);

  1194. 

  1195.     return 0;

  1196. fail:

  1197.     // damaged block, write zero for the rest of the frame

  1198.     zero_remaining(b, ctx->num_blocks, div_blocks, bd[0].raw_samples);

  1199.     zero_remaining(b, ctx->num_blocks, div_blocks, bd[1].raw_samples);

  1200.     return ret;

  1201. }

  1202. 

  1203. static inline int als_weighting(GetBitContext *gb, int k, int off)

  1204. {

  1205.     int idx = av_clip(decode_rice(gb, k) + off,

  1206.                       0, FF_ARRAY_ELEMS(mcc_weightings) - 1);

  1207.     return mcc_weightings[idx];

  1208. }

  1209. 

  1210. /** Read the channel data.

  1211.   */

  1212. static int read_channel_data(ALSDecContext *ctx, ALSChannelData *cd, int c)

  1213. {

  1214.     GetBitContext *gb       = &ctx->gb;

  1215.     ALSChannelData *current = cd;

  1216.     unsigned int channels   = ctx->avctx->channels;

  1217.     int entries             = 0;

  1218. 

  1219.     while (entries < channels && !(current->stop_flag = get_bits1(gb))) {

  1220.         current->master_channel = get_bits_long(gb, av_ceil_log2(channels));

  1221. 

  1222.         if (current->master_channel >= channels) {

  1223.             av_log(ctx->avctx, AV_LOG_ERROR, "Invalid master channel.\n");

  1224.             return AVERROR_INVALIDDATA;

  1225.         }

  1226. 

  1227.         if (current->master_channel != c) {

  1228.             current->time_diff_flag = get_bits1(gb);

  1229.             current->weighting[0]   = als_weighting(gb, 1, 16);

  1230.             current->weighting[1]   = als_weighting(gb, 2, 14);

  1231.             current->weighting[2]   = als_weighting(gb, 1, 16);

  1232. 

  1233.             if (current->time_diff_flag) {

  1234.                 current->weighting[3] = als_weighting(gb, 1, 16);

  1235.                 current->weighting[4] = als_weighting(gb, 1, 16);

  1236.                 current->weighting[5] = als_weighting(gb, 1, 16);

  1237. 

  1238.                 current->time_diff_sign  = get_bits1(gb);

  1239.                 current->time_diff_index = get_bits(gb, ctx->ltp_lag_length - 3) + 3;

  1240.             }

  1241.         }

  1242. 

  1243.         current++;

  1244.         entries++;

  1245.     }

  1246. 

  1247.     if (entries == channels) {

  1248.         av_log(ctx->avctx, AV_LOG_ERROR, "Damaged channel data.\n");

  1249.         return AVERROR_INVALIDDATA;

  1250.     }

  1251. 

  1252.     align_get_bits(gb);

  1253.     return 0;

  1254. }

  1255. 

  1256. 

  1257. /** Recursively reverts the inter-channel correlation for a block.

  1258.  */

  1259. static int revert_channel_correlation(ALSDecContext *ctx, ALSBlockData *bd,

  1260.                                        ALSChannelData **cd, int *reverted,

  1261.                                        unsigned int offset, int c)

  1262. {

  1263.     ALSChannelData *ch = cd[c];

  1264.     unsigned int   dep = 0;

  1265.     unsigned int channels = ctx->avctx->channels;

  1266.     unsigned int channel_size = ctx->sconf.frame_length + ctx->sconf.max_order;

  1267. 

  1268.     if (reverted[c])

  1269.         return 0;

  1270. 

  1271.     reverted[c] = 1;

  1272. 

  1273.     while (dep < channels && !ch[dep].stop_flag) {

  1274.         revert_channel_correlation(ctx, bd, cd, reverted, offset,

  1275.                                    ch[dep].master_channel);

  1276. 

  1277.         dep++;

  1278.     }

  1279. 

  1280.     if (dep == channels) {

  1281.         av_log(ctx->avctx, AV_LOG_WARNING, "Invalid channel correlation.\n");

  1282.         return AVERROR_INVALIDDATA;

  1283.     }

  1284. 

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

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

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

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

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

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

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

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

  1293.     bd->quant_cof   = ctx->quant_cof[c];

  1294.     bd->raw_samples = ctx->raw_samples[c] + offset;

  1295. 

  1296.     for (dep = 0; !ch[dep].stop_flag; dep++) {

  1297.         ptrdiff_t smp;

  1298.         ptrdiff_t begin = 1;

  1299.         ptrdiff_t end   = bd->block_length - 1;

  1300.         int64_t y;

  1301.         int32_t *master = ctx->raw_samples[ch[dep].master_channel] + offset;

  1302. 

  1303.         if (ch[dep].master_channel == c)

  1304.             continue;

  1305. 

  1306.         if (ch[dep].time_diff_flag) {

  1307.             int t = ch[dep].time_diff_index;

  1308. 

  1309.             if (ch[dep].time_diff_sign) {

  1310.                 t      = -t;

  1311.                 if (begin < t) {

  1312.                     av_log(ctx->avctx, AV_LOG_ERROR, "begin %"PTRDIFF_SPECIFIER" smaller than time diff index %d.\n", begin, t);

  1313.                     return AVERROR_INVALIDDATA;

  1314.                 }

  1315.                 begin -= t;

  1316.             } else {

  1317.                 if (end < t) {

  1318.                     av_log(ctx->avctx, AV_LOG_ERROR, "end %"PTRDIFF_SPECIFIER" smaller than time diff index %d.\n", end, t);

  1319.                     return AVERROR_INVALIDDATA;

  1320.                 }

  1321.                 end   -= t;

  1322.             }

  1323. 

  1324.             if (FFMIN(begin - 1, begin - 1 + t) < ctx->raw_buffer - master ||

  1325.                 FFMAX(end   + 1,   end + 1 + t) > ctx->raw_buffer + channels * channel_size - master) {

  1326.                 av_log(ctx->avctx, AV_LOG_ERROR,

  1327.                        "sample pointer range [%p, %p] not contained in raw_buffer [%p, %p].\n",

  1328.                        master + FFMIN(begin - 1, begin - 1 + t), master + FFMAX(end + 1,   end + 1 + t),

  1329.                        ctx->raw_buffer, ctx->raw_buffer + channels * channel_size);

  1330.                 return AVERROR_INVALIDDATA;

  1331.             }

  1332. 

  1333.             for (smp = begin; smp < end; smp++) {

  1334.                 y  = (1 << 6) +

  1335.                      MUL64(ch[dep].weighting[0], master[smp - 1    ]) +

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

  1337.                      MUL64(ch[dep].weighting[2], master[smp + 1    ]) +

  1338.                      MUL64(ch[dep].weighting[3], master[smp - 1 + t]) +

  1339.                      MUL64(ch[dep].weighting[4], master[smp     + t]) +

  1340.                      MUL64(ch[dep].weighting[5], master[smp + 1 + t]);

  1341. 

  1342.                 bd->raw_samples[smp] += y >> 7;

  1343.             }

  1344.         } else {

  1345. 

  1346.             if (begin - 1 < ctx->raw_buffer - master ||

  1347.                 end   + 1 > ctx->raw_buffer + channels * channel_size - master) {

  1348.                 av_log(ctx->avctx, AV_LOG_ERROR,

  1349.                        "sample pointer range [%p, %p] not contained in raw_buffer [%p, %p].\n",

  1350.                        master + begin - 1, master + end + 1,

  1351.                        ctx->raw_buffer, ctx->raw_buffer + channels * channel_size);

  1352.                 return AVERROR_INVALIDDATA;

  1353.             }

  1354. 

  1355.             for (smp = begin; smp < end; smp++) {

  1356.                 y  = (1 << 6) +

  1357.                      MUL64(ch[dep].weighting[0], master[smp - 1]) +

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

  1359.                      MUL64(ch[dep].weighting[2], master[smp + 1]);

  1360. 

  1361.                 bd->raw_samples[smp] += y >> 7;

  1362.             }

  1363.         }

  1364.     }

  1365. 

  1366.     return 0;

  1367. }

  1368. 

  1369. 

  1370. /** multiply two softfloats and handle the rounding off

  1371.  */

  1372. static SoftFloat_IEEE754 multiply(SoftFloat_IEEE754 a, SoftFloat_IEEE754 b) {

  1373.     uint64_t mantissa_temp;

  1374.     uint64_t mask_64;

  1375.     int cutoff_bit_count;

  1376.     unsigned char last_2_bits;

  1377.     unsigned int mantissa;

  1378.     int32_t sign;

  1379.     uint32_t return_val = 0;

  1380.     int bit_count       = 48;

  1381. 

  1382.     sign = a.sign ^ b.sign;

  1383. 

  1384.     // Multiply mantissa bits in a 64-bit register

  1385.     mantissa_temp = (uint64_t)a.mant * (uint64_t)b.mant;

  1386.     mask_64       = (uint64_t)0x1 << 47;

  1387. 

  1388.     if (!mantissa_temp)

  1389.         return FLOAT_0;

  1390. 

  1391.     // Count the valid bit count

  1392.     while (!(mantissa_temp & mask_64) && mask_64) {

  1393.         bit_count--;

  1394.         mask_64 >>= 1;

  1395.     }

  1396. 

  1397.     // Round off

  1398.     cutoff_bit_count = bit_count - 24;

  1399.     if (cutoff_bit_count > 0) {

  1400.         last_2_bits = (unsigned char)(((unsigned int)mantissa_temp >> (cutoff_bit_count - 1)) & 0x3 );

  1401.         if ((last_2_bits == 0x3) || ((last_2_bits == 0x1) && ((unsigned int)mantissa_temp & ((0x1UL << (cutoff_bit_count - 1)) - 1)))) {

  1402.             // Need to round up

  1403.             mantissa_temp += (uint64_t)0x1 << cutoff_bit_count;

  1404.         }

  1405.     }

  1406. 

  1407.     mantissa = (unsigned int)(mantissa_temp >> cutoff_bit_count);

  1408. 

  1409.     // Need one more shift?

  1410.     if (mantissa & 0x01000000ul) {

  1411.         bit_count++;

  1412.         mantissa >>= 1;

  1413.     }

  1414. 

  1415.     if (!sign) {

  1416.         return_val = 0x80000000U;

  1417.     }

  1418. 

  1419.     return_val |= (a.exp + b.exp + bit_count - 47) << 23;

  1420.     return_val |= mantissa;

  1421.     return av_bits2sf_ieee754(return_val);

  1422. }

  1423. 

  1424. 

  1425. /** Read and decode the floating point sample data

  1426.  */

  1427. static int read_diff_float_data(ALSDecContext *ctx, unsigned int ra_frame) {

  1428.     AVCodecContext *avctx   = ctx->avctx;

  1429.     GetBitContext *gb       = &ctx->gb;

  1430.     SoftFloat_IEEE754 *acf  = ctx->acf;

  1431.     int *shift_value        = ctx->shift_value;

  1432.     int *last_shift_value   = ctx->last_shift_value;

  1433.     int *last_acf_mantissa  = ctx->last_acf_mantissa;

  1434.     int **raw_mantissa      = ctx->raw_mantissa;

  1435.     int *nbits              = ctx->nbits;

  1436.     unsigned char *larray   = ctx->larray;

  1437.     int frame_length        = ctx->cur_frame_length;

  1438.     SoftFloat_IEEE754 scale = av_int2sf_ieee754(0x1u, 23);

  1439.     unsigned int partA_flag;

  1440.     unsigned int highest_byte;

  1441.     unsigned int shift_amp;

  1442.     uint32_t tmp_32;

  1443.     int use_acf;

  1444.     int nchars;

  1445.     int i;

  1446.     int c;

  1447.     long k;

  1448.     long nbits_aligned;

  1449.     unsigned long acc;

  1450.     unsigned long j;

  1451.     uint32_t sign;

  1452.     uint32_t e;

  1453.     uint32_t mantissa;

  1454. 

  1455.     skip_bits_long(gb, 32); //num_bytes_diff_float

  1456.     use_acf = get_bits1(gb);

  1457. 

  1458.     if (ra_frame) {

  1459.         memset(last_acf_mantissa, 0, avctx->channels * sizeof(*last_acf_mantissa));

  1460.         memset(last_shift_value,  0, avctx->channels * sizeof(*last_shift_value) );

  1461.         ff_mlz_flush_dict(ctx->mlz);

  1462.     }

  1463. 

  1464.     for (c = 0; c < avctx->channels; ++c) {

  1465.         if (use_acf) {

  1466.             //acf_flag

  1467.             if (get_bits1(gb)) {

  1468.                 tmp_32 = get_bits(gb, 23);

  1469.                 last_acf_mantissa[c] = tmp_32;

  1470.             } else {

  1471.                 tmp_32 = last_acf_mantissa[c];

  1472.             }

  1473.             acf[c] = av_bits2sf_ieee754(tmp_32);

  1474.         } else {

  1475.             acf[c] = FLOAT_1;

  1476.         }

  1477. 

  1478.         highest_byte = get_bits(gb, 2);

  1479.         partA_flag   = get_bits1(gb);

  1480.         shift_amp    = get_bits1(gb);

  1481. 

  1482.         if (shift_amp) {

  1483.             shift_value[c] = get_bits(gb, 8);

  1484.             last_shift_value[c] = shift_value[c];

  1485.         } else {

  1486.             shift_value[c] = last_shift_value[c];

  1487.         }

  1488. 

  1489.         if (partA_flag) {

  1490.             if (!get_bits1(gb)) { //uncompressed

  1491.                 for (i = 0; i < frame_length; ++i) {

  1492.                     if (ctx->raw_samples[c][i] == 0) {

  1493.                         ctx->raw_mantissa[c][i] = get_bits_long(gb, 32);

  1494.                     }

  1495.                 }

  1496.             } else { //compressed

  1497.                 nchars = 0;

  1498.                 for (i = 0; i < frame_length; ++i) {

  1499.                     if (ctx->raw_samples[c][i] == 0) {

  1500.                         nchars += 4;

  1501.                     }

  1502.                 }

  1503. 

  1504.                 tmp_32 = ff_mlz_decompression(ctx->mlz, gb, nchars, larray);

  1505.                 if(tmp_32 != nchars) {

  1506.                     av_log(ctx->avctx, AV_LOG_ERROR, "Error in MLZ decompression (%d, %d).\n", tmp_32, nchars);

  1507.                     return AVERROR_INVALIDDATA;

  1508.                 }

  1509. 

  1510.                 for (i = 0; i < frame_length; ++i) {

  1511.                     ctx->raw_mantissa[c][i] = AV_RB32(larray);

  1512.                 }

  1513.             }

  1514.         }

  1515. 

  1516.         //decode part B

  1517.         if (highest_byte) {

  1518.             for (i = 0; i < frame_length; ++i) {

  1519.                 if (ctx->raw_samples[c][i] != 0) {

  1520.                     //The following logic is taken from Tabel 14.45 and 14.46 from the ISO spec

  1521.                     if (av_cmp_sf_ieee754(acf[c], FLOAT_1)) {

  1522.                         nbits[i] = 23 - av_log2(abs(ctx->raw_samples[c][i]));

  1523.                     } else {

  1524.                         nbits[i] = 23;

  1525.                     }

  1526.                     nbits[i] = FFMIN(nbits[i], highest_byte*8);

  1527.                 }

  1528.             }

  1529. 

  1530.             if (!get_bits1(gb)) { //uncompressed

  1531.                 for (i = 0; i < frame_length; ++i) {

  1532.                     if (ctx->raw_samples[c][i] != 0) {

  1533.                         raw_mantissa[c][i] = get_bitsz(gb, nbits[i]);

  1534.                     }

  1535.                 }

  1536.             } else { //compressed

  1537.                 nchars = 0;

  1538.                 for (i = 0; i < frame_length; ++i) {

  1539.                     if (ctx->raw_samples[c][i]) {

  1540.                         nchars += (int) nbits[i] / 8;

  1541.                         if (nbits[i] & 7) {

  1542.                             ++nchars;

  1543.                         }

  1544.                     }

  1545.                 }

  1546. 

  1547.                 tmp_32 = ff_mlz_decompression(ctx->mlz, gb, nchars, larray);

  1548.                 if(tmp_32 != nchars) {

  1549.                     av_log(ctx->avctx, AV_LOG_ERROR, "Error in MLZ decompression (%d, %d).\n", tmp_32, nchars);

  1550.                     return AVERROR_INVALIDDATA;

  1551.                 }

  1552. 

  1553.                 j = 0;

  1554.                 for (i = 0; i < frame_length; ++i) {

  1555.                     if (ctx->raw_samples[c][i]) {

  1556.                         if (nbits[i] & 7) {

  1557.                             nbits_aligned = 8 * ((unsigned int)(nbits[i] / 8) + 1);

  1558.                         } else {

  1559.                             nbits_aligned = nbits[i];

  1560.                         }

  1561.                         acc = 0;

  1562.                         for (k = 0; k < nbits_aligned/8; ++k) {

  1563.                             acc = (acc << 8) + larray[j++];

  1564.                         }

  1565.                         acc >>= (nbits_aligned - nbits[i]);

  1566.                         raw_mantissa[c][i] = acc;

  1567.                     }

  1568.                 }

  1569.             }

  1570.         }

  1571. 

  1572.         for (i = 0; i < frame_length; ++i) {

  1573.             SoftFloat_IEEE754 pcm_sf = av_int2sf_ieee754(ctx->raw_samples[c][i], 0);

  1574.             pcm_sf = av_div_sf_ieee754(pcm_sf, scale);

  1575. 

  1576.             if (ctx->raw_samples[c][i] != 0) {

  1577.                 if (!av_cmp_sf_ieee754(acf[c], FLOAT_1)) {

  1578.                     pcm_sf = multiply(acf[c], pcm_sf);

  1579.                 }

  1580. 

  1581.                 sign = pcm_sf.sign;

  1582.                 e = pcm_sf.exp;

  1583.                 mantissa = (pcm_sf.mant | 0x800000) + raw_mantissa[c][i];

  1584. 

  1585.                 while(mantissa >= 0x1000000) {

  1586.                     e++;

  1587.                     mantissa >>= 1;

  1588.                 }

  1589. 

  1590.                 if (mantissa) e += (shift_value[c] - 127);

  1591.                 mantissa &= 0x007fffffUL;

  1592. 

  1593.                 tmp_32 = (sign << 31) | ((e + EXP_BIAS) << 23) | (mantissa);

  1594.                 ctx->raw_samples[c][i] = tmp_32;

  1595.             } else {

  1596.                 ctx->raw_samples[c][i] = raw_mantissa[c][i] & 0x007fffffUL;

  1597.             }

  1598.         }

  1599.         align_get_bits(gb);

  1600.     }

  1601.     return 0;

  1602. }

  1603. 

  1604. 

  1605. /** Read the frame data.

  1606.  */

  1607. static int read_frame_data(ALSDecContext *ctx, unsigned int ra_frame)

  1608. {

  1609.     ALSSpecificConfig *sconf = &ctx->sconf;

  1610.     AVCodecContext *avctx    = ctx->avctx;

  1611.     GetBitContext *gb = &ctx->gb;

  1612.     unsigned int div_blocks[32];                ///< block sizes.

  1613.     unsigned int c;

  1614.     unsigned int js_blocks[2];

  1615.     uint32_t bs_info = 0;

  1616.     int ret;

  1617. 

  1618.     // skip the size of the ra unit if present in the frame

  1619.     if (sconf->ra_flag == RA_FLAG_FRAMES && ra_frame)

  1620.         skip_bits_long(gb, 32);

  1621. 

  1622.     if (sconf->mc_coding && sconf->joint_stereo) {

  1623.         ctx->js_switch = get_bits1(gb);

  1624.         align_get_bits(gb);

  1625.     }

  1626. 

  1627.     if (!sconf->mc_coding || ctx->js_switch) {

  1628.         int independent_bs = !sconf->joint_stereo;

  1629. 

  1630.         for (c = 0; c < avctx->channels; c++) {

  1631.             js_blocks[0] = 0;

  1632.             js_blocks[1] = 0;

  1633. 

  1634.             get_block_sizes(ctx, div_blocks, &bs_info);

  1635. 

  1636.             // if joint_stereo and block_switching is set, independent decoding

  1637.             // is signaled via the first bit of bs_info

  1638.             if (sconf->joint_stereo && sconf->block_switching)

  1639.                 if (bs_info >> 31)

  1640.                     independent_bs = 2;

  1641. 

  1642.             // if this is the last channel, it has to be decoded independently

  1643.             if (c == avctx->channels - 1)

  1644.                 independent_bs = 1;

  1645. 

  1646.             if (independent_bs) {

  1647.                 ret = decode_blocks_ind(ctx, ra_frame, c,

  1648.                                         div_blocks, js_blocks);

  1649.                 if (ret < 0)

  1650.                     return ret;

  1651.                 independent_bs--;

  1652.             } else {

  1653.                 ret = decode_blocks(ctx, ra_frame, c, div_blocks, js_blocks);

  1654.                 if (ret < 0)

  1655.                     return ret;

  1656. 

  1657.                 c++;

  1658.             }

  1659. 

  1660.             // store carryover raw samples

  1661.             memmove(ctx->raw_samples[c] - sconf->max_order,

  1662.                     ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,

  1663.                     sizeof(*ctx->raw_samples[c]) * sconf->max_order);

  1664.         }

  1665.     } else { // multi-channel coding

  1666.         ALSBlockData   bd = { 0 };

  1667.         int            b, ret;

  1668.         int            *reverted_channels = ctx->reverted_channels;

  1669.         unsigned int   offset             = 0;

  1670. 

  1671.         for (c = 0; c < avctx->channels; c++)

  1672.             if (ctx->chan_data[c] < ctx->chan_data_buffer) {

  1673.                 av_log(ctx->avctx, AV_LOG_ERROR, "Invalid channel data.\n");

  1674.                 return AVERROR_INVALIDDATA;

  1675.             }

  1676. 

  1677.         memset(reverted_channels, 0, sizeof(*reverted_channels) * avctx->channels);

  1678. 

  1679.         bd.ra_block         = ra_frame;

  1680.         bd.prev_raw_samples = ctx->prev_raw_samples;

  1681. 

  1682.         get_block_sizes(ctx, div_blocks, &bs_info);

  1683. 

  1684.         for (b = 0; b < ctx->num_blocks; b++) {

  1685.             bd.block_length = div_blocks[b];

  1686.             if (bd.block_length <= 0) {

  1687.                 av_log(ctx->avctx, AV_LOG_WARNING,

  1688.                        "Invalid block length %u in channel data!\n",

  1689.                        bd.block_length);

  1690.                 continue;

  1691.             }

  1692. 

  1693.             for (c = 0; c < avctx->channels; c++) {

  1694.                 bd.const_block = ctx->const_block + c;

  1695.                 bd.shift_lsbs  = ctx->shift_lsbs + c;

  1696.                 bd.opt_order   = ctx->opt_order + c;

  1697.                 bd.store_prev_samples = ctx->store_prev_samples + c;

  1698.                 bd.use_ltp     = ctx->use_ltp + c;

  1699.                 bd.ltp_lag     = ctx->ltp_lag + c;

  1700.                 bd.ltp_gain    = ctx->ltp_gain[c];

  1701.                 bd.lpc_cof     = ctx->lpc_cof[c];

  1702.                 bd.quant_cof   = ctx->quant_cof[c];

  1703.                 bd.raw_samples = ctx->raw_samples[c] + offset;

  1704.                 bd.raw_other   = NULL;

  1705. 

  1706.                 if ((ret = read_block(ctx, &bd)) < 0)

  1707.                     return ret;

  1708.                 if ((ret = read_channel_data(ctx, ctx->chan_data[c], c)) < 0)

  1709.                     return ret;

  1710.             }

  1711. 

  1712.             for (c = 0; c < avctx->channels; c++) {

  1713.                 ret = revert_channel_correlation(ctx, &bd, ctx->chan_data,

  1714.                                                  reverted_channels, offset, c);

  1715.                 if (ret < 0)

  1716.                     return ret;

  1717.             }

  1718.             for (c = 0; c < avctx->channels; c++) {

  1719.                 bd.const_block = ctx->const_block + c;

  1720.                 bd.shift_lsbs  = ctx->shift_lsbs + c;

  1721.                 bd.opt_order   = ctx->opt_order + c;

  1722.                 bd.store_prev_samples = ctx->store_prev_samples + c;

  1723.                 bd.use_ltp     = ctx->use_ltp + c;

  1724.                 bd.ltp_lag     = ctx->ltp_lag + c;

  1725.                 bd.ltp_gain    = ctx->ltp_gain[c];

  1726.                 bd.lpc_cof     = ctx->lpc_cof[c];

  1727.                 bd.quant_cof   = ctx->quant_cof[c];

  1728.                 bd.raw_samples = ctx->raw_samples[c] + offset;

  1729. 

  1730.                 if ((ret = decode_block(ctx, &bd)) < 0)

  1731.                     return ret;

  1732.             }

  1733. 

  1734.             memset(reverted_channels, 0, avctx->channels * sizeof(*reverted_channels));

  1735.             offset      += div_blocks[b];

  1736.             bd.ra_block  = 0;

  1737.         }

  1738. 

  1739.         // store carryover raw samples

  1740.         for (c = 0; c < avctx->channels; c++)

  1741.             memmove(ctx->raw_samples[c] - sconf->max_order,

  1742.                     ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,

  1743.                     sizeof(*ctx->raw_samples[c]) * sconf->max_order);

  1744.     }

  1745. 

  1746.     if (sconf->floating) {

  1747.         read_diff_float_data(ctx, ra_frame);

  1748.     }

  1749. 

  1750.     if (get_bits_left(gb) < 0) {

  1751.         av_log(ctx->avctx, AV_LOG_ERROR, "Overread %d\n", -get_bits_left(gb));

  1752.         return AVERROR_INVALIDDATA;

  1753.     }

  1754. 

  1755.     return 0;

  1756. }

  1757. 

  1758. 

  1759. /** Decode an ALS frame.

  1760.  */

  1761. static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr,

  1762.                         AVPacket *avpkt)

  1763. {

  1764.     ALSDecContext *ctx       = avctx->priv_data;

  1765.     AVFrame *frame           = data;

  1766.     ALSSpecificConfig *sconf = &ctx->sconf;

  1767.     const uint8_t *buffer    = avpkt->data;

  1768.     int buffer_size          = avpkt->size;

  1769.     int invalid_frame, ret;

  1770.     unsigned int c, sample, ra_frame, bytes_read, shift;

  1771. 

  1772.     if ((ret = init_get_bits8(&ctx->gb, buffer, buffer_size)) < 0)

  1773.         return ret;

  1774. 

  1775.     // In the case that the distance between random access frames is set to zero

  1776.     // (sconf->ra_distance == 0) no frame is treated as a random access frame.

  1777.     // For the first frame, if prediction is used, all samples used from the

  1778.     // previous frame are assumed to be zero.

  1779.     ra_frame = sconf->ra_distance && !(ctx->frame_id % sconf->ra_distance);

  1780. 

  1781.     // the last frame to decode might have a different length

  1782.     if (sconf->samples != 0xFFFFFFFF)

  1783.         ctx->cur_frame_length = FFMIN(sconf->samples - ctx->frame_id * (uint64_t) sconf->frame_length,

  1784.                                       sconf->frame_length);

  1785.     else

  1786.         ctx->cur_frame_length = sconf->frame_length;

  1787. 

  1788.     // decode the frame data

  1789.     if ((invalid_frame = read_frame_data(ctx, ra_frame)) < 0)

  1790.         av_log(ctx->avctx, AV_LOG_WARNING,

  1791.                "Reading frame data failed. Skipping RA unit.\n");

  1792. 

  1793.     ctx->frame_id++;

  1794. 

  1795.     /* get output buffer */

  1796.     frame->nb_samples = ctx->cur_frame_length;

  1797.     if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)

  1798.         return ret;

  1799. 

  1800.     // transform decoded frame into output format

  1801.     #define INTERLEAVE_OUTPUT(bps)                                                   \

  1802.     {                                                                                \

  1803.         int##bps##_t *dest = (int##bps##_t*)frame->data[0];                          \

  1804.         shift = bps - ctx->avctx->bits_per_raw_sample;                               \

  1805.         if (!ctx->cs_switch) {                                                       \

  1806.             for (sample = 0; sample < ctx->cur_frame_length; sample++)               \

  1807.                 for (c = 0; c < avctx->channels; c++)                                \

  1808.                     *dest++ = ctx->raw_samples[c][sample] * (1U << shift);            \

  1809.         } else {                                                                     \

  1810.             for (sample = 0; sample < ctx->cur_frame_length; sample++)               \

  1811.                 for (c = 0; c < avctx->channels; c++)                                \

  1812.                     *dest++ = ctx->raw_samples[sconf->chan_pos[c]][sample] * (1U << shift); \

  1813.         }                                                                            \

  1814.     }

  1815. 

  1816.     if (ctx->avctx->bits_per_raw_sample <= 16) {

  1817.         INTERLEAVE_OUTPUT(16)

  1818.     } else {

  1819.         INTERLEAVE_OUTPUT(32)

  1820.     }

  1821. 

  1822.     // update CRC

  1823.     if (sconf->crc_enabled && (avctx->err_recognition & (AV_EF_CRCCHECK|AV_EF_CAREFUL))) {

  1824.         int swap = HAVE_BIGENDIAN != sconf->msb_first;

  1825. 

  1826.         if (ctx->avctx->bits_per_raw_sample == 24) {

  1827.             int32_t *src = (int32_t *)frame->data[0];

  1828. 

  1829.             for (sample = 0;

  1830.                  sample < ctx->cur_frame_length * avctx->channels;

  1831.                  sample++) {

  1832.                 int32_t v;

  1833. 

  1834.                 if (swap)

  1835.                     v = av_bswap32(src[sample]);

  1836.                 else

  1837.                     v = src[sample];

  1838.                 if (!HAVE_BIGENDIAN)

  1839.                     v >>= 8;

  1840. 

  1841.                 ctx->crc = av_crc(ctx->crc_table, ctx->crc, (uint8_t*)(&v), 3);

  1842.             }

  1843.         } else {

  1844.             uint8_t *crc_source;

  1845. 

  1846.             if (swap) {

  1847.                 if (ctx->avctx->bits_per_raw_sample <= 16) {

  1848.                     int16_t *src  = (int16_t*) frame->data[0];

  1849.                     int16_t *dest = (int16_t*) ctx->crc_buffer;

  1850.                     for (sample = 0;

  1851.                          sample < ctx->cur_frame_length * avctx->channels;

  1852.                          sample++)

  1853.                         *dest++ = av_bswap16(src[sample]);

  1854.                 } else {

  1855.                     ctx->bdsp.bswap_buf((uint32_t *) ctx->crc_buffer,

  1856.                                         (uint32_t *) frame->data[0],

  1857.                                         ctx->cur_frame_length * avctx->channels);

  1858.                 }

  1859.                 crc_source = ctx->crc_buffer;

  1860.             } else {

  1861.                 crc_source = frame->data[0];

  1862.             }

  1863. 

  1864.             ctx->crc = av_crc(ctx->crc_table, ctx->crc, crc_source,

  1865.                               ctx->cur_frame_length * avctx->channels *

  1866.                               av_get_bytes_per_sample(avctx->sample_fmt));

  1867.         }

  1868. 

  1869. 

  1870.         // check CRC sums if this is the last frame

  1871.         if (ctx->cur_frame_length != sconf->frame_length &&

  1872.             ctx->crc_org != ctx->crc) {

  1873.             av_log(avctx, AV_LOG_ERROR, "CRC error.\n");

  1874.             if (avctx->err_recognition & AV_EF_EXPLODE)

  1875.                 return AVERROR_INVALIDDATA;

  1876.         }

  1877.     }

  1878. 

  1879.     *got_frame_ptr = 1;

  1880. 

  1881.     bytes_read = invalid_frame ? buffer_size :

  1882.                                  (get_bits_count(&ctx->gb) + 7) >> 3;

  1883. 

  1884.     return bytes_read;

  1885. }

  1886. 

  1887. 

  1888. /** Uninitialize the ALS decoder.

  1889.  */

  1890. static av_cold int decode_end(AVCodecContext *avctx)

  1891. {

  1892.     ALSDecContext *ctx = avctx->priv_data;

  1893.     int i;

  1894. 

  1895.     av_freep(&ctx->sconf.chan_pos);

  1896. 

  1897.     ff_bgmc_end(&ctx->bgmc_lut, &ctx->bgmc_lut_status);

  1898. 

  1899.     av_freep(&ctx->const_block);

  1900.     av_freep(&ctx->shift_lsbs);

  1901.     av_freep(&ctx->opt_order);

  1902.     av_freep(&ctx->store_prev_samples);

  1903.     av_freep(&ctx->use_ltp);

  1904.     av_freep(&ctx->ltp_lag);

  1905.     av_freep(&ctx->ltp_gain);

  1906.     av_freep(&ctx->ltp_gain_buffer);

  1907.     av_freep(&ctx->quant_cof);

  1908.     av_freep(&ctx->lpc_cof);

  1909.     av_freep(&ctx->quant_cof_buffer);

  1910.     av_freep(&ctx->lpc_cof_buffer);

  1911.     av_freep(&ctx->lpc_cof_reversed_buffer);

  1912.     av_freep(&ctx->prev_raw_samples);

  1913.     av_freep(&ctx->raw_samples);

  1914.     av_freep(&ctx->raw_buffer);

  1915.     av_freep(&ctx->chan_data);

  1916.     av_freep(&ctx->chan_data_buffer);

  1917.     av_freep(&ctx->reverted_channels);

  1918.     av_freep(&ctx->crc_buffer);

  1919.     if (ctx->mlz) {

  1920.         av_freep(&ctx->mlz->dict);

  1921.         av_freep(&ctx->mlz);

  1922.     }

  1923.     av_freep(&ctx->acf);

  1924.     av_freep(&ctx->last_acf_mantissa);

  1925.     av_freep(&ctx->shift_value);

  1926.     av_freep(&ctx->last_shift_value);

  1927.     if (ctx->raw_mantissa) {

  1928.         for (i = 0; i < avctx->channels; i++) {

  1929.             av_freep(&ctx->raw_mantissa[i]);

  1930.         }

  1931.         av_freep(&ctx->raw_mantissa);

  1932.     }

  1933.     av_freep(&ctx->larray);

  1934.     av_freep(&ctx->nbits);

  1935. 

  1936.     return 0;

  1937. }

  1938. 

  1939. 

  1940. /** Initialize the ALS decoder.

  1941.  */

  1942. static av_cold int decode_init(AVCodecContext *avctx)

  1943. {

  1944.     unsigned int c;

  1945.     unsigned int channel_size;

  1946.     int num_buffers, ret;

  1947.     ALSDecContext *ctx = avctx->priv_data;

  1948.     ALSSpecificConfig *sconf = &ctx->sconf;

  1949.     ctx->avctx = avctx;

  1950. 

  1951.     if (!avctx->extradata) {

  1952.         av_log(avctx, AV_LOG_ERROR, "Missing required ALS extradata.\n");

  1953.         return AVERROR_INVALIDDATA;

  1954.     }

  1955. 

  1956.     if ((ret = read_specific_config(ctx)) < 0) {

  1957.         av_log(avctx, AV_LOG_ERROR, "Reading ALSSpecificConfig failed.\n");

  1958.         goto fail;

  1959.     }

  1960. 

  1961.     if ((ret = check_specific_config(ctx)) < 0) {

  1962.         goto fail;

  1963.     }

  1964. 

  1965.     if (sconf->bgmc) {

  1966.         ret = ff_bgmc_init(avctx, &ctx->bgmc_lut, &ctx->bgmc_lut_status);

  1967.         if (ret < 0)

  1968.             goto fail;

  1969.     }

  1970.     if (sconf->floating) {

  1971.         avctx->sample_fmt          = AV_SAMPLE_FMT_FLT;

  1972.         avctx->bits_per_raw_sample = 32;

  1973.     } else {

  1974.         avctx->sample_fmt          = sconf->resolution > 1

  1975.                                      ? AV_SAMPLE_FMT_S32 : AV_SAMPLE_FMT_S16;

  1976.         avctx->bits_per_raw_sample = (sconf->resolution + 1) * 8;

  1977.         if (avctx->bits_per_raw_sample > 32) {

  1978.             av_log(avctx, AV_LOG_ERROR, "Bits per raw sample %d larger than 32.\n",

  1979.                    avctx->bits_per_raw_sample);

  1980.             ret = AVERROR_INVALIDDATA;

  1981.             goto fail;

  1982.         }

  1983.     }

  1984. 

  1985.     // set maximum Rice parameter for progressive decoding based on resolution

  1986.     // This is not specified in 14496-3 but actually done by the reference

  1987.     // codec RM22 revision 2.

  1988.     ctx->s_max = sconf->resolution > 1 ? 31 : 15;

  1989. 

  1990.     // set lag value for long-term prediction

  1991.     ctx->ltp_lag_length = 8 + (avctx->sample_rate >=  96000) +

  1992.                               (avctx->sample_rate >= 192000);

  1993. 

  1994.     // allocate quantized parcor coefficient buffer

  1995.     num_buffers = sconf->mc_coding ? avctx->channels : 1;

  1996. 

  1997.     ctx->quant_cof        = av_malloc_array(num_buffers, sizeof(*ctx->quant_cof));

  1998.     ctx->lpc_cof          = av_malloc_array(num_buffers, sizeof(*ctx->lpc_cof));

  1999.     ctx->quant_cof_buffer = av_malloc_array(num_buffers * sconf->max_order,

  2000.                                             sizeof(*ctx->quant_cof_buffer));

  2001.     ctx->lpc_cof_buffer   = av_malloc_array(num_buffers * sconf->max_order,

  2002.                                             sizeof(*ctx->lpc_cof_buffer));

  2003.     ctx->lpc_cof_reversed_buffer = av_malloc_array(sconf->max_order,

  2004.                                                    sizeof(*ctx->lpc_cof_buffer));

  2005. 

  2006.     if (!ctx->quant_cof              || !ctx->lpc_cof        ||

  2007.         !ctx->quant_cof_buffer       || !ctx->lpc_cof_buffer ||

  2008.         !ctx->lpc_cof_reversed_buffer) {

  2009.         av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");

  2010.         ret = AVERROR(ENOMEM);

  2011.         goto fail;

  2012.     }

  2013. 

  2014.     // assign quantized parcor coefficient buffers

  2015.     for (c = 0; c < num_buffers; c++) {

  2016.         ctx->quant_cof[c] = ctx->quant_cof_buffer + c * sconf->max_order;

  2017.         ctx->lpc_cof[c]   = ctx->lpc_cof_buffer   + c * sconf->max_order;

  2018.     }

  2019. 

  2020.     // allocate and assign lag and gain data buffer for ltp mode

  2021.     ctx->const_block     = av_malloc_array(num_buffers, sizeof(*ctx->const_block));

  2022.     ctx->shift_lsbs      = av_malloc_array(num_buffers, sizeof(*ctx->shift_lsbs));

  2023.     ctx->opt_order       = av_malloc_array(num_buffers, sizeof(*ctx->opt_order));

  2024.     ctx->store_prev_samples = av_malloc_array(num_buffers, sizeof(*ctx->store_prev_samples));

  2025.     ctx->use_ltp         = av_mallocz_array(num_buffers, sizeof(*ctx->use_ltp));

  2026.     ctx->ltp_lag         = av_malloc_array(num_buffers, sizeof(*ctx->ltp_lag));

  2027.     ctx->ltp_gain        = av_malloc_array(num_buffers, sizeof(*ctx->ltp_gain));

  2028.     ctx->ltp_gain_buffer = av_malloc_array(num_buffers * 5, sizeof(*ctx->ltp_gain_buffer));

  2029. 

  2030.     if (!ctx->const_block || !ctx->shift_lsbs ||

  2031.         !ctx->opt_order || !ctx->store_prev_samples ||

  2032.         !ctx->use_ltp  || !ctx->ltp_lag ||

  2033.         !ctx->ltp_gain || !ctx->ltp_gain_buffer) {

  2034.         av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");

  2035.         ret = AVERROR(ENOMEM);

  2036.         goto fail;

  2037.     }

  2038. 

  2039.     for (c = 0; c < num_buffers; c++)

  2040.         ctx->ltp_gain[c] = ctx->ltp_gain_buffer + c * 5;

  2041. 

  2042.     // allocate and assign channel data buffer for mcc mode

  2043.     if (sconf->mc_coding) {

  2044.         ctx->chan_data_buffer  = av_mallocz_array(num_buffers * num_buffers,

  2045.                                                  sizeof(*ctx->chan_data_buffer));

  2046.         ctx->chan_data         = av_mallocz_array(num_buffers,

  2047.                                                  sizeof(*ctx->chan_data));

  2048.         ctx->reverted_channels = av_malloc_array(num_buffers,

  2049.                                                  sizeof(*ctx->reverted_channels));

  2050. 

  2051.         if (!ctx->chan_data_buffer || !ctx->chan_data || !ctx->reverted_channels) {

  2052.             av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");

  2053.             ret = AVERROR(ENOMEM);

  2054.             goto fail;

  2055.         }

  2056. 

  2057.         for (c = 0; c < num_buffers; c++)

  2058.             ctx->chan_data[c] = ctx->chan_data_buffer + c * num_buffers;

  2059.     } else {

  2060.         ctx->chan_data         = NULL;

  2061.         ctx->chan_data_buffer  = NULL;

  2062.         ctx->reverted_channels = NULL;

  2063.     }

  2064. 

  2065.     channel_size      = sconf->frame_length + sconf->max_order;

  2066. 

  2067.     ctx->prev_raw_samples = av_malloc_array(sconf->max_order, sizeof(*ctx->prev_raw_samples));

  2068.     ctx->raw_buffer       = av_mallocz_array(avctx->channels * channel_size, sizeof(*ctx->raw_buffer));

  2069.     ctx->raw_samples      = av_malloc_array(avctx->channels, sizeof(*ctx->raw_samples));

  2070. 

  2071.     if (sconf->floating) {

  2072.         ctx->acf               = av_malloc_array(avctx->channels, sizeof(*ctx->acf));

  2073.         ctx->shift_value       = av_malloc_array(avctx->channels, sizeof(*ctx->shift_value));

  2074.         ctx->last_shift_value  = av_malloc_array(avctx->channels, sizeof(*ctx->last_shift_value));

  2075.         ctx->last_acf_mantissa = av_malloc_array(avctx->channels, sizeof(*ctx->last_acf_mantissa));

  2076.         ctx->raw_mantissa      = av_mallocz_array(avctx->channels, sizeof(*ctx->raw_mantissa));

  2077. 

  2078.         ctx->larray = av_malloc_array(ctx->cur_frame_length * 4, sizeof(*ctx->larray));

  2079.         ctx->nbits  = av_malloc_array(ctx->cur_frame_length, sizeof(*ctx->nbits));

  2080.         ctx->mlz    = av_mallocz(sizeof(*ctx->mlz));

  2081. 

  2082.         if (!ctx->mlz || !ctx->acf || !ctx->shift_value || !ctx->last_shift_value

  2083.             || !ctx->last_acf_mantissa || !ctx->raw_mantissa) {

  2084.             av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");

  2085.             ret = AVERROR(ENOMEM);

  2086.             goto fail;

  2087.         }

  2088. 

  2089.         ff_mlz_init_dict(avctx, ctx->mlz);

  2090.         ff_mlz_flush_dict(ctx->mlz);

  2091. 

  2092.         for (c = 0; c < avctx->channels; ++c) {

  2093.             ctx->raw_mantissa[c] = av_mallocz_array(ctx->cur_frame_length, sizeof(**ctx->raw_mantissa));

  2094.         }

  2095.     }

  2096. 

  2097.     // allocate previous raw sample buffer

  2098.     if (!ctx->prev_raw_samples || !ctx->raw_buffer|| !ctx->raw_samples) {

  2099.         av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");

  2100.         ret = AVERROR(ENOMEM);

  2101.         goto fail;

  2102.     }

  2103. 

  2104.     // assign raw samples buffers

  2105.     ctx->raw_samples[0] = ctx->raw_buffer + sconf->max_order;

  2106.     for (c = 1; c < avctx->channels; c++)

  2107.         ctx->raw_samples[c] = ctx->raw_samples[c - 1] + channel_size;

  2108. 

  2109.     // allocate crc buffer

  2110.     if (HAVE_BIGENDIAN != sconf->msb_first && sconf->crc_enabled &&

  2111.         (avctx->err_recognition & (AV_EF_CRCCHECK|AV_EF_CAREFUL))) {

  2112.         ctx->crc_buffer = av_malloc_array(ctx->cur_frame_length *

  2113.                                           avctx->channels *

  2114.                                           av_get_bytes_per_sample(avctx->sample_fmt),

  2115.                                           sizeof(*ctx->crc_buffer));

  2116.         if (!ctx->crc_buffer) {

  2117.             av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");

  2118.             ret = AVERROR(ENOMEM);

  2119.             goto fail;

  2120.         }

  2121.     }

  2122. 

  2123.     ff_bswapdsp_init(&ctx->bdsp);

  2124. 

  2125.     return 0;

  2126. 

  2127. fail:

  2128.     decode_end(avctx);

  2129.     return ret;

  2130. }

  2131. 

  2132. 

  2133. /** Flush (reset) the frame ID after seeking.

  2134.  */

  2135. static av_cold void flush(AVCodecContext *avctx)

  2136. {

  2137.     ALSDecContext *ctx = avctx->priv_data;

  2138. 

  2139.     ctx->frame_id = 0;

  2140. }

  2141. 

  2142. 

  2143. AVCodec ff_als_decoder = {

  2144.     .name           = "als",

  2145.     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-4 Audio Lossless Coding (ALS)"),

  2146.     .type           = AVMEDIA_TYPE_AUDIO,

  2147.     .id             = AV_CODEC_ID_MP4ALS,

  2148.     .priv_data_size = sizeof(ALSDecContext),

  2149.     .init           = decode_init,

  2150.     .close          = decode_end,

  2151.     .decode         = decode_frame,

  2152.     .flush          = flush,

  2153.     .capabilities   = AV_CODEC_CAP_SUBFRAMES | AV_CODEC_CAP_DR1,

  2154. };