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libavcodec/wmaprodec.c

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00001 /*
00002  * Wmapro compatible decoder
00003  * Copyright (c) 2007 Baptiste Coudurier, Benjamin Larsson, Ulion
00004  * Copyright (c) 2008 - 2009 Sascha Sommer, Benjamin Larsson
00005  *
00006  * This file is part of FFmpeg.
00007  *
00008  * FFmpeg is free software; you can redistribute it and/or
00009  * modify it under the terms of the GNU Lesser General Public
00010  * License as published by the Free Software Foundation; either
00011  * version 2.1 of the License, or (at your option) any later version.
00012  *
00013  * FFmpeg is distributed in the hope that it will be useful,
00014  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00015  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00016  * Lesser General Public License for more details.
00017  *
00018  * You should have received a copy of the GNU Lesser General Public
00019  * License along with FFmpeg; if not, write to the Free Software
00020  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00021  */
00022 
00089 #include "avcodec.h"
00090 #include "internal.h"
00091 #include "get_bits.h"
00092 #include "put_bits.h"
00093 #include "wmaprodata.h"
00094 #include "dsputil.h"
00095 #include "wma.h"
00096 
00098 #define WMAPRO_MAX_CHANNELS    8                             ///< max number of handled channels
00099 #define MAX_SUBFRAMES  32                                    ///< max number of subframes per channel
00100 #define MAX_BANDS      29                                    ///< max number of scale factor bands
00101 #define MAX_FRAMESIZE  32768                                 ///< maximum compressed frame size
00102 
00103 #define WMAPRO_BLOCK_MAX_BITS 12                                           ///< log2 of max block size
00104 #define WMAPRO_BLOCK_MAX_SIZE (1 << WMAPRO_BLOCK_MAX_BITS)                 ///< maximum block size
00105 #define WMAPRO_BLOCK_SIZES    (WMAPRO_BLOCK_MAX_BITS - BLOCK_MIN_BITS + 1) ///< possible block sizes
00106 
00107 
00108 #define VLCBITS            9
00109 #define SCALEVLCBITS       8
00110 #define VEC4MAXDEPTH    ((HUFF_VEC4_MAXBITS+VLCBITS-1)/VLCBITS)
00111 #define VEC2MAXDEPTH    ((HUFF_VEC2_MAXBITS+VLCBITS-1)/VLCBITS)
00112 #define VEC1MAXDEPTH    ((HUFF_VEC1_MAXBITS+VLCBITS-1)/VLCBITS)
00113 #define SCALEMAXDEPTH   ((HUFF_SCALE_MAXBITS+SCALEVLCBITS-1)/SCALEVLCBITS)
00114 #define SCALERLMAXDEPTH ((HUFF_SCALE_RL_MAXBITS+VLCBITS-1)/VLCBITS)
00115 
00116 static VLC              sf_vlc;           
00117 static VLC              sf_rl_vlc;        
00118 static VLC              vec4_vlc;         
00119 static VLC              vec2_vlc;         
00120 static VLC              vec1_vlc;         
00121 static VLC              coef_vlc[2];      
00122 static float            sin64[33];        
00123 
00127 typedef struct {
00128     int16_t  prev_block_len;                          
00129     uint8_t  transmit_coefs;
00130     uint8_t  num_subframes;
00131     uint16_t subframe_len[MAX_SUBFRAMES];             
00132     uint16_t subframe_offset[MAX_SUBFRAMES];          
00133     uint8_t  cur_subframe;                            
00134     uint16_t decoded_samples;                         
00135     uint8_t  grouped;                                 
00136     int      quant_step;                              
00137     int8_t   reuse_sf;                                
00138     int8_t   scale_factor_step;                       
00139     int      max_scale_factor;                        
00140     int      saved_scale_factors[2][MAX_BANDS];       
00141     int8_t   scale_factor_idx;                        
00142     int*     scale_factors;                           
00143     uint8_t  table_idx;                               
00144     float*   coeffs;                                  
00145     DECLARE_ALIGNED(16, float, out)[WMAPRO_BLOCK_MAX_SIZE + WMAPRO_BLOCK_MAX_SIZE / 2]; 
00146 } WMAProChannelCtx;
00147 
00151 typedef struct {
00152     uint8_t num_channels;                                     
00153     int8_t  transform;                                        
00154     int8_t  transform_band[MAX_BANDS];                        
00155     float   decorrelation_matrix[WMAPRO_MAX_CHANNELS*WMAPRO_MAX_CHANNELS];
00156     float*  channel_data[WMAPRO_MAX_CHANNELS];                
00157 } WMAProChannelGrp;
00158 
00162 typedef struct WMAProDecodeCtx {
00163     /* generic decoder variables */
00164     AVCodecContext*  avctx;                         
00165     DSPContext       dsp;                           
00166     uint8_t          frame_data[MAX_FRAMESIZE +
00167                       FF_INPUT_BUFFER_PADDING_SIZE];
00168     PutBitContext    pb;                            
00169     FFTContext       mdct_ctx[WMAPRO_BLOCK_SIZES];  
00170     DECLARE_ALIGNED(16, float, tmp)[WMAPRO_BLOCK_MAX_SIZE]; 
00171     float*           windows[WMAPRO_BLOCK_SIZES];   
00172 
00173     /* frame size dependent frame information (set during initialization) */
00174     uint32_t         decode_flags;                  
00175     uint8_t          len_prefix;                    
00176     uint8_t          dynamic_range_compression;     
00177     uint8_t          bits_per_sample;               
00178     uint16_t         samples_per_frame;             
00179     uint16_t         log2_frame_size;
00180     int8_t           num_channels;                  
00181     int8_t           lfe_channel;                   
00182     uint8_t          max_num_subframes;
00183     uint8_t          subframe_len_bits;             
00184     uint8_t          max_subframe_len_bit;          
00185     uint16_t         min_samples_per_subframe;
00186     int8_t           num_sfb[WMAPRO_BLOCK_SIZES];   
00187     int16_t          sfb_offsets[WMAPRO_BLOCK_SIZES][MAX_BANDS];                    
00188     int8_t           sf_offsets[WMAPRO_BLOCK_SIZES][WMAPRO_BLOCK_SIZES][MAX_BANDS]; 
00189     int16_t          subwoofer_cutoffs[WMAPRO_BLOCK_SIZES]; 
00190 
00191     /* packet decode state */
00192     GetBitContext    pgb;                           
00193     uint8_t          packet_offset;                 
00194     uint8_t          packet_sequence_number;        
00195     int              num_saved_bits;                
00196     int              frame_offset;                  
00197     int              subframe_offset;               
00198     uint8_t          packet_loss;                   
00199     uint8_t          packet_done;                   
00200 
00201     /* frame decode state */
00202     uint32_t         frame_num;                     
00203     GetBitContext    gb;                            
00204     int              buf_bit_size;                  
00205     float*           samples;                       
00206     float*           samples_end;                   
00207     uint8_t          drc_gain;                      
00208     int8_t           skip_frame;                    
00209     int8_t           parsed_all_subframes;          
00210 
00211     /* subframe/block decode state */
00212     int16_t          subframe_len;                  
00213     int8_t           channels_for_cur_subframe;     
00214     int8_t           channel_indexes_for_cur_subframe[WMAPRO_MAX_CHANNELS];
00215     int8_t           num_bands;                     
00216     int16_t*         cur_sfb_offsets;               
00217     uint8_t          table_idx;                     
00218     int8_t           esc_len;                       
00219 
00220     uint8_t          num_chgroups;                  
00221     WMAProChannelGrp chgroup[WMAPRO_MAX_CHANNELS];  
00222 
00223     WMAProChannelCtx channel[WMAPRO_MAX_CHANNELS];  
00224 } WMAProDecodeCtx;
00225 
00226 
00231 static void av_cold dump_context(WMAProDecodeCtx *s)
00232 {
00233 #define PRINT(a, b)     av_log(s->avctx, AV_LOG_DEBUG, " %s = %d\n", a, b);
00234 #define PRINT_HEX(a, b) av_log(s->avctx, AV_LOG_DEBUG, " %s = %x\n", a, b);
00235 
00236     PRINT("ed sample bit depth", s->bits_per_sample);
00237     PRINT_HEX("ed decode flags", s->decode_flags);
00238     PRINT("samples per frame",   s->samples_per_frame);
00239     PRINT("log2 frame size",     s->log2_frame_size);
00240     PRINT("max num subframes",   s->max_num_subframes);
00241     PRINT("len prefix",          s->len_prefix);
00242     PRINT("num channels",        s->num_channels);
00243 }
00244 
00250 static av_cold int decode_end(AVCodecContext *avctx)
00251 {
00252     WMAProDecodeCtx *s = avctx->priv_data;
00253     int i;
00254 
00255     for (i = 0; i < WMAPRO_BLOCK_SIZES; i++)
00256         ff_mdct_end(&s->mdct_ctx[i]);
00257 
00258     return 0;
00259 }
00260 
00266 static av_cold int decode_init(AVCodecContext *avctx)
00267 {
00268     WMAProDecodeCtx *s = avctx->priv_data;
00269     uint8_t *edata_ptr = avctx->extradata;
00270     unsigned int channel_mask;
00271     int i;
00272     int log2_max_num_subframes;
00273     int num_possible_block_sizes;
00274 
00275     s->avctx = avctx;
00276     dsputil_init(&s->dsp, avctx);
00277     init_put_bits(&s->pb, s->frame_data, MAX_FRAMESIZE);
00278 
00279     avctx->sample_fmt = SAMPLE_FMT_FLT;
00280 
00281     if (avctx->extradata_size >= 18) {
00282         s->decode_flags    = AV_RL16(edata_ptr+14);
00283         channel_mask       = AV_RL32(edata_ptr+2);
00284         s->bits_per_sample = AV_RL16(edata_ptr);
00286         for (i = 0; i < avctx->extradata_size; i++)
00287             dprintf(avctx, "[%x] ", avctx->extradata[i]);
00288         dprintf(avctx, "\n");
00289 
00290     } else {
00291         av_log_ask_for_sample(avctx, "Unknown extradata size\n");
00292         return AVERROR_INVALIDDATA;
00293     }
00294 
00296     s->log2_frame_size = av_log2(avctx->block_align) + 4;
00297 
00299     s->skip_frame  = 1; 
00300     s->packet_loss = 1;
00301     s->len_prefix  = (s->decode_flags & 0x40);
00302 
00303     if (!s->len_prefix) {
00304         av_log_ask_for_sample(avctx, "no length prefix\n");
00305         return AVERROR_INVALIDDATA;
00306     }
00307 
00309     s->samples_per_frame = 1 << ff_wma_get_frame_len_bits(avctx->sample_rate,
00310                                                           3, s->decode_flags);
00311 
00313     for (i = 0; i < avctx->channels; i++)
00314         s->channel[i].prev_block_len = s->samples_per_frame;
00315 
00317     log2_max_num_subframes       = ((s->decode_flags & 0x38) >> 3);
00318     s->max_num_subframes         = 1 << log2_max_num_subframes;
00319     if (s->max_num_subframes == 16)
00320         s->max_subframe_len_bit = 1;
00321     s->subframe_len_bits = av_log2(log2_max_num_subframes) + 1;
00322 
00323     num_possible_block_sizes     = log2_max_num_subframes + 1;
00324     s->min_samples_per_subframe  = s->samples_per_frame / s->max_num_subframes;
00325     s->dynamic_range_compression = (s->decode_flags & 0x80);
00326 
00327     if (s->max_num_subframes > MAX_SUBFRAMES) {
00328         av_log(avctx, AV_LOG_ERROR, "invalid number of subframes %i\n",
00329                s->max_num_subframes);
00330         return AVERROR_INVALIDDATA;
00331     }
00332 
00333     s->num_channels = avctx->channels;
00334 
00336     s->lfe_channel = -1;
00337 
00338     if (channel_mask & 8) {
00339         unsigned int mask;
00340         for (mask = 1; mask < 16; mask <<= 1) {
00341             if (channel_mask & mask)
00342                 ++s->lfe_channel;
00343         }
00344     }
00345 
00346     if (s->num_channels < 0) {
00347         av_log(avctx, AV_LOG_ERROR, "invalid number of channels %d\n", s->num_channels);
00348         return AVERROR_INVALIDDATA;
00349     } else if (s->num_channels > WMAPRO_MAX_CHANNELS) {
00350         av_log_ask_for_sample(avctx, "unsupported number of channels\n");
00351         return AVERROR_PATCHWELCOME;
00352     }
00353 
00354     INIT_VLC_STATIC(&sf_vlc, SCALEVLCBITS, HUFF_SCALE_SIZE,
00355                     scale_huffbits, 1, 1,
00356                     scale_huffcodes, 2, 2, 616);
00357 
00358     INIT_VLC_STATIC(&sf_rl_vlc, VLCBITS, HUFF_SCALE_RL_SIZE,
00359                     scale_rl_huffbits, 1, 1,
00360                     scale_rl_huffcodes, 4, 4, 1406);
00361 
00362     INIT_VLC_STATIC(&coef_vlc[0], VLCBITS, HUFF_COEF0_SIZE,
00363                     coef0_huffbits, 1, 1,
00364                     coef0_huffcodes, 4, 4, 2108);
00365 
00366     INIT_VLC_STATIC(&coef_vlc[1], VLCBITS, HUFF_COEF1_SIZE,
00367                     coef1_huffbits, 1, 1,
00368                     coef1_huffcodes, 4, 4, 3912);
00369 
00370     INIT_VLC_STATIC(&vec4_vlc, VLCBITS, HUFF_VEC4_SIZE,
00371                     vec4_huffbits, 1, 1,
00372                     vec4_huffcodes, 2, 2, 604);
00373 
00374     INIT_VLC_STATIC(&vec2_vlc, VLCBITS, HUFF_VEC2_SIZE,
00375                     vec2_huffbits, 1, 1,
00376                     vec2_huffcodes, 2, 2, 562);
00377 
00378     INIT_VLC_STATIC(&vec1_vlc, VLCBITS, HUFF_VEC1_SIZE,
00379                     vec1_huffbits, 1, 1,
00380                     vec1_huffcodes, 2, 2, 562);
00381 
00384     for (i = 0; i < num_possible_block_sizes; i++) {
00385         int subframe_len = s->samples_per_frame >> i;
00386         int x;
00387         int band = 1;
00388 
00389         s->sfb_offsets[i][0] = 0;
00390 
00391         for (x = 0; x < MAX_BANDS-1 && s->sfb_offsets[i][band - 1] < subframe_len; x++) {
00392             int offset = (subframe_len * 2 * critical_freq[x])
00393                           / s->avctx->sample_rate + 2;
00394             offset &= ~3;
00395             if (offset > s->sfb_offsets[i][band - 1])
00396                 s->sfb_offsets[i][band++] = offset;
00397         }
00398         s->sfb_offsets[i][band - 1] = subframe_len;
00399         s->num_sfb[i]               = band - 1;
00400     }
00401 
00402 
00408     for (i = 0; i < num_possible_block_sizes; i++) {
00409         int b;
00410         for (b = 0; b < s->num_sfb[i]; b++) {
00411             int x;
00412             int offset = ((s->sfb_offsets[i][b]
00413                            + s->sfb_offsets[i][b + 1] - 1) << i) >> 1;
00414             for (x = 0; x < num_possible_block_sizes; x++) {
00415                 int v = 0;
00416                 while (s->sfb_offsets[x][v + 1] << x < offset)
00417                     ++v;
00418                 s->sf_offsets[i][x][b] = v;
00419             }
00420         }
00421     }
00422 
00424     for (i = 0; i < WMAPRO_BLOCK_SIZES; i++)
00425         ff_mdct_init(&s->mdct_ctx[i], BLOCK_MIN_BITS+1+i, 1,
00426                      1.0 / (1 << (BLOCK_MIN_BITS + i - 1))
00427                      / (1 << (s->bits_per_sample - 1)));
00428 
00430     for (i = 0; i < WMAPRO_BLOCK_SIZES; i++) {
00431         const int win_idx = WMAPRO_BLOCK_MAX_BITS - i;
00432         ff_init_ff_sine_windows(win_idx);
00433         s->windows[WMAPRO_BLOCK_SIZES - i - 1] = ff_sine_windows[win_idx];
00434     }
00435 
00437     for (i = 0; i < num_possible_block_sizes; i++) {
00438         int block_size = s->samples_per_frame >> i;
00439         int cutoff = (440*block_size + 3 * (s->avctx->sample_rate >> 1) - 1)
00440                      / s->avctx->sample_rate;
00441         s->subwoofer_cutoffs[i] = av_clip(cutoff, 4, block_size);
00442     }
00443 
00445     for (i = 0; i < 33; i++)
00446         sin64[i] = sin(i*M_PI / 64.0);
00447 
00448     if (avctx->debug & FF_DEBUG_BITSTREAM)
00449         dump_context(s);
00450 
00451     avctx->channel_layout = channel_mask;
00452     return 0;
00453 }
00454 
00461 static int decode_subframe_length(WMAProDecodeCtx *s, int offset)
00462 {
00463     int frame_len_shift = 0;
00464     int subframe_len;
00465 
00467     if (offset == s->samples_per_frame - s->min_samples_per_subframe)
00468         return s->min_samples_per_subframe;
00469 
00471     if (s->max_subframe_len_bit) {
00472         if (get_bits1(&s->gb))
00473             frame_len_shift = 1 + get_bits(&s->gb, s->subframe_len_bits-1);
00474     } else
00475         frame_len_shift = get_bits(&s->gb, s->subframe_len_bits);
00476 
00477     subframe_len = s->samples_per_frame >> frame_len_shift;
00478 
00480     if (subframe_len < s->min_samples_per_subframe ||
00481         subframe_len > s->samples_per_frame) {
00482         av_log(s->avctx, AV_LOG_ERROR, "broken frame: subframe_len %i\n",
00483                subframe_len);
00484         return AVERROR_INVALIDDATA;
00485     }
00486     return subframe_len;
00487 }
00488 
00509 static int decode_tilehdr(WMAProDecodeCtx *s)
00510 {
00511     uint16_t num_samples[WMAPRO_MAX_CHANNELS];        
00512     uint8_t  contains_subframe[WMAPRO_MAX_CHANNELS];  
00513     int channels_for_cur_subframe = s->num_channels;  
00514     int fixed_channel_layout = 0;                     
00515     int min_channel_len = 0;                          
00516     int c;
00517 
00518     /* Should never consume more than 3073 bits (256 iterations for the
00519      * while loop when always the minimum amount of 128 samples is substracted
00520      * from missing samples in the 8 channel case).
00521      * 1 + BLOCK_MAX_SIZE * MAX_CHANNELS / BLOCK_MIN_SIZE * (MAX_CHANNELS  + 4)
00522      */
00523 
00525     for (c = 0; c < s->num_channels; c++)
00526         s->channel[c].num_subframes = 0;
00527 
00528     memset(num_samples, 0, sizeof(num_samples));
00529 
00530     if (s->max_num_subframes == 1 || get_bits1(&s->gb))
00531         fixed_channel_layout = 1;
00532 
00534     do {
00535         int subframe_len;
00536 
00538         for (c = 0; c < s->num_channels; c++) {
00539             if (num_samples[c] == min_channel_len) {
00540                 if (fixed_channel_layout || channels_for_cur_subframe == 1 ||
00541                    (min_channel_len == s->samples_per_frame - s->min_samples_per_subframe))
00542                     contains_subframe[c] = 1;
00543                 else
00544                     contains_subframe[c] = get_bits1(&s->gb);
00545             } else
00546                 contains_subframe[c] = 0;
00547         }
00548 
00550         if ((subframe_len = decode_subframe_length(s, min_channel_len)) <= 0)
00551             return AVERROR_INVALIDDATA;
00552 
00554         min_channel_len += subframe_len;
00555         for (c = 0; c < s->num_channels; c++) {
00556             WMAProChannelCtx* chan = &s->channel[c];
00557 
00558             if (contains_subframe[c]) {
00559                 if (chan->num_subframes >= MAX_SUBFRAMES) {
00560                     av_log(s->avctx, AV_LOG_ERROR,
00561                            "broken frame: num subframes > 31\n");
00562                     return AVERROR_INVALIDDATA;
00563                 }
00564                 chan->subframe_len[chan->num_subframes] = subframe_len;
00565                 num_samples[c] += subframe_len;
00566                 ++chan->num_subframes;
00567                 if (num_samples[c] > s->samples_per_frame) {
00568                     av_log(s->avctx, AV_LOG_ERROR, "broken frame: "
00569                            "channel len > samples_per_frame\n");
00570                     return AVERROR_INVALIDDATA;
00571                 }
00572             } else if (num_samples[c] <= min_channel_len) {
00573                 if (num_samples[c] < min_channel_len) {
00574                     channels_for_cur_subframe = 0;
00575                     min_channel_len = num_samples[c];
00576                 }
00577                 ++channels_for_cur_subframe;
00578             }
00579         }
00580     } while (min_channel_len < s->samples_per_frame);
00581 
00582     for (c = 0; c < s->num_channels; c++) {
00583         int i;
00584         int offset = 0;
00585         for (i = 0; i < s->channel[c].num_subframes; i++) {
00586             dprintf(s->avctx, "frame[%i] channel[%i] subframe[%i]"
00587                     " len %i\n", s->frame_num, c, i,
00588                     s->channel[c].subframe_len[i]);
00589             s->channel[c].subframe_offset[i] = offset;
00590             offset += s->channel[c].subframe_len[i];
00591         }
00592     }
00593 
00594     return 0;
00595 }
00596 
00602 static void decode_decorrelation_matrix(WMAProDecodeCtx *s,
00603                                         WMAProChannelGrp *chgroup)
00604 {
00605     int i;
00606     int offset = 0;
00607     int8_t rotation_offset[WMAPRO_MAX_CHANNELS * WMAPRO_MAX_CHANNELS];
00608     memset(chgroup->decorrelation_matrix, 0, s->num_channels *
00609            s->num_channels * sizeof(*chgroup->decorrelation_matrix));
00610 
00611     for (i = 0; i < chgroup->num_channels * (chgroup->num_channels - 1) >> 1; i++)
00612         rotation_offset[i] = get_bits(&s->gb, 6);
00613 
00614     for (i = 0; i < chgroup->num_channels; i++)
00615         chgroup->decorrelation_matrix[chgroup->num_channels * i + i] =
00616             get_bits1(&s->gb) ? 1.0 : -1.0;
00617 
00618     for (i = 1; i < chgroup->num_channels; i++) {
00619         int x;
00620         for (x = 0; x < i; x++) {
00621             int y;
00622             for (y = 0; y < i + 1; y++) {
00623                 float v1 = chgroup->decorrelation_matrix[x * chgroup->num_channels + y];
00624                 float v2 = chgroup->decorrelation_matrix[i * chgroup->num_channels + y];
00625                 int n = rotation_offset[offset + x];
00626                 float sinv;
00627                 float cosv;
00628 
00629                 if (n < 32) {
00630                     sinv = sin64[n];
00631                     cosv = sin64[32 - n];
00632                 } else {
00633                     sinv =  sin64[64 -  n];
00634                     cosv = -sin64[n  - 32];
00635                 }
00636 
00637                 chgroup->decorrelation_matrix[y + x * chgroup->num_channels] =
00638                                                (v1 * sinv) - (v2 * cosv);
00639                 chgroup->decorrelation_matrix[y + i * chgroup->num_channels] =
00640                                                (v1 * cosv) + (v2 * sinv);
00641             }
00642         }
00643         offset += i;
00644     }
00645 }
00646 
00652 static int decode_channel_transform(WMAProDecodeCtx* s)
00653 {
00654     int i;
00655     /* should never consume more than 1921 bits for the 8 channel case
00656      * 1 + MAX_CHANNELS * (MAX_CHANNELS + 2 + 3 * MAX_CHANNELS * MAX_CHANNELS
00657      * + MAX_CHANNELS + MAX_BANDS + 1)
00658      */
00659 
00661     s->num_chgroups = 0;
00662     if (s->num_channels > 1) {
00663         int remaining_channels = s->channels_for_cur_subframe;
00664 
00665         if (get_bits1(&s->gb)) {
00666             av_log_ask_for_sample(s->avctx,
00667                                   "unsupported channel transform bit\n");
00668             return AVERROR_INVALIDDATA;
00669         }
00670 
00671         for (s->num_chgroups = 0; remaining_channels &&
00672              s->num_chgroups < s->channels_for_cur_subframe; s->num_chgroups++) {
00673             WMAProChannelGrp* chgroup = &s->chgroup[s->num_chgroups];
00674             float** channel_data = chgroup->channel_data;
00675             chgroup->num_channels = 0;
00676             chgroup->transform = 0;
00677 
00679             if (remaining_channels > 2) {
00680                 for (i = 0; i < s->channels_for_cur_subframe; i++) {
00681                     int channel_idx = s->channel_indexes_for_cur_subframe[i];
00682                     if (!s->channel[channel_idx].grouped
00683                         && get_bits1(&s->gb)) {
00684                         ++chgroup->num_channels;
00685                         s->channel[channel_idx].grouped = 1;
00686                         *channel_data++ = s->channel[channel_idx].coeffs;
00687                     }
00688                 }
00689             } else {
00690                 chgroup->num_channels = remaining_channels;
00691                 for (i = 0; i < s->channels_for_cur_subframe; i++) {
00692                     int channel_idx = s->channel_indexes_for_cur_subframe[i];
00693                     if (!s->channel[channel_idx].grouped)
00694                         *channel_data++ = s->channel[channel_idx].coeffs;
00695                     s->channel[channel_idx].grouped = 1;
00696                 }
00697             }
00698 
00700             if (chgroup->num_channels == 2) {
00701                 if (get_bits1(&s->gb)) {
00702                     if (get_bits1(&s->gb)) {
00703                         av_log_ask_for_sample(s->avctx,
00704                                               "unsupported channel transform type\n");
00705                     }
00706                 } else {
00707                     chgroup->transform = 1;
00708                     if (s->num_channels == 2) {
00709                         chgroup->decorrelation_matrix[0] =  1.0;
00710                         chgroup->decorrelation_matrix[1] = -1.0;
00711                         chgroup->decorrelation_matrix[2] =  1.0;
00712                         chgroup->decorrelation_matrix[3] =  1.0;
00713                     } else {
00715                         chgroup->decorrelation_matrix[0] =  0.70703125;
00716                         chgroup->decorrelation_matrix[1] = -0.70703125;
00717                         chgroup->decorrelation_matrix[2] =  0.70703125;
00718                         chgroup->decorrelation_matrix[3] =  0.70703125;
00719                     }
00720                 }
00721             } else if (chgroup->num_channels > 2) {
00722                 if (get_bits1(&s->gb)) {
00723                     chgroup->transform = 1;
00724                     if (get_bits1(&s->gb)) {
00725                         decode_decorrelation_matrix(s, chgroup);
00726                     } else {
00728                         if (chgroup->num_channels > 6) {
00729                             av_log_ask_for_sample(s->avctx,
00730                                                   "coupled channels > 6\n");
00731                         } else {
00732                             memcpy(chgroup->decorrelation_matrix,
00733                                    default_decorrelation[chgroup->num_channels],
00734                                    chgroup->num_channels * chgroup->num_channels *
00735                                    sizeof(*chgroup->decorrelation_matrix));
00736                         }
00737                     }
00738                 }
00739             }
00740 
00742             if (chgroup->transform) {
00743                 if (!get_bits1(&s->gb)) {
00744                     int i;
00746                     for (i = 0; i < s->num_bands; i++) {
00747                         chgroup->transform_band[i] = get_bits1(&s->gb);
00748                     }
00749                 } else {
00750                     memset(chgroup->transform_band, 1, s->num_bands);
00751                 }
00752             }
00753             remaining_channels -= chgroup->num_channels;
00754         }
00755     }
00756     return 0;
00757 }
00758 
00765 static int decode_coeffs(WMAProDecodeCtx *s, int c)
00766 {
00767     /* Integers 0..15 as single-precision floats.  The table saves a
00768        costly int to float conversion, and storing the values as
00769        integers allows fast sign-flipping. */
00770     static const int fval_tab[16] = {
00771         0x00000000, 0x3f800000, 0x40000000, 0x40400000,
00772         0x40800000, 0x40a00000, 0x40c00000, 0x40e00000,
00773         0x41000000, 0x41100000, 0x41200000, 0x41300000,
00774         0x41400000, 0x41500000, 0x41600000, 0x41700000,
00775     };
00776     int vlctable;
00777     VLC* vlc;
00778     WMAProChannelCtx* ci = &s->channel[c];
00779     int rl_mode = 0;
00780     int cur_coeff = 0;
00781     int num_zeros = 0;
00782     const uint16_t* run;
00783     const float* level;
00784 
00785     dprintf(s->avctx, "decode coefficients for channel %i\n", c);
00786 
00787     vlctable = get_bits1(&s->gb);
00788     vlc = &coef_vlc[vlctable];
00789 
00790     if (vlctable) {
00791         run = coef1_run;
00792         level = coef1_level;
00793     } else {
00794         run = coef0_run;
00795         level = coef0_level;
00796     }
00797 
00800     while (!rl_mode && cur_coeff + 3 < s->subframe_len) {
00801         int vals[4];
00802         int i;
00803         unsigned int idx;
00804 
00805         idx = get_vlc2(&s->gb, vec4_vlc.table, VLCBITS, VEC4MAXDEPTH);
00806 
00807         if (idx == HUFF_VEC4_SIZE - 1) {
00808             for (i = 0; i < 4; i += 2) {
00809                 idx = get_vlc2(&s->gb, vec2_vlc.table, VLCBITS, VEC2MAXDEPTH);
00810                 if (idx == HUFF_VEC2_SIZE - 1) {
00811                     int v0, v1;
00812                     v0 = get_vlc2(&s->gb, vec1_vlc.table, VLCBITS, VEC1MAXDEPTH);
00813                     if (v0 == HUFF_VEC1_SIZE - 1)
00814                         v0 += ff_wma_get_large_val(&s->gb);
00815                     v1 = get_vlc2(&s->gb, vec1_vlc.table, VLCBITS, VEC1MAXDEPTH);
00816                     if (v1 == HUFF_VEC1_SIZE - 1)
00817                         v1 += ff_wma_get_large_val(&s->gb);
00818                     ((float*)vals)[i  ] = v0;
00819                     ((float*)vals)[i+1] = v1;
00820                 } else {
00821                     vals[i]   = fval_tab[symbol_to_vec2[idx] >> 4 ];
00822                     vals[i+1] = fval_tab[symbol_to_vec2[idx] & 0xF];
00823                 }
00824             }
00825         } else {
00826             vals[0] = fval_tab[ symbol_to_vec4[idx] >> 12      ];
00827             vals[1] = fval_tab[(symbol_to_vec4[idx] >> 8) & 0xF];
00828             vals[2] = fval_tab[(symbol_to_vec4[idx] >> 4) & 0xF];
00829             vals[3] = fval_tab[ symbol_to_vec4[idx]       & 0xF];
00830         }
00831 
00833         for (i = 0; i < 4; i++) {
00834             if (vals[i]) {
00835                 int sign = get_bits1(&s->gb) - 1;
00836                 *(uint32_t*)&ci->coeffs[cur_coeff] = vals[i] ^ sign<<31;
00837                 num_zeros = 0;
00838             } else {
00839                 ci->coeffs[cur_coeff] = 0;
00842                 rl_mode |= (++num_zeros > s->subframe_len >> 8);
00843             }
00844             ++cur_coeff;
00845         }
00846     }
00847 
00849     if (rl_mode) {
00850         memset(&ci->coeffs[cur_coeff], 0,
00851                sizeof(*ci->coeffs) * (s->subframe_len - cur_coeff));
00852         if (ff_wma_run_level_decode(s->avctx, &s->gb, vlc,
00853                                     level, run, 1, ci->coeffs,
00854                                     cur_coeff, s->subframe_len,
00855                                     s->subframe_len, s->esc_len, 0))
00856             return AVERROR_INVALIDDATA;
00857     }
00858 
00859     return 0;
00860 }
00861 
00867 static int decode_scale_factors(WMAProDecodeCtx* s)
00868 {
00869     int i;
00870 
00875     for (i = 0; i < s->channels_for_cur_subframe; i++) {
00876         int c = s->channel_indexes_for_cur_subframe[i];
00877         int* sf;
00878         int* sf_end;
00879         s->channel[c].scale_factors = s->channel[c].saved_scale_factors[!s->channel[c].scale_factor_idx];
00880         sf_end = s->channel[c].scale_factors + s->num_bands;
00881 
00887         if (s->channel[c].reuse_sf) {
00888             const int8_t* sf_offsets = s->sf_offsets[s->table_idx][s->channel[c].table_idx];
00889             int b;
00890             for (b = 0; b < s->num_bands; b++)
00891                 s->channel[c].scale_factors[b] =
00892                     s->channel[c].saved_scale_factors[s->channel[c].scale_factor_idx][*sf_offsets++];
00893         }
00894 
00895         if (!s->channel[c].cur_subframe || get_bits1(&s->gb)) {
00896 
00897             if (!s->channel[c].reuse_sf) {
00898                 int val;
00900                 s->channel[c].scale_factor_step = get_bits(&s->gb, 2) + 1;
00901                 val = 45 / s->channel[c].scale_factor_step;
00902                 for (sf = s->channel[c].scale_factors; sf < sf_end; sf++) {
00903                     val += get_vlc2(&s->gb, sf_vlc.table, SCALEVLCBITS, SCALEMAXDEPTH) - 60;
00904                     *sf = val;
00905                 }
00906             } else {
00907                 int i;
00909                 for (i = 0; i < s->num_bands; i++) {
00910                     int idx;
00911                     int skip;
00912                     int val;
00913                     int sign;
00914 
00915                     idx = get_vlc2(&s->gb, sf_rl_vlc.table, VLCBITS, SCALERLMAXDEPTH);
00916 
00917                     if (!idx) {
00918                         uint32_t code = get_bits(&s->gb, 14);
00919                         val  =  code >> 6;
00920                         sign = (code & 1) - 1;
00921                         skip = (code & 0x3f) >> 1;
00922                     } else if (idx == 1) {
00923                         break;
00924                     } else {
00925                         skip = scale_rl_run[idx];
00926                         val  = scale_rl_level[idx];
00927                         sign = get_bits1(&s->gb)-1;
00928                     }
00929 
00930                     i += skip;
00931                     if (i >= s->num_bands) {
00932                         av_log(s->avctx, AV_LOG_ERROR,
00933                                "invalid scale factor coding\n");
00934                         return AVERROR_INVALIDDATA;
00935                     }
00936                     s->channel[c].scale_factors[i] += (val ^ sign) - sign;
00937                 }
00938             }
00940             s->channel[c].scale_factor_idx = !s->channel[c].scale_factor_idx;
00941             s->channel[c].table_idx = s->table_idx;
00942             s->channel[c].reuse_sf  = 1;
00943         }
00944 
00946         s->channel[c].max_scale_factor = s->channel[c].scale_factors[0];
00947         for (sf = s->channel[c].scale_factors + 1; sf < sf_end; sf++) {
00948             s->channel[c].max_scale_factor =
00949                 FFMAX(s->channel[c].max_scale_factor, *sf);
00950         }
00951 
00952     }
00953     return 0;
00954 }
00955 
00960 static void inverse_channel_transform(WMAProDecodeCtx *s)
00961 {
00962     int i;
00963 
00964     for (i = 0; i < s->num_chgroups; i++) {
00965         if (s->chgroup[i].transform) {
00966             float data[WMAPRO_MAX_CHANNELS];
00967             const int num_channels = s->chgroup[i].num_channels;
00968             float** ch_data = s->chgroup[i].channel_data;
00969             float** ch_end = ch_data + num_channels;
00970             const int8_t* tb = s->chgroup[i].transform_band;
00971             int16_t* sfb;
00972 
00974             for (sfb = s->cur_sfb_offsets;
00975                  sfb < s->cur_sfb_offsets + s->num_bands; sfb++) {
00976                 int y;
00977                 if (*tb++ == 1) {
00979                     for (y = sfb[0]; y < FFMIN(sfb[1], s->subframe_len); y++) {
00980                         const float* mat = s->chgroup[i].decorrelation_matrix;
00981                         const float* data_end = data + num_channels;
00982                         float* data_ptr = data;
00983                         float** ch;
00984 
00985                         for (ch = ch_data; ch < ch_end; ch++)
00986                             *data_ptr++ = (*ch)[y];
00987 
00988                         for (ch = ch_data; ch < ch_end; ch++) {
00989                             float sum = 0;
00990                             data_ptr = data;
00991                             while (data_ptr < data_end)
00992                                 sum += *data_ptr++ * *mat++;
00993 
00994                             (*ch)[y] = sum;
00995                         }
00996                     }
00997                 } else if (s->num_channels == 2) {
00998                     int len = FFMIN(sfb[1], s->subframe_len) - sfb[0];
00999                     s->dsp.vector_fmul_scalar(ch_data[0] + sfb[0],
01000                                               ch_data[0] + sfb[0],
01001                                               181.0 / 128, len);
01002                     s->dsp.vector_fmul_scalar(ch_data[1] + sfb[0],
01003                                               ch_data[1] + sfb[0],
01004                                               181.0 / 128, len);
01005                 }
01006             }
01007         }
01008     }
01009 }
01010 
01015 static void wmapro_window(WMAProDecodeCtx *s)
01016 {
01017     int i;
01018     for (i = 0; i < s->channels_for_cur_subframe; i++) {
01019         int c = s->channel_indexes_for_cur_subframe[i];
01020         float* window;
01021         int winlen = s->channel[c].prev_block_len;
01022         float* start = s->channel[c].coeffs - (winlen >> 1);
01023 
01024         if (s->subframe_len < winlen) {
01025             start += (winlen - s->subframe_len) >> 1;
01026             winlen = s->subframe_len;
01027         }
01028 
01029         window = s->windows[av_log2(winlen) - BLOCK_MIN_BITS];
01030 
01031         winlen >>= 1;
01032 
01033         s->dsp.vector_fmul_window(start, start, start + winlen,
01034                                   window, 0, winlen);
01035 
01036         s->channel[c].prev_block_len = s->subframe_len;
01037     }
01038 }
01039 
01045 static int decode_subframe(WMAProDecodeCtx *s)
01046 {
01047     int offset = s->samples_per_frame;
01048     int subframe_len = s->samples_per_frame;
01049     int i;
01050     int total_samples   = s->samples_per_frame * s->num_channels;
01051     int transmit_coeffs = 0;
01052     int cur_subwoofer_cutoff;
01053 
01054     s->subframe_offset = get_bits_count(&s->gb);
01055 
01060     for (i = 0; i < s->num_channels; i++) {
01061         s->channel[i].grouped = 0;
01062         if (offset > s->channel[i].decoded_samples) {
01063             offset = s->channel[i].decoded_samples;
01064             subframe_len =
01065                 s->channel[i].subframe_len[s->channel[i].cur_subframe];
01066         }
01067     }
01068 
01069     dprintf(s->avctx,
01070             "processing subframe with offset %i len %i\n", offset, subframe_len);
01071 
01073     s->channels_for_cur_subframe = 0;
01074     for (i = 0; i < s->num_channels; i++) {
01075         const int cur_subframe = s->channel[i].cur_subframe;
01077         total_samples -= s->channel[i].decoded_samples;
01078 
01080         if (offset == s->channel[i].decoded_samples &&
01081             subframe_len == s->channel[i].subframe_len[cur_subframe]) {
01082             total_samples -= s->channel[i].subframe_len[cur_subframe];
01083             s->channel[i].decoded_samples +=
01084                 s->channel[i].subframe_len[cur_subframe];
01085             s->channel_indexes_for_cur_subframe[s->channels_for_cur_subframe] = i;
01086             ++s->channels_for_cur_subframe;
01087         }
01088     }
01089 
01092     if (!total_samples)
01093         s->parsed_all_subframes = 1;
01094 
01095 
01096     dprintf(s->avctx, "subframe is part of %i channels\n",
01097             s->channels_for_cur_subframe);
01098 
01100     s->table_idx         = av_log2(s->samples_per_frame/subframe_len);
01101     s->num_bands         = s->num_sfb[s->table_idx];
01102     s->cur_sfb_offsets   = s->sfb_offsets[s->table_idx];
01103     cur_subwoofer_cutoff = s->subwoofer_cutoffs[s->table_idx];
01104 
01106     for (i = 0; i < s->channels_for_cur_subframe; i++) {
01107         int c = s->channel_indexes_for_cur_subframe[i];
01108 
01109         s->channel[c].coeffs = &s->channel[c].out[(s->samples_per_frame >> 1)
01110                                                   + offset];
01111     }
01112 
01113     s->subframe_len = subframe_len;
01114     s->esc_len = av_log2(s->subframe_len - 1) + 1;
01115 
01117     if (get_bits1(&s->gb)) {
01118         int num_fill_bits;
01119         if (!(num_fill_bits = get_bits(&s->gb, 2))) {
01120             int len = get_bits(&s->gb, 4);
01121             num_fill_bits = get_bits(&s->gb, len) + 1;
01122         }
01123 
01124         if (num_fill_bits >= 0) {
01125             if (get_bits_count(&s->gb) + num_fill_bits > s->num_saved_bits) {
01126                 av_log(s->avctx, AV_LOG_ERROR, "invalid number of fill bits\n");
01127                 return AVERROR_INVALIDDATA;
01128             }
01129 
01130             skip_bits_long(&s->gb, num_fill_bits);
01131         }
01132     }
01133 
01135     if (get_bits1(&s->gb)) {
01136         av_log_ask_for_sample(s->avctx, "reserved bit set\n");
01137         return AVERROR_INVALIDDATA;
01138     }
01139 
01140 
01141     if (decode_channel_transform(s) < 0)
01142         return AVERROR_INVALIDDATA;
01143 
01144 
01145     for (i = 0; i < s->channels_for_cur_subframe; i++) {
01146         int c = s->channel_indexes_for_cur_subframe[i];
01147         if ((s->channel[c].transmit_coefs = get_bits1(&s->gb)))
01148             transmit_coeffs = 1;
01149     }
01150 
01151     if (transmit_coeffs) {
01152         int step;
01153         int quant_step = 90 * s->bits_per_sample >> 4;
01154         if ((get_bits1(&s->gb))) {
01156             av_log_ask_for_sample(s->avctx, "unsupported quant step coding\n");
01157             return AVERROR_INVALIDDATA;
01158         }
01160         step = get_sbits(&s->gb, 6);
01161         quant_step += step;
01162         if (step == -32 || step == 31) {
01163             const int sign = (step == 31) - 1;
01164             int quant = 0;
01165             while (get_bits_count(&s->gb) + 5 < s->num_saved_bits &&
01166                    (step = get_bits(&s->gb, 5)) == 31) {
01167                 quant += 31;
01168             }
01169             quant_step += ((quant + step) ^ sign) - sign;
01170         }
01171         if (quant_step < 0) {
01172             av_log(s->avctx, AV_LOG_DEBUG, "negative quant step\n");
01173         }
01174 
01177         if (s->channels_for_cur_subframe == 1) {
01178             s->channel[s->channel_indexes_for_cur_subframe[0]].quant_step = quant_step;
01179         } else {
01180             int modifier_len = get_bits(&s->gb, 3);
01181             for (i = 0; i < s->channels_for_cur_subframe; i++) {
01182                 int c = s->channel_indexes_for_cur_subframe[i];
01183                 s->channel[c].quant_step = quant_step;
01184                 if (get_bits1(&s->gb)) {
01185                     if (modifier_len) {
01186                         s->channel[c].quant_step += get_bits(&s->gb, modifier_len) + 1;
01187                     } else
01188                         ++s->channel[c].quant_step;
01189                 }
01190             }
01191         }
01192 
01194         if (decode_scale_factors(s) < 0)
01195             return AVERROR_INVALIDDATA;
01196     }
01197 
01198     dprintf(s->avctx, "BITSTREAM: subframe header length was %i\n",
01199             get_bits_count(&s->gb) - s->subframe_offset);
01200 
01202     for (i = 0; i < s->channels_for_cur_subframe; i++) {
01203         int c = s->channel_indexes_for_cur_subframe[i];
01204         if (s->channel[c].transmit_coefs &&
01205             get_bits_count(&s->gb) < s->num_saved_bits) {
01206             decode_coeffs(s, c);
01207         } else
01208             memset(s->channel[c].coeffs, 0,
01209                    sizeof(*s->channel[c].coeffs) * subframe_len);
01210     }
01211 
01212     dprintf(s->avctx, "BITSTREAM: subframe length was %i\n",
01213             get_bits_count(&s->gb) - s->subframe_offset);
01214 
01215     if (transmit_coeffs) {
01217         inverse_channel_transform(s);
01218         for (i = 0; i < s->channels_for_cur_subframe; i++) {
01219             int c = s->channel_indexes_for_cur_subframe[i];
01220             const int* sf = s->channel[c].scale_factors;
01221             int b;
01222 
01223             if (c == s->lfe_channel)
01224                 memset(&s->tmp[cur_subwoofer_cutoff], 0, sizeof(*s->tmp) *
01225                        (subframe_len - cur_subwoofer_cutoff));
01226 
01228             for (b = 0; b < s->num_bands; b++) {
01229                 const int end = FFMIN(s->cur_sfb_offsets[b+1], s->subframe_len);
01230                 const int exp = s->channel[c].quant_step -
01231                             (s->channel[c].max_scale_factor - *sf++) *
01232                             s->channel[c].scale_factor_step;
01233                 const float quant = pow(10.0, exp / 20.0);
01234                 int start = s->cur_sfb_offsets[b];
01235                 s->dsp.vector_fmul_scalar(s->tmp + start,
01236                                           s->channel[c].coeffs + start,
01237                                           quant, end - start);
01238             }
01239 
01241             ff_imdct_half(&s->mdct_ctx[av_log2(subframe_len) - BLOCK_MIN_BITS],
01242                           s->channel[c].coeffs, s->tmp);
01243         }
01244     }
01245 
01247     wmapro_window(s);
01248 
01250     for (i = 0; i < s->channels_for_cur_subframe; i++) {
01251         int c = s->channel_indexes_for_cur_subframe[i];
01252         if (s->channel[c].cur_subframe >= s->channel[c].num_subframes) {
01253             av_log(s->avctx, AV_LOG_ERROR, "broken subframe\n");
01254             return AVERROR_INVALIDDATA;
01255         }
01256         ++s->channel[c].cur_subframe;
01257     }
01258 
01259     return 0;
01260 }
01261 
01268 static int decode_frame(WMAProDecodeCtx *s)
01269 {
01270     GetBitContext* gb = &s->gb;
01271     int more_frames = 0;
01272     int len = 0;
01273     int i;
01274 
01276     if (s->num_channels * s->samples_per_frame > s->samples_end - s->samples) {
01278         av_log(s->avctx, AV_LOG_ERROR,
01279                "not enough space for the output samples\n");
01280         s->packet_loss = 1;
01281         return 0;
01282     }
01283 
01285     if (s->len_prefix)
01286         len = get_bits(gb, s->log2_frame_size);
01287 
01288     dprintf(s->avctx, "decoding frame with length %x\n", len);
01289 
01291     if (decode_tilehdr(s)) {
01292         s->packet_loss = 1;
01293         return 0;
01294     }
01295 
01297     if (s->num_channels > 1 && get_bits1(gb)) {
01298         av_log_ask_for_sample(s->avctx, "Unsupported postproc transform found\n");
01299         s->packet_loss = 1;
01300         return 0;
01301     }
01302 
01304     if (s->dynamic_range_compression) {
01305         s->drc_gain = get_bits(gb, 8);
01306         dprintf(s->avctx, "drc_gain %i\n", s->drc_gain);
01307     }
01308 
01311     if (get_bits1(gb)) {
01312         int skip;
01313 
01315         if (get_bits1(gb)) {
01316             skip = get_bits(gb, av_log2(s->samples_per_frame * 2));
01317             dprintf(s->avctx, "start skip: %i\n", skip);
01318         }
01319 
01321         if (get_bits1(gb)) {
01322             skip = get_bits(gb, av_log2(s->samples_per_frame * 2));
01323             dprintf(s->avctx, "end skip: %i\n", skip);
01324         }
01325 
01326     }
01327 
01328     dprintf(s->avctx, "BITSTREAM: frame header length was %i\n",
01329             get_bits_count(gb) - s->frame_offset);
01330 
01332     s->parsed_all_subframes = 0;
01333     for (i = 0; i < s->num_channels; i++) {
01334         s->channel[i].decoded_samples = 0;
01335         s->channel[i].cur_subframe    = 0;
01336         s->channel[i].reuse_sf        = 0;
01337     }
01338 
01340     while (!s->parsed_all_subframes) {
01341         if (decode_subframe(s) < 0) {
01342             s->packet_loss = 1;
01343             return 0;
01344         }
01345     }
01346 
01348     for (i = 0; i < s->num_channels; i++) {
01349         float* ptr  = s->samples + i;
01350         int incr = s->num_channels;
01351         float* iptr = s->channel[i].out;
01352         float* iend = iptr + s->samples_per_frame;
01353 
01354         // FIXME should create/use a DSP function here
01355         while (iptr < iend) {
01356             *ptr = *iptr++;
01357             ptr += incr;
01358         }
01359 
01361         memcpy(&s->channel[i].out[0],
01362                &s->channel[i].out[s->samples_per_frame],
01363                s->samples_per_frame * sizeof(*s->channel[i].out) >> 1);
01364     }
01365 
01366     if (s->skip_frame) {
01367         s->skip_frame = 0;
01368     } else
01369         s->samples += s->num_channels * s->samples_per_frame;
01370 
01371     if (len != (get_bits_count(gb) - s->frame_offset) + 2) {
01373         av_log(s->avctx, AV_LOG_ERROR, "frame[%i] would have to skip %i bits\n",
01374                s->frame_num, len - (get_bits_count(gb) - s->frame_offset) - 1);
01375         s->packet_loss = 1;
01376         return 0;
01377     }
01378 
01380     skip_bits_long(gb, len - (get_bits_count(gb) - s->frame_offset) - 1);
01381 
01383     more_frames = get_bits1(gb);
01384 
01385     ++s->frame_num;
01386     return more_frames;
01387 }
01388 
01395 static int remaining_bits(WMAProDecodeCtx *s, GetBitContext *gb)
01396 {
01397     return s->buf_bit_size - get_bits_count(gb);
01398 }
01399 
01407 static void save_bits(WMAProDecodeCtx *s, GetBitContext* gb, int len,
01408                       int append)
01409 {
01410     int buflen;
01411 
01416     if (!append) {
01417         s->frame_offset = get_bits_count(gb) & 7;
01418         s->num_saved_bits = s->frame_offset;
01419         init_put_bits(&s->pb, s->frame_data, MAX_FRAMESIZE);
01420     }
01421 
01422     buflen = (s->num_saved_bits + len + 8) >> 3;
01423 
01424     if (len <= 0 || buflen > MAX_FRAMESIZE) {
01425         av_log_ask_for_sample(s->avctx, "input buffer too small\n");
01426         s->packet_loss = 1;
01427         return;
01428     }
01429 
01430     s->num_saved_bits += len;
01431     if (!append) {
01432         ff_copy_bits(&s->pb, gb->buffer + (get_bits_count(gb) >> 3),
01433                      s->num_saved_bits);
01434     } else {
01435         int align = 8 - (get_bits_count(gb) & 7);
01436         align = FFMIN(align, len);
01437         put_bits(&s->pb, align, get_bits(gb, align));
01438         len -= align;
01439         ff_copy_bits(&s->pb, gb->buffer + (get_bits_count(gb) >> 3), len);
01440     }
01441     skip_bits_long(gb, len);
01442 
01443     {
01444         PutBitContext tmp = s->pb;
01445         flush_put_bits(&tmp);
01446     }
01447 
01448     init_get_bits(&s->gb, s->frame_data, s->num_saved_bits);
01449     skip_bits(&s->gb, s->frame_offset);
01450 }
01451 
01460 static int decode_packet(AVCodecContext *avctx,
01461                          void *data, int *data_size, AVPacket* avpkt)
01462 {
01463     WMAProDecodeCtx *s = avctx->priv_data;
01464     GetBitContext* gb  = &s->pgb;
01465     const uint8_t* buf = avpkt->data;
01466     int buf_size       = avpkt->size;
01467     int num_bits_prev_frame;
01468     int packet_sequence_number;
01469 
01470     s->samples       = data;
01471     s->samples_end   = (float*)((int8_t*)data + *data_size);
01472     *data_size = 0;
01473 
01474     if (s->packet_done || s->packet_loss) {
01475         s->packet_done = 0;
01476         s->buf_bit_size = buf_size << 3;
01477 
01479         if (buf_size < avctx->block_align)
01480             return 0;
01481 
01482         buf_size = avctx->block_align;
01483 
01485         init_get_bits(gb, buf, s->buf_bit_size);
01486         packet_sequence_number = get_bits(gb, 4);
01487         skip_bits(gb, 2);
01488 
01490         num_bits_prev_frame = get_bits(gb, s->log2_frame_size);
01491         dprintf(avctx, "packet[%d]: nbpf %x\n", avctx->frame_number,
01492                 num_bits_prev_frame);
01493 
01495         if (!s->packet_loss &&
01496             ((s->packet_sequence_number + 1) & 0xF) != packet_sequence_number) {
01497             s->packet_loss = 1;
01498             av_log(avctx, AV_LOG_ERROR, "Packet loss detected! seq %x vs %x\n",
01499                    s->packet_sequence_number, packet_sequence_number);
01500         }
01501         s->packet_sequence_number = packet_sequence_number;
01502 
01503         if (num_bits_prev_frame > 0) {
01506             save_bits(s, gb, num_bits_prev_frame, 1);
01507             dprintf(avctx, "accumulated %x bits of frame data\n",
01508                     s->num_saved_bits - s->frame_offset);
01509 
01511             if (!s->packet_loss)
01512                 decode_frame(s);
01513         } else if (s->num_saved_bits - s->frame_offset) {
01514             dprintf(avctx, "ignoring %x previously saved bits\n",
01515                     s->num_saved_bits - s->frame_offset);
01516         }
01517 
01518         s->packet_loss = 0;
01519 
01520     } else {
01521         int frame_size;
01522         s->buf_bit_size = avpkt->size << 3;
01523         init_get_bits(gb, avpkt->data, s->buf_bit_size);
01524         skip_bits(gb, s->packet_offset);
01525         if (remaining_bits(s, gb) > s->log2_frame_size &&
01526             (frame_size = show_bits(gb, s->log2_frame_size)) &&
01527             frame_size <= remaining_bits(s, gb)) {
01528             save_bits(s, gb, frame_size, 0);
01529             s->packet_done = !decode_frame(s);
01530         } else
01531             s->packet_done = 1;
01532     }
01533 
01534     if (s->packet_done && !s->packet_loss &&
01535         remaining_bits(s, gb) > 0) {
01538         save_bits(s, gb, remaining_bits(s, gb), 0);
01539     }
01540 
01541     *data_size = (int8_t *)s->samples - (int8_t *)data;
01542     s->packet_offset = get_bits_count(gb) & 7;
01543 
01544     return (s->packet_loss) ? AVERROR_INVALIDDATA : get_bits_count(gb) >> 3;
01545 }
01546 
01551 static void flush(AVCodecContext *avctx)
01552 {
01553     WMAProDecodeCtx *s = avctx->priv_data;
01554     int i;
01557     for (i = 0; i < s->num_channels; i++)
01558         memset(s->channel[i].out, 0, s->samples_per_frame *
01559                sizeof(*s->channel[i].out));
01560     s->packet_loss = 1;
01561 }
01562 
01563 
01567 AVCodec wmapro_decoder = {
01568     "wmapro",
01569     AVMEDIA_TYPE_AUDIO,
01570     CODEC_ID_WMAPRO,
01571     sizeof(WMAProDecodeCtx),
01572     decode_init,
01573     NULL,
01574     decode_end,
01575     decode_packet,
01576     .capabilities = CODEC_CAP_SUBFRAMES,
01577     .flush= flush,
01578     .long_name = NULL_IF_CONFIG_SMALL("Windows Media Audio 9 Professional"),
01579 };

Generated on Fri Sep 16 2011 17:17:46 for FFmpeg by  doxygen 1.7.1