libavcodec/alsdec.c
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00001 /*
00002  * MPEG-4 ALS decoder
00003  * Copyright (c) 2009 Thilo Borgmann <thilo.borgmann _at_ googlemail.com>
00004  *
00005  * This file is part of Libav.
00006  *
00007  * Libav is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * Libav is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with Libav; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00029 //#define DEBUG
00030 
00031 
00032 #include "avcodec.h"
00033 #include "internal.h"
00034 #include "get_bits.h"
00035 #include "unary.h"
00036 #include "mpeg4audio.h"
00037 #include "bytestream.h"
00038 #include "bgmc.h"
00039 #include "dsputil.h"
00040 #include "libavutil/samplefmt.h"
00041 #include "libavutil/crc.h"
00042 
00043 #include <stdint.h>
00044 
00049 static const int8_t parcor_rice_table[3][20][2] = {
00050     { {-52, 4}, {-29, 5}, {-31, 4}, { 19, 4}, {-16, 4},
00051       { 12, 3}, { -7, 3}, {  9, 3}, { -5, 3}, {  6, 3},
00052       { -4, 3}, {  3, 3}, { -3, 2}, {  3, 2}, { -2, 2},
00053       {  3, 2}, { -1, 2}, {  2, 2}, { -1, 2}, {  2, 2} },
00054     { {-58, 3}, {-42, 4}, {-46, 4}, { 37, 5}, {-36, 4},
00055       { 29, 4}, {-29, 4}, { 25, 4}, {-23, 4}, { 20, 4},
00056       {-17, 4}, { 16, 4}, {-12, 4}, { 12, 3}, {-10, 4},
00057       {  7, 3}, { -4, 4}, {  3, 3}, { -1, 3}, {  1, 3} },
00058     { {-59, 3}, {-45, 5}, {-50, 4}, { 38, 4}, {-39, 4},
00059       { 32, 4}, {-30, 4}, { 25, 3}, {-23, 3}, { 20, 3},
00060       {-20, 3}, { 16, 3}, {-13, 3}, { 10, 3}, { -7, 3},
00061       {  3, 3}, {  0, 3}, { -1, 3}, {  2, 3}, { -1, 2} }
00062 };
00063 
00064 
00070 static const int16_t parcor_scaled_values[] = {
00071     -1048544 / 32, -1048288 / 32, -1047776 / 32, -1047008 / 32,
00072     -1045984 / 32, -1044704 / 32, -1043168 / 32, -1041376 / 32,
00073     -1039328 / 32, -1037024 / 32, -1034464 / 32, -1031648 / 32,
00074     -1028576 / 32, -1025248 / 32, -1021664 / 32, -1017824 / 32,
00075     -1013728 / 32, -1009376 / 32, -1004768 / 32,  -999904 / 32,
00076      -994784 / 32,  -989408 / 32,  -983776 / 32,  -977888 / 32,
00077      -971744 / 32,  -965344 / 32,  -958688 / 32,  -951776 / 32,
00078      -944608 / 32,  -937184 / 32,  -929504 / 32,  -921568 / 32,
00079      -913376 / 32,  -904928 / 32,  -896224 / 32,  -887264 / 32,
00080      -878048 / 32,  -868576 / 32,  -858848 / 32,  -848864 / 32,
00081      -838624 / 32,  -828128 / 32,  -817376 / 32,  -806368 / 32,
00082      -795104 / 32,  -783584 / 32,  -771808 / 32,  -759776 / 32,
00083      -747488 / 32,  -734944 / 32,  -722144 / 32,  -709088 / 32,
00084      -695776 / 32,  -682208 / 32,  -668384 / 32,  -654304 / 32,
00085      -639968 / 32,  -625376 / 32,  -610528 / 32,  -595424 / 32,
00086      -580064 / 32,  -564448 / 32,  -548576 / 32,  -532448 / 32,
00087      -516064 / 32,  -499424 / 32,  -482528 / 32,  -465376 / 32,
00088      -447968 / 32,  -430304 / 32,  -412384 / 32,  -394208 / 32,
00089      -375776 / 32,  -357088 / 32,  -338144 / 32,  -318944 / 32,
00090      -299488 / 32,  -279776 / 32,  -259808 / 32,  -239584 / 32,
00091      -219104 / 32,  -198368 / 32,  -177376 / 32,  -156128 / 32,
00092      -134624 / 32,  -112864 / 32,   -90848 / 32,   -68576 / 32,
00093       -46048 / 32,   -23264 / 32,     -224 / 32,    23072 / 32,
00094        46624 / 32,    70432 / 32,    94496 / 32,   118816 / 32,
00095       143392 / 32,   168224 / 32,   193312 / 32,   218656 / 32,
00096       244256 / 32,   270112 / 32,   296224 / 32,   322592 / 32,
00097       349216 / 32,   376096 / 32,   403232 / 32,   430624 / 32,
00098       458272 / 32,   486176 / 32,   514336 / 32,   542752 / 32,
00099       571424 / 32,   600352 / 32,   629536 / 32,   658976 / 32,
00100       688672 / 32,   718624 / 32,   748832 / 32,   779296 / 32,
00101       810016 / 32,   840992 / 32,   872224 / 32,   903712 / 32,
00102       935456 / 32,   967456 / 32,   999712 / 32,  1032224 / 32
00103 };
00104 
00105 
00109 static const uint8_t ltp_gain_values [4][4] = {
00110     { 0,  8, 16,  24},
00111     {32, 40, 48,  56},
00112     {64, 70, 76,  82},
00113     {88, 92, 96, 100}
00114 };
00115 
00116 
00120 static const int16_t mcc_weightings[] = {
00121     204,  192,  179,  166,  153,  140,  128,  115,
00122     102,   89,   76,   64,   51,   38,   25,   12,
00123       0,  -12,  -25,  -38,  -51,  -64,  -76,  -89,
00124    -102, -115, -128, -140, -153, -166, -179, -192
00125 };
00126 
00127 
00130 static const uint8_t tail_code[16][6] = {
00131     { 74, 44, 25, 13,  7, 3},
00132     { 68, 42, 24, 13,  7, 3},
00133     { 58, 39, 23, 13,  7, 3},
00134     {126, 70, 37, 19, 10, 5},
00135     {132, 70, 37, 20, 10, 5},
00136     {124, 70, 38, 20, 10, 5},
00137     {120, 69, 37, 20, 11, 5},
00138     {116, 67, 37, 20, 11, 5},
00139     {108, 66, 36, 20, 10, 5},
00140     {102, 62, 36, 20, 10, 5},
00141     { 88, 58, 34, 19, 10, 5},
00142     {162, 89, 49, 25, 13, 7},
00143     {156, 87, 49, 26, 14, 7},
00144     {150, 86, 47, 26, 14, 7},
00145     {142, 84, 47, 26, 14, 7},
00146     {131, 79, 46, 26, 14, 7}
00147 };
00148 
00149 
00150 enum RA_Flag {
00151     RA_FLAG_NONE,
00152     RA_FLAG_FRAMES,
00153     RA_FLAG_HEADER
00154 };
00155 
00156 
00157 typedef struct {
00158     uint32_t samples;         
00159     int resolution;           
00160     int floating;             
00161     int msb_first;            
00162     int frame_length;         
00163     int ra_distance;          
00164     enum RA_Flag ra_flag;     
00165     int adapt_order;          
00166     int coef_table;           
00167     int long_term_prediction; 
00168     int max_order;            
00169     int block_switching;      
00170     int bgmc;                 
00171     int sb_part;              
00172     int joint_stereo;         
00173     int mc_coding;            
00174     int chan_config;          
00175     int chan_sort;            
00176     int rlslms;               
00177     int chan_config_info;     
00178     int *chan_pos;            
00179     int crc_enabled;          
00180 } ALSSpecificConfig;
00181 
00182 
00183 typedef struct {
00184     int stop_flag;
00185     int master_channel;
00186     int time_diff_flag;
00187     int time_diff_sign;
00188     int time_diff_index;
00189     int weighting[6];
00190 } ALSChannelData;
00191 
00192 
00193 typedef struct {
00194     AVCodecContext *avctx;
00195     AVFrame frame;
00196     ALSSpecificConfig sconf;
00197     GetBitContext gb;
00198     DSPContext dsp;
00199     const AVCRC *crc_table;
00200     uint32_t crc_org;               
00201     uint32_t crc;                   
00202     unsigned int cur_frame_length;  
00203     unsigned int frame_id;          
00204     unsigned int js_switch;         
00205     unsigned int num_blocks;        
00206     unsigned int s_max;             
00207     uint8_t *bgmc_lut;              
00208     int *bgmc_lut_status;           
00209     int ltp_lag_length;             
00210     int *const_block;               
00211     unsigned int *shift_lsbs;       
00212     unsigned int *opt_order;        
00213     int *store_prev_samples;        
00214     int *use_ltp;                   
00215     int *ltp_lag;                   
00216     int **ltp_gain;                 
00217     int *ltp_gain_buffer;           
00218     int32_t **quant_cof;            
00219     int32_t *quant_cof_buffer;      
00220     int32_t **lpc_cof;              
00221     int32_t *lpc_cof_buffer;        
00222     int32_t *lpc_cof_reversed_buffer; 
00223     ALSChannelData **chan_data;     
00224     ALSChannelData *chan_data_buffer; 
00225     int *reverted_channels;         
00226     int32_t *prev_raw_samples;      
00227     int32_t **raw_samples;          
00228     int32_t *raw_buffer;            
00229     uint8_t *crc_buffer;            
00230 } ALSDecContext;
00231 
00232 
00233 typedef struct {
00234     unsigned int block_length;      
00235     unsigned int ra_block;          
00236     int          *const_block;      
00237     int          js_blocks;         
00238     unsigned int *shift_lsbs;       
00239     unsigned int *opt_order;        
00240     int          *store_prev_samples;
00241     int          *use_ltp;          
00242     int          *ltp_lag;          
00243     int          *ltp_gain;         
00244     int32_t      *quant_cof;        
00245     int32_t      *lpc_cof;          
00246     int32_t      *raw_samples;      
00247     int32_t      *prev_raw_samples; 
00248     int32_t      *raw_other;        
00249 } ALSBlockData;
00250 
00251 
00252 static av_cold void dprint_specific_config(ALSDecContext *ctx)
00253 {
00254 #ifdef DEBUG
00255     AVCodecContext *avctx    = ctx->avctx;
00256     ALSSpecificConfig *sconf = &ctx->sconf;
00257 
00258     av_dlog(avctx, "resolution = %i\n",           sconf->resolution);
00259     av_dlog(avctx, "floating = %i\n",             sconf->floating);
00260     av_dlog(avctx, "frame_length = %i\n",         sconf->frame_length);
00261     av_dlog(avctx, "ra_distance = %i\n",          sconf->ra_distance);
00262     av_dlog(avctx, "ra_flag = %i\n",              sconf->ra_flag);
00263     av_dlog(avctx, "adapt_order = %i\n",          sconf->adapt_order);
00264     av_dlog(avctx, "coef_table = %i\n",           sconf->coef_table);
00265     av_dlog(avctx, "long_term_prediction = %i\n", sconf->long_term_prediction);
00266     av_dlog(avctx, "max_order = %i\n",            sconf->max_order);
00267     av_dlog(avctx, "block_switching = %i\n",      sconf->block_switching);
00268     av_dlog(avctx, "bgmc = %i\n",                 sconf->bgmc);
00269     av_dlog(avctx, "sb_part = %i\n",              sconf->sb_part);
00270     av_dlog(avctx, "joint_stereo = %i\n",         sconf->joint_stereo);
00271     av_dlog(avctx, "mc_coding = %i\n",            sconf->mc_coding);
00272     av_dlog(avctx, "chan_config = %i\n",          sconf->chan_config);
00273     av_dlog(avctx, "chan_sort = %i\n",            sconf->chan_sort);
00274     av_dlog(avctx, "RLSLMS = %i\n",               sconf->rlslms);
00275     av_dlog(avctx, "chan_config_info = %i\n",     sconf->chan_config_info);
00276 #endif
00277 }
00278 
00279 
00282 static av_cold int read_specific_config(ALSDecContext *ctx)
00283 {
00284     GetBitContext gb;
00285     uint64_t ht_size;
00286     int i, config_offset;
00287     MPEG4AudioConfig m4ac;
00288     ALSSpecificConfig *sconf = &ctx->sconf;
00289     AVCodecContext *avctx    = ctx->avctx;
00290     uint32_t als_id, header_size, trailer_size;
00291 
00292     init_get_bits(&gb, avctx->extradata, avctx->extradata_size * 8);
00293 
00294     config_offset = avpriv_mpeg4audio_get_config(&m4ac, avctx->extradata,
00295                                                  avctx->extradata_size * 8, 1);
00296 
00297     if (config_offset < 0)
00298         return AVERROR_INVALIDDATA;
00299 
00300     skip_bits_long(&gb, config_offset);
00301 
00302     if (get_bits_left(&gb) < (30 << 3))
00303         return AVERROR_INVALIDDATA;
00304 
00305     // read the fixed items
00306     als_id                      = get_bits_long(&gb, 32);
00307     avctx->sample_rate          = m4ac.sample_rate;
00308     skip_bits_long(&gb, 32); // sample rate already known
00309     sconf->samples              = get_bits_long(&gb, 32);
00310     avctx->channels             = m4ac.channels;
00311     skip_bits(&gb, 16);      // number of channels already knwon
00312     skip_bits(&gb, 3);       // skip file_type
00313     sconf->resolution           = get_bits(&gb, 3);
00314     sconf->floating             = get_bits1(&gb);
00315     sconf->msb_first            = get_bits1(&gb);
00316     sconf->frame_length         = get_bits(&gb, 16) + 1;
00317     sconf->ra_distance          = get_bits(&gb, 8);
00318     sconf->ra_flag              = get_bits(&gb, 2);
00319     sconf->adapt_order          = get_bits1(&gb);
00320     sconf->coef_table           = get_bits(&gb, 2);
00321     sconf->long_term_prediction = get_bits1(&gb);
00322     sconf->max_order            = get_bits(&gb, 10);
00323     sconf->block_switching      = get_bits(&gb, 2);
00324     sconf->bgmc                 = get_bits1(&gb);
00325     sconf->sb_part              = get_bits1(&gb);
00326     sconf->joint_stereo         = get_bits1(&gb);
00327     sconf->mc_coding            = get_bits1(&gb);
00328     sconf->chan_config          = get_bits1(&gb);
00329     sconf->chan_sort            = get_bits1(&gb);
00330     sconf->crc_enabled          = get_bits1(&gb);
00331     sconf->rlslms               = get_bits1(&gb);
00332     skip_bits(&gb, 5);       // skip 5 reserved bits
00333     skip_bits1(&gb);         // skip aux_data_enabled
00334 
00335 
00336     // check for ALSSpecificConfig struct
00337     if (als_id != MKBETAG('A','L','S','\0'))
00338         return AVERROR_INVALIDDATA;
00339 
00340     ctx->cur_frame_length = sconf->frame_length;
00341 
00342     // read channel config
00343     if (sconf->chan_config)
00344         sconf->chan_config_info = get_bits(&gb, 16);
00345     // TODO: use this to set avctx->channel_layout
00346 
00347 
00348     // read channel sorting
00349     if (sconf->chan_sort && avctx->channels > 1) {
00350         int chan_pos_bits = av_ceil_log2(avctx->channels);
00351         int bits_needed  = avctx->channels * chan_pos_bits + 7;
00352         if (get_bits_left(&gb) < bits_needed)
00353             return AVERROR_INVALIDDATA;
00354 
00355         if (!(sconf->chan_pos = av_malloc(avctx->channels * sizeof(*sconf->chan_pos))))
00356             return AVERROR(ENOMEM);
00357 
00358         for (i = 0; i < avctx->channels; i++)
00359             sconf->chan_pos[i] = get_bits(&gb, chan_pos_bits);
00360 
00361         align_get_bits(&gb);
00362         // TODO: use this to actually do channel sorting
00363     } else {
00364         sconf->chan_sort = 0;
00365     }
00366 
00367 
00368     // read fixed header and trailer sizes,
00369     // if size = 0xFFFFFFFF then there is no data field!
00370     if (get_bits_left(&gb) < 64)
00371         return AVERROR_INVALIDDATA;
00372 
00373     header_size  = get_bits_long(&gb, 32);
00374     trailer_size = get_bits_long(&gb, 32);
00375     if (header_size  == 0xFFFFFFFF)
00376         header_size  = 0;
00377     if (trailer_size == 0xFFFFFFFF)
00378         trailer_size = 0;
00379 
00380     ht_size = ((int64_t)(header_size) + (int64_t)(trailer_size)) << 3;
00381 
00382 
00383     // skip the header and trailer data
00384     if (get_bits_left(&gb) < ht_size)
00385         return AVERROR_INVALIDDATA;
00386 
00387     if (ht_size > INT32_MAX)
00388         return AVERROR_PATCHWELCOME;
00389 
00390     skip_bits_long(&gb, ht_size);
00391 
00392 
00393     // initialize CRC calculation
00394     if (sconf->crc_enabled) {
00395         if (get_bits_left(&gb) < 32)
00396             return AVERROR_INVALIDDATA;
00397 
00398         if (avctx->err_recognition & AV_EF_CRCCHECK) {
00399             ctx->crc_table = av_crc_get_table(AV_CRC_32_IEEE_LE);
00400             ctx->crc       = 0xFFFFFFFF;
00401             ctx->crc_org   = ~get_bits_long(&gb, 32);
00402         } else
00403             skip_bits_long(&gb, 32);
00404     }
00405 
00406 
00407     // no need to read the rest of ALSSpecificConfig (ra_unit_size & aux data)
00408 
00409     dprint_specific_config(ctx);
00410 
00411     return 0;
00412 }
00413 
00414 
00417 static int check_specific_config(ALSDecContext *ctx)
00418 {
00419     ALSSpecificConfig *sconf = &ctx->sconf;
00420     int error = 0;
00421 
00422     // report unsupported feature and set error value
00423     #define MISSING_ERR(cond, str, errval)              \
00424     {                                                   \
00425         if (cond) {                                     \
00426             av_log_missing_feature(ctx->avctx, str, 0); \
00427             error = errval;                             \
00428         }                                               \
00429     }
00430 
00431     MISSING_ERR(sconf->floating,             "Floating point decoding",     -1);
00432     MISSING_ERR(sconf->rlslms,               "Adaptive RLS-LMS prediction", -1);
00433     MISSING_ERR(sconf->chan_sort,            "Channel sorting",              0);
00434 
00435     return error;
00436 }
00437 
00438 
00442 static void parse_bs_info(const uint32_t bs_info, unsigned int n,
00443                           unsigned int div, unsigned int **div_blocks,
00444                           unsigned int *num_blocks)
00445 {
00446     if (n < 31 && ((bs_info << n) & 0x40000000)) {
00447         // if the level is valid and the investigated bit n is set
00448         // then recursively check both children at bits (2n+1) and (2n+2)
00449         n   *= 2;
00450         div += 1;
00451         parse_bs_info(bs_info, n + 1, div, div_blocks, num_blocks);
00452         parse_bs_info(bs_info, n + 2, div, div_blocks, num_blocks);
00453     } else {
00454         // else the bit is not set or the last level has been reached
00455         // (bit implicitly not set)
00456         **div_blocks = div;
00457         (*div_blocks)++;
00458         (*num_blocks)++;
00459     }
00460 }
00461 
00462 
00465 static int32_t decode_rice(GetBitContext *gb, unsigned int k)
00466 {
00467     int max = get_bits_left(gb) - k;
00468     int q   = get_unary(gb, 0, max);
00469     int r   = k ? get_bits1(gb) : !(q & 1);
00470 
00471     if (k > 1) {
00472         q <<= (k - 1);
00473         q  += get_bits_long(gb, k - 1);
00474     } else if (!k) {
00475         q >>= 1;
00476     }
00477     return r ? q : ~q;
00478 }
00479 
00480 
00483 static void parcor_to_lpc(unsigned int k, const int32_t *par, int32_t *cof)
00484 {
00485     int i, j;
00486 
00487     for (i = 0, j = k - 1; i < j; i++, j--) {
00488         int tmp1 = ((MUL64(par[k], cof[j]) + (1 << 19)) >> 20);
00489         cof[j]  += ((MUL64(par[k], cof[i]) + (1 << 19)) >> 20);
00490         cof[i]  += tmp1;
00491     }
00492     if (i == j)
00493         cof[i] += ((MUL64(par[k], cof[j]) + (1 << 19)) >> 20);
00494 
00495     cof[k] = par[k];
00496 }
00497 
00498 
00503 static void get_block_sizes(ALSDecContext *ctx, unsigned int *div_blocks,
00504                             uint32_t *bs_info)
00505 {
00506     ALSSpecificConfig *sconf     = &ctx->sconf;
00507     GetBitContext *gb            = &ctx->gb;
00508     unsigned int *ptr_div_blocks = div_blocks;
00509     unsigned int b;
00510 
00511     if (sconf->block_switching) {
00512         unsigned int bs_info_len = 1 << (sconf->block_switching + 2);
00513         *bs_info = get_bits_long(gb, bs_info_len);
00514         *bs_info <<= (32 - bs_info_len);
00515     }
00516 
00517     ctx->num_blocks = 0;
00518     parse_bs_info(*bs_info, 0, 0, &ptr_div_blocks, &ctx->num_blocks);
00519 
00520     // The last frame may have an overdetermined block structure given in
00521     // the bitstream. In that case the defined block structure would need
00522     // more samples than available to be consistent.
00523     // The block structure is actually used but the block sizes are adapted
00524     // to fit the actual number of available samples.
00525     // Example: 5 samples, 2nd level block sizes: 2 2 2 2.
00526     // This results in the actual block sizes:    2 2 1 0.
00527     // This is not specified in 14496-3 but actually done by the reference
00528     // codec RM22 revision 2.
00529     // This appears to happen in case of an odd number of samples in the last
00530     // frame which is actually not allowed by the block length switching part
00531     // of 14496-3.
00532     // The ALS conformance files feature an odd number of samples in the last
00533     // frame.
00534 
00535     for (b = 0; b < ctx->num_blocks; b++)
00536         div_blocks[b] = ctx->sconf.frame_length >> div_blocks[b];
00537 
00538     if (ctx->cur_frame_length != ctx->sconf.frame_length) {
00539         unsigned int remaining = ctx->cur_frame_length;
00540 
00541         for (b = 0; b < ctx->num_blocks; b++) {
00542             if (remaining <= div_blocks[b]) {
00543                 div_blocks[b] = remaining;
00544                 ctx->num_blocks = b + 1;
00545                 break;
00546             }
00547 
00548             remaining -= div_blocks[b];
00549         }
00550     }
00551 }
00552 
00553 
00556 static void read_const_block_data(ALSDecContext *ctx, ALSBlockData *bd)
00557 {
00558     ALSSpecificConfig *sconf = &ctx->sconf;
00559     AVCodecContext *avctx    = ctx->avctx;
00560     GetBitContext *gb        = &ctx->gb;
00561 
00562     *bd->raw_samples = 0;
00563     *bd->const_block = get_bits1(gb);    // 1 = constant value, 0 = zero block (silence)
00564     bd->js_blocks    = get_bits1(gb);
00565 
00566     // skip 5 reserved bits
00567     skip_bits(gb, 5);
00568 
00569     if (*bd->const_block) {
00570         unsigned int const_val_bits = sconf->floating ? 24 : avctx->bits_per_raw_sample;
00571         *bd->raw_samples = get_sbits_long(gb, const_val_bits);
00572     }
00573 
00574     // ensure constant block decoding by reusing this field
00575     *bd->const_block = 1;
00576 }
00577 
00578 
00581 static void decode_const_block_data(ALSDecContext *ctx, ALSBlockData *bd)
00582 {
00583     int      smp = bd->block_length - 1;
00584     int32_t  val = *bd->raw_samples;
00585     int32_t *dst = bd->raw_samples + 1;
00586 
00587     // write raw samples into buffer
00588     for (; smp; smp--)
00589         *dst++ = val;
00590 }
00591 
00592 
00595 static int read_var_block_data(ALSDecContext *ctx, ALSBlockData *bd)
00596 {
00597     ALSSpecificConfig *sconf = &ctx->sconf;
00598     AVCodecContext *avctx    = ctx->avctx;
00599     GetBitContext *gb        = &ctx->gb;
00600     unsigned int k;
00601     unsigned int s[8];
00602     unsigned int sx[8];
00603     unsigned int sub_blocks, log2_sub_blocks, sb_length;
00604     unsigned int start      = 0;
00605     unsigned int opt_order;
00606     int          sb;
00607     int32_t      *quant_cof = bd->quant_cof;
00608     int32_t      *current_res;
00609 
00610 
00611     // ensure variable block decoding by reusing this field
00612     *bd->const_block = 0;
00613 
00614     *bd->opt_order  = 1;
00615     bd->js_blocks   = get_bits1(gb);
00616 
00617     opt_order       = *bd->opt_order;
00618 
00619     // determine the number of subblocks for entropy decoding
00620     if (!sconf->bgmc && !sconf->sb_part) {
00621         log2_sub_blocks = 0;
00622     } else {
00623         if (sconf->bgmc && sconf->sb_part)
00624             log2_sub_blocks = get_bits(gb, 2);
00625         else
00626             log2_sub_blocks = 2 * get_bits1(gb);
00627     }
00628 
00629     sub_blocks = 1 << log2_sub_blocks;
00630 
00631     // do not continue in case of a damaged stream since
00632     // block_length must be evenly divisible by sub_blocks
00633     if (bd->block_length & (sub_blocks - 1)) {
00634         av_log(avctx, AV_LOG_WARNING,
00635                "Block length is not evenly divisible by the number of subblocks.\n");
00636         return AVERROR_INVALIDDATA;
00637     }
00638 
00639     sb_length = bd->block_length >> log2_sub_blocks;
00640 
00641     if (sconf->bgmc) {
00642         s[0] = get_bits(gb, 8 + (sconf->resolution > 1));
00643         for (k = 1; k < sub_blocks; k++)
00644             s[k] = s[k - 1] + decode_rice(gb, 2);
00645 
00646         for (k = 0; k < sub_blocks; k++) {
00647             sx[k]   = s[k] & 0x0F;
00648             s [k] >>= 4;
00649         }
00650     } else {
00651         s[0] = get_bits(gb, 4 + (sconf->resolution > 1));
00652         for (k = 1; k < sub_blocks; k++)
00653             s[k] = s[k - 1] + decode_rice(gb, 0);
00654     }
00655     for (k = 1; k < sub_blocks; k++)
00656         if (s[k] > 32) {
00657             av_log(avctx, AV_LOG_ERROR, "k invalid for rice code.\n");
00658             return AVERROR_INVALIDDATA;
00659         }
00660 
00661     if (get_bits1(gb))
00662         *bd->shift_lsbs = get_bits(gb, 4) + 1;
00663 
00664     *bd->store_prev_samples = (bd->js_blocks && bd->raw_other) || *bd->shift_lsbs;
00665 
00666 
00667     if (!sconf->rlslms) {
00668         if (sconf->adapt_order) {
00669             int opt_order_length = av_ceil_log2(av_clip((bd->block_length >> 3) - 1,
00670                                                 2, sconf->max_order + 1));
00671             *bd->opt_order       = get_bits(gb, opt_order_length);
00672             if (*bd->opt_order > sconf->max_order) {
00673                 *bd->opt_order = sconf->max_order;
00674                 av_log(avctx, AV_LOG_ERROR, "Predictor order too large!\n");
00675                 return AVERROR_INVALIDDATA;
00676             }
00677         } else {
00678             *bd->opt_order = sconf->max_order;
00679         }
00680 
00681         opt_order = *bd->opt_order;
00682 
00683         if (opt_order) {
00684             int add_base;
00685 
00686             if (sconf->coef_table == 3) {
00687                 add_base = 0x7F;
00688 
00689                 // read coefficient 0
00690                 quant_cof[0] = 32 * parcor_scaled_values[get_bits(gb, 7)];
00691 
00692                 // read coefficient 1
00693                 if (opt_order > 1)
00694                     quant_cof[1] = -32 * parcor_scaled_values[get_bits(gb, 7)];
00695 
00696                 // read coefficients 2 to opt_order
00697                 for (k = 2; k < opt_order; k++)
00698                     quant_cof[k] = get_bits(gb, 7);
00699             } else {
00700                 int k_max;
00701                 add_base = 1;
00702 
00703                 // read coefficient 0 to 19
00704                 k_max = FFMIN(opt_order, 20);
00705                 for (k = 0; k < k_max; k++) {
00706                     int rice_param = parcor_rice_table[sconf->coef_table][k][1];
00707                     int offset     = parcor_rice_table[sconf->coef_table][k][0];
00708                     quant_cof[k] = decode_rice(gb, rice_param) + offset;
00709                     if (quant_cof[k] < -64 || quant_cof[k] > 63) {
00710                         av_log(avctx, AV_LOG_ERROR, "quant_cof %d is out of range\n", quant_cof[k]);
00711                         return AVERROR_INVALIDDATA;
00712                     }
00713                 }
00714 
00715                 // read coefficients 20 to 126
00716                 k_max = FFMIN(opt_order, 127);
00717                 for (; k < k_max; k++)
00718                     quant_cof[k] = decode_rice(gb, 2) + (k & 1);
00719 
00720                 // read coefficients 127 to opt_order
00721                 for (; k < opt_order; k++)
00722                     quant_cof[k] = decode_rice(gb, 1);
00723 
00724                 quant_cof[0] = 32 * parcor_scaled_values[quant_cof[0] + 64];
00725 
00726                 if (opt_order > 1)
00727                     quant_cof[1] = -32 * parcor_scaled_values[quant_cof[1] + 64];
00728             }
00729 
00730             for (k = 2; k < opt_order; k++)
00731                 quant_cof[k] = (quant_cof[k] << 14) + (add_base << 13);
00732         }
00733     }
00734 
00735     // read LTP gain and lag values
00736     if (sconf->long_term_prediction) {
00737         *bd->use_ltp = get_bits1(gb);
00738 
00739         if (*bd->use_ltp) {
00740             int r, c;
00741 
00742             bd->ltp_gain[0]   = decode_rice(gb, 1) << 3;
00743             bd->ltp_gain[1]   = decode_rice(gb, 2) << 3;
00744 
00745             r                 = get_unary(gb, 0, 3);
00746             c                 = get_bits(gb, 2);
00747             bd->ltp_gain[2]   = ltp_gain_values[r][c];
00748 
00749             bd->ltp_gain[3]   = decode_rice(gb, 2) << 3;
00750             bd->ltp_gain[4]   = decode_rice(gb, 1) << 3;
00751 
00752             *bd->ltp_lag      = get_bits(gb, ctx->ltp_lag_length);
00753             *bd->ltp_lag     += FFMAX(4, opt_order + 1);
00754         }
00755     }
00756 
00757     // read first value and residuals in case of a random access block
00758     if (bd->ra_block) {
00759         if (opt_order)
00760             bd->raw_samples[0] = decode_rice(gb, avctx->bits_per_raw_sample - 4);
00761         if (opt_order > 1)
00762             bd->raw_samples[1] = decode_rice(gb, FFMIN(s[0] + 3, ctx->s_max));
00763         if (opt_order > 2)
00764             bd->raw_samples[2] = decode_rice(gb, FFMIN(s[0] + 1, ctx->s_max));
00765 
00766         start = FFMIN(opt_order, 3);
00767     }
00768 
00769     // read all residuals
00770     if (sconf->bgmc) {
00771         int          delta[8];
00772         unsigned int k    [8];
00773         unsigned int b = av_clip((av_ceil_log2(bd->block_length) - 3) >> 1, 0, 5);
00774 
00775         // read most significant bits
00776         unsigned int high;
00777         unsigned int low;
00778         unsigned int value;
00779 
00780         ff_bgmc_decode_init(gb, &high, &low, &value);
00781 
00782         current_res = bd->raw_samples + start;
00783 
00784         for (sb = 0; sb < sub_blocks; sb++) {
00785             unsigned int sb_len  = sb_length - (sb ? 0 : start);
00786 
00787             k    [sb] = s[sb] > b ? s[sb] - b : 0;
00788             delta[sb] = 5 - s[sb] + k[sb];
00789 
00790             ff_bgmc_decode(gb, sb_len, current_res,
00791                         delta[sb], sx[sb], &high, &low, &value, ctx->bgmc_lut, ctx->bgmc_lut_status);
00792 
00793             current_res += sb_len;
00794         }
00795 
00796         ff_bgmc_decode_end(gb);
00797 
00798 
00799         // read least significant bits and tails
00800         current_res = bd->raw_samples + start;
00801 
00802         for (sb = 0; sb < sub_blocks; sb++, start = 0) {
00803             unsigned int cur_tail_code = tail_code[sx[sb]][delta[sb]];
00804             unsigned int cur_k         = k[sb];
00805             unsigned int cur_s         = s[sb];
00806 
00807             for (; start < sb_length; start++) {
00808                 int32_t res = *current_res;
00809 
00810                 if (res == cur_tail_code) {
00811                     unsigned int max_msb =   (2 + (sx[sb] > 2) + (sx[sb] > 10))
00812                                           << (5 - delta[sb]);
00813 
00814                     res = decode_rice(gb, cur_s);
00815 
00816                     if (res >= 0) {
00817                         res += (max_msb    ) << cur_k;
00818                     } else {
00819                         res -= (max_msb - 1) << cur_k;
00820                     }
00821                 } else {
00822                     if (res > cur_tail_code)
00823                         res--;
00824 
00825                     if (res & 1)
00826                         res = -res;
00827 
00828                     res >>= 1;
00829 
00830                     if (cur_k) {
00831                         res <<= cur_k;
00832                         res  |= get_bits_long(gb, cur_k);
00833                     }
00834                 }
00835 
00836                 *current_res++ = res;
00837             }
00838         }
00839     } else {
00840         current_res = bd->raw_samples + start;
00841 
00842         for (sb = 0; sb < sub_blocks; sb++, start = 0)
00843             for (; start < sb_length; start++)
00844                 *current_res++ = decode_rice(gb, s[sb]);
00845      }
00846 
00847     if (!sconf->mc_coding || ctx->js_switch)
00848         align_get_bits(gb);
00849 
00850     return 0;
00851 }
00852 
00853 
00856 static int decode_var_block_data(ALSDecContext *ctx, ALSBlockData *bd)
00857 {
00858     ALSSpecificConfig *sconf = &ctx->sconf;
00859     unsigned int block_length = bd->block_length;
00860     unsigned int smp = 0;
00861     unsigned int k;
00862     int opt_order             = *bd->opt_order;
00863     int sb;
00864     int64_t y;
00865     int32_t *quant_cof        = bd->quant_cof;
00866     int32_t *lpc_cof          = bd->lpc_cof;
00867     int32_t *raw_samples      = bd->raw_samples;
00868     int32_t *raw_samples_end  = bd->raw_samples + bd->block_length;
00869     int32_t *lpc_cof_reversed = ctx->lpc_cof_reversed_buffer;
00870 
00871     // reverse long-term prediction
00872     if (*bd->use_ltp) {
00873         int ltp_smp;
00874 
00875         for (ltp_smp = FFMAX(*bd->ltp_lag - 2, 0); ltp_smp < block_length; ltp_smp++) {
00876             int center = ltp_smp - *bd->ltp_lag;
00877             int begin  = FFMAX(0, center - 2);
00878             int end    = center + 3;
00879             int tab    = 5 - (end - begin);
00880             int base;
00881 
00882             y = 1 << 6;
00883 
00884             for (base = begin; base < end; base++, tab++)
00885                 y += MUL64(bd->ltp_gain[tab], raw_samples[base]);
00886 
00887             raw_samples[ltp_smp] += y >> 7;
00888         }
00889     }
00890 
00891     // reconstruct all samples from residuals
00892     if (bd->ra_block) {
00893         for (smp = 0; smp < opt_order; smp++) {
00894             y = 1 << 19;
00895 
00896             for (sb = 0; sb < smp; sb++)
00897                 y += MUL64(lpc_cof[sb], raw_samples[-(sb + 1)]);
00898 
00899             *raw_samples++ -= y >> 20;
00900             parcor_to_lpc(smp, quant_cof, lpc_cof);
00901         }
00902     } else {
00903         for (k = 0; k < opt_order; k++)
00904             parcor_to_lpc(k, quant_cof, lpc_cof);
00905 
00906         // store previous samples in case that they have to be altered
00907         if (*bd->store_prev_samples)
00908             memcpy(bd->prev_raw_samples, raw_samples - sconf->max_order,
00909                    sizeof(*bd->prev_raw_samples) * sconf->max_order);
00910 
00911         // reconstruct difference signal for prediction (joint-stereo)
00912         if (bd->js_blocks && bd->raw_other) {
00913             int32_t *left, *right;
00914 
00915             if (bd->raw_other > raw_samples) {  // D = R - L
00916                 left  = raw_samples;
00917                 right = bd->raw_other;
00918             } else {                                // D = R - L
00919                 left  = bd->raw_other;
00920                 right = raw_samples;
00921             }
00922 
00923             for (sb = -1; sb >= -sconf->max_order; sb--)
00924                 raw_samples[sb] = right[sb] - left[sb];
00925         }
00926 
00927         // reconstruct shifted signal
00928         if (*bd->shift_lsbs)
00929             for (sb = -1; sb >= -sconf->max_order; sb--)
00930                 raw_samples[sb] >>= *bd->shift_lsbs;
00931     }
00932 
00933     // reverse linear prediction coefficients for efficiency
00934     lpc_cof = lpc_cof + opt_order;
00935 
00936     for (sb = 0; sb < opt_order; sb++)
00937         lpc_cof_reversed[sb] = lpc_cof[-(sb + 1)];
00938 
00939     // reconstruct raw samples
00940     raw_samples = bd->raw_samples + smp;
00941     lpc_cof     = lpc_cof_reversed + opt_order;
00942 
00943     for (; raw_samples < raw_samples_end; raw_samples++) {
00944         y = 1 << 19;
00945 
00946         for (sb = -opt_order; sb < 0; sb++)
00947             y += MUL64(lpc_cof[sb], raw_samples[sb]);
00948 
00949         *raw_samples -= y >> 20;
00950     }
00951 
00952     raw_samples = bd->raw_samples;
00953 
00954     // restore previous samples in case that they have been altered
00955     if (*bd->store_prev_samples)
00956         memcpy(raw_samples - sconf->max_order, bd->prev_raw_samples,
00957                sizeof(*raw_samples) * sconf->max_order);
00958 
00959     return 0;
00960 }
00961 
00962 
00965 static int read_block(ALSDecContext *ctx, ALSBlockData *bd)
00966 {
00967     int ret = 0;
00968     GetBitContext *gb        = &ctx->gb;
00969 
00970     *bd->shift_lsbs = 0;
00971     // read block type flag and read the samples accordingly
00972     if (get_bits1(gb)) {
00973         ret = read_var_block_data(ctx, bd);
00974     } else {
00975         read_const_block_data(ctx, bd);
00976     }
00977 
00978     return ret;
00979 }
00980 
00981 
00984 static int decode_block(ALSDecContext *ctx, ALSBlockData *bd)
00985 {
00986     unsigned int smp;
00987     int ret = 0;
00988 
00989     // read block type flag and read the samples accordingly
00990     if (*bd->const_block)
00991         decode_const_block_data(ctx, bd);
00992     else
00993         ret = decode_var_block_data(ctx, bd); // always return 0
00994 
00995     if (ret < 0)
00996         return ret;
00997 
00998     // TODO: read RLSLMS extension data
00999 
01000     if (*bd->shift_lsbs)
01001         for (smp = 0; smp < bd->block_length; smp++)
01002             bd->raw_samples[smp] <<= *bd->shift_lsbs;
01003 
01004     return 0;
01005 }
01006 
01007 
01010 static int read_decode_block(ALSDecContext *ctx, ALSBlockData *bd)
01011 {
01012     int ret;
01013 
01014     if ((ret = read_block(ctx, bd)) < 0)
01015         return ret;
01016 
01017     return decode_block(ctx, bd);
01018 }
01019 
01020 
01024 static void zero_remaining(unsigned int b, unsigned int b_max,
01025                            const unsigned int *div_blocks, int32_t *buf)
01026 {
01027     unsigned int count = 0;
01028 
01029     for (; b < b_max; b++)
01030         count += div_blocks[b];
01031 
01032     if (count)
01033         memset(buf, 0, sizeof(*buf) * count);
01034 }
01035 
01036 
01039 static int decode_blocks_ind(ALSDecContext *ctx, unsigned int ra_frame,
01040                              unsigned int c, const unsigned int *div_blocks,
01041                              unsigned int *js_blocks)
01042 {
01043     int ret;
01044     unsigned int b;
01045     ALSBlockData bd;
01046 
01047     memset(&bd, 0, sizeof(ALSBlockData));
01048 
01049     bd.ra_block         = ra_frame;
01050     bd.const_block      = ctx->const_block;
01051     bd.shift_lsbs       = ctx->shift_lsbs;
01052     bd.opt_order        = ctx->opt_order;
01053     bd.store_prev_samples = ctx->store_prev_samples;
01054     bd.use_ltp          = ctx->use_ltp;
01055     bd.ltp_lag          = ctx->ltp_lag;
01056     bd.ltp_gain         = ctx->ltp_gain[0];
01057     bd.quant_cof        = ctx->quant_cof[0];
01058     bd.lpc_cof          = ctx->lpc_cof[0];
01059     bd.prev_raw_samples = ctx->prev_raw_samples;
01060     bd.raw_samples      = ctx->raw_samples[c];
01061 
01062 
01063     for (b = 0; b < ctx->num_blocks; b++) {
01064         bd.block_length     = div_blocks[b];
01065 
01066         if ((ret = read_decode_block(ctx, &bd)) < 0) {
01067             // damaged block, write zero for the rest of the frame
01068             zero_remaining(b, ctx->num_blocks, div_blocks, bd.raw_samples);
01069             return ret;
01070         }
01071         bd.raw_samples += div_blocks[b];
01072         bd.ra_block     = 0;
01073     }
01074 
01075     return 0;
01076 }
01077 
01078 
01081 static int decode_blocks(ALSDecContext *ctx, unsigned int ra_frame,
01082                          unsigned int c, const unsigned int *div_blocks,
01083                          unsigned int *js_blocks)
01084 {
01085     ALSSpecificConfig *sconf = &ctx->sconf;
01086     unsigned int offset = 0;
01087     unsigned int b;
01088     int ret;
01089     ALSBlockData bd[2];
01090 
01091     memset(bd, 0, 2 * sizeof(ALSBlockData));
01092 
01093     bd[0].ra_block         = ra_frame;
01094     bd[0].const_block      = ctx->const_block;
01095     bd[0].shift_lsbs       = ctx->shift_lsbs;
01096     bd[0].opt_order        = ctx->opt_order;
01097     bd[0].store_prev_samples = ctx->store_prev_samples;
01098     bd[0].use_ltp          = ctx->use_ltp;
01099     bd[0].ltp_lag          = ctx->ltp_lag;
01100     bd[0].ltp_gain         = ctx->ltp_gain[0];
01101     bd[0].quant_cof        = ctx->quant_cof[0];
01102     bd[0].lpc_cof          = ctx->lpc_cof[0];
01103     bd[0].prev_raw_samples = ctx->prev_raw_samples;
01104     bd[0].js_blocks        = *js_blocks;
01105 
01106     bd[1].ra_block         = ra_frame;
01107     bd[1].const_block      = ctx->const_block;
01108     bd[1].shift_lsbs       = ctx->shift_lsbs;
01109     bd[1].opt_order        = ctx->opt_order;
01110     bd[1].store_prev_samples = ctx->store_prev_samples;
01111     bd[1].use_ltp          = ctx->use_ltp;
01112     bd[1].ltp_lag          = ctx->ltp_lag;
01113     bd[1].ltp_gain         = ctx->ltp_gain[0];
01114     bd[1].quant_cof        = ctx->quant_cof[0];
01115     bd[1].lpc_cof          = ctx->lpc_cof[0];
01116     bd[1].prev_raw_samples = ctx->prev_raw_samples;
01117     bd[1].js_blocks        = *(js_blocks + 1);
01118 
01119     // decode all blocks
01120     for (b = 0; b < ctx->num_blocks; b++) {
01121         unsigned int s;
01122 
01123         bd[0].block_length = div_blocks[b];
01124         bd[1].block_length = div_blocks[b];
01125 
01126         bd[0].raw_samples  = ctx->raw_samples[c    ] + offset;
01127         bd[1].raw_samples  = ctx->raw_samples[c + 1] + offset;
01128 
01129         bd[0].raw_other    = bd[1].raw_samples;
01130         bd[1].raw_other    = bd[0].raw_samples;
01131 
01132         if ((ret = read_decode_block(ctx, &bd[0])) < 0 ||
01133             (ret = read_decode_block(ctx, &bd[1])) < 0)
01134             goto fail;
01135 
01136 
01137         // reconstruct joint-stereo blocks
01138         if (bd[0].js_blocks) {
01139             if (bd[1].js_blocks)
01140                 av_log(ctx->avctx, AV_LOG_WARNING, "Invalid channel pair!\n");
01141 
01142             for (s = 0; s < div_blocks[b]; s++)
01143                 bd[0].raw_samples[s] = bd[1].raw_samples[s] - bd[0].raw_samples[s];
01144         } else if (bd[1].js_blocks) {
01145             for (s = 0; s < div_blocks[b]; s++)
01146                 bd[1].raw_samples[s] = bd[1].raw_samples[s] + bd[0].raw_samples[s];
01147         }
01148 
01149         offset  += div_blocks[b];
01150         bd[0].ra_block = 0;
01151         bd[1].ra_block = 0;
01152     }
01153 
01154     // store carryover raw samples,
01155     // the others channel raw samples are stored by the calling function.
01156     memmove(ctx->raw_samples[c] - sconf->max_order,
01157             ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,
01158             sizeof(*ctx->raw_samples[c]) * sconf->max_order);
01159 
01160     return 0;
01161 fail:
01162     // damaged block, write zero for the rest of the frame
01163     zero_remaining(b, ctx->num_blocks, div_blocks, bd[0].raw_samples);
01164     zero_remaining(b, ctx->num_blocks, div_blocks, bd[1].raw_samples);
01165     return ret;
01166 }
01167 
01168 static inline int als_weighting(GetBitContext *gb, int k, int off)
01169 {
01170     int idx = av_clip(decode_rice(gb, k) + off,
01171                       0, FF_ARRAY_ELEMS(mcc_weightings) - 1);
01172     return mcc_weightings[idx];
01173 }
01174 
01177 static int read_channel_data(ALSDecContext *ctx, ALSChannelData *cd, int c)
01178 {
01179     GetBitContext *gb       = &ctx->gb;
01180     ALSChannelData *current = cd;
01181     unsigned int channels   = ctx->avctx->channels;
01182     int entries             = 0;
01183 
01184     while (entries < channels && !(current->stop_flag = get_bits1(gb))) {
01185         current->master_channel = get_bits_long(gb, av_ceil_log2(channels));
01186 
01187         if (current->master_channel >= channels) {
01188             av_log(ctx->avctx, AV_LOG_ERROR, "Invalid master channel!\n");
01189             return AVERROR_INVALIDDATA;
01190         }
01191 
01192         if (current->master_channel != c) {
01193             current->time_diff_flag = get_bits1(gb);
01194             current->weighting[0]   = als_weighting(gb, 1, 16);
01195             current->weighting[1]   = als_weighting(gb, 2, 14);
01196             current->weighting[2]   = als_weighting(gb, 1, 16);
01197 
01198             if (current->time_diff_flag) {
01199                 current->weighting[3] = als_weighting(gb, 1, 16);
01200                 current->weighting[4] = als_weighting(gb, 1, 16);
01201                 current->weighting[5] = als_weighting(gb, 1, 16);
01202 
01203                 current->time_diff_sign  = get_bits1(gb);
01204                 current->time_diff_index = get_bits(gb, ctx->ltp_lag_length - 3) + 3;
01205             }
01206         }
01207 
01208         current++;
01209         entries++;
01210     }
01211 
01212     if (entries == channels) {
01213         av_log(ctx->avctx, AV_LOG_ERROR, "Damaged channel data!\n");
01214         return AVERROR_INVALIDDATA;
01215     }
01216 
01217     align_get_bits(gb);
01218     return 0;
01219 }
01220 
01221 
01224 static int revert_channel_correlation(ALSDecContext *ctx, ALSBlockData *bd,
01225                                        ALSChannelData **cd, int *reverted,
01226                                        unsigned int offset, int c)
01227 {
01228     ALSChannelData *ch = cd[c];
01229     unsigned int   dep = 0;
01230     unsigned int channels = ctx->avctx->channels;
01231 
01232     if (reverted[c])
01233         return 0;
01234 
01235     reverted[c] = 1;
01236 
01237     while (dep < channels && !ch[dep].stop_flag) {
01238         revert_channel_correlation(ctx, bd, cd, reverted, offset,
01239                                    ch[dep].master_channel);
01240 
01241         dep++;
01242     }
01243 
01244     if (dep == channels) {
01245         av_log(ctx->avctx, AV_LOG_WARNING, "Invalid channel correlation!\n");
01246         return AVERROR_INVALIDDATA;
01247     }
01248 
01249     bd->const_block = ctx->const_block + c;
01250     bd->shift_lsbs  = ctx->shift_lsbs + c;
01251     bd->opt_order   = ctx->opt_order + c;
01252     bd->store_prev_samples = ctx->store_prev_samples + c;
01253     bd->use_ltp     = ctx->use_ltp + c;
01254     bd->ltp_lag     = ctx->ltp_lag + c;
01255     bd->ltp_gain    = ctx->ltp_gain[c];
01256     bd->lpc_cof     = ctx->lpc_cof[c];
01257     bd->quant_cof   = ctx->quant_cof[c];
01258     bd->raw_samples = ctx->raw_samples[c] + offset;
01259 
01260     dep = 0;
01261     while (!ch[dep].stop_flag) {
01262         unsigned int smp;
01263         unsigned int begin = 1;
01264         unsigned int end   = bd->block_length - 1;
01265         int64_t y;
01266         int32_t *master = ctx->raw_samples[ch[dep].master_channel] + offset;
01267 
01268         if (ch[dep].time_diff_flag) {
01269             int t = ch[dep].time_diff_index;
01270 
01271             if (ch[dep].time_diff_sign) {
01272                 t      = -t;
01273                 begin -= t;
01274             } else {
01275                 end   -= t;
01276             }
01277 
01278             for (smp = begin; smp < end; smp++) {
01279                 y  = (1 << 6) +
01280                      MUL64(ch[dep].weighting[0], master[smp - 1    ]) +
01281                      MUL64(ch[dep].weighting[1], master[smp        ]) +
01282                      MUL64(ch[dep].weighting[2], master[smp + 1    ]) +
01283                      MUL64(ch[dep].weighting[3], master[smp - 1 + t]) +
01284                      MUL64(ch[dep].weighting[4], master[smp     + t]) +
01285                      MUL64(ch[dep].weighting[5], master[smp + 1 + t]);
01286 
01287                 bd->raw_samples[smp] += y >> 7;
01288             }
01289         } else {
01290             for (smp = begin; smp < end; smp++) {
01291                 y  = (1 << 6) +
01292                      MUL64(ch[dep].weighting[0], master[smp - 1]) +
01293                      MUL64(ch[dep].weighting[1], master[smp    ]) +
01294                      MUL64(ch[dep].weighting[2], master[smp + 1]);
01295 
01296                 bd->raw_samples[smp] += y >> 7;
01297             }
01298         }
01299 
01300         dep++;
01301     }
01302 
01303     return 0;
01304 }
01305 
01306 
01309 static int read_frame_data(ALSDecContext *ctx, unsigned int ra_frame)
01310 {
01311     ALSSpecificConfig *sconf = &ctx->sconf;
01312     AVCodecContext *avctx    = ctx->avctx;
01313     GetBitContext *gb = &ctx->gb;
01314     unsigned int div_blocks[32];                
01315     unsigned int c;
01316     unsigned int js_blocks[2];
01317 
01318     uint32_t bs_info = 0;
01319     int ret;
01320 
01321     // skip the size of the ra unit if present in the frame
01322     if (sconf->ra_flag == RA_FLAG_FRAMES && ra_frame)
01323         skip_bits_long(gb, 32);
01324 
01325     if (sconf->mc_coding && sconf->joint_stereo) {
01326         ctx->js_switch = get_bits1(gb);
01327         align_get_bits(gb);
01328     }
01329 
01330     if (!sconf->mc_coding || ctx->js_switch) {
01331         int independent_bs = !sconf->joint_stereo;
01332 
01333         for (c = 0; c < avctx->channels; c++) {
01334             js_blocks[0] = 0;
01335             js_blocks[1] = 0;
01336 
01337             get_block_sizes(ctx, div_blocks, &bs_info);
01338 
01339             // if joint_stereo and block_switching is set, independent decoding
01340             // is signaled via the first bit of bs_info
01341             if (sconf->joint_stereo && sconf->block_switching)
01342                 if (bs_info >> 31)
01343                     independent_bs = 2;
01344 
01345             // if this is the last channel, it has to be decoded independently
01346             if (c == avctx->channels - 1)
01347                 independent_bs = 1;
01348 
01349             if (independent_bs) {
01350                 ret = decode_blocks_ind(ctx, ra_frame, c,
01351                                         div_blocks, js_blocks);
01352                 if (ret < 0)
01353                     return ret;
01354                 independent_bs--;
01355             } else {
01356                 ret = decode_blocks(ctx, ra_frame, c, div_blocks, js_blocks);
01357                 if (ret < 0)
01358                     return ret;
01359 
01360                 c++;
01361             }
01362 
01363             // store carryover raw samples
01364             memmove(ctx->raw_samples[c] - sconf->max_order,
01365                     ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,
01366                     sizeof(*ctx->raw_samples[c]) * sconf->max_order);
01367         }
01368     } else { // multi-channel coding
01369         ALSBlockData   bd;
01370         int            b;
01371         int            *reverted_channels = ctx->reverted_channels;
01372         unsigned int   offset             = 0;
01373 
01374         for (c = 0; c < avctx->channels; c++)
01375             if (ctx->chan_data[c] < ctx->chan_data_buffer) {
01376                 av_log(ctx->avctx, AV_LOG_ERROR, "Invalid channel data!\n");
01377                 return AVERROR_INVALIDDATA;
01378             }
01379 
01380         memset(&bd,               0, sizeof(ALSBlockData));
01381         memset(reverted_channels, 0, sizeof(*reverted_channels) * avctx->channels);
01382 
01383         bd.ra_block         = ra_frame;
01384         bd.prev_raw_samples = ctx->prev_raw_samples;
01385 
01386         get_block_sizes(ctx, div_blocks, &bs_info);
01387 
01388         for (b = 0; b < ctx->num_blocks; b++) {
01389             bd.block_length = div_blocks[b];
01390             if (bd.block_length <= 0) {
01391                 av_log(ctx->avctx, AV_LOG_WARNING,
01392                        "Invalid block length %d in channel data!\n", bd.block_length);
01393                 continue;
01394             }
01395 
01396             for (c = 0; c < avctx->channels; c++) {
01397                 bd.const_block = ctx->const_block + c;
01398                 bd.shift_lsbs  = ctx->shift_lsbs + c;
01399                 bd.opt_order   = ctx->opt_order + c;
01400                 bd.store_prev_samples = ctx->store_prev_samples + c;
01401                 bd.use_ltp     = ctx->use_ltp + c;
01402                 bd.ltp_lag     = ctx->ltp_lag + c;
01403                 bd.ltp_gain    = ctx->ltp_gain[c];
01404                 bd.lpc_cof     = ctx->lpc_cof[c];
01405                 bd.quant_cof   = ctx->quant_cof[c];
01406                 bd.raw_samples = ctx->raw_samples[c] + offset;
01407                 bd.raw_other   = NULL;
01408 
01409                 read_block(ctx, &bd);
01410                 if (read_channel_data(ctx, ctx->chan_data[c], c))
01411                     return -1;
01412             }
01413 
01414             for (c = 0; c < avctx->channels; c++) {
01415                 ret = revert_channel_correlation(ctx, &bd, ctx->chan_data,
01416                                                  reverted_channels, offset, c);
01417                 if (ret < 0)
01418                     return ret;
01419             }
01420             for (c = 0; c < avctx->channels; c++) {
01421                 bd.const_block = ctx->const_block + c;
01422                 bd.shift_lsbs  = ctx->shift_lsbs + c;
01423                 bd.opt_order   = ctx->opt_order + c;
01424                 bd.store_prev_samples = ctx->store_prev_samples + c;
01425                 bd.use_ltp     = ctx->use_ltp + c;
01426                 bd.ltp_lag     = ctx->ltp_lag + c;
01427                 bd.ltp_gain    = ctx->ltp_gain[c];
01428                 bd.lpc_cof     = ctx->lpc_cof[c];
01429                 bd.quant_cof   = ctx->quant_cof[c];
01430                 bd.raw_samples = ctx->raw_samples[c] + offset;
01431                 decode_block(ctx, &bd);
01432             }
01433 
01434             memset(reverted_channels, 0, avctx->channels * sizeof(*reverted_channels));
01435             offset      += div_blocks[b];
01436             bd.ra_block  = 0;
01437         }
01438 
01439         // store carryover raw samples
01440         for (c = 0; c < avctx->channels; c++)
01441             memmove(ctx->raw_samples[c] - sconf->max_order,
01442                     ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,
01443                     sizeof(*ctx->raw_samples[c]) * sconf->max_order);
01444     }
01445 
01446     // TODO: read_diff_float_data
01447 
01448     return 0;
01449 }
01450 
01451 
01454 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr,
01455                         AVPacket *avpkt)
01456 {
01457     ALSDecContext *ctx       = avctx->priv_data;
01458     ALSSpecificConfig *sconf = &ctx->sconf;
01459     const uint8_t *buffer    = avpkt->data;
01460     int buffer_size          = avpkt->size;
01461     int invalid_frame, ret;
01462     unsigned int c, sample, ra_frame, bytes_read, shift;
01463 
01464     init_get_bits(&ctx->gb, buffer, buffer_size * 8);
01465 
01466     // In the case that the distance between random access frames is set to zero
01467     // (sconf->ra_distance == 0) no frame is treated as a random access frame.
01468     // For the first frame, if prediction is used, all samples used from the
01469     // previous frame are assumed to be zero.
01470     ra_frame = sconf->ra_distance && !(ctx->frame_id % sconf->ra_distance);
01471 
01472     // the last frame to decode might have a different length
01473     if (sconf->samples != 0xFFFFFFFF)
01474         ctx->cur_frame_length = FFMIN(sconf->samples - ctx->frame_id * (uint64_t) sconf->frame_length,
01475                                       sconf->frame_length);
01476     else
01477         ctx->cur_frame_length = sconf->frame_length;
01478 
01479     // decode the frame data
01480     if ((invalid_frame = read_frame_data(ctx, ra_frame) < 0))
01481         av_log(ctx->avctx, AV_LOG_WARNING,
01482                "Reading frame data failed. Skipping RA unit.\n");
01483 
01484     ctx->frame_id++;
01485 
01486     /* get output buffer */
01487     ctx->frame.nb_samples = ctx->cur_frame_length;
01488     if ((ret = ff_get_buffer(avctx, &ctx->frame)) < 0) {
01489         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
01490         return ret;
01491     }
01492 
01493     // transform decoded frame into output format
01494     #define INTERLEAVE_OUTPUT(bps)                                 \
01495     {                                                              \
01496         int##bps##_t *dest = (int##bps##_t*)ctx->frame.data[0];    \
01497         shift = bps - ctx->avctx->bits_per_raw_sample;             \
01498         for (sample = 0; sample < ctx->cur_frame_length; sample++) \
01499             for (c = 0; c < avctx->channels; c++)                  \
01500                 *dest++ = ctx->raw_samples[c][sample] << shift;    \
01501     }
01502 
01503     if (ctx->avctx->bits_per_raw_sample <= 16) {
01504         INTERLEAVE_OUTPUT(16)
01505     } else {
01506         INTERLEAVE_OUTPUT(32)
01507     }
01508 
01509     // update CRC
01510     if (sconf->crc_enabled && (avctx->err_recognition & AV_EF_CRCCHECK)) {
01511         int swap = HAVE_BIGENDIAN != sconf->msb_first;
01512 
01513         if (ctx->avctx->bits_per_raw_sample == 24) {
01514             int32_t *src = (int32_t *)ctx->frame.data[0];
01515 
01516             for (sample = 0;
01517                  sample < ctx->cur_frame_length * avctx->channels;
01518                  sample++) {
01519                 int32_t v;
01520 
01521                 if (swap)
01522                     v = av_bswap32(src[sample]);
01523                 else
01524                     v = src[sample];
01525                 if (!HAVE_BIGENDIAN)
01526                     v >>= 8;
01527 
01528                 ctx->crc = av_crc(ctx->crc_table, ctx->crc, (uint8_t*)(&v), 3);
01529             }
01530         } else {
01531             uint8_t *crc_source;
01532 
01533             if (swap) {
01534                 if (ctx->avctx->bits_per_raw_sample <= 16) {
01535                     int16_t *src  = (int16_t*) ctx->frame.data[0];
01536                     int16_t *dest = (int16_t*) ctx->crc_buffer;
01537                     for (sample = 0;
01538                          sample < ctx->cur_frame_length * avctx->channels;
01539                          sample++)
01540                         *dest++ = av_bswap16(src[sample]);
01541                 } else {
01542                     ctx->dsp.bswap_buf((uint32_t*)ctx->crc_buffer,
01543                                        (uint32_t *)ctx->frame.data[0],
01544                                        ctx->cur_frame_length * avctx->channels);
01545                 }
01546                 crc_source = ctx->crc_buffer;
01547             } else {
01548                 crc_source = ctx->frame.data[0];
01549             }
01550 
01551             ctx->crc = av_crc(ctx->crc_table, ctx->crc, crc_source,
01552                               ctx->cur_frame_length * avctx->channels *
01553                               av_get_bytes_per_sample(avctx->sample_fmt));
01554         }
01555 
01556 
01557         // check CRC sums if this is the last frame
01558         if (ctx->cur_frame_length != sconf->frame_length &&
01559             ctx->crc_org != ctx->crc) {
01560             av_log(avctx, AV_LOG_ERROR, "CRC error.\n");
01561         }
01562     }
01563 
01564     *got_frame_ptr   = 1;
01565     *(AVFrame *)data = ctx->frame;
01566 
01567 
01568     bytes_read = invalid_frame ? buffer_size :
01569                                  (get_bits_count(&ctx->gb) + 7) >> 3;
01570 
01571     return bytes_read;
01572 }
01573 
01574 
01577 static av_cold int decode_end(AVCodecContext *avctx)
01578 {
01579     ALSDecContext *ctx = avctx->priv_data;
01580 
01581     av_freep(&ctx->sconf.chan_pos);
01582 
01583     ff_bgmc_end(&ctx->bgmc_lut, &ctx->bgmc_lut_status);
01584 
01585     av_freep(&ctx->const_block);
01586     av_freep(&ctx->shift_lsbs);
01587     av_freep(&ctx->opt_order);
01588     av_freep(&ctx->store_prev_samples);
01589     av_freep(&ctx->use_ltp);
01590     av_freep(&ctx->ltp_lag);
01591     av_freep(&ctx->ltp_gain);
01592     av_freep(&ctx->ltp_gain_buffer);
01593     av_freep(&ctx->quant_cof);
01594     av_freep(&ctx->lpc_cof);
01595     av_freep(&ctx->quant_cof_buffer);
01596     av_freep(&ctx->lpc_cof_buffer);
01597     av_freep(&ctx->lpc_cof_reversed_buffer);
01598     av_freep(&ctx->prev_raw_samples);
01599     av_freep(&ctx->raw_samples);
01600     av_freep(&ctx->raw_buffer);
01601     av_freep(&ctx->chan_data);
01602     av_freep(&ctx->chan_data_buffer);
01603     av_freep(&ctx->reverted_channels);
01604     av_freep(&ctx->crc_buffer);
01605 
01606     return 0;
01607 }
01608 
01609 
01612 static av_cold int decode_init(AVCodecContext *avctx)
01613 {
01614     unsigned int c;
01615     unsigned int channel_size;
01616     int num_buffers, ret;
01617     ALSDecContext *ctx = avctx->priv_data;
01618     ALSSpecificConfig *sconf = &ctx->sconf;
01619     ctx->avctx = avctx;
01620 
01621     if (!avctx->extradata) {
01622         av_log(avctx, AV_LOG_ERROR, "Missing required ALS extradata.\n");
01623         return AVERROR_INVALIDDATA;
01624     }
01625 
01626     if ((ret = read_specific_config(ctx)) < 0) {
01627         av_log(avctx, AV_LOG_ERROR, "Reading ALSSpecificConfig failed.\n");
01628         goto fail;
01629     }
01630 
01631     if ((ret = check_specific_config(ctx)) < 0) {
01632         goto fail;
01633     }
01634 
01635     if (sconf->bgmc) {
01636         ret = ff_bgmc_init(avctx, &ctx->bgmc_lut, &ctx->bgmc_lut_status);
01637         if (ret < 0)
01638             goto fail;
01639     }
01640 
01641     if (sconf->floating) {
01642         avctx->sample_fmt          = AV_SAMPLE_FMT_FLT;
01643         avctx->bits_per_raw_sample = 32;
01644     } else {
01645         avctx->sample_fmt          = sconf->resolution > 1
01646                                      ? AV_SAMPLE_FMT_S32 : AV_SAMPLE_FMT_S16;
01647         avctx->bits_per_raw_sample = (sconf->resolution + 1) * 8;
01648     }
01649 
01650     // set maximum Rice parameter for progressive decoding based on resolution
01651     // This is not specified in 14496-3 but actually done by the reference
01652     // codec RM22 revision 2.
01653     ctx->s_max = sconf->resolution > 1 ? 31 : 15;
01654 
01655     // set lag value for long-term prediction
01656     ctx->ltp_lag_length = 8 + (avctx->sample_rate >=  96000) +
01657                               (avctx->sample_rate >= 192000);
01658 
01659     // allocate quantized parcor coefficient buffer
01660     num_buffers = sconf->mc_coding ? avctx->channels : 1;
01661 
01662     ctx->quant_cof        = av_malloc(sizeof(*ctx->quant_cof) * num_buffers);
01663     ctx->lpc_cof          = av_malloc(sizeof(*ctx->lpc_cof)   * num_buffers);
01664     ctx->quant_cof_buffer = av_malloc(sizeof(*ctx->quant_cof_buffer) *
01665                                       num_buffers * sconf->max_order);
01666     ctx->lpc_cof_buffer   = av_malloc(sizeof(*ctx->lpc_cof_buffer) *
01667                                       num_buffers * sconf->max_order);
01668     ctx->lpc_cof_reversed_buffer = av_malloc(sizeof(*ctx->lpc_cof_buffer) *
01669                                              sconf->max_order);
01670 
01671     if (!ctx->quant_cof              || !ctx->lpc_cof        ||
01672         !ctx->quant_cof_buffer       || !ctx->lpc_cof_buffer ||
01673         !ctx->lpc_cof_reversed_buffer) {
01674         av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
01675         ret = AVERROR(ENOMEM);
01676         goto fail;
01677     }
01678 
01679     // assign quantized parcor coefficient buffers
01680     for (c = 0; c < num_buffers; c++) {
01681         ctx->quant_cof[c] = ctx->quant_cof_buffer + c * sconf->max_order;
01682         ctx->lpc_cof[c]   = ctx->lpc_cof_buffer   + c * sconf->max_order;
01683     }
01684 
01685     // allocate and assign lag and gain data buffer for ltp mode
01686     ctx->const_block     = av_malloc (sizeof(*ctx->const_block) * num_buffers);
01687     ctx->shift_lsbs      = av_malloc (sizeof(*ctx->shift_lsbs)  * num_buffers);
01688     ctx->opt_order       = av_malloc (sizeof(*ctx->opt_order)   * num_buffers);
01689     ctx->store_prev_samples = av_malloc(sizeof(*ctx->store_prev_samples) * num_buffers);
01690     ctx->use_ltp         = av_mallocz(sizeof(*ctx->use_ltp)  * num_buffers);
01691     ctx->ltp_lag         = av_malloc (sizeof(*ctx->ltp_lag)  * num_buffers);
01692     ctx->ltp_gain        = av_malloc (sizeof(*ctx->ltp_gain) * num_buffers);
01693     ctx->ltp_gain_buffer = av_malloc (sizeof(*ctx->ltp_gain_buffer) *
01694                                       num_buffers * 5);
01695 
01696     if (!ctx->const_block || !ctx->shift_lsbs ||
01697         !ctx->opt_order || !ctx->store_prev_samples ||
01698         !ctx->use_ltp  || !ctx->ltp_lag ||
01699         !ctx->ltp_gain || !ctx->ltp_gain_buffer) {
01700         av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
01701         ret = AVERROR(ENOMEM);
01702         goto fail;
01703     }
01704 
01705     for (c = 0; c < num_buffers; c++)
01706         ctx->ltp_gain[c] = ctx->ltp_gain_buffer + c * 5;
01707 
01708     // allocate and assign channel data buffer for mcc mode
01709     if (sconf->mc_coding) {
01710         ctx->chan_data_buffer  = av_malloc(sizeof(*ctx->chan_data_buffer) *
01711                                            num_buffers * num_buffers);
01712         ctx->chan_data         = av_malloc(sizeof(*ctx->chan_data) *
01713                                            num_buffers);
01714         ctx->reverted_channels = av_malloc(sizeof(*ctx->reverted_channels) *
01715                                            num_buffers);
01716 
01717         if (!ctx->chan_data_buffer || !ctx->chan_data || !ctx->reverted_channels) {
01718             av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
01719             ret = AVERROR(ENOMEM);
01720             goto fail;
01721         }
01722 
01723         for (c = 0; c < num_buffers; c++)
01724             ctx->chan_data[c] = ctx->chan_data_buffer + c * num_buffers;
01725     } else {
01726         ctx->chan_data         = NULL;
01727         ctx->chan_data_buffer  = NULL;
01728         ctx->reverted_channels = NULL;
01729     }
01730 
01731     avctx->frame_size = sconf->frame_length;
01732     channel_size      = sconf->frame_length + sconf->max_order;
01733 
01734     ctx->prev_raw_samples = av_malloc (sizeof(*ctx->prev_raw_samples) * sconf->max_order);
01735     ctx->raw_buffer       = av_mallocz(sizeof(*ctx->     raw_buffer)  * avctx->channels * channel_size);
01736     ctx->raw_samples      = av_malloc (sizeof(*ctx->     raw_samples) * avctx->channels);
01737 
01738     // allocate previous raw sample buffer
01739     if (!ctx->prev_raw_samples || !ctx->raw_buffer|| !ctx->raw_samples) {
01740         av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
01741         ret = AVERROR(ENOMEM);
01742         goto fail;
01743     }
01744 
01745     // assign raw samples buffers
01746     ctx->raw_samples[0] = ctx->raw_buffer + sconf->max_order;
01747     for (c = 1; c < avctx->channels; c++)
01748         ctx->raw_samples[c] = ctx->raw_samples[c - 1] + channel_size;
01749 
01750     // allocate crc buffer
01751     if (HAVE_BIGENDIAN != sconf->msb_first && sconf->crc_enabled &&
01752         (avctx->err_recognition & AV_EF_CRCCHECK)) {
01753         ctx->crc_buffer = av_malloc(sizeof(*ctx->crc_buffer) *
01754                                     ctx->cur_frame_length *
01755                                     avctx->channels *
01756                                     av_get_bytes_per_sample(avctx->sample_fmt));
01757         if (!ctx->crc_buffer) {
01758             av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
01759             ret = AVERROR(ENOMEM);
01760             goto fail;
01761         }
01762     }
01763 
01764     dsputil_init(&ctx->dsp, avctx);
01765 
01766     avcodec_get_frame_defaults(&ctx->frame);
01767     avctx->coded_frame = &ctx->frame;
01768 
01769     return 0;
01770 
01771 fail:
01772     decode_end(avctx);
01773     return ret;
01774 }
01775 
01776 
01779 static av_cold void flush(AVCodecContext *avctx)
01780 {
01781     ALSDecContext *ctx = avctx->priv_data;
01782 
01783     ctx->frame_id = 0;
01784 }
01785 
01786 
01787 AVCodec ff_als_decoder = {
01788     .name           = "als",
01789     .type           = AVMEDIA_TYPE_AUDIO,
01790     .id             = CODEC_ID_MP4ALS,
01791     .priv_data_size = sizeof(ALSDecContext),
01792     .init           = decode_init,
01793     .close          = decode_end,
01794     .decode         = decode_frame,
01795     .flush = flush,
01796     .capabilities = CODEC_CAP_SUBFRAMES | CODEC_CAP_DR1,
01797     .long_name = NULL_IF_CONFIG_SMALL("MPEG-4 Audio Lossless Coding (ALS)"),
01798 };
01799