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 "get_bits.h"
00034 #include "unary.h"
00035 #include "mpeg4audio.h"
00036 #include "bytestream.h"
00037 #include "bgmc.h"
00038 #include "dsputil.h"
00039 #include "libavutil/samplefmt.h"
00040 #include "libavutil/crc.h"
00041 
00042 #include <stdint.h>
00043 
00048 static const int8_t parcor_rice_table[3][20][2] = {
00049     { {-52, 4}, {-29, 5}, {-31, 4}, { 19, 4}, {-16, 4},
00050       { 12, 3}, { -7, 3}, {  9, 3}, { -5, 3}, {  6, 3},
00051       { -4, 3}, {  3, 3}, { -3, 2}, {  3, 2}, { -2, 2},
00052       {  3, 2}, { -1, 2}, {  2, 2}, { -1, 2}, {  2, 2} },
00053     { {-58, 3}, {-42, 4}, {-46, 4}, { 37, 5}, {-36, 4},
00054       { 29, 4}, {-29, 4}, { 25, 4}, {-23, 4}, { 20, 4},
00055       {-17, 4}, { 16, 4}, {-12, 4}, { 12, 3}, {-10, 4},
00056       {  7, 3}, { -4, 4}, {  3, 3}, { -1, 3}, {  1, 3} },
00057     { {-59, 3}, {-45, 5}, {-50, 4}, { 38, 4}, {-39, 4},
00058       { 32, 4}, {-30, 4}, { 25, 3}, {-23, 3}, { 20, 3},
00059       {-20, 3}, { 16, 3}, {-13, 3}, { 10, 3}, { -7, 3},
00060       {  3, 3}, {  0, 3}, { -1, 3}, {  2, 3}, { -1, 2} }
00061 };
00062 
00063 
00069 static const int16_t parcor_scaled_values[] = {
00070     -1048544 / 32, -1048288 / 32, -1047776 / 32, -1047008 / 32,
00071     -1045984 / 32, -1044704 / 32, -1043168 / 32, -1041376 / 32,
00072     -1039328 / 32, -1037024 / 32, -1034464 / 32, -1031648 / 32,
00073     -1028576 / 32, -1025248 / 32, -1021664 / 32, -1017824 / 32,
00074     -1013728 / 32, -1009376 / 32, -1004768 / 32,  -999904 / 32,
00075      -994784 / 32,  -989408 / 32,  -983776 / 32,  -977888 / 32,
00076      -971744 / 32,  -965344 / 32,  -958688 / 32,  -951776 / 32,
00077      -944608 / 32,  -937184 / 32,  -929504 / 32,  -921568 / 32,
00078      -913376 / 32,  -904928 / 32,  -896224 / 32,  -887264 / 32,
00079      -878048 / 32,  -868576 / 32,  -858848 / 32,  -848864 / 32,
00080      -838624 / 32,  -828128 / 32,  -817376 / 32,  -806368 / 32,
00081      -795104 / 32,  -783584 / 32,  -771808 / 32,  -759776 / 32,
00082      -747488 / 32,  -734944 / 32,  -722144 / 32,  -709088 / 32,
00083      -695776 / 32,  -682208 / 32,  -668384 / 32,  -654304 / 32,
00084      -639968 / 32,  -625376 / 32,  -610528 / 32,  -595424 / 32,
00085      -580064 / 32,  -564448 / 32,  -548576 / 32,  -532448 / 32,
00086      -516064 / 32,  -499424 / 32,  -482528 / 32,  -465376 / 32,
00087      -447968 / 32,  -430304 / 32,  -412384 / 32,  -394208 / 32,
00088      -375776 / 32,  -357088 / 32,  -338144 / 32,  -318944 / 32,
00089      -299488 / 32,  -279776 / 32,  -259808 / 32,  -239584 / 32,
00090      -219104 / 32,  -198368 / 32,  -177376 / 32,  -156128 / 32,
00091      -134624 / 32,  -112864 / 32,   -90848 / 32,   -68576 / 32,
00092       -46048 / 32,   -23264 / 32,     -224 / 32,    23072 / 32,
00093        46624 / 32,    70432 / 32,    94496 / 32,   118816 / 32,
00094       143392 / 32,   168224 / 32,   193312 / 32,   218656 / 32,
00095       244256 / 32,   270112 / 32,   296224 / 32,   322592 / 32,
00096       349216 / 32,   376096 / 32,   403232 / 32,   430624 / 32,
00097       458272 / 32,   486176 / 32,   514336 / 32,   542752 / 32,
00098       571424 / 32,   600352 / 32,   629536 / 32,   658976 / 32,
00099       688672 / 32,   718624 / 32,   748832 / 32,   779296 / 32,
00100       810016 / 32,   840992 / 32,   872224 / 32,   903712 / 32,
00101       935456 / 32,   967456 / 32,   999712 / 32,  1032224 / 32
00102 };
00103 
00104 
00108 static const uint8_t ltp_gain_values [4][4] = {
00109     { 0,  8, 16,  24},
00110     {32, 40, 48,  56},
00111     {64, 70, 76,  82},
00112     {88, 92, 96, 100}
00113 };
00114 
00115 
00119 static const int16_t mcc_weightings[] = {
00120     204,  192,  179,  166,  153,  140,  128,  115,
00121     102,   89,   76,   64,   51,   38,   25,   12,
00122       0,  -12,  -25,  -38,  -51,  -64,  -76,  -89,
00123    -102, -115, -128, -140, -153, -166, -179, -192
00124 };
00125 
00126 
00129 static const uint8_t tail_code[16][6] = {
00130     { 74, 44, 25, 13,  7, 3},
00131     { 68, 42, 24, 13,  7, 3},
00132     { 58, 39, 23, 13,  7, 3},
00133     {126, 70, 37, 19, 10, 5},
00134     {132, 70, 37, 20, 10, 5},
00135     {124, 70, 38, 20, 10, 5},
00136     {120, 69, 37, 20, 11, 5},
00137     {116, 67, 37, 20, 11, 5},
00138     {108, 66, 36, 20, 10, 5},
00139     {102, 62, 36, 20, 10, 5},
00140     { 88, 58, 34, 19, 10, 5},
00141     {162, 89, 49, 25, 13, 7},
00142     {156, 87, 49, 26, 14, 7},
00143     {150, 86, 47, 26, 14, 7},
00144     {142, 84, 47, 26, 14, 7},
00145     {131, 79, 46, 26, 14, 7}
00146 };
00147 
00148 
00149 enum RA_Flag {
00150     RA_FLAG_NONE,
00151     RA_FLAG_FRAMES,
00152     RA_FLAG_HEADER
00153 };
00154 
00155 
00156 typedef struct {
00157     uint32_t samples;         
00158     int resolution;           
00159     int floating;             
00160     int msb_first;            
00161     int frame_length;         
00162     int ra_distance;          
00163     enum RA_Flag ra_flag;     
00164     int adapt_order;          
00165     int coef_table;           
00166     int long_term_prediction; 
00167     int max_order;            
00168     int block_switching;      
00169     int bgmc;                 
00170     int sb_part;              
00171     int joint_stereo;         
00172     int mc_coding;            
00173     int chan_config;          
00174     int chan_sort;            
00175     int rlslms;               
00176     int chan_config_info;     
00177     int *chan_pos;            
00178     int crc_enabled;          
00179 } ALSSpecificConfig;
00180 
00181 
00182 typedef struct {
00183     int stop_flag;
00184     int master_channel;
00185     int time_diff_flag;
00186     int time_diff_sign;
00187     int time_diff_index;
00188     int weighting[6];
00189 } ALSChannelData;
00190 
00191 
00192 typedef struct {
00193     AVCodecContext *avctx;
00194     AVFrame frame;
00195     ALSSpecificConfig sconf;
00196     GetBitContext gb;
00197     DSPContext dsp;
00198     const AVCRC *crc_table;
00199     uint32_t crc_org;               
00200     uint32_t crc;                   
00201     unsigned int cur_frame_length;  
00202     unsigned int frame_id;          
00203     unsigned int js_switch;         
00204     unsigned int num_blocks;        
00205     unsigned int s_max;             
00206     uint8_t *bgmc_lut;              
00207     int *bgmc_lut_status;           
00208     int ltp_lag_length;             
00209     int *const_block;               
00210     unsigned int *shift_lsbs;       
00211     unsigned int *opt_order;        
00212     int *store_prev_samples;        
00213     int *use_ltp;                   
00214     int *ltp_lag;                   
00215     int **ltp_gain;                 
00216     int *ltp_gain_buffer;           
00217     int32_t **quant_cof;            
00218     int32_t *quant_cof_buffer;      
00219     int32_t **lpc_cof;              
00220     int32_t *lpc_cof_buffer;        
00221     int32_t *lpc_cof_reversed_buffer; 
00222     ALSChannelData **chan_data;     
00223     ALSChannelData *chan_data_buffer; 
00224     int *reverted_channels;         
00225     int32_t *prev_raw_samples;      
00226     int32_t **raw_samples;          
00227     int32_t *raw_buffer;            
00228     uint8_t *crc_buffer;            
00229 } ALSDecContext;
00230 
00231 
00232 typedef struct {
00233     unsigned int block_length;      
00234     unsigned int ra_block;          
00235     int          *const_block;      
00236     int          js_blocks;         
00237     unsigned int *shift_lsbs;       
00238     unsigned int *opt_order;        
00239     int          *store_prev_samples;
00240     int          *use_ltp;          
00241     int          *ltp_lag;          
00242     int          *ltp_gain;         
00243     int32_t      *quant_cof;        
00244     int32_t      *lpc_cof;          
00245     int32_t      *raw_samples;      
00246     int32_t      *prev_raw_samples; 
00247     int32_t      *raw_other;        
00248 } ALSBlockData;
00249 
00250 
00251 static av_cold void dprint_specific_config(ALSDecContext *ctx)
00252 {
00253 #ifdef DEBUG
00254     AVCodecContext *avctx    = ctx->avctx;
00255     ALSSpecificConfig *sconf = &ctx->sconf;
00256 
00257     av_dlog(avctx, "resolution = %i\n",           sconf->resolution);
00258     av_dlog(avctx, "floating = %i\n",             sconf->floating);
00259     av_dlog(avctx, "frame_length = %i\n",         sconf->frame_length);
00260     av_dlog(avctx, "ra_distance = %i\n",          sconf->ra_distance);
00261     av_dlog(avctx, "ra_flag = %i\n",              sconf->ra_flag);
00262     av_dlog(avctx, "adapt_order = %i\n",          sconf->adapt_order);
00263     av_dlog(avctx, "coef_table = %i\n",           sconf->coef_table);
00264     av_dlog(avctx, "long_term_prediction = %i\n", sconf->long_term_prediction);
00265     av_dlog(avctx, "max_order = %i\n",            sconf->max_order);
00266     av_dlog(avctx, "block_switching = %i\n",      sconf->block_switching);
00267     av_dlog(avctx, "bgmc = %i\n",                 sconf->bgmc);
00268     av_dlog(avctx, "sb_part = %i\n",              sconf->sb_part);
00269     av_dlog(avctx, "joint_stereo = %i\n",         sconf->joint_stereo);
00270     av_dlog(avctx, "mc_coding = %i\n",            sconf->mc_coding);
00271     av_dlog(avctx, "chan_config = %i\n",          sconf->chan_config);
00272     av_dlog(avctx, "chan_sort = %i\n",            sconf->chan_sort);
00273     av_dlog(avctx, "RLSLMS = %i\n",               sconf->rlslms);
00274     av_dlog(avctx, "chan_config_info = %i\n",     sconf->chan_config_info);
00275 #endif
00276 }
00277 
00278 
00281 static av_cold int read_specific_config(ALSDecContext *ctx)
00282 {
00283     GetBitContext gb;
00284     uint64_t ht_size;
00285     int i, config_offset;
00286     MPEG4AudioConfig m4ac;
00287     ALSSpecificConfig *sconf = &ctx->sconf;
00288     AVCodecContext *avctx    = ctx->avctx;
00289     uint32_t als_id, header_size, trailer_size;
00290 
00291     init_get_bits(&gb, avctx->extradata, avctx->extradata_size * 8);
00292 
00293     config_offset = avpriv_mpeg4audio_get_config(&m4ac, avctx->extradata,
00294                                                  avctx->extradata_size * 8, 1);
00295 
00296     if (config_offset < 0)
00297         return -1;
00298 
00299     skip_bits_long(&gb, config_offset);
00300 
00301     if (get_bits_left(&gb) < (30 << 3))
00302         return -1;
00303 
00304     // read the fixed items
00305     als_id                      = get_bits_long(&gb, 32);
00306     avctx->sample_rate          = m4ac.sample_rate;
00307     skip_bits_long(&gb, 32); // sample rate already known
00308     sconf->samples              = get_bits_long(&gb, 32);
00309     avctx->channels             = m4ac.channels;
00310     skip_bits(&gb, 16);      // number of channels already knwon
00311     skip_bits(&gb, 3);       // skip file_type
00312     sconf->resolution           = get_bits(&gb, 3);
00313     sconf->floating             = get_bits1(&gb);
00314     sconf->msb_first            = get_bits1(&gb);
00315     sconf->frame_length         = get_bits(&gb, 16) + 1;
00316     sconf->ra_distance          = get_bits(&gb, 8);
00317     sconf->ra_flag              = get_bits(&gb, 2);
00318     sconf->adapt_order          = get_bits1(&gb);
00319     sconf->coef_table           = get_bits(&gb, 2);
00320     sconf->long_term_prediction = get_bits1(&gb);
00321     sconf->max_order            = get_bits(&gb, 10);
00322     sconf->block_switching      = get_bits(&gb, 2);
00323     sconf->bgmc                 = get_bits1(&gb);
00324     sconf->sb_part              = get_bits1(&gb);
00325     sconf->joint_stereo         = get_bits1(&gb);
00326     sconf->mc_coding            = get_bits1(&gb);
00327     sconf->chan_config          = get_bits1(&gb);
00328     sconf->chan_sort            = get_bits1(&gb);
00329     sconf->crc_enabled          = get_bits1(&gb);
00330     sconf->rlslms               = get_bits1(&gb);
00331     skip_bits(&gb, 5);       // skip 5 reserved bits
00332     skip_bits1(&gb);         // skip aux_data_enabled
00333 
00334 
00335     // check for ALSSpecificConfig struct
00336     if (als_id != MKBETAG('A','L','S','\0'))
00337         return -1;
00338 
00339     ctx->cur_frame_length = sconf->frame_length;
00340 
00341     // read channel config
00342     if (sconf->chan_config)
00343         sconf->chan_config_info = get_bits(&gb, 16);
00344     // TODO: use this to set avctx->channel_layout
00345 
00346 
00347     // read channel sorting
00348     if (sconf->chan_sort && avctx->channels > 1) {
00349         int chan_pos_bits = av_ceil_log2(avctx->channels);
00350         int bits_needed  = avctx->channels * chan_pos_bits + 7;
00351         if (get_bits_left(&gb) < bits_needed)
00352             return -1;
00353 
00354         if (!(sconf->chan_pos = av_malloc(avctx->channels * sizeof(*sconf->chan_pos))))
00355             return AVERROR(ENOMEM);
00356 
00357         for (i = 0; i < avctx->channels; i++)
00358             sconf->chan_pos[i] = get_bits(&gb, chan_pos_bits);
00359 
00360         align_get_bits(&gb);
00361         // TODO: use this to actually do channel sorting
00362     } else {
00363         sconf->chan_sort = 0;
00364     }
00365 
00366 
00367     // read fixed header and trailer sizes,
00368     // if size = 0xFFFFFFFF then there is no data field!
00369     if (get_bits_left(&gb) < 64)
00370         return -1;
00371 
00372     header_size  = get_bits_long(&gb, 32);
00373     trailer_size = get_bits_long(&gb, 32);
00374     if (header_size  == 0xFFFFFFFF)
00375         header_size  = 0;
00376     if (trailer_size == 0xFFFFFFFF)
00377         trailer_size = 0;
00378 
00379     ht_size = ((int64_t)(header_size) + (int64_t)(trailer_size)) << 3;
00380 
00381 
00382     // skip the header and trailer data
00383     if (get_bits_left(&gb) < ht_size)
00384         return -1;
00385 
00386     if (ht_size > INT32_MAX)
00387         return -1;
00388 
00389     skip_bits_long(&gb, ht_size);
00390 
00391 
00392     // initialize CRC calculation
00393     if (sconf->crc_enabled) {
00394         if (get_bits_left(&gb) < 32)
00395             return -1;
00396 
00397         if (avctx->err_recognition & AV_EF_CRCCHECK) {
00398             ctx->crc_table = av_crc_get_table(AV_CRC_32_IEEE_LE);
00399             ctx->crc       = 0xFFFFFFFF;
00400             ctx->crc_org   = ~get_bits_long(&gb, 32);
00401         } else
00402             skip_bits_long(&gb, 32);
00403     }
00404 
00405 
00406     // no need to read the rest of ALSSpecificConfig (ra_unit_size & aux data)
00407 
00408     dprint_specific_config(ctx);
00409 
00410     return 0;
00411 }
00412 
00413 
00416 static int check_specific_config(ALSDecContext *ctx)
00417 {
00418     ALSSpecificConfig *sconf = &ctx->sconf;
00419     int error = 0;
00420 
00421     // report unsupported feature and set error value
00422     #define MISSING_ERR(cond, str, errval)              \
00423     {                                                   \
00424         if (cond) {                                     \
00425             av_log_missing_feature(ctx->avctx, str, 0); \
00426             error = errval;                             \
00427         }                                               \
00428     }
00429 
00430     MISSING_ERR(sconf->floating,             "Floating point decoding",     -1);
00431     MISSING_ERR(sconf->rlslms,               "Adaptive RLS-LMS prediction", -1);
00432     MISSING_ERR(sconf->chan_sort,            "Channel sorting",              0);
00433 
00434     return error;
00435 }
00436 
00437 
00441 static void parse_bs_info(const uint32_t bs_info, unsigned int n,
00442                           unsigned int div, unsigned int **div_blocks,
00443                           unsigned int *num_blocks)
00444 {
00445     if (n < 31 && ((bs_info << n) & 0x40000000)) {
00446         // if the level is valid and the investigated bit n is set
00447         // then recursively check both children at bits (2n+1) and (2n+2)
00448         n   *= 2;
00449         div += 1;
00450         parse_bs_info(bs_info, n + 1, div, div_blocks, num_blocks);
00451         parse_bs_info(bs_info, n + 2, div, div_blocks, num_blocks);
00452     } else {
00453         // else the bit is not set or the last level has been reached
00454         // (bit implicitly not set)
00455         **div_blocks = div;
00456         (*div_blocks)++;
00457         (*num_blocks)++;
00458     }
00459 }
00460 
00461 
00464 static int32_t decode_rice(GetBitContext *gb, unsigned int k)
00465 {
00466     int max = get_bits_left(gb) - k;
00467     int q   = get_unary(gb, 0, max);
00468     int r   = k ? get_bits1(gb) : !(q & 1);
00469 
00470     if (k > 1) {
00471         q <<= (k - 1);
00472         q  += get_bits_long(gb, k - 1);
00473     } else if (!k) {
00474         q >>= 1;
00475     }
00476     return r ? q : ~q;
00477 }
00478 
00479 
00482 static void parcor_to_lpc(unsigned int k, const int32_t *par, int32_t *cof)
00483 {
00484     int i, j;
00485 
00486     for (i = 0, j = k - 1; i < j; i++, j--) {
00487         int tmp1 = ((MUL64(par[k], cof[j]) + (1 << 19)) >> 20);
00488         cof[j]  += ((MUL64(par[k], cof[i]) + (1 << 19)) >> 20);
00489         cof[i]  += tmp1;
00490     }
00491     if (i == j)
00492         cof[i] += ((MUL64(par[k], cof[j]) + (1 << 19)) >> 20);
00493 
00494     cof[k] = par[k];
00495 }
00496 
00497 
00502 static void get_block_sizes(ALSDecContext *ctx, unsigned int *div_blocks,
00503                             uint32_t *bs_info)
00504 {
00505     ALSSpecificConfig *sconf     = &ctx->sconf;
00506     GetBitContext *gb            = &ctx->gb;
00507     unsigned int *ptr_div_blocks = div_blocks;
00508     unsigned int b;
00509 
00510     if (sconf->block_switching) {
00511         unsigned int bs_info_len = 1 << (sconf->block_switching + 2);
00512         *bs_info = get_bits_long(gb, bs_info_len);
00513         *bs_info <<= (32 - bs_info_len);
00514     }
00515 
00516     ctx->num_blocks = 0;
00517     parse_bs_info(*bs_info, 0, 0, &ptr_div_blocks, &ctx->num_blocks);
00518 
00519     // The last frame may have an overdetermined block structure given in
00520     // the bitstream. In that case the defined block structure would need
00521     // more samples than available to be consistent.
00522     // The block structure is actually used but the block sizes are adapted
00523     // to fit the actual number of available samples.
00524     // Example: 5 samples, 2nd level block sizes: 2 2 2 2.
00525     // This results in the actual block sizes:    2 2 1 0.
00526     // This is not specified in 14496-3 but actually done by the reference
00527     // codec RM22 revision 2.
00528     // This appears to happen in case of an odd number of samples in the last
00529     // frame which is actually not allowed by the block length switching part
00530     // of 14496-3.
00531     // The ALS conformance files feature an odd number of samples in the last
00532     // frame.
00533 
00534     for (b = 0; b < ctx->num_blocks; b++)
00535         div_blocks[b] = ctx->sconf.frame_length >> div_blocks[b];
00536 
00537     if (ctx->cur_frame_length != ctx->sconf.frame_length) {
00538         unsigned int remaining = ctx->cur_frame_length;
00539 
00540         for (b = 0; b < ctx->num_blocks; b++) {
00541             if (remaining <= div_blocks[b]) {
00542                 div_blocks[b] = remaining;
00543                 ctx->num_blocks = b + 1;
00544                 break;
00545             }
00546 
00547             remaining -= div_blocks[b];
00548         }
00549     }
00550 }
00551 
00552 
00555 static void read_const_block_data(ALSDecContext *ctx, ALSBlockData *bd)
00556 {
00557     ALSSpecificConfig *sconf = &ctx->sconf;
00558     AVCodecContext *avctx    = ctx->avctx;
00559     GetBitContext *gb        = &ctx->gb;
00560 
00561     *bd->raw_samples = 0;
00562     *bd->const_block = get_bits1(gb);    // 1 = constant value, 0 = zero block (silence)
00563     bd->js_blocks    = get_bits1(gb);
00564 
00565     // skip 5 reserved bits
00566     skip_bits(gb, 5);
00567 
00568     if (*bd->const_block) {
00569         unsigned int const_val_bits = sconf->floating ? 24 : avctx->bits_per_raw_sample;
00570         *bd->raw_samples = get_sbits_long(gb, const_val_bits);
00571     }
00572 
00573     // ensure constant block decoding by reusing this field
00574     *bd->const_block = 1;
00575 }
00576 
00577 
00580 static void decode_const_block_data(ALSDecContext *ctx, ALSBlockData *bd)
00581 {
00582     int      smp = bd->block_length - 1;
00583     int32_t  val = *bd->raw_samples;
00584     int32_t *dst = bd->raw_samples + 1;
00585 
00586     // write raw samples into buffer
00587     for (; smp; smp--)
00588         *dst++ = val;
00589 }
00590 
00591 
00594 static int read_var_block_data(ALSDecContext *ctx, ALSBlockData *bd)
00595 {
00596     ALSSpecificConfig *sconf = &ctx->sconf;
00597     AVCodecContext *avctx    = ctx->avctx;
00598     GetBitContext *gb        = &ctx->gb;
00599     unsigned int k;
00600     unsigned int s[8];
00601     unsigned int sx[8];
00602     unsigned int sub_blocks, log2_sub_blocks, sb_length;
00603     unsigned int start      = 0;
00604     unsigned int opt_order;
00605     int          sb;
00606     int32_t      *quant_cof = bd->quant_cof;
00607     int32_t      *current_res;
00608 
00609 
00610     // ensure variable block decoding by reusing this field
00611     *bd->const_block = 0;
00612 
00613     *bd->opt_order  = 1;
00614     bd->js_blocks   = get_bits1(gb);
00615 
00616     opt_order       = *bd->opt_order;
00617 
00618     // determine the number of subblocks for entropy decoding
00619     if (!sconf->bgmc && !sconf->sb_part) {
00620         log2_sub_blocks = 0;
00621     } else {
00622         if (sconf->bgmc && sconf->sb_part)
00623             log2_sub_blocks = get_bits(gb, 2);
00624         else
00625             log2_sub_blocks = 2 * get_bits1(gb);
00626     }
00627 
00628     sub_blocks = 1 << log2_sub_blocks;
00629 
00630     // do not continue in case of a damaged stream since
00631     // block_length must be evenly divisible by sub_blocks
00632     if (bd->block_length & (sub_blocks - 1)) {
00633         av_log(avctx, AV_LOG_WARNING,
00634                "Block length is not evenly divisible by the number of subblocks.\n");
00635         return -1;
00636     }
00637 
00638     sb_length = bd->block_length >> log2_sub_blocks;
00639 
00640     if (sconf->bgmc) {
00641         s[0] = get_bits(gb, 8 + (sconf->resolution > 1));
00642         for (k = 1; k < sub_blocks; k++)
00643             s[k] = s[k - 1] + decode_rice(gb, 2);
00644 
00645         for (k = 0; k < sub_blocks; k++) {
00646             sx[k]   = s[k] & 0x0F;
00647             s [k] >>= 4;
00648         }
00649     } else {
00650         s[0] = get_bits(gb, 4 + (sconf->resolution > 1));
00651         for (k = 1; k < sub_blocks; k++)
00652             s[k] = s[k - 1] + decode_rice(gb, 0);
00653     }
00654 
00655     if (get_bits1(gb))
00656         *bd->shift_lsbs = get_bits(gb, 4) + 1;
00657 
00658     *bd->store_prev_samples = (bd->js_blocks && bd->raw_other) || *bd->shift_lsbs;
00659 
00660 
00661     if (!sconf->rlslms) {
00662         if (sconf->adapt_order) {
00663             int opt_order_length = av_ceil_log2(av_clip((bd->block_length >> 3) - 1,
00664                                                 2, sconf->max_order + 1));
00665             *bd->opt_order       = get_bits(gb, opt_order_length);
00666         } else {
00667             *bd->opt_order = sconf->max_order;
00668         }
00669 
00670         opt_order = *bd->opt_order;
00671 
00672         if (opt_order) {
00673             int add_base;
00674 
00675             if (sconf->coef_table == 3) {
00676                 add_base = 0x7F;
00677 
00678                 // read coefficient 0
00679                 quant_cof[0] = 32 * parcor_scaled_values[get_bits(gb, 7)];
00680 
00681                 // read coefficient 1
00682                 if (opt_order > 1)
00683                     quant_cof[1] = -32 * parcor_scaled_values[get_bits(gb, 7)];
00684 
00685                 // read coefficients 2 to opt_order
00686                 for (k = 2; k < opt_order; k++)
00687                     quant_cof[k] = get_bits(gb, 7);
00688             } else {
00689                 int k_max;
00690                 add_base = 1;
00691 
00692                 // read coefficient 0 to 19
00693                 k_max = FFMIN(opt_order, 20);
00694                 for (k = 0; k < k_max; k++) {
00695                     int rice_param = parcor_rice_table[sconf->coef_table][k][1];
00696                     int offset     = parcor_rice_table[sconf->coef_table][k][0];
00697                     quant_cof[k] = decode_rice(gb, rice_param) + offset;
00698                 }
00699 
00700                 // read coefficients 20 to 126
00701                 k_max = FFMIN(opt_order, 127);
00702                 for (; k < k_max; k++)
00703                     quant_cof[k] = decode_rice(gb, 2) + (k & 1);
00704 
00705                 // read coefficients 127 to opt_order
00706                 for (; k < opt_order; k++)
00707                     quant_cof[k] = decode_rice(gb, 1);
00708 
00709                 quant_cof[0] = 32 * parcor_scaled_values[quant_cof[0] + 64];
00710 
00711                 if (opt_order > 1)
00712                     quant_cof[1] = -32 * parcor_scaled_values[quant_cof[1] + 64];
00713             }
00714 
00715             for (k = 2; k < opt_order; k++)
00716                 quant_cof[k] = (quant_cof[k] << 14) + (add_base << 13);
00717         }
00718     }
00719 
00720     // read LTP gain and lag values
00721     if (sconf->long_term_prediction) {
00722         *bd->use_ltp = get_bits1(gb);
00723 
00724         if (*bd->use_ltp) {
00725             int r, c;
00726 
00727             bd->ltp_gain[0]   = decode_rice(gb, 1) << 3;
00728             bd->ltp_gain[1]   = decode_rice(gb, 2) << 3;
00729 
00730             r                 = get_unary(gb, 0, 4);
00731             c                 = get_bits(gb, 2);
00732             bd->ltp_gain[2]   = ltp_gain_values[r][c];
00733 
00734             bd->ltp_gain[3]   = decode_rice(gb, 2) << 3;
00735             bd->ltp_gain[4]   = decode_rice(gb, 1) << 3;
00736 
00737             *bd->ltp_lag      = get_bits(gb, ctx->ltp_lag_length);
00738             *bd->ltp_lag     += FFMAX(4, opt_order + 1);
00739         }
00740     }
00741 
00742     // read first value and residuals in case of a random access block
00743     if (bd->ra_block) {
00744         if (opt_order)
00745             bd->raw_samples[0] = decode_rice(gb, avctx->bits_per_raw_sample - 4);
00746         if (opt_order > 1)
00747             bd->raw_samples[1] = decode_rice(gb, FFMIN(s[0] + 3, ctx->s_max));
00748         if (opt_order > 2)
00749             bd->raw_samples[2] = decode_rice(gb, FFMIN(s[0] + 1, ctx->s_max));
00750 
00751         start = FFMIN(opt_order, 3);
00752     }
00753 
00754     // read all residuals
00755     if (sconf->bgmc) {
00756         int          delta[8];
00757         unsigned int k    [8];
00758         unsigned int b = av_clip((av_ceil_log2(bd->block_length) - 3) >> 1, 0, 5);
00759         unsigned int i = start;
00760 
00761         // read most significant bits
00762         unsigned int high;
00763         unsigned int low;
00764         unsigned int value;
00765 
00766         ff_bgmc_decode_init(gb, &high, &low, &value);
00767 
00768         current_res = bd->raw_samples + start;
00769 
00770         for (sb = 0; sb < sub_blocks; sb++, i = 0) {
00771             k    [sb] = s[sb] > b ? s[sb] - b : 0;
00772             delta[sb] = 5 - s[sb] + k[sb];
00773 
00774             ff_bgmc_decode(gb, sb_length, current_res,
00775                         delta[sb], sx[sb], &high, &low, &value, ctx->bgmc_lut, ctx->bgmc_lut_status);
00776 
00777             current_res += sb_length;
00778         }
00779 
00780         ff_bgmc_decode_end(gb);
00781 
00782 
00783         // read least significant bits and tails
00784         i = start;
00785         current_res = bd->raw_samples + start;
00786 
00787         for (sb = 0; sb < sub_blocks; sb++, i = 0) {
00788             unsigned int cur_tail_code = tail_code[sx[sb]][delta[sb]];
00789             unsigned int cur_k         = k[sb];
00790             unsigned int cur_s         = s[sb];
00791 
00792             for (; i < sb_length; i++) {
00793                 int32_t res = *current_res;
00794 
00795                 if (res == cur_tail_code) {
00796                     unsigned int max_msb =   (2 + (sx[sb] > 2) + (sx[sb] > 10))
00797                                           << (5 - delta[sb]);
00798 
00799                     res = decode_rice(gb, cur_s);
00800 
00801                     if (res >= 0) {
00802                         res += (max_msb    ) << cur_k;
00803                     } else {
00804                         res -= (max_msb - 1) << cur_k;
00805                     }
00806                 } else {
00807                     if (res > cur_tail_code)
00808                         res--;
00809 
00810                     if (res & 1)
00811                         res = -res;
00812 
00813                     res >>= 1;
00814 
00815                     if (cur_k) {
00816                         res <<= cur_k;
00817                         res  |= get_bits_long(gb, cur_k);
00818                     }
00819                 }
00820 
00821                 *current_res++ = res;
00822             }
00823         }
00824     } else {
00825         current_res = bd->raw_samples + start;
00826 
00827         for (sb = 0; sb < sub_blocks; sb++, start = 0)
00828             for (; start < sb_length; start++)
00829                 *current_res++ = decode_rice(gb, s[sb]);
00830      }
00831 
00832     if (!sconf->mc_coding || ctx->js_switch)
00833         align_get_bits(gb);
00834 
00835     return 0;
00836 }
00837 
00838 
00841 static int decode_var_block_data(ALSDecContext *ctx, ALSBlockData *bd)
00842 {
00843     ALSSpecificConfig *sconf = &ctx->sconf;
00844     unsigned int block_length = bd->block_length;
00845     unsigned int smp = 0;
00846     unsigned int k;
00847     int opt_order             = *bd->opt_order;
00848     int sb;
00849     int64_t y;
00850     int32_t *quant_cof        = bd->quant_cof;
00851     int32_t *lpc_cof          = bd->lpc_cof;
00852     int32_t *raw_samples      = bd->raw_samples;
00853     int32_t *raw_samples_end  = bd->raw_samples + bd->block_length;
00854     int32_t *lpc_cof_reversed = ctx->lpc_cof_reversed_buffer;
00855 
00856     // reverse long-term prediction
00857     if (*bd->use_ltp) {
00858         int ltp_smp;
00859 
00860         for (ltp_smp = FFMAX(*bd->ltp_lag - 2, 0); ltp_smp < block_length; ltp_smp++) {
00861             int center = ltp_smp - *bd->ltp_lag;
00862             int begin  = FFMAX(0, center - 2);
00863             int end    = center + 3;
00864             int tab    = 5 - (end - begin);
00865             int base;
00866 
00867             y = 1 << 6;
00868 
00869             for (base = begin; base < end; base++, tab++)
00870                 y += MUL64(bd->ltp_gain[tab], raw_samples[base]);
00871 
00872             raw_samples[ltp_smp] += y >> 7;
00873         }
00874     }
00875 
00876     // reconstruct all samples from residuals
00877     if (bd->ra_block) {
00878         for (smp = 0; smp < opt_order; smp++) {
00879             y = 1 << 19;
00880 
00881             for (sb = 0; sb < smp; sb++)
00882                 y += MUL64(lpc_cof[sb], raw_samples[-(sb + 1)]);
00883 
00884             *raw_samples++ -= y >> 20;
00885             parcor_to_lpc(smp, quant_cof, lpc_cof);
00886         }
00887     } else {
00888         for (k = 0; k < opt_order; k++)
00889             parcor_to_lpc(k, quant_cof, lpc_cof);
00890 
00891         // store previous samples in case that they have to be altered
00892         if (*bd->store_prev_samples)
00893             memcpy(bd->prev_raw_samples, raw_samples - sconf->max_order,
00894                    sizeof(*bd->prev_raw_samples) * sconf->max_order);
00895 
00896         // reconstruct difference signal for prediction (joint-stereo)
00897         if (bd->js_blocks && bd->raw_other) {
00898             int32_t *left, *right;
00899 
00900             if (bd->raw_other > raw_samples) {  // D = R - L
00901                 left  = raw_samples;
00902                 right = bd->raw_other;
00903             } else {                                // D = R - L
00904                 left  = bd->raw_other;
00905                 right = raw_samples;
00906             }
00907 
00908             for (sb = -1; sb >= -sconf->max_order; sb--)
00909                 raw_samples[sb] = right[sb] - left[sb];
00910         }
00911 
00912         // reconstruct shifted signal
00913         if (*bd->shift_lsbs)
00914             for (sb = -1; sb >= -sconf->max_order; sb--)
00915                 raw_samples[sb] >>= *bd->shift_lsbs;
00916     }
00917 
00918     // reverse linear prediction coefficients for efficiency
00919     lpc_cof = lpc_cof + opt_order;
00920 
00921     for (sb = 0; sb < opt_order; sb++)
00922         lpc_cof_reversed[sb] = lpc_cof[-(sb + 1)];
00923 
00924     // reconstruct raw samples
00925     raw_samples = bd->raw_samples + smp;
00926     lpc_cof     = lpc_cof_reversed + opt_order;
00927 
00928     for (; raw_samples < raw_samples_end; raw_samples++) {
00929         y = 1 << 19;
00930 
00931         for (sb = -opt_order; sb < 0; sb++)
00932             y += MUL64(lpc_cof[sb], raw_samples[sb]);
00933 
00934         *raw_samples -= y >> 20;
00935     }
00936 
00937     raw_samples = bd->raw_samples;
00938 
00939     // restore previous samples in case that they have been altered
00940     if (*bd->store_prev_samples)
00941         memcpy(raw_samples - sconf->max_order, bd->prev_raw_samples,
00942                sizeof(*raw_samples) * sconf->max_order);
00943 
00944     return 0;
00945 }
00946 
00947 
00950 static int read_block(ALSDecContext *ctx, ALSBlockData *bd)
00951 {
00952     GetBitContext *gb        = &ctx->gb;
00953 
00954     *bd->shift_lsbs = 0;
00955     // read block type flag and read the samples accordingly
00956     if (get_bits1(gb)) {
00957         if (read_var_block_data(ctx, bd))
00958             return -1;
00959     } else {
00960         read_const_block_data(ctx, bd);
00961     }
00962 
00963     return 0;
00964 }
00965 
00966 
00969 static int decode_block(ALSDecContext *ctx, ALSBlockData *bd)
00970 {
00971     unsigned int smp;
00972 
00973     // read block type flag and read the samples accordingly
00974     if (*bd->const_block)
00975         decode_const_block_data(ctx, bd);
00976     else if (decode_var_block_data(ctx, bd))
00977         return -1;
00978 
00979     // TODO: read RLSLMS extension data
00980 
00981     if (*bd->shift_lsbs)
00982         for (smp = 0; smp < bd->block_length; smp++)
00983             bd->raw_samples[smp] <<= *bd->shift_lsbs;
00984 
00985     return 0;
00986 }
00987 
00988 
00991 static int read_decode_block(ALSDecContext *ctx, ALSBlockData *bd)
00992 {
00993     int ret;
00994 
00995     ret = read_block(ctx, bd);
00996 
00997     if (ret)
00998         return ret;
00999 
01000     ret = decode_block(ctx, bd);
01001 
01002     return ret;
01003 }
01004 
01005 
01009 static void zero_remaining(unsigned int b, unsigned int b_max,
01010                            const unsigned int *div_blocks, int32_t *buf)
01011 {
01012     unsigned int count = 0;
01013 
01014     for (; b < b_max; b++)
01015         count += div_blocks[b];
01016 
01017     if (count)
01018         memset(buf, 0, sizeof(*buf) * count);
01019 }
01020 
01021 
01024 static int decode_blocks_ind(ALSDecContext *ctx, unsigned int ra_frame,
01025                              unsigned int c, const unsigned int *div_blocks,
01026                              unsigned int *js_blocks)
01027 {
01028     unsigned int b;
01029     ALSBlockData bd;
01030 
01031     memset(&bd, 0, sizeof(ALSBlockData));
01032 
01033     bd.ra_block         = ra_frame;
01034     bd.const_block      = ctx->const_block;
01035     bd.shift_lsbs       = ctx->shift_lsbs;
01036     bd.opt_order        = ctx->opt_order;
01037     bd.store_prev_samples = ctx->store_prev_samples;
01038     bd.use_ltp          = ctx->use_ltp;
01039     bd.ltp_lag          = ctx->ltp_lag;
01040     bd.ltp_gain         = ctx->ltp_gain[0];
01041     bd.quant_cof        = ctx->quant_cof[0];
01042     bd.lpc_cof          = ctx->lpc_cof[0];
01043     bd.prev_raw_samples = ctx->prev_raw_samples;
01044     bd.raw_samples      = ctx->raw_samples[c];
01045 
01046 
01047     for (b = 0; b < ctx->num_blocks; b++) {
01048         bd.block_length     = div_blocks[b];
01049 
01050         if (read_decode_block(ctx, &bd)) {
01051             // damaged block, write zero for the rest of the frame
01052             zero_remaining(b, ctx->num_blocks, div_blocks, bd.raw_samples);
01053             return -1;
01054         }
01055         bd.raw_samples += div_blocks[b];
01056         bd.ra_block     = 0;
01057     }
01058 
01059     return 0;
01060 }
01061 
01062 
01065 static int decode_blocks(ALSDecContext *ctx, unsigned int ra_frame,
01066                          unsigned int c, const unsigned int *div_blocks,
01067                          unsigned int *js_blocks)
01068 {
01069     ALSSpecificConfig *sconf = &ctx->sconf;
01070     unsigned int offset = 0;
01071     unsigned int b;
01072     ALSBlockData bd[2];
01073 
01074     memset(bd, 0, 2 * sizeof(ALSBlockData));
01075 
01076     bd[0].ra_block         = ra_frame;
01077     bd[0].const_block      = ctx->const_block;
01078     bd[0].shift_lsbs       = ctx->shift_lsbs;
01079     bd[0].opt_order        = ctx->opt_order;
01080     bd[0].store_prev_samples = ctx->store_prev_samples;
01081     bd[0].use_ltp          = ctx->use_ltp;
01082     bd[0].ltp_lag          = ctx->ltp_lag;
01083     bd[0].ltp_gain         = ctx->ltp_gain[0];
01084     bd[0].quant_cof        = ctx->quant_cof[0];
01085     bd[0].lpc_cof          = ctx->lpc_cof[0];
01086     bd[0].prev_raw_samples = ctx->prev_raw_samples;
01087     bd[0].js_blocks        = *js_blocks;
01088 
01089     bd[1].ra_block         = ra_frame;
01090     bd[1].const_block      = ctx->const_block;
01091     bd[1].shift_lsbs       = ctx->shift_lsbs;
01092     bd[1].opt_order        = ctx->opt_order;
01093     bd[1].store_prev_samples = ctx->store_prev_samples;
01094     bd[1].use_ltp          = ctx->use_ltp;
01095     bd[1].ltp_lag          = ctx->ltp_lag;
01096     bd[1].ltp_gain         = ctx->ltp_gain[0];
01097     bd[1].quant_cof        = ctx->quant_cof[0];
01098     bd[1].lpc_cof          = ctx->lpc_cof[0];
01099     bd[1].prev_raw_samples = ctx->prev_raw_samples;
01100     bd[1].js_blocks        = *(js_blocks + 1);
01101 
01102     // decode all blocks
01103     for (b = 0; b < ctx->num_blocks; b++) {
01104         unsigned int s;
01105 
01106         bd[0].block_length = div_blocks[b];
01107         bd[1].block_length = div_blocks[b];
01108 
01109         bd[0].raw_samples  = ctx->raw_samples[c    ] + offset;
01110         bd[1].raw_samples  = ctx->raw_samples[c + 1] + offset;
01111 
01112         bd[0].raw_other    = bd[1].raw_samples;
01113         bd[1].raw_other    = bd[0].raw_samples;
01114 
01115         if(read_decode_block(ctx, &bd[0]) || read_decode_block(ctx, &bd[1])) {
01116             // damaged block, write zero for the rest of the frame
01117             zero_remaining(b, ctx->num_blocks, div_blocks, bd[0].raw_samples);
01118             zero_remaining(b, ctx->num_blocks, div_blocks, bd[1].raw_samples);
01119             return -1;
01120         }
01121 
01122         // reconstruct joint-stereo blocks
01123         if (bd[0].js_blocks) {
01124             if (bd[1].js_blocks)
01125                 av_log(ctx->avctx, AV_LOG_WARNING, "Invalid channel pair!\n");
01126 
01127             for (s = 0; s < div_blocks[b]; s++)
01128                 bd[0].raw_samples[s] = bd[1].raw_samples[s] - bd[0].raw_samples[s];
01129         } else if (bd[1].js_blocks) {
01130             for (s = 0; s < div_blocks[b]; s++)
01131                 bd[1].raw_samples[s] = bd[1].raw_samples[s] + bd[0].raw_samples[s];
01132         }
01133 
01134         offset  += div_blocks[b];
01135         bd[0].ra_block = 0;
01136         bd[1].ra_block = 0;
01137     }
01138 
01139     // store carryover raw samples,
01140     // the others channel raw samples are stored by the calling function.
01141     memmove(ctx->raw_samples[c] - sconf->max_order,
01142             ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,
01143             sizeof(*ctx->raw_samples[c]) * sconf->max_order);
01144 
01145     return 0;
01146 }
01147 
01148 
01151 static int read_channel_data(ALSDecContext *ctx, ALSChannelData *cd, int c)
01152 {
01153     GetBitContext *gb       = &ctx->gb;
01154     ALSChannelData *current = cd;
01155     unsigned int channels   = ctx->avctx->channels;
01156     int entries             = 0;
01157 
01158     while (entries < channels && !(current->stop_flag = get_bits1(gb))) {
01159         current->master_channel = get_bits_long(gb, av_ceil_log2(channels));
01160 
01161         if (current->master_channel >= channels) {
01162             av_log(ctx->avctx, AV_LOG_ERROR, "Invalid master channel!\n");
01163             return -1;
01164         }
01165 
01166         if (current->master_channel != c) {
01167             current->time_diff_flag = get_bits1(gb);
01168             current->weighting[0]   = mcc_weightings[av_clip(decode_rice(gb, 1) + 16, 0, 32)];
01169             current->weighting[1]   = mcc_weightings[av_clip(decode_rice(gb, 2) + 14, 0, 32)];
01170             current->weighting[2]   = mcc_weightings[av_clip(decode_rice(gb, 1) + 16, 0, 32)];
01171 
01172             if (current->time_diff_flag) {
01173                 current->weighting[3] = mcc_weightings[av_clip(decode_rice(gb, 1) + 16, 0, 32)];
01174                 current->weighting[4] = mcc_weightings[av_clip(decode_rice(gb, 1) + 16, 0, 32)];
01175                 current->weighting[5] = mcc_weightings[av_clip(decode_rice(gb, 1) + 16, 0, 32)];
01176 
01177                 current->time_diff_sign  = get_bits1(gb);
01178                 current->time_diff_index = get_bits(gb, ctx->ltp_lag_length - 3) + 3;
01179             }
01180         }
01181 
01182         current++;
01183         entries++;
01184     }
01185 
01186     if (entries == channels) {
01187         av_log(ctx->avctx, AV_LOG_ERROR, "Damaged channel data!\n");
01188         return -1;
01189     }
01190 
01191     align_get_bits(gb);
01192     return 0;
01193 }
01194 
01195 
01198 static int revert_channel_correlation(ALSDecContext *ctx, ALSBlockData *bd,
01199                                        ALSChannelData **cd, int *reverted,
01200                                        unsigned int offset, int c)
01201 {
01202     ALSChannelData *ch = cd[c];
01203     unsigned int   dep = 0;
01204     unsigned int channels = ctx->avctx->channels;
01205 
01206     if (reverted[c])
01207         return 0;
01208 
01209     reverted[c] = 1;
01210 
01211     while (dep < channels && !ch[dep].stop_flag) {
01212         revert_channel_correlation(ctx, bd, cd, reverted, offset,
01213                                    ch[dep].master_channel);
01214 
01215         dep++;
01216     }
01217 
01218     if (dep == channels) {
01219         av_log(ctx->avctx, AV_LOG_WARNING, "Invalid channel correlation!\n");
01220         return -1;
01221     }
01222 
01223     bd->const_block = ctx->const_block + c;
01224     bd->shift_lsbs  = ctx->shift_lsbs + c;
01225     bd->opt_order   = ctx->opt_order + c;
01226     bd->store_prev_samples = ctx->store_prev_samples + c;
01227     bd->use_ltp     = ctx->use_ltp + c;
01228     bd->ltp_lag     = ctx->ltp_lag + c;
01229     bd->ltp_gain    = ctx->ltp_gain[c];
01230     bd->lpc_cof     = ctx->lpc_cof[c];
01231     bd->quant_cof   = ctx->quant_cof[c];
01232     bd->raw_samples = ctx->raw_samples[c] + offset;
01233 
01234     dep = 0;
01235     while (!ch[dep].stop_flag) {
01236         unsigned int smp;
01237         unsigned int begin = 1;
01238         unsigned int end   = bd->block_length - 1;
01239         int64_t y;
01240         int32_t *master = ctx->raw_samples[ch[dep].master_channel] + offset;
01241 
01242         if (ch[dep].time_diff_flag) {
01243             int t = ch[dep].time_diff_index;
01244 
01245             if (ch[dep].time_diff_sign) {
01246                 t      = -t;
01247                 begin -= t;
01248             } else {
01249                 end   -= t;
01250             }
01251 
01252             for (smp = begin; smp < end; smp++) {
01253                 y  = (1 << 6) +
01254                      MUL64(ch[dep].weighting[0], master[smp - 1    ]) +
01255                      MUL64(ch[dep].weighting[1], master[smp        ]) +
01256                      MUL64(ch[dep].weighting[2], master[smp + 1    ]) +
01257                      MUL64(ch[dep].weighting[3], master[smp - 1 + t]) +
01258                      MUL64(ch[dep].weighting[4], master[smp     + t]) +
01259                      MUL64(ch[dep].weighting[5], master[smp + 1 + t]);
01260 
01261                 bd->raw_samples[smp] += y >> 7;
01262             }
01263         } else {
01264             for (smp = begin; smp < end; smp++) {
01265                 y  = (1 << 6) +
01266                      MUL64(ch[dep].weighting[0], master[smp - 1]) +
01267                      MUL64(ch[dep].weighting[1], master[smp    ]) +
01268                      MUL64(ch[dep].weighting[2], master[smp + 1]);
01269 
01270                 bd->raw_samples[smp] += y >> 7;
01271             }
01272         }
01273 
01274         dep++;
01275     }
01276 
01277     return 0;
01278 }
01279 
01280 
01283 static int read_frame_data(ALSDecContext *ctx, unsigned int ra_frame)
01284 {
01285     ALSSpecificConfig *sconf = &ctx->sconf;
01286     AVCodecContext *avctx    = ctx->avctx;
01287     GetBitContext *gb = &ctx->gb;
01288     unsigned int div_blocks[32];                
01289     unsigned int c;
01290     unsigned int js_blocks[2];
01291 
01292     uint32_t bs_info = 0;
01293 
01294     // skip the size of the ra unit if present in the frame
01295     if (sconf->ra_flag == RA_FLAG_FRAMES && ra_frame)
01296         skip_bits_long(gb, 32);
01297 
01298     if (sconf->mc_coding && sconf->joint_stereo) {
01299         ctx->js_switch = get_bits1(gb);
01300         align_get_bits(gb);
01301     }
01302 
01303     if (!sconf->mc_coding || ctx->js_switch) {
01304         int independent_bs = !sconf->joint_stereo;
01305 
01306         for (c = 0; c < avctx->channels; c++) {
01307             js_blocks[0] = 0;
01308             js_blocks[1] = 0;
01309 
01310             get_block_sizes(ctx, div_blocks, &bs_info);
01311 
01312             // if joint_stereo and block_switching is set, independent decoding
01313             // is signaled via the first bit of bs_info
01314             if (sconf->joint_stereo && sconf->block_switching)
01315                 if (bs_info >> 31)
01316                     independent_bs = 2;
01317 
01318             // if this is the last channel, it has to be decoded independently
01319             if (c == avctx->channels - 1)
01320                 independent_bs = 1;
01321 
01322             if (independent_bs) {
01323                 if (decode_blocks_ind(ctx, ra_frame, c, div_blocks, js_blocks))
01324                     return -1;
01325 
01326                 independent_bs--;
01327             } else {
01328                 if (decode_blocks(ctx, ra_frame, c, div_blocks, js_blocks))
01329                     return -1;
01330 
01331                 c++;
01332             }
01333 
01334             // store carryover raw samples
01335             memmove(ctx->raw_samples[c] - sconf->max_order,
01336                     ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,
01337                     sizeof(*ctx->raw_samples[c]) * sconf->max_order);
01338         }
01339     } else { // multi-channel coding
01340         ALSBlockData   bd;
01341         int            b;
01342         int            *reverted_channels = ctx->reverted_channels;
01343         unsigned int   offset             = 0;
01344 
01345         for (c = 0; c < avctx->channels; c++)
01346             if (ctx->chan_data[c] < ctx->chan_data_buffer) {
01347                 av_log(ctx->avctx, AV_LOG_ERROR, "Invalid channel data!\n");
01348                 return -1;
01349             }
01350 
01351         memset(&bd,               0, sizeof(ALSBlockData));
01352         memset(reverted_channels, 0, sizeof(*reverted_channels) * avctx->channels);
01353 
01354         bd.ra_block         = ra_frame;
01355         bd.prev_raw_samples = ctx->prev_raw_samples;
01356 
01357         get_block_sizes(ctx, div_blocks, &bs_info);
01358 
01359         for (b = 0; b < ctx->num_blocks; b++) {
01360             bd.block_length = div_blocks[b];
01361 
01362             for (c = 0; c < avctx->channels; c++) {
01363                 bd.const_block = ctx->const_block + c;
01364                 bd.shift_lsbs  = ctx->shift_lsbs + c;
01365                 bd.opt_order   = ctx->opt_order + c;
01366                 bd.store_prev_samples = ctx->store_prev_samples + c;
01367                 bd.use_ltp     = ctx->use_ltp + c;
01368                 bd.ltp_lag     = ctx->ltp_lag + c;
01369                 bd.ltp_gain    = ctx->ltp_gain[c];
01370                 bd.lpc_cof     = ctx->lpc_cof[c];
01371                 bd.quant_cof   = ctx->quant_cof[c];
01372                 bd.raw_samples = ctx->raw_samples[c] + offset;
01373                 bd.raw_other   = NULL;
01374 
01375                 read_block(ctx, &bd);
01376                 if (read_channel_data(ctx, ctx->chan_data[c], c))
01377                     return -1;
01378             }
01379 
01380             for (c = 0; c < avctx->channels; c++)
01381                 if (revert_channel_correlation(ctx, &bd, ctx->chan_data,
01382                                                reverted_channels, offset, c))
01383                     return -1;
01384 
01385             for (c = 0; c < avctx->channels; c++) {
01386                 bd.const_block = ctx->const_block + c;
01387                 bd.shift_lsbs  = ctx->shift_lsbs + c;
01388                 bd.opt_order   = ctx->opt_order + c;
01389                 bd.store_prev_samples = ctx->store_prev_samples + c;
01390                 bd.use_ltp     = ctx->use_ltp + c;
01391                 bd.ltp_lag     = ctx->ltp_lag + c;
01392                 bd.ltp_gain    = ctx->ltp_gain[c];
01393                 bd.lpc_cof     = ctx->lpc_cof[c];
01394                 bd.quant_cof   = ctx->quant_cof[c];
01395                 bd.raw_samples = ctx->raw_samples[c] + offset;
01396                 decode_block(ctx, &bd);
01397             }
01398 
01399             memset(reverted_channels, 0, avctx->channels * sizeof(*reverted_channels));
01400             offset      += div_blocks[b];
01401             bd.ra_block  = 0;
01402         }
01403 
01404         // store carryover raw samples
01405         for (c = 0; c < avctx->channels; c++)
01406             memmove(ctx->raw_samples[c] - sconf->max_order,
01407                     ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,
01408                     sizeof(*ctx->raw_samples[c]) * sconf->max_order);
01409     }
01410 
01411     // TODO: read_diff_float_data
01412 
01413     return 0;
01414 }
01415 
01416 
01419 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr,
01420                         AVPacket *avpkt)
01421 {
01422     ALSDecContext *ctx       = avctx->priv_data;
01423     ALSSpecificConfig *sconf = &ctx->sconf;
01424     const uint8_t *buffer    = avpkt->data;
01425     int buffer_size          = avpkt->size;
01426     int invalid_frame, ret;
01427     unsigned int c, sample, ra_frame, bytes_read, shift;
01428 
01429     init_get_bits(&ctx->gb, buffer, buffer_size * 8);
01430 
01431     // In the case that the distance between random access frames is set to zero
01432     // (sconf->ra_distance == 0) no frame is treated as a random access frame.
01433     // For the first frame, if prediction is used, all samples used from the
01434     // previous frame are assumed to be zero.
01435     ra_frame = sconf->ra_distance && !(ctx->frame_id % sconf->ra_distance);
01436 
01437     // the last frame to decode might have a different length
01438     if (sconf->samples != 0xFFFFFFFF)
01439         ctx->cur_frame_length = FFMIN(sconf->samples - ctx->frame_id * (uint64_t) sconf->frame_length,
01440                                       sconf->frame_length);
01441     else
01442         ctx->cur_frame_length = sconf->frame_length;
01443 
01444     // decode the frame data
01445     if ((invalid_frame = read_frame_data(ctx, ra_frame) < 0))
01446         av_log(ctx->avctx, AV_LOG_WARNING,
01447                "Reading frame data failed. Skipping RA unit.\n");
01448 
01449     ctx->frame_id++;
01450 
01451     /* get output buffer */
01452     ctx->frame.nb_samples = ctx->cur_frame_length;
01453     if ((ret = avctx->get_buffer(avctx, &ctx->frame)) < 0) {
01454         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
01455         return ret;
01456     }
01457 
01458     // transform decoded frame into output format
01459     #define INTERLEAVE_OUTPUT(bps)                                 \
01460     {                                                              \
01461         int##bps##_t *dest = (int##bps##_t*)ctx->frame.data[0];    \
01462         shift = bps - ctx->avctx->bits_per_raw_sample;             \
01463         for (sample = 0; sample < ctx->cur_frame_length; sample++) \
01464             for (c = 0; c < avctx->channels; c++)                  \
01465                 *dest++ = ctx->raw_samples[c][sample] << shift;    \
01466     }
01467 
01468     if (ctx->avctx->bits_per_raw_sample <= 16) {
01469         INTERLEAVE_OUTPUT(16)
01470     } else {
01471         INTERLEAVE_OUTPUT(32)
01472     }
01473 
01474     // update CRC
01475     if (sconf->crc_enabled && (avctx->err_recognition & AV_EF_CRCCHECK)) {
01476         int swap = HAVE_BIGENDIAN != sconf->msb_first;
01477 
01478         if (ctx->avctx->bits_per_raw_sample == 24) {
01479             int32_t *src = (int32_t *)ctx->frame.data[0];
01480 
01481             for (sample = 0;
01482                  sample < ctx->cur_frame_length * avctx->channels;
01483                  sample++) {
01484                 int32_t v;
01485 
01486                 if (swap)
01487                     v = av_bswap32(src[sample]);
01488                 else
01489                     v = src[sample];
01490                 if (!HAVE_BIGENDIAN)
01491                     v >>= 8;
01492 
01493                 ctx->crc = av_crc(ctx->crc_table, ctx->crc, (uint8_t*)(&v), 3);
01494             }
01495         } else {
01496             uint8_t *crc_source;
01497 
01498             if (swap) {
01499                 if (ctx->avctx->bits_per_raw_sample <= 16) {
01500                     int16_t *src  = (int16_t*) ctx->frame.data[0];
01501                     int16_t *dest = (int16_t*) ctx->crc_buffer;
01502                     for (sample = 0;
01503                          sample < ctx->cur_frame_length * avctx->channels;
01504                          sample++)
01505                         *dest++ = av_bswap16(src[sample]);
01506                 } else {
01507                     ctx->dsp.bswap_buf((uint32_t*)ctx->crc_buffer,
01508                                        (uint32_t *)ctx->frame.data[0],
01509                                        ctx->cur_frame_length * avctx->channels);
01510                 }
01511                 crc_source = ctx->crc_buffer;
01512             } else {
01513                 crc_source = ctx->frame.data[0];
01514             }
01515 
01516             ctx->crc = av_crc(ctx->crc_table, ctx->crc, crc_source,
01517                               ctx->cur_frame_length * avctx->channels *
01518                               av_get_bytes_per_sample(avctx->sample_fmt));
01519         }
01520 
01521 
01522         // check CRC sums if this is the last frame
01523         if (ctx->cur_frame_length != sconf->frame_length &&
01524             ctx->crc_org != ctx->crc) {
01525             av_log(avctx, AV_LOG_ERROR, "CRC error.\n");
01526         }
01527     }
01528 
01529     *got_frame_ptr   = 1;
01530     *(AVFrame *)data = ctx->frame;
01531 
01532 
01533     bytes_read = invalid_frame ? buffer_size :
01534                                  (get_bits_count(&ctx->gb) + 7) >> 3;
01535 
01536     return bytes_read;
01537 }
01538 
01539 
01542 static av_cold int decode_end(AVCodecContext *avctx)
01543 {
01544     ALSDecContext *ctx = avctx->priv_data;
01545 
01546     av_freep(&ctx->sconf.chan_pos);
01547 
01548     ff_bgmc_end(&ctx->bgmc_lut, &ctx->bgmc_lut_status);
01549 
01550     av_freep(&ctx->const_block);
01551     av_freep(&ctx->shift_lsbs);
01552     av_freep(&ctx->opt_order);
01553     av_freep(&ctx->store_prev_samples);
01554     av_freep(&ctx->use_ltp);
01555     av_freep(&ctx->ltp_lag);
01556     av_freep(&ctx->ltp_gain);
01557     av_freep(&ctx->ltp_gain_buffer);
01558     av_freep(&ctx->quant_cof);
01559     av_freep(&ctx->lpc_cof);
01560     av_freep(&ctx->quant_cof_buffer);
01561     av_freep(&ctx->lpc_cof_buffer);
01562     av_freep(&ctx->lpc_cof_reversed_buffer);
01563     av_freep(&ctx->prev_raw_samples);
01564     av_freep(&ctx->raw_samples);
01565     av_freep(&ctx->raw_buffer);
01566     av_freep(&ctx->chan_data);
01567     av_freep(&ctx->chan_data_buffer);
01568     av_freep(&ctx->reverted_channels);
01569     av_freep(&ctx->crc_buffer);
01570 
01571     return 0;
01572 }
01573 
01574 
01577 static av_cold int decode_init(AVCodecContext *avctx)
01578 {
01579     unsigned int c;
01580     unsigned int channel_size;
01581     int num_buffers;
01582     ALSDecContext *ctx = avctx->priv_data;
01583     ALSSpecificConfig *sconf = &ctx->sconf;
01584     ctx->avctx = avctx;
01585 
01586     if (!avctx->extradata) {
01587         av_log(avctx, AV_LOG_ERROR, "Missing required ALS extradata.\n");
01588         return -1;
01589     }
01590 
01591     if (read_specific_config(ctx)) {
01592         av_log(avctx, AV_LOG_ERROR, "Reading ALSSpecificConfig failed.\n");
01593         decode_end(avctx);
01594         return -1;
01595     }
01596 
01597     if (check_specific_config(ctx)) {
01598         decode_end(avctx);
01599         return -1;
01600     }
01601 
01602     if (sconf->bgmc)
01603         ff_bgmc_init(avctx, &ctx->bgmc_lut, &ctx->bgmc_lut_status);
01604 
01605     if (sconf->floating) {
01606         avctx->sample_fmt          = AV_SAMPLE_FMT_FLT;
01607         avctx->bits_per_raw_sample = 32;
01608     } else {
01609         avctx->sample_fmt          = sconf->resolution > 1
01610                                      ? AV_SAMPLE_FMT_S32 : AV_SAMPLE_FMT_S16;
01611         avctx->bits_per_raw_sample = (sconf->resolution + 1) * 8;
01612     }
01613 
01614     // set maximum Rice parameter for progressive decoding based on resolution
01615     // This is not specified in 14496-3 but actually done by the reference
01616     // codec RM22 revision 2.
01617     ctx->s_max = sconf->resolution > 1 ? 31 : 15;
01618 
01619     // set lag value for long-term prediction
01620     ctx->ltp_lag_length = 8 + (avctx->sample_rate >=  96000) +
01621                               (avctx->sample_rate >= 192000);
01622 
01623     // allocate quantized parcor coefficient buffer
01624     num_buffers = sconf->mc_coding ? avctx->channels : 1;
01625 
01626     ctx->quant_cof        = av_malloc(sizeof(*ctx->quant_cof) * num_buffers);
01627     ctx->lpc_cof          = av_malloc(sizeof(*ctx->lpc_cof)   * num_buffers);
01628     ctx->quant_cof_buffer = av_malloc(sizeof(*ctx->quant_cof_buffer) *
01629                                       num_buffers * sconf->max_order);
01630     ctx->lpc_cof_buffer   = av_malloc(sizeof(*ctx->lpc_cof_buffer) *
01631                                       num_buffers * sconf->max_order);
01632     ctx->lpc_cof_reversed_buffer = av_malloc(sizeof(*ctx->lpc_cof_buffer) *
01633                                              sconf->max_order);
01634 
01635     if (!ctx->quant_cof              || !ctx->lpc_cof        ||
01636         !ctx->quant_cof_buffer       || !ctx->lpc_cof_buffer ||
01637         !ctx->lpc_cof_reversed_buffer) {
01638         av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
01639         return AVERROR(ENOMEM);
01640     }
01641 
01642     // assign quantized parcor coefficient buffers
01643     for (c = 0; c < num_buffers; c++) {
01644         ctx->quant_cof[c] = ctx->quant_cof_buffer + c * sconf->max_order;
01645         ctx->lpc_cof[c]   = ctx->lpc_cof_buffer   + c * sconf->max_order;
01646     }
01647 
01648     // allocate and assign lag and gain data buffer for ltp mode
01649     ctx->const_block     = av_malloc (sizeof(*ctx->const_block) * num_buffers);
01650     ctx->shift_lsbs      = av_malloc (sizeof(*ctx->shift_lsbs)  * num_buffers);
01651     ctx->opt_order       = av_malloc (sizeof(*ctx->opt_order)   * num_buffers);
01652     ctx->store_prev_samples = av_malloc(sizeof(*ctx->store_prev_samples) * num_buffers);
01653     ctx->use_ltp         = av_mallocz(sizeof(*ctx->use_ltp)  * num_buffers);
01654     ctx->ltp_lag         = av_malloc (sizeof(*ctx->ltp_lag)  * num_buffers);
01655     ctx->ltp_gain        = av_malloc (sizeof(*ctx->ltp_gain) * num_buffers);
01656     ctx->ltp_gain_buffer = av_malloc (sizeof(*ctx->ltp_gain_buffer) *
01657                                       num_buffers * 5);
01658 
01659     if (!ctx->const_block || !ctx->shift_lsbs ||
01660         !ctx->opt_order || !ctx->store_prev_samples ||
01661         !ctx->use_ltp  || !ctx->ltp_lag ||
01662         !ctx->ltp_gain || !ctx->ltp_gain_buffer) {
01663         av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
01664         decode_end(avctx);
01665         return AVERROR(ENOMEM);
01666     }
01667 
01668     for (c = 0; c < num_buffers; c++)
01669         ctx->ltp_gain[c] = ctx->ltp_gain_buffer + c * 5;
01670 
01671     // allocate and assign channel data buffer for mcc mode
01672     if (sconf->mc_coding) {
01673         ctx->chan_data_buffer  = av_malloc(sizeof(*ctx->chan_data_buffer) *
01674                                            num_buffers * num_buffers);
01675         ctx->chan_data         = av_malloc(sizeof(*ctx->chan_data) *
01676                                            num_buffers);
01677         ctx->reverted_channels = av_malloc(sizeof(*ctx->reverted_channels) *
01678                                            num_buffers);
01679 
01680         if (!ctx->chan_data_buffer || !ctx->chan_data || !ctx->reverted_channels) {
01681             av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
01682             decode_end(avctx);
01683             return AVERROR(ENOMEM);
01684         }
01685 
01686         for (c = 0; c < num_buffers; c++)
01687             ctx->chan_data[c] = ctx->chan_data_buffer + c * num_buffers;
01688     } else {
01689         ctx->chan_data         = NULL;
01690         ctx->chan_data_buffer  = NULL;
01691         ctx->reverted_channels = NULL;
01692     }
01693 
01694     avctx->frame_size = sconf->frame_length;
01695     channel_size      = sconf->frame_length + sconf->max_order;
01696 
01697     ctx->prev_raw_samples = av_malloc (sizeof(*ctx->prev_raw_samples) * sconf->max_order);
01698     ctx->raw_buffer       = av_mallocz(sizeof(*ctx->     raw_buffer)  * avctx->channels * channel_size);
01699     ctx->raw_samples      = av_malloc (sizeof(*ctx->     raw_samples) * avctx->channels);
01700 
01701     // allocate previous raw sample buffer
01702     if (!ctx->prev_raw_samples || !ctx->raw_buffer|| !ctx->raw_samples) {
01703         av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
01704         decode_end(avctx);
01705         return AVERROR(ENOMEM);
01706     }
01707 
01708     // assign raw samples buffers
01709     ctx->raw_samples[0] = ctx->raw_buffer + sconf->max_order;
01710     for (c = 1; c < avctx->channels; c++)
01711         ctx->raw_samples[c] = ctx->raw_samples[c - 1] + channel_size;
01712 
01713     // allocate crc buffer
01714     if (HAVE_BIGENDIAN != sconf->msb_first && sconf->crc_enabled &&
01715         (avctx->err_recognition & AV_EF_CRCCHECK)) {
01716         ctx->crc_buffer = av_malloc(sizeof(*ctx->crc_buffer) *
01717                                     ctx->cur_frame_length *
01718                                     avctx->channels *
01719                                     av_get_bytes_per_sample(avctx->sample_fmt));
01720         if (!ctx->crc_buffer) {
01721             av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
01722             decode_end(avctx);
01723             return AVERROR(ENOMEM);
01724         }
01725     }
01726 
01727     dsputil_init(&ctx->dsp, avctx);
01728 
01729     avcodec_get_frame_defaults(&ctx->frame);
01730     avctx->coded_frame = &ctx->frame;
01731 
01732     return 0;
01733 }
01734 
01735 
01738 static av_cold void flush(AVCodecContext *avctx)
01739 {
01740     ALSDecContext *ctx = avctx->priv_data;
01741 
01742     ctx->frame_id = 0;
01743 }
01744 
01745 
01746 AVCodec ff_als_decoder = {
01747     .name           = "als",
01748     .type           = AVMEDIA_TYPE_AUDIO,
01749     .id             = CODEC_ID_MP4ALS,
01750     .priv_data_size = sizeof(ALSDecContext),
01751     .init           = decode_init,
01752     .close          = decode_end,
01753     .decode         = decode_frame,
01754     .flush = flush,
01755     .capabilities = CODEC_CAP_SUBFRAMES | CODEC_CAP_DR1,
01756     .long_name = NULL_IF_CONFIG_SMALL("MPEG-4 Audio Lossless Coding (ALS)"),
01757 };
01758