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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 FFmpeg.
00006  *
00007  * FFmpeg 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  * FFmpeg 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 FFmpeg; 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     ALSSpecificConfig sconf;
00195     GetBitContext gb;
00196     DSPContext dsp;
00197     const AVCRC *crc_table;
00198     uint32_t crc_org;               
00199     uint32_t crc;                   
00200     unsigned int cur_frame_length;  
00201     unsigned int frame_id;          
00202     unsigned int js_switch;         
00203     unsigned int num_blocks;        
00204     unsigned int s_max;             
00205     uint8_t *bgmc_lut;              
00206     int *bgmc_lut_status;           
00207     int ltp_lag_length;             
00208     int *const_block;               
00209     unsigned int *shift_lsbs;       
00210     unsigned int *opt_order;        
00211     int *store_prev_samples;        
00212     int *use_ltp;                   
00213     int *ltp_lag;                   
00214     int **ltp_gain;                 
00215     int *ltp_gain_buffer;           
00216     int32_t **quant_cof;            
00217     int32_t *quant_cof_buffer;      
00218     int32_t **lpc_cof;              
00219     int32_t *lpc_cof_buffer;        
00220     int32_t *lpc_cof_reversed_buffer; 
00221     ALSChannelData **chan_data;     
00222     ALSChannelData *chan_data_buffer; 
00223     int *reverted_channels;         
00224     int32_t *prev_raw_samples;      
00225     int32_t **raw_samples;          
00226     int32_t *raw_buffer;            
00227     uint8_t *crc_buffer;            
00228 } ALSDecContext;
00229 
00230 
00231 typedef struct {
00232     unsigned int block_length;      
00233     unsigned int ra_block;          
00234     int          *const_block;      
00235     int          js_blocks;         
00236     unsigned int *shift_lsbs;       
00237     unsigned int *opt_order;        
00238     int          *store_prev_samples;
00239     int          *use_ltp;          
00240     int          *ltp_lag;          
00241     int          *ltp_gain;         
00242     int32_t      *quant_cof;        
00243     int32_t      *lpc_cof;          
00244     int32_t      *raw_samples;      
00245     int32_t      *prev_raw_samples; 
00246     int32_t      *raw_other;        
00247 } ALSBlockData;
00248 
00249 
00250 static av_cold void dprint_specific_config(ALSDecContext *ctx)
00251 {
00252 #ifdef DEBUG
00253     AVCodecContext *avctx    = ctx->avctx;
00254     ALSSpecificConfig *sconf = &ctx->sconf;
00255 
00256     av_dlog(avctx, "resolution = %i\n",           sconf->resolution);
00257     av_dlog(avctx, "floating = %i\n",             sconf->floating);
00258     av_dlog(avctx, "frame_length = %i\n",         sconf->frame_length);
00259     av_dlog(avctx, "ra_distance = %i\n",          sconf->ra_distance);
00260     av_dlog(avctx, "ra_flag = %i\n",              sconf->ra_flag);
00261     av_dlog(avctx, "adapt_order = %i\n",          sconf->adapt_order);
00262     av_dlog(avctx, "coef_table = %i\n",           sconf->coef_table);
00263     av_dlog(avctx, "long_term_prediction = %i\n", sconf->long_term_prediction);
00264     av_dlog(avctx, "max_order = %i\n",            sconf->max_order);
00265     av_dlog(avctx, "block_switching = %i\n",      sconf->block_switching);
00266     av_dlog(avctx, "bgmc = %i\n",                 sconf->bgmc);
00267     av_dlog(avctx, "sb_part = %i\n",              sconf->sb_part);
00268     av_dlog(avctx, "joint_stereo = %i\n",         sconf->joint_stereo);
00269     av_dlog(avctx, "mc_coding = %i\n",            sconf->mc_coding);
00270     av_dlog(avctx, "chan_config = %i\n",          sconf->chan_config);
00271     av_dlog(avctx, "chan_sort = %i\n",            sconf->chan_sort);
00272     av_dlog(avctx, "RLSLMS = %i\n",               sconf->rlslms);
00273     av_dlog(avctx, "chan_config_info = %i\n",     sconf->chan_config_info);
00274 #endif
00275 }
00276 
00277 
00280 static av_cold int read_specific_config(ALSDecContext *ctx)
00281 {
00282     GetBitContext gb;
00283     uint64_t ht_size;
00284     int i, config_offset;
00285     MPEG4AudioConfig m4ac;
00286     ALSSpecificConfig *sconf = &ctx->sconf;
00287     AVCodecContext *avctx    = ctx->avctx;
00288     uint32_t als_id, header_size, trailer_size;
00289 
00290     init_get_bits(&gb, avctx->extradata, avctx->extradata_size * 8);
00291 
00292     config_offset = ff_mpeg4audio_get_config(&m4ac, avctx->extradata,
00293                                              avctx->extradata_size);
00294 
00295     if (config_offset < 0)
00296         return -1;
00297 
00298     skip_bits_long(&gb, config_offset);
00299 
00300     if (get_bits_left(&gb) < (30 << 3))
00301         return -1;
00302 
00303     // read the fixed items
00304     als_id                      = get_bits_long(&gb, 32);
00305     avctx->sample_rate          = m4ac.sample_rate;
00306     skip_bits_long(&gb, 32); // sample rate already known
00307     sconf->samples              = get_bits_long(&gb, 32);
00308     avctx->channels             = m4ac.channels;
00309     skip_bits(&gb, 16);      // number of channels already knwon
00310     skip_bits(&gb, 3);       // skip file_type
00311     sconf->resolution           = get_bits(&gb, 3);
00312     sconf->floating             = get_bits1(&gb);
00313     sconf->msb_first            = get_bits1(&gb);
00314     sconf->frame_length         = get_bits(&gb, 16) + 1;
00315     sconf->ra_distance          = get_bits(&gb, 8);
00316     sconf->ra_flag              = get_bits(&gb, 2);
00317     sconf->adapt_order          = get_bits1(&gb);
00318     sconf->coef_table           = get_bits(&gb, 2);
00319     sconf->long_term_prediction = get_bits1(&gb);
00320     sconf->max_order            = get_bits(&gb, 10);
00321     sconf->block_switching      = get_bits(&gb, 2);
00322     sconf->bgmc                 = get_bits1(&gb);
00323     sconf->sb_part              = get_bits1(&gb);
00324     sconf->joint_stereo         = get_bits1(&gb);
00325     sconf->mc_coding            = get_bits1(&gb);
00326     sconf->chan_config          = get_bits1(&gb);
00327     sconf->chan_sort            = get_bits1(&gb);
00328     sconf->crc_enabled          = get_bits1(&gb);
00329     sconf->rlslms               = get_bits1(&gb);
00330     skip_bits(&gb, 5);       // skip 5 reserved bits
00331     skip_bits1(&gb);         // skip aux_data_enabled
00332 
00333 
00334     // check for ALSSpecificConfig struct
00335     if (als_id != MKBETAG('A','L','S','\0'))
00336         return -1;
00337 
00338     ctx->cur_frame_length = sconf->frame_length;
00339 
00340     // read channel config
00341     if (sconf->chan_config)
00342         sconf->chan_config_info = get_bits(&gb, 16);
00343     // TODO: use this to set avctx->channel_layout
00344 
00345 
00346     // read channel sorting
00347     if (sconf->chan_sort && avctx->channels > 1) {
00348         int chan_pos_bits = av_ceil_log2(avctx->channels);
00349         int bits_needed  = avctx->channels * chan_pos_bits + 7;
00350         if (get_bits_left(&gb) < bits_needed)
00351             return -1;
00352 
00353         if (!(sconf->chan_pos = av_malloc(avctx->channels * sizeof(*sconf->chan_pos))))
00354             return AVERROR(ENOMEM);
00355 
00356         for (i = 0; i < avctx->channels; i++)
00357             sconf->chan_pos[i] = get_bits(&gb, chan_pos_bits);
00358 
00359         align_get_bits(&gb);
00360         // TODO: use this to actually do channel sorting
00361     } else {
00362         sconf->chan_sort = 0;
00363     }
00364 
00365 
00366     // read fixed header and trailer sizes,
00367     // if size = 0xFFFFFFFF then there is no data field!
00368     if (get_bits_left(&gb) < 64)
00369         return -1;
00370 
00371     header_size  = get_bits_long(&gb, 32);
00372     trailer_size = get_bits_long(&gb, 32);
00373     if (header_size  == 0xFFFFFFFF)
00374         header_size  = 0;
00375     if (trailer_size == 0xFFFFFFFF)
00376         trailer_size = 0;
00377 
00378     ht_size = ((int64_t)(header_size) + (int64_t)(trailer_size)) << 3;
00379 
00380 
00381     // skip the header and trailer data
00382     if (get_bits_left(&gb) < ht_size)
00383         return -1;
00384 
00385     if (ht_size > INT32_MAX)
00386         return -1;
00387 
00388     skip_bits_long(&gb, ht_size);
00389 
00390 
00391     // initialize CRC calculation
00392     if (sconf->crc_enabled) {
00393         if (get_bits_left(&gb) < 32)
00394             return -1;
00395 
00396         if (avctx->error_recognition >= FF_ER_CAREFUL) {
00397             ctx->crc_table = av_crc_get_table(AV_CRC_32_IEEE_LE);
00398             ctx->crc       = 0xFFFFFFFF;
00399             ctx->crc_org   = ~get_bits_long(&gb, 32);
00400         } else
00401             skip_bits_long(&gb, 32);
00402     }
00403 
00404 
00405     // no need to read the rest of ALSSpecificConfig (ra_unit_size & aux data)
00406 
00407     dprint_specific_config(ctx);
00408 
00409     return 0;
00410 }
00411 
00412 
00415 static int check_specific_config(ALSDecContext *ctx)
00416 {
00417     ALSSpecificConfig *sconf = &ctx->sconf;
00418     int error = 0;
00419 
00420     // report unsupported feature and set error value
00421     #define MISSING_ERR(cond, str, errval)              \
00422     {                                                   \
00423         if (cond) {                                     \
00424             av_log_missing_feature(ctx->avctx, str, 0); \
00425             error = errval;                             \
00426         }                                               \
00427     }
00428 
00429     MISSING_ERR(sconf->floating,             "Floating point decoding",     -1);
00430     MISSING_ERR(sconf->rlslms,               "Adaptive RLS-LMS prediction", -1);
00431     MISSING_ERR(sconf->chan_sort,            "Channel sorting",              0);
00432 
00433     return error;
00434 }
00435 
00436 
00440 static void parse_bs_info(const uint32_t bs_info, unsigned int n,
00441                           unsigned int div, unsigned int **div_blocks,
00442                           unsigned int *num_blocks)
00443 {
00444     if (n < 31 && ((bs_info << n) & 0x40000000)) {
00445         // if the level is valid and the investigated bit n is set
00446         // then recursively check both children at bits (2n+1) and (2n+2)
00447         n   *= 2;
00448         div += 1;
00449         parse_bs_info(bs_info, n + 1, div, div_blocks, num_blocks);
00450         parse_bs_info(bs_info, n + 2, div, div_blocks, num_blocks);
00451     } else {
00452         // else the bit is not set or the last level has been reached
00453         // (bit implicitly not set)
00454         **div_blocks = div;
00455         (*div_blocks)++;
00456         (*num_blocks)++;
00457     }
00458 }
00459 
00460 
00463 static int32_t decode_rice(GetBitContext *gb, unsigned int k)
00464 {
00465     int max = get_bits_left(gb) - k;
00466     int q   = get_unary(gb, 0, max);
00467     int r   = k ? get_bits1(gb) : !(q & 1);
00468 
00469     if (k > 1) {
00470         q <<= (k - 1);
00471         q  += get_bits_long(gb, k - 1);
00472     } else if (!k) {
00473         q >>= 1;
00474     }
00475     return r ? q : ~q;
00476 }
00477 
00478 
00481 static void parcor_to_lpc(unsigned int k, const int32_t *par, int32_t *cof)
00482 {
00483     int i, j;
00484 
00485     for (i = 0, j = k - 1; i < j; i++, j--) {
00486         int tmp1 = ((MUL64(par[k], cof[j]) + (1 << 19)) >> 20);
00487         cof[j]  += ((MUL64(par[k], cof[i]) + (1 << 19)) >> 20);
00488         cof[i]  += tmp1;
00489     }
00490     if (i == j)
00491         cof[i] += ((MUL64(par[k], cof[j]) + (1 << 19)) >> 20);
00492 
00493     cof[k] = par[k];
00494 }
00495 
00496 
00501 static void get_block_sizes(ALSDecContext *ctx, unsigned int *div_blocks,
00502                             uint32_t *bs_info)
00503 {
00504     ALSSpecificConfig *sconf     = &ctx->sconf;
00505     GetBitContext *gb            = &ctx->gb;
00506     unsigned int *ptr_div_blocks = div_blocks;
00507     unsigned int b;
00508 
00509     if (sconf->block_switching) {
00510         unsigned int bs_info_len = 1 << (sconf->block_switching + 2);
00511         *bs_info = get_bits_long(gb, bs_info_len);
00512         *bs_info <<= (32 - bs_info_len);
00513     }
00514 
00515     ctx->num_blocks = 0;
00516     parse_bs_info(*bs_info, 0, 0, &ptr_div_blocks, &ctx->num_blocks);
00517 
00518     // The last frame may have an overdetermined block structure given in
00519     // the bitstream. In that case the defined block structure would need
00520     // more samples than available to be consistent.
00521     // The block structure is actually used but the block sizes are adapted
00522     // to fit the actual number of available samples.
00523     // Example: 5 samples, 2nd level block sizes: 2 2 2 2.
00524     // This results in the actual block sizes:    2 2 1 0.
00525     // This is not specified in 14496-3 but actually done by the reference
00526     // codec RM22 revision 2.
00527     // This appears to happen in case of an odd number of samples in the last
00528     // frame which is actually not allowed by the block length switching part
00529     // of 14496-3.
00530     // The ALS conformance files feature an odd number of samples in the last
00531     // frame.
00532 
00533     for (b = 0; b < ctx->num_blocks; b++)
00534         div_blocks[b] = ctx->sconf.frame_length >> div_blocks[b];
00535 
00536     if (ctx->cur_frame_length != ctx->sconf.frame_length) {
00537         unsigned int remaining = ctx->cur_frame_length;
00538 
00539         for (b = 0; b < ctx->num_blocks; b++) {
00540             if (remaining <= div_blocks[b]) {
00541                 div_blocks[b] = remaining;
00542                 ctx->num_blocks = b + 1;
00543                 break;
00544             }
00545 
00546             remaining -= div_blocks[b];
00547         }
00548     }
00549 }
00550 
00551 
00554 static int read_const_block_data(ALSDecContext *ctx, ALSBlockData *bd)
00555 {
00556     ALSSpecificConfig *sconf = &ctx->sconf;
00557     AVCodecContext *avctx    = ctx->avctx;
00558     GetBitContext *gb        = &ctx->gb;
00559 
00560     if (bd->block_length <= 0)
00561         return -1;
00562 
00563     *bd->raw_samples = 0;
00564     *bd->const_block = get_bits1(gb);    // 1 = constant value, 0 = zero block (silence)
00565     bd->js_blocks    = get_bits1(gb);
00566 
00567     // skip 5 reserved bits
00568     skip_bits(gb, 5);
00569 
00570     if (*bd->const_block) {
00571         unsigned int const_val_bits = sconf->floating ? 24 : avctx->bits_per_raw_sample;
00572         *bd->raw_samples = get_sbits_long(gb, const_val_bits);
00573     }
00574 
00575     // ensure constant block decoding by reusing this field
00576     *bd->const_block = 1;
00577 
00578     return 0;
00579 }
00580 
00581 
00584 static void decode_const_block_data(ALSDecContext *ctx, ALSBlockData *bd)
00585 {
00586     int      smp = bd->block_length - 1;
00587     int32_t  val = *bd->raw_samples;
00588     int32_t *dst = bd->raw_samples + 1;
00589 
00590     // write raw samples into buffer
00591     for (; smp; smp--)
00592         *dst++ = val;
00593 }
00594 
00595 
00598 static int read_var_block_data(ALSDecContext *ctx, ALSBlockData *bd)
00599 {
00600     ALSSpecificConfig *sconf = &ctx->sconf;
00601     AVCodecContext *avctx    = ctx->avctx;
00602     GetBitContext *gb        = &ctx->gb;
00603     unsigned int k;
00604     unsigned int s[8];
00605     unsigned int sx[8];
00606     unsigned int sub_blocks, log2_sub_blocks, sb_length;
00607     unsigned int start      = 0;
00608     unsigned int opt_order;
00609     int          sb;
00610     int32_t      *quant_cof = bd->quant_cof;
00611     int32_t      *current_res;
00612 
00613 
00614     // ensure variable block decoding by reusing this field
00615     *bd->const_block = 0;
00616 
00617     *bd->opt_order  = 1;
00618     bd->js_blocks   = get_bits1(gb);
00619 
00620     opt_order       = *bd->opt_order;
00621 
00622     // determine the number of subblocks for entropy decoding
00623     if (!sconf->bgmc && !sconf->sb_part) {
00624         log2_sub_blocks = 0;
00625     } else {
00626         if (sconf->bgmc && sconf->sb_part)
00627             log2_sub_blocks = get_bits(gb, 2);
00628         else
00629             log2_sub_blocks = 2 * get_bits1(gb);
00630     }
00631 
00632     sub_blocks = 1 << log2_sub_blocks;
00633 
00634     // do not continue in case of a damaged stream since
00635     // block_length must be evenly divisible by sub_blocks
00636     if (bd->block_length & (sub_blocks - 1)) {
00637         av_log(avctx, AV_LOG_WARNING,
00638                "Block length is not evenly divisible by the number of subblocks.\n");
00639         return -1;
00640     }
00641 
00642     sb_length = bd->block_length >> log2_sub_blocks;
00643 
00644     if (sconf->bgmc) {
00645         s[0] = get_bits(gb, 8 + (sconf->resolution > 1));
00646         for (k = 1; k < sub_blocks; k++)
00647             s[k] = s[k - 1] + decode_rice(gb, 2);
00648 
00649         for (k = 0; k < sub_blocks; k++) {
00650             sx[k]   = s[k] & 0x0F;
00651             s [k] >>= 4;
00652         }
00653     } else {
00654         s[0] = get_bits(gb, 4 + (sconf->resolution > 1));
00655         for (k = 1; k < sub_blocks; k++)
00656             s[k] = s[k - 1] + decode_rice(gb, 0);
00657     }
00658     for (k = 1; k < sub_blocks; k++)
00659         if (s[k] > 32) {
00660             av_log(avctx, AV_LOG_ERROR, "k invalid for rice code.\n");
00661             return AVERROR_INVALIDDATA;
00662         }
00663 
00664     if (get_bits1(gb))
00665         *bd->shift_lsbs = get_bits(gb, 4) + 1;
00666 
00667     *bd->store_prev_samples = (bd->js_blocks && bd->raw_other) || *bd->shift_lsbs;
00668 
00669 
00670     if (!sconf->rlslms) {
00671         if (sconf->adapt_order) {
00672             int opt_order_length = av_ceil_log2(av_clip((bd->block_length >> 3) - 1,
00673                                                 2, sconf->max_order + 1));
00674             *bd->opt_order       = get_bits(gb, opt_order_length);
00675             if (*bd->opt_order > sconf->max_order) {
00676                 *bd->opt_order = sconf->max_order;
00677                 av_log(avctx, AV_LOG_ERROR, "Predictor order too large!\n");
00678                 return AVERROR_INVALIDDATA;
00679             }
00680         } else {
00681             *bd->opt_order = sconf->max_order;
00682         }
00683 
00684         opt_order = *bd->opt_order;
00685 
00686         if (opt_order) {
00687             int add_base;
00688 
00689             if (sconf->coef_table == 3) {
00690                 add_base = 0x7F;
00691 
00692                 // read coefficient 0
00693                 quant_cof[0] = 32 * parcor_scaled_values[get_bits(gb, 7)];
00694 
00695                 // read coefficient 1
00696                 if (opt_order > 1)
00697                     quant_cof[1] = -32 * parcor_scaled_values[get_bits(gb, 7)];
00698 
00699                 // read coefficients 2 to opt_order
00700                 for (k = 2; k < opt_order; k++)
00701                     quant_cof[k] = get_bits(gb, 7);
00702             } else {
00703                 int k_max;
00704                 add_base = 1;
00705 
00706                 // read coefficient 0 to 19
00707                 k_max = FFMIN(opt_order, 20);
00708                 for (k = 0; k < k_max; k++) {
00709                     int rice_param = parcor_rice_table[sconf->coef_table][k][1];
00710                     int offset     = parcor_rice_table[sconf->coef_table][k][0];
00711                     quant_cof[k] = decode_rice(gb, rice_param) + offset;
00712                     if (quant_cof[k] < -64 || quant_cof[k] > 63) {
00713                         av_log(avctx, AV_LOG_ERROR, "quant_cof %d is out of range\n", quant_cof[k]);
00714                         return AVERROR_INVALIDDATA;
00715                     }
00716                 }
00717 
00718                 // read coefficients 20 to 126
00719                 k_max = FFMIN(opt_order, 127);
00720                 for (; k < k_max; k++)
00721                     quant_cof[k] = decode_rice(gb, 2) + (k & 1);
00722 
00723                 // read coefficients 127 to opt_order
00724                 for (; k < opt_order; k++)
00725                     quant_cof[k] = decode_rice(gb, 1);
00726 
00727                 quant_cof[0] = 32 * parcor_scaled_values[quant_cof[0] + 64];
00728 
00729                 if (opt_order > 1)
00730                     quant_cof[1] = -32 * parcor_scaled_values[quant_cof[1] + 64];
00731             }
00732 
00733             for (k = 2; k < opt_order; k++)
00734                 quant_cof[k] = (quant_cof[k] << 14) + (add_base << 13);
00735         }
00736     }
00737 
00738     // read LTP gain and lag values
00739     if (sconf->long_term_prediction) {
00740         *bd->use_ltp = get_bits1(gb);
00741 
00742         if (*bd->use_ltp) {
00743             int r, c;
00744 
00745             bd->ltp_gain[0]   = decode_rice(gb, 1) << 3;
00746             bd->ltp_gain[1]   = decode_rice(gb, 2) << 3;
00747 
00748             r                 = get_unary(gb, 0, 3);
00749             c                 = get_bits(gb, 2);
00750             bd->ltp_gain[2]   = ltp_gain_values[r][c];
00751 
00752             bd->ltp_gain[3]   = decode_rice(gb, 2) << 3;
00753             bd->ltp_gain[4]   = decode_rice(gb, 1) << 3;
00754 
00755             *bd->ltp_lag      = get_bits(gb, ctx->ltp_lag_length);
00756             *bd->ltp_lag     += FFMAX(4, opt_order + 1);
00757         }
00758     }
00759 
00760     // read first value and residuals in case of a random access block
00761     if (bd->ra_block) {
00762         if (opt_order)
00763             bd->raw_samples[0] = decode_rice(gb, avctx->bits_per_raw_sample - 4);
00764         if (opt_order > 1)
00765             bd->raw_samples[1] = decode_rice(gb, FFMIN(s[0] + 3, ctx->s_max));
00766         if (opt_order > 2)
00767             bd->raw_samples[2] = decode_rice(gb, FFMIN(s[0] + 1, ctx->s_max));
00768 
00769         start = FFMIN(opt_order, 3);
00770     }
00771 
00772     // read all residuals
00773     if (sconf->bgmc) {
00774         int          delta[8];
00775         unsigned int k    [8];
00776         unsigned int b = av_clip((av_ceil_log2(bd->block_length) - 3) >> 1, 0, 5);
00777 
00778         // read most significant bits
00779         unsigned int high;
00780         unsigned int low;
00781         unsigned int value;
00782 
00783         ff_bgmc_decode_init(gb, &high, &low, &value);
00784 
00785         current_res = bd->raw_samples + start;
00786 
00787         for (sb = 0; sb < sub_blocks; sb++) {
00788             unsigned int sb_len  = sb_length - (sb ? 0 : start);
00789 
00790             k    [sb] = s[sb] > b ? s[sb] - b : 0;
00791             delta[sb] = 5 - s[sb] + k[sb];
00792 
00793             ff_bgmc_decode(gb, sb_len, current_res,
00794                         delta[sb], sx[sb], &high, &low, &value, ctx->bgmc_lut, ctx->bgmc_lut_status);
00795 
00796             current_res += sb_len;
00797         }
00798 
00799         ff_bgmc_decode_end(gb);
00800 
00801 
00802         // read least significant bits and tails
00803         current_res = bd->raw_samples + start;
00804 
00805         for (sb = 0; sb < sub_blocks; sb++, start = 0) {
00806             unsigned int cur_tail_code = tail_code[sx[sb]][delta[sb]];
00807             unsigned int cur_k         = k[sb];
00808             unsigned int cur_s         = s[sb];
00809 
00810             for (; start < sb_length; start++) {
00811                 int32_t res = *current_res;
00812 
00813                 if (res == cur_tail_code) {
00814                     unsigned int max_msb =   (2 + (sx[sb] > 2) + (sx[sb] > 10))
00815                                           << (5 - delta[sb]);
00816 
00817                     res = decode_rice(gb, cur_s);
00818 
00819                     if (res >= 0) {
00820                         res += (max_msb    ) << cur_k;
00821                     } else {
00822                         res -= (max_msb - 1) << cur_k;
00823                     }
00824                 } else {
00825                     if (res > cur_tail_code)
00826                         res--;
00827 
00828                     if (res & 1)
00829                         res = -res;
00830 
00831                     res >>= 1;
00832 
00833                     if (cur_k) {
00834                         res <<= cur_k;
00835                         res  |= get_bits_long(gb, cur_k);
00836                     }
00837                 }
00838 
00839                 *current_res++ = res;
00840             }
00841         }
00842     } else {
00843         current_res = bd->raw_samples + start;
00844 
00845         for (sb = 0; sb < sub_blocks; sb++, start = 0)
00846             for (; start < sb_length; start++)
00847                 *current_res++ = decode_rice(gb, s[sb]);
00848      }
00849 
00850     if (!sconf->mc_coding || ctx->js_switch)
00851         align_get_bits(gb);
00852 
00853     return 0;
00854 }
00855 
00856 
00859 static int decode_var_block_data(ALSDecContext *ctx, ALSBlockData *bd)
00860 {
00861     ALSSpecificConfig *sconf = &ctx->sconf;
00862     unsigned int block_length = bd->block_length;
00863     unsigned int smp = 0;
00864     unsigned int k;
00865     int opt_order             = *bd->opt_order;
00866     int sb;
00867     int64_t y;
00868     int32_t *quant_cof        = bd->quant_cof;
00869     int32_t *lpc_cof          = bd->lpc_cof;
00870     int32_t *raw_samples      = bd->raw_samples;
00871     int32_t *raw_samples_end  = bd->raw_samples + bd->block_length;
00872     int32_t *lpc_cof_reversed = ctx->lpc_cof_reversed_buffer;
00873 
00874     // reverse long-term prediction
00875     if (*bd->use_ltp) {
00876         int ltp_smp;
00877 
00878         for (ltp_smp = FFMAX(*bd->ltp_lag - 2, 0); ltp_smp < block_length; ltp_smp++) {
00879             int center = ltp_smp - *bd->ltp_lag;
00880             int begin  = FFMAX(0, center - 2);
00881             int end    = center + 3;
00882             int tab    = 5 - (end - begin);
00883             int base;
00884 
00885             y = 1 << 6;
00886 
00887             for (base = begin; base < end; base++, tab++)
00888                 y += MUL64(bd->ltp_gain[tab], raw_samples[base]);
00889 
00890             raw_samples[ltp_smp] += y >> 7;
00891         }
00892     }
00893 
00894     // reconstruct all samples from residuals
00895     if (bd->ra_block) {
00896         for (smp = 0; smp < opt_order; smp++) {
00897             y = 1 << 19;
00898 
00899             for (sb = 0; sb < smp; sb++)
00900                 y += MUL64(lpc_cof[sb], raw_samples[-(sb + 1)]);
00901 
00902             *raw_samples++ -= y >> 20;
00903             parcor_to_lpc(smp, quant_cof, lpc_cof);
00904         }
00905     } else {
00906         for (k = 0; k < opt_order; k++)
00907             parcor_to_lpc(k, quant_cof, lpc_cof);
00908 
00909         // store previous samples in case that they have to be altered
00910         if (*bd->store_prev_samples)
00911             memcpy(bd->prev_raw_samples, raw_samples - sconf->max_order,
00912                    sizeof(*bd->prev_raw_samples) * sconf->max_order);
00913 
00914         // reconstruct difference signal for prediction (joint-stereo)
00915         if (bd->js_blocks && bd->raw_other) {
00916             int32_t *left, *right;
00917 
00918             if (bd->raw_other > raw_samples) {  // D = R - L
00919                 left  = raw_samples;
00920                 right = bd->raw_other;
00921             } else {                                // D = R - L
00922                 left  = bd->raw_other;
00923                 right = raw_samples;
00924             }
00925 
00926             for (sb = -1; sb >= -sconf->max_order; sb--)
00927                 raw_samples[sb] = right[sb] - left[sb];
00928         }
00929 
00930         // reconstruct shifted signal
00931         if (*bd->shift_lsbs)
00932             for (sb = -1; sb >= -sconf->max_order; sb--)
00933                 raw_samples[sb] >>= *bd->shift_lsbs;
00934     }
00935 
00936     // reverse linear prediction coefficients for efficiency
00937     lpc_cof = lpc_cof + opt_order;
00938 
00939     for (sb = 0; sb < opt_order; sb++)
00940         lpc_cof_reversed[sb] = lpc_cof[-(sb + 1)];
00941 
00942     // reconstruct raw samples
00943     raw_samples = bd->raw_samples + smp;
00944     lpc_cof     = lpc_cof_reversed + opt_order;
00945 
00946     for (; raw_samples < raw_samples_end; raw_samples++) {
00947         y = 1 << 19;
00948 
00949         for (sb = -opt_order; sb < 0; sb++)
00950             y += MUL64(lpc_cof[sb], raw_samples[sb]);
00951 
00952         *raw_samples -= y >> 20;
00953     }
00954 
00955     raw_samples = bd->raw_samples;
00956 
00957     // restore previous samples in case that they have been altered
00958     if (*bd->store_prev_samples)
00959         memcpy(raw_samples - sconf->max_order, bd->prev_raw_samples,
00960                sizeof(*raw_samples) * sconf->max_order);
00961 
00962     return 0;
00963 }
00964 
00965 
00968 static int read_block(ALSDecContext *ctx, ALSBlockData *bd)
00969 {
00970     GetBitContext *gb        = &ctx->gb;
00971 
00972     *bd->shift_lsbs = 0;
00973     // read block type flag and read the samples accordingly
00974     if (get_bits1(gb)) {
00975         if (read_var_block_data(ctx, bd))
00976             return -1;
00977     } else {
00978         if (read_const_block_data(ctx, bd) < 0)
00979             return -1;
00980     }
00981 
00982     return 0;
00983 }
00984 
00985 
00988 static int decode_block(ALSDecContext *ctx, ALSBlockData *bd)
00989 {
00990     unsigned int smp;
00991 
00992     // read block type flag and read the samples accordingly
00993     if (*bd->const_block)
00994         decode_const_block_data(ctx, bd);
00995     else if (decode_var_block_data(ctx, bd))
00996         return -1;
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     ret = read_block(ctx, bd);
01015 
01016     if (ret)
01017         return ret;
01018 
01019     ret = decode_block(ctx, bd);
01020 
01021     return ret;
01022 }
01023 
01024 
01028 static void zero_remaining(unsigned int b, unsigned int b_max,
01029                            const unsigned int *div_blocks, int32_t *buf)
01030 {
01031     unsigned int count = 0;
01032 
01033     for (; b < b_max; b++)
01034         count += div_blocks[b];
01035 
01036     if (count)
01037         memset(buf, 0, sizeof(*buf) * count);
01038 }
01039 
01040 
01043 static int decode_blocks_ind(ALSDecContext *ctx, unsigned int ra_frame,
01044                              unsigned int c, const unsigned int *div_blocks,
01045                              unsigned int *js_blocks)
01046 {
01047     unsigned int b;
01048     ALSBlockData bd;
01049 
01050     memset(&bd, 0, sizeof(ALSBlockData));
01051 
01052     bd.ra_block         = ra_frame;
01053     bd.const_block      = ctx->const_block;
01054     bd.shift_lsbs       = ctx->shift_lsbs;
01055     bd.opt_order        = ctx->opt_order;
01056     bd.store_prev_samples = ctx->store_prev_samples;
01057     bd.use_ltp          = ctx->use_ltp;
01058     bd.ltp_lag          = ctx->ltp_lag;
01059     bd.ltp_gain         = ctx->ltp_gain[0];
01060     bd.quant_cof        = ctx->quant_cof[0];
01061     bd.lpc_cof          = ctx->lpc_cof[0];
01062     bd.prev_raw_samples = ctx->prev_raw_samples;
01063     bd.raw_samples      = ctx->raw_samples[c];
01064 
01065 
01066     for (b = 0; b < ctx->num_blocks; b++) {
01067         bd.block_length     = div_blocks[b];
01068 
01069         if (read_decode_block(ctx, &bd)) {
01070             // damaged block, write zero for the rest of the frame
01071             zero_remaining(b, ctx->num_blocks, div_blocks, bd.raw_samples);
01072             return -1;
01073         }
01074         bd.raw_samples += div_blocks[b];
01075         bd.ra_block     = 0;
01076     }
01077 
01078     return 0;
01079 }
01080 
01081 
01084 static int decode_blocks(ALSDecContext *ctx, unsigned int ra_frame,
01085                          unsigned int c, const unsigned int *div_blocks,
01086                          unsigned int *js_blocks)
01087 {
01088     ALSSpecificConfig *sconf = &ctx->sconf;
01089     unsigned int offset = 0;
01090     unsigned int b;
01091     ALSBlockData bd[2];
01092 
01093     memset(bd, 0, 2 * sizeof(ALSBlockData));
01094 
01095     bd[0].ra_block         = ra_frame;
01096     bd[0].const_block      = ctx->const_block;
01097     bd[0].shift_lsbs       = ctx->shift_lsbs;
01098     bd[0].opt_order        = ctx->opt_order;
01099     bd[0].store_prev_samples = ctx->store_prev_samples;
01100     bd[0].use_ltp          = ctx->use_ltp;
01101     bd[0].ltp_lag          = ctx->ltp_lag;
01102     bd[0].ltp_gain         = ctx->ltp_gain[0];
01103     bd[0].quant_cof        = ctx->quant_cof[0];
01104     bd[0].lpc_cof          = ctx->lpc_cof[0];
01105     bd[0].prev_raw_samples = ctx->prev_raw_samples;
01106     bd[0].js_blocks        = *js_blocks;
01107 
01108     bd[1].ra_block         = ra_frame;
01109     bd[1].const_block      = ctx->const_block;
01110     bd[1].shift_lsbs       = ctx->shift_lsbs;
01111     bd[1].opt_order        = ctx->opt_order;
01112     bd[1].store_prev_samples = ctx->store_prev_samples;
01113     bd[1].use_ltp          = ctx->use_ltp;
01114     bd[1].ltp_lag          = ctx->ltp_lag;
01115     bd[1].ltp_gain         = ctx->ltp_gain[0];
01116     bd[1].quant_cof        = ctx->quant_cof[0];
01117     bd[1].lpc_cof          = ctx->lpc_cof[0];
01118     bd[1].prev_raw_samples = ctx->prev_raw_samples;
01119     bd[1].js_blocks        = *(js_blocks + 1);
01120 
01121     // decode all blocks
01122     for (b = 0; b < ctx->num_blocks; b++) {
01123         unsigned int s;
01124 
01125         bd[0].block_length = div_blocks[b];
01126         bd[1].block_length = div_blocks[b];
01127 
01128         bd[0].raw_samples  = ctx->raw_samples[c    ] + offset;
01129         bd[1].raw_samples  = ctx->raw_samples[c + 1] + offset;
01130 
01131         bd[0].raw_other    = bd[1].raw_samples;
01132         bd[1].raw_other    = bd[0].raw_samples;
01133 
01134         if(read_decode_block(ctx, &bd[0]) || read_decode_block(ctx, &bd[1])) {
01135             // damaged block, write zero for the rest of the frame
01136             zero_remaining(b, ctx->num_blocks, div_blocks, bd[0].raw_samples);
01137             zero_remaining(b, ctx->num_blocks, div_blocks, bd[1].raw_samples);
01138             return -1;
01139         }
01140 
01141         // reconstruct joint-stereo blocks
01142         if (bd[0].js_blocks) {
01143             if (bd[1].js_blocks)
01144                 av_log(ctx->avctx, AV_LOG_WARNING, "Invalid channel pair!\n");
01145 
01146             for (s = 0; s < div_blocks[b]; s++)
01147                 bd[0].raw_samples[s] = bd[1].raw_samples[s] - bd[0].raw_samples[s];
01148         } else if (bd[1].js_blocks) {
01149             for (s = 0; s < div_blocks[b]; s++)
01150                 bd[1].raw_samples[s] = bd[1].raw_samples[s] + bd[0].raw_samples[s];
01151         }
01152 
01153         offset  += div_blocks[b];
01154         bd[0].ra_block = 0;
01155         bd[1].ra_block = 0;
01156     }
01157 
01158     // store carryover raw samples,
01159     // the others channel raw samples are stored by the calling function.
01160     memmove(ctx->raw_samples[c] - sconf->max_order,
01161             ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,
01162             sizeof(*ctx->raw_samples[c]) * sconf->max_order);
01163 
01164     return 0;
01165 }
01166 
01167 
01170 static int read_channel_data(ALSDecContext *ctx, ALSChannelData *cd, int c)
01171 {
01172     GetBitContext *gb       = &ctx->gb;
01173     ALSChannelData *current = cd;
01174     unsigned int channels   = ctx->avctx->channels;
01175     int entries             = 0;
01176 
01177     while (entries < channels && !(current->stop_flag = get_bits1(gb))) {
01178         current->master_channel = get_bits_long(gb, av_ceil_log2(channels));
01179 
01180         if (current->master_channel >= channels) {
01181             av_log(ctx->avctx, AV_LOG_ERROR, "Invalid master channel!\n");
01182             return -1;
01183         }
01184 
01185         if (current->master_channel != c) {
01186             current->time_diff_flag = get_bits1(gb);
01187             current->weighting[0]   = mcc_weightings[av_clip(decode_rice(gb, 1) + 16, 0, 32)];
01188             current->weighting[1]   = mcc_weightings[av_clip(decode_rice(gb, 2) + 14, 0, 32)];
01189             current->weighting[2]   = mcc_weightings[av_clip(decode_rice(gb, 1) + 16, 0, 32)];
01190 
01191             if (current->time_diff_flag) {
01192                 current->weighting[3] = mcc_weightings[av_clip(decode_rice(gb, 1) + 16, 0, 32)];
01193                 current->weighting[4] = mcc_weightings[av_clip(decode_rice(gb, 1) + 16, 0, 32)];
01194                 current->weighting[5] = mcc_weightings[av_clip(decode_rice(gb, 1) + 16, 0, 32)];
01195 
01196                 current->time_diff_sign  = get_bits1(gb);
01197                 current->time_diff_index = get_bits(gb, ctx->ltp_lag_length - 3) + 3;
01198             }
01199         }
01200 
01201         current++;
01202         entries++;
01203     }
01204 
01205     if (entries == channels) {
01206         av_log(ctx->avctx, AV_LOG_ERROR, "Damaged channel data!\n");
01207         return -1;
01208     }
01209 
01210     align_get_bits(gb);
01211     return 0;
01212 }
01213 
01214 
01217 static int revert_channel_correlation(ALSDecContext *ctx, ALSBlockData *bd,
01218                                        ALSChannelData **cd, int *reverted,
01219                                        unsigned int offset, int c)
01220 {
01221     ALSChannelData *ch = cd[c];
01222     unsigned int   dep = 0;
01223     unsigned int channels = ctx->avctx->channels;
01224 
01225     if (reverted[c])
01226         return 0;
01227 
01228     reverted[c] = 1;
01229 
01230     while (dep < channels && !ch[dep].stop_flag) {
01231         revert_channel_correlation(ctx, bd, cd, reverted, offset,
01232                                    ch[dep].master_channel);
01233 
01234         dep++;
01235     }
01236 
01237     if (dep == channels) {
01238         av_log(ctx->avctx, AV_LOG_WARNING, "Invalid channel correlation!\n");
01239         return -1;
01240     }
01241 
01242     bd->const_block = ctx->const_block + c;
01243     bd->shift_lsbs  = ctx->shift_lsbs + c;
01244     bd->opt_order   = ctx->opt_order + c;
01245     bd->store_prev_samples = ctx->store_prev_samples + c;
01246     bd->use_ltp     = ctx->use_ltp + c;
01247     bd->ltp_lag     = ctx->ltp_lag + c;
01248     bd->ltp_gain    = ctx->ltp_gain[c];
01249     bd->lpc_cof     = ctx->lpc_cof[c];
01250     bd->quant_cof   = ctx->quant_cof[c];
01251     bd->raw_samples = ctx->raw_samples[c] + offset;
01252 
01253     dep = 0;
01254     while (!ch[dep].stop_flag) {
01255         unsigned int smp;
01256         unsigned int begin = 1;
01257         unsigned int end   = bd->block_length - 1;
01258         int64_t y;
01259         int32_t *master = ctx->raw_samples[ch[dep].master_channel] + offset;
01260 
01261         if (ch[dep].time_diff_flag) {
01262             int t = ch[dep].time_diff_index;
01263 
01264             if (ch[dep].time_diff_sign) {
01265                 t      = -t;
01266                 begin -= t;
01267             } else {
01268                 end   -= t;
01269             }
01270 
01271             for (smp = begin; smp < end; smp++) {
01272                 y  = (1 << 6) +
01273                      MUL64(ch[dep].weighting[0], master[smp - 1    ]) +
01274                      MUL64(ch[dep].weighting[1], master[smp        ]) +
01275                      MUL64(ch[dep].weighting[2], master[smp + 1    ]) +
01276                      MUL64(ch[dep].weighting[3], master[smp - 1 + t]) +
01277                      MUL64(ch[dep].weighting[4], master[smp     + t]) +
01278                      MUL64(ch[dep].weighting[5], master[smp + 1 + t]);
01279 
01280                 bd->raw_samples[smp] += y >> 7;
01281             }
01282         } else {
01283             for (smp = begin; smp < end; smp++) {
01284                 y  = (1 << 6) +
01285                      MUL64(ch[dep].weighting[0], master[smp - 1]) +
01286                      MUL64(ch[dep].weighting[1], master[smp    ]) +
01287                      MUL64(ch[dep].weighting[2], master[smp + 1]);
01288 
01289                 bd->raw_samples[smp] += y >> 7;
01290             }
01291         }
01292 
01293         dep++;
01294     }
01295 
01296     return 0;
01297 }
01298 
01299 
01302 static int read_frame_data(ALSDecContext *ctx, unsigned int ra_frame)
01303 {
01304     ALSSpecificConfig *sconf = &ctx->sconf;
01305     AVCodecContext *avctx    = ctx->avctx;
01306     GetBitContext *gb = &ctx->gb;
01307     unsigned int div_blocks[32];                
01308     unsigned int c;
01309     unsigned int js_blocks[2];
01310 
01311     uint32_t bs_info = 0;
01312 
01313     // skip the size of the ra unit if present in the frame
01314     if (sconf->ra_flag == RA_FLAG_FRAMES && ra_frame)
01315         skip_bits_long(gb, 32);
01316 
01317     if (sconf->mc_coding && sconf->joint_stereo) {
01318         ctx->js_switch = get_bits1(gb);
01319         align_get_bits(gb);
01320     }
01321 
01322     if (!sconf->mc_coding || ctx->js_switch) {
01323         int independent_bs = !sconf->joint_stereo;
01324 
01325         for (c = 0; c < avctx->channels; c++) {
01326             js_blocks[0] = 0;
01327             js_blocks[1] = 0;
01328 
01329             get_block_sizes(ctx, div_blocks, &bs_info);
01330 
01331             // if joint_stereo and block_switching is set, independent decoding
01332             // is signaled via the first bit of bs_info
01333             if (sconf->joint_stereo && sconf->block_switching)
01334                 if (bs_info >> 31)
01335                     independent_bs = 2;
01336 
01337             // if this is the last channel, it has to be decoded independently
01338             if (c == avctx->channels - 1)
01339                 independent_bs = 1;
01340 
01341             if (independent_bs) {
01342                 if (decode_blocks_ind(ctx, ra_frame, c, div_blocks, js_blocks))
01343                     return -1;
01344 
01345                 independent_bs--;
01346             } else {
01347                 if (decode_blocks(ctx, ra_frame, c, div_blocks, js_blocks))
01348                     return -1;
01349 
01350                 c++;
01351             }
01352 
01353             // store carryover raw samples
01354             memmove(ctx->raw_samples[c] - sconf->max_order,
01355                     ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,
01356                     sizeof(*ctx->raw_samples[c]) * sconf->max_order);
01357         }
01358     } else { // multi-channel coding
01359         ALSBlockData   bd;
01360         int            b;
01361         int            *reverted_channels = ctx->reverted_channels;
01362         unsigned int   offset             = 0;
01363 
01364         for (c = 0; c < avctx->channels; c++)
01365             if (ctx->chan_data[c] < ctx->chan_data_buffer) {
01366                 av_log(ctx->avctx, AV_LOG_ERROR, "Invalid channel data!\n");
01367                 return -1;
01368             }
01369 
01370         memset(&bd,               0, sizeof(ALSBlockData));
01371         memset(reverted_channels, 0, sizeof(*reverted_channels) * avctx->channels);
01372 
01373         bd.ra_block         = ra_frame;
01374         bd.prev_raw_samples = ctx->prev_raw_samples;
01375 
01376         get_block_sizes(ctx, div_blocks, &bs_info);
01377 
01378         for (b = 0; b < ctx->num_blocks; b++) {
01379             bd.block_length = div_blocks[b];
01380 
01381             for (c = 0; c < avctx->channels; c++) {
01382                 bd.const_block = ctx->const_block + c;
01383                 bd.shift_lsbs  = ctx->shift_lsbs + c;
01384                 bd.opt_order   = ctx->opt_order + c;
01385                 bd.store_prev_samples = ctx->store_prev_samples + c;
01386                 bd.use_ltp     = ctx->use_ltp + c;
01387                 bd.ltp_lag     = ctx->ltp_lag + c;
01388                 bd.ltp_gain    = ctx->ltp_gain[c];
01389                 bd.lpc_cof     = ctx->lpc_cof[c];
01390                 bd.quant_cof   = ctx->quant_cof[c];
01391                 bd.raw_samples = ctx->raw_samples[c] + offset;
01392                 bd.raw_other   = NULL;
01393 
01394                 read_block(ctx, &bd);
01395                 if (read_channel_data(ctx, ctx->chan_data[c], c))
01396                     return -1;
01397             }
01398 
01399             for (c = 0; c < avctx->channels; c++)
01400                 if (revert_channel_correlation(ctx, &bd, ctx->chan_data,
01401                                                reverted_channels, offset, c))
01402                     return -1;
01403 
01404             for (c = 0; c < avctx->channels; c++) {
01405                 bd.const_block = ctx->const_block + c;
01406                 bd.shift_lsbs  = ctx->shift_lsbs + c;
01407                 bd.opt_order   = ctx->opt_order + c;
01408                 bd.store_prev_samples = ctx->store_prev_samples + c;
01409                 bd.use_ltp     = ctx->use_ltp + c;
01410                 bd.ltp_lag     = ctx->ltp_lag + c;
01411                 bd.ltp_gain    = ctx->ltp_gain[c];
01412                 bd.lpc_cof     = ctx->lpc_cof[c];
01413                 bd.quant_cof   = ctx->quant_cof[c];
01414                 bd.raw_samples = ctx->raw_samples[c] + offset;
01415                 decode_block(ctx, &bd);
01416             }
01417 
01418             memset(reverted_channels, 0, avctx->channels * sizeof(*reverted_channels));
01419             offset      += div_blocks[b];
01420             bd.ra_block  = 0;
01421         }
01422 
01423         // store carryover raw samples
01424         for (c = 0; c < avctx->channels; c++)
01425             memmove(ctx->raw_samples[c] - sconf->max_order,
01426                     ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,
01427                     sizeof(*ctx->raw_samples[c]) * sconf->max_order);
01428     }
01429 
01430     // TODO: read_diff_float_data
01431 
01432     return 0;
01433 }
01434 
01435 
01438 static int decode_frame(AVCodecContext *avctx,
01439                         void *data, int *data_size,
01440                         AVPacket *avpkt)
01441 {
01442     ALSDecContext *ctx       = avctx->priv_data;
01443     ALSSpecificConfig *sconf = &ctx->sconf;
01444     const uint8_t *buffer    = avpkt->data;
01445     int buffer_size          = avpkt->size;
01446     int invalid_frame, size;
01447     unsigned int c, sample, ra_frame, bytes_read, shift;
01448 
01449     init_get_bits(&ctx->gb, buffer, buffer_size * 8);
01450 
01451     // In the case that the distance between random access frames is set to zero
01452     // (sconf->ra_distance == 0) no frame is treated as a random access frame.
01453     // For the first frame, if prediction is used, all samples used from the
01454     // previous frame are assumed to be zero.
01455     ra_frame = sconf->ra_distance && !(ctx->frame_id % sconf->ra_distance);
01456 
01457     // the last frame to decode might have a different length
01458     if (sconf->samples != 0xFFFFFFFF)
01459         ctx->cur_frame_length = FFMIN(sconf->samples - ctx->frame_id * (uint64_t) sconf->frame_length,
01460                                       sconf->frame_length);
01461     else
01462         ctx->cur_frame_length = sconf->frame_length;
01463 
01464     // decode the frame data
01465     if ((invalid_frame = read_frame_data(ctx, ra_frame) < 0))
01466         av_log(ctx->avctx, AV_LOG_WARNING,
01467                "Reading frame data failed. Skipping RA unit.\n");
01468 
01469     ctx->frame_id++;
01470 
01471     // check for size of decoded data
01472     size = ctx->cur_frame_length * avctx->channels *
01473            av_get_bytes_per_sample(avctx->sample_fmt);
01474 
01475     if (size > *data_size) {
01476         av_log(avctx, AV_LOG_ERROR, "Decoded data exceeds buffer size.\n");
01477         return -1;
01478     }
01479 
01480     *data_size = size;
01481 
01482     // transform decoded frame into output format
01483     #define INTERLEAVE_OUTPUT(bps)                                 \
01484     {                                                              \
01485         int##bps##_t *dest = (int##bps##_t*) data;                 \
01486         shift = bps - ctx->avctx->bits_per_raw_sample;             \
01487         for (sample = 0; sample < ctx->cur_frame_length; sample++) \
01488             for (c = 0; c < avctx->channels; c++)                  \
01489                 *dest++ = ctx->raw_samples[c][sample] << shift;    \
01490     }
01491 
01492     if (ctx->avctx->bits_per_raw_sample <= 16) {
01493         INTERLEAVE_OUTPUT(16)
01494     } else {
01495         INTERLEAVE_OUTPUT(32)
01496     }
01497 
01498     // update CRC
01499     if (sconf->crc_enabled && avctx->error_recognition >= FF_ER_CAREFUL) {
01500         int swap = HAVE_BIGENDIAN != sconf->msb_first;
01501 
01502         if (ctx->avctx->bits_per_raw_sample == 24) {
01503             int32_t *src = data;
01504 
01505             for (sample = 0;
01506                  sample < ctx->cur_frame_length * avctx->channels;
01507                  sample++) {
01508                 int32_t v;
01509 
01510                 if (swap)
01511                     v = av_bswap32(src[sample]);
01512                 else
01513                     v = src[sample];
01514                 if (!HAVE_BIGENDIAN)
01515                     v >>= 8;
01516 
01517                 ctx->crc = av_crc(ctx->crc_table, ctx->crc, (uint8_t*)(&v), 3);
01518             }
01519         } else {
01520             uint8_t *crc_source;
01521 
01522             if (swap) {
01523                 if (ctx->avctx->bits_per_raw_sample <= 16) {
01524                     int16_t *src  = (int16_t*) data;
01525                     int16_t *dest = (int16_t*) ctx->crc_buffer;
01526                     for (sample = 0;
01527                          sample < ctx->cur_frame_length * avctx->channels;
01528                          sample++)
01529                         *dest++ = av_bswap16(src[sample]);
01530                 } else {
01531                     ctx->dsp.bswap_buf((uint32_t*)ctx->crc_buffer, data,
01532                                        ctx->cur_frame_length * avctx->channels);
01533                 }
01534                 crc_source = ctx->crc_buffer;
01535             } else {
01536                 crc_source = data;
01537             }
01538 
01539             ctx->crc = av_crc(ctx->crc_table, ctx->crc, crc_source, size);
01540         }
01541 
01542 
01543         // check CRC sums if this is the last frame
01544         if (ctx->cur_frame_length != sconf->frame_length &&
01545             ctx->crc_org != ctx->crc) {
01546             av_log(avctx, AV_LOG_ERROR, "CRC error.\n");
01547         }
01548     }
01549 
01550 
01551     bytes_read = invalid_frame ? buffer_size :
01552                                  (get_bits_count(&ctx->gb) + 7) >> 3;
01553 
01554     return bytes_read;
01555 }
01556 
01557 
01560 static av_cold int decode_end(AVCodecContext *avctx)
01561 {
01562     ALSDecContext *ctx = avctx->priv_data;
01563 
01564     av_freep(&ctx->sconf.chan_pos);
01565 
01566     ff_bgmc_end(&ctx->bgmc_lut, &ctx->bgmc_lut_status);
01567 
01568     av_freep(&ctx->const_block);
01569     av_freep(&ctx->shift_lsbs);
01570     av_freep(&ctx->opt_order);
01571     av_freep(&ctx->store_prev_samples);
01572     av_freep(&ctx->use_ltp);
01573     av_freep(&ctx->ltp_lag);
01574     av_freep(&ctx->ltp_gain);
01575     av_freep(&ctx->ltp_gain_buffer);
01576     av_freep(&ctx->quant_cof);
01577     av_freep(&ctx->lpc_cof);
01578     av_freep(&ctx->quant_cof_buffer);
01579     av_freep(&ctx->lpc_cof_buffer);
01580     av_freep(&ctx->lpc_cof_reversed_buffer);
01581     av_freep(&ctx->prev_raw_samples);
01582     av_freep(&ctx->raw_samples);
01583     av_freep(&ctx->raw_buffer);
01584     av_freep(&ctx->chan_data);
01585     av_freep(&ctx->chan_data_buffer);
01586     av_freep(&ctx->reverted_channels);
01587     av_freep(&ctx->crc_buffer);
01588 
01589     return 0;
01590 }
01591 
01592 
01595 static av_cold int decode_init(AVCodecContext *avctx)
01596 {
01597     unsigned int c;
01598     unsigned int channel_size;
01599     int num_buffers;
01600     ALSDecContext *ctx = avctx->priv_data;
01601     ALSSpecificConfig *sconf = &ctx->sconf;
01602     ctx->avctx = avctx;
01603 
01604     if (!avctx->extradata) {
01605         av_log(avctx, AV_LOG_ERROR, "Missing required ALS extradata.\n");
01606         return -1;
01607     }
01608 
01609     if (read_specific_config(ctx)) {
01610         av_log(avctx, AV_LOG_ERROR, "Reading ALSSpecificConfig failed.\n");
01611         decode_end(avctx);
01612         return -1;
01613     }
01614 
01615     if (check_specific_config(ctx)) {
01616         decode_end(avctx);
01617         return -1;
01618     }
01619 
01620     if (sconf->bgmc)
01621         ff_bgmc_init(avctx, &ctx->bgmc_lut, &ctx->bgmc_lut_status);
01622 
01623     if (sconf->floating) {
01624         avctx->sample_fmt          = AV_SAMPLE_FMT_FLT;
01625         avctx->bits_per_raw_sample = 32;
01626     } else {
01627         avctx->sample_fmt          = sconf->resolution > 1
01628                                      ? AV_SAMPLE_FMT_S32 : AV_SAMPLE_FMT_S16;
01629         avctx->bits_per_raw_sample = (sconf->resolution + 1) * 8;
01630     }
01631 
01632     // set maximum Rice parameter for progressive decoding based on resolution
01633     // This is not specified in 14496-3 but actually done by the reference
01634     // codec RM22 revision 2.
01635     ctx->s_max = sconf->resolution > 1 ? 31 : 15;
01636 
01637     // set lag value for long-term prediction
01638     ctx->ltp_lag_length = 8 + (avctx->sample_rate >=  96000) +
01639                               (avctx->sample_rate >= 192000);
01640 
01641     // allocate quantized parcor coefficient buffer
01642     num_buffers = sconf->mc_coding ? avctx->channels : 1;
01643 
01644     ctx->quant_cof        = av_malloc(sizeof(*ctx->quant_cof) * num_buffers);
01645     ctx->lpc_cof          = av_malloc(sizeof(*ctx->lpc_cof)   * num_buffers);
01646     ctx->quant_cof_buffer = av_malloc(sizeof(*ctx->quant_cof_buffer) *
01647                                       num_buffers * sconf->max_order);
01648     ctx->lpc_cof_buffer   = av_malloc(sizeof(*ctx->lpc_cof_buffer) *
01649                                       num_buffers * sconf->max_order);
01650     ctx->lpc_cof_reversed_buffer = av_malloc(sizeof(*ctx->lpc_cof_buffer) *
01651                                              sconf->max_order);
01652 
01653     if (!ctx->quant_cof              || !ctx->lpc_cof        ||
01654         !ctx->quant_cof_buffer       || !ctx->lpc_cof_buffer ||
01655         !ctx->lpc_cof_reversed_buffer) {
01656         av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
01657         return AVERROR(ENOMEM);
01658     }
01659 
01660     // assign quantized parcor coefficient buffers
01661     for (c = 0; c < num_buffers; c++) {
01662         ctx->quant_cof[c] = ctx->quant_cof_buffer + c * sconf->max_order;
01663         ctx->lpc_cof[c]   = ctx->lpc_cof_buffer   + c * sconf->max_order;
01664     }
01665 
01666     // allocate and assign lag and gain data buffer for ltp mode
01667     ctx->const_block     = av_malloc (sizeof(*ctx->const_block) * num_buffers);
01668     ctx->shift_lsbs      = av_malloc (sizeof(*ctx->shift_lsbs)  * num_buffers);
01669     ctx->opt_order       = av_malloc (sizeof(*ctx->opt_order)   * num_buffers);
01670     ctx->store_prev_samples = av_malloc(sizeof(*ctx->store_prev_samples) * num_buffers);
01671     ctx->use_ltp         = av_mallocz(sizeof(*ctx->use_ltp)  * num_buffers);
01672     ctx->ltp_lag         = av_malloc (sizeof(*ctx->ltp_lag)  * num_buffers);
01673     ctx->ltp_gain        = av_malloc (sizeof(*ctx->ltp_gain) * num_buffers);
01674     ctx->ltp_gain_buffer = av_malloc (sizeof(*ctx->ltp_gain_buffer) *
01675                                       num_buffers * 5);
01676 
01677     if (!ctx->const_block || !ctx->shift_lsbs ||
01678         !ctx->opt_order || !ctx->store_prev_samples ||
01679         !ctx->use_ltp  || !ctx->ltp_lag ||
01680         !ctx->ltp_gain || !ctx->ltp_gain_buffer) {
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->ltp_gain[c] = ctx->ltp_gain_buffer + c * 5;
01688 
01689     // allocate and assign channel data buffer for mcc mode
01690     if (sconf->mc_coding) {
01691         ctx->chan_data_buffer  = av_malloc(sizeof(*ctx->chan_data_buffer) *
01692                                            num_buffers * num_buffers);
01693         ctx->chan_data         = av_malloc(sizeof(*ctx->chan_data) *
01694                                            num_buffers);
01695         ctx->reverted_channels = av_malloc(sizeof(*ctx->reverted_channels) *
01696                                            num_buffers);
01697 
01698         if (!ctx->chan_data_buffer || !ctx->chan_data || !ctx->reverted_channels) {
01699             av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
01700             decode_end(avctx);
01701             return AVERROR(ENOMEM);
01702         }
01703 
01704         for (c = 0; c < num_buffers; c++)
01705             ctx->chan_data[c] = ctx->chan_data_buffer + c * num_buffers;
01706     } else {
01707         ctx->chan_data         = NULL;
01708         ctx->chan_data_buffer  = NULL;
01709         ctx->reverted_channels = NULL;
01710     }
01711 
01712     avctx->frame_size = sconf->frame_length;
01713     channel_size      = sconf->frame_length + sconf->max_order;
01714 
01715     ctx->prev_raw_samples = av_malloc (sizeof(*ctx->prev_raw_samples) * sconf->max_order);
01716     ctx->raw_buffer       = av_mallocz(sizeof(*ctx->     raw_buffer)  * avctx->channels * channel_size);
01717     ctx->raw_samples      = av_malloc (sizeof(*ctx->     raw_samples) * avctx->channels);
01718 
01719     // allocate previous raw sample buffer
01720     if (!ctx->prev_raw_samples || !ctx->raw_buffer|| !ctx->raw_samples) {
01721         av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
01722         decode_end(avctx);
01723         return AVERROR(ENOMEM);
01724     }
01725 
01726     // assign raw samples buffers
01727     ctx->raw_samples[0] = ctx->raw_buffer + sconf->max_order;
01728     for (c = 1; c < avctx->channels; c++)
01729         ctx->raw_samples[c] = ctx->raw_samples[c - 1] + channel_size;
01730 
01731     // allocate crc buffer
01732     if (HAVE_BIGENDIAN != sconf->msb_first && sconf->crc_enabled &&
01733         avctx->error_recognition >= FF_ER_CAREFUL) {
01734         ctx->crc_buffer = av_malloc(sizeof(*ctx->crc_buffer) *
01735                                     ctx->cur_frame_length *
01736                                     avctx->channels *
01737                                     av_get_bytes_per_sample(avctx->sample_fmt));
01738         if (!ctx->crc_buffer) {
01739             av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
01740             decode_end(avctx);
01741             return AVERROR(ENOMEM);
01742         }
01743     }
01744 
01745     dsputil_init(&ctx->dsp, avctx);
01746 
01747     return 0;
01748 }
01749 
01750 
01753 static av_cold void flush(AVCodecContext *avctx)
01754 {
01755     ALSDecContext *ctx = avctx->priv_data;
01756 
01757     ctx->frame_id = 0;
01758 }
01759 
01760 
01761 AVCodec ff_als_decoder = {
01762     "als",
01763     AVMEDIA_TYPE_AUDIO,
01764     CODEC_ID_MP4ALS,
01765     sizeof(ALSDecContext),
01766     decode_init,
01767     NULL,
01768     decode_end,
01769     decode_frame,
01770     .flush = flush,
01771     .capabilities = CODEC_CAP_SUBFRAMES,
01772     .long_name = NULL_IF_CONFIG_SMALL("MPEG-4 Audio Lossless Coding (ALS)"),
01773 };
01774 

Generated on Fri Feb 22 2013 07:24:25 for FFmpeg by  doxygen 1.7.1