git.sesse.net Git - vlc/blob - modules/demux/flac.c

   1 /*****************************************************************************
   2  * flac.c : FLAC demux module for vlc
   3  *****************************************************************************
   4  * Copyright (C) 2001-2008 VLC authors and VideoLAN
   5  * $Id$
   6  *
   7  * Authors: Gildas Bazin <gbazin@netcourrier.com>
   8  *          Laurent Aimar <fenrir@via.ecp.fr>
   9  *
  10  * This program is free software; you can redistribute it and/or modify it
  11  * under the terms of the GNU Lesser General Public License as published by
  12  * the Free Software Foundation; either version 2.1 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  18  * GNU Lesser General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU Lesser General Public License
  21  * along with this program; if not, write to the Free Software Foundation,
  22  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  23  *****************************************************************************/
  24
  25 /*****************************************************************************
  26  * Preamble
  27  *****************************************************************************/
  28 #ifdef HAVE_CONFIG_H
  29 # include "config.h"
  30 #endif
  31
  32 #include <vlc_common.h>
  33 #include <vlc_plugin.h>
  34 #include <vlc_demux.h>
  35 #include <vlc_meta.h>                 /* vlc_meta_* */
  36 #include <vlc_input.h>                /* vlc_input_attachment, vlc_seekpoint */
  37 #include <vlc_codec.h>                /* decoder_t */
  38 #include <vlc_charset.h>              /* EnsureUTF8 */
  39
  40 #include <assert.h>
  41 #include "xiph_metadata.h"            /* vorbis comments */
  42
  43 /*****************************************************************************
  44  * Module descriptor
  45  *****************************************************************************/
  46 static int  Open  ( vlc_object_t * );
  47 static void Close ( vlc_object_t * );
  48
  49 vlc_module_begin ()
  50     set_description( N_("FLAC demuxer") )
  51     set_capability( "demux", 155 )
  52     set_category( CAT_INPUT )
  53     set_subcategory( SUBCAT_INPUT_DEMUX )
  54     set_callbacks( Open, Close )
  55     add_shortcut( "flac" )
  56 vlc_module_end ()
  57
  58 /*****************************************************************************
  59  * Local prototypes
  60  *****************************************************************************/
  61 static int Demux  ( demux_t * );
  62 static int Control( demux_t *, int, va_list );
  63
  64 static int  ReadMeta( demux_t *, uint8_t **pp_streaminfo, int *pi_streaminfo );
  65
  66 struct demux_sys_t
  67 {
  68     bool  b_start;
  69     es_out_id_t *p_es;
  70
  71     /* Packetizer */
  72     decoder_t *p_packetizer;
  73
  74     vlc_meta_t *p_meta;
  75
  76     int64_t i_time_offset;
  77     int64_t i_pts;
  78     int64_t i_pts_start;
  79
  80     int64_t i_length; /* Length from stream info */
  81     int64_t i_data_pos;
  82
  83     /* */
  84     int         i_seekpoint;
  85     seekpoint_t **seekpoint;
  86
  87     /* */
  88     int                i_attachments;
  89     input_attachment_t **attachments;
  90     int                i_cover_idx;
  91     int                i_cover_score;
  92 };
  93
  94 #define STREAMINFO_SIZE 38
  95 #define FLAC_PACKET_SIZE 16384
  96
  97 /*****************************************************************************
  98  * Open: initializes ES structures
  99  *****************************************************************************/
 100 static int Open( vlc_object_t * p_this )
 101 {
 102     demux_t     *p_demux = (demux_t*)p_this;
 103     demux_sys_t *p_sys;
 104     const uint8_t *p_peek;
 105     uint8_t     *p_streaminfo;
 106     int         i_streaminfo;
 107     es_format_t fmt;
 108
 109     /* Have a peep at the show. */
 110     if( stream_Peek( p_demux->s, &p_peek, 4 ) < 4 ) return VLC_EGENERIC;
 111
 112     if( p_peek[0]!='f' || p_peek[1]!='L' || p_peek[2]!='a' || p_peek[3]!='C' )
 113     {
 114         if( !p_demux->b_force ) return VLC_EGENERIC;
 115
 116         /* User forced */
 117         msg_Err( p_demux, "this doesn't look like a flac stream, "
 118                  "continuing anyway" );
 119     }
 120
 121     p_sys = malloc( sizeof( demux_sys_t ) );
 122     if( unlikely(p_sys == NULL) )
 123         return VLC_ENOMEM;
 124
 125     p_demux->pf_demux   = Demux;
 126     p_demux->pf_control = Control;
 127     p_demux->p_sys      = p_sys;
 128     p_sys->b_start = true;
 129     p_sys->p_meta = NULL;
 130     p_sys->i_length = 0;
 131     p_sys->i_time_offset = 0;
 132     p_sys->i_pts = 0;
 133     p_sys->i_pts_start = 0;
 134     p_sys->p_es = NULL;
 135     TAB_INIT( p_sys->i_seekpoint, p_sys->seekpoint );
 136     TAB_INIT( p_sys->i_attachments, p_sys->attachments);
 137     p_sys->i_cover_idx = 0;
 138     p_sys->i_cover_score = 0;
 139
 140     /* We need to read and store the STREAMINFO metadata */
 141     if( ReadMeta( p_demux, &p_streaminfo, &i_streaminfo ) )
 142     {
 143         free( p_sys );
 144         return VLC_EGENERIC;
 145     }
 146
 147     /* Load the FLAC packetizer */
 148     /* Store STREAMINFO for the decoder and packetizer */
 149     p_streaminfo[4] |= 0x80; /* Fake this as the last metadata block */
 150     es_format_Init( &fmt, AUDIO_ES, VLC_CODEC_FLAC );
 151     fmt.i_extra = i_streaminfo;
 152     fmt.p_extra = p_streaminfo;
 153
 154     p_sys->p_packetizer = demux_PacketizerNew( p_demux, &fmt, "flac" );
 155     if( !p_sys->p_packetizer )
 156     {
 157         free( p_sys );
 158         return VLC_EGENERIC;
 159     }
 160
 161     if( p_sys->i_cover_idx < p_sys->i_attachments )
 162     {
 163         char psz_url[128];
 164         if( !p_sys->p_meta )
 165             p_sys->p_meta = vlc_meta_New();
 166         snprintf( psz_url, sizeof(psz_url), "attachment://%s",
 167                   p_sys->attachments[p_sys->i_cover_idx]->psz_name );
 168         vlc_meta_Set( p_sys->p_meta, vlc_meta_ArtworkURL, psz_url );
 169     }
 170     return VLC_SUCCESS;
 171 }
 172
 173 /*****************************************************************************
 174  * Close: frees unused data
 175  *****************************************************************************/
 176 static void Close( vlc_object_t * p_this )
 177 {
 178     demux_t     *p_demux = (demux_t*)p_this;
 179     demux_sys_t *p_sys = p_demux->p_sys;
 180
 181     for( int i = 0; i < p_sys->i_seekpoint; i++ )
 182         vlc_seekpoint_Delete(p_sys->seekpoint[i]);
 183     TAB_CLEAN( p_sys->i_seekpoint, p_sys->seekpoint );
 184
 185     for( int i = 0; i < p_sys->i_attachments; i++ )
 186         vlc_input_attachment_Delete( p_sys->attachments[i] );
 187     TAB_CLEAN( p_sys->i_attachments, p_sys->attachments);
 188
 189     /* Delete the decoder */
 190     demux_PacketizerDestroy( p_sys->p_packetizer );
 191
 192     if( p_sys->p_meta )
 193         vlc_meta_Delete( p_sys->p_meta );
 194     free( p_sys );
 195 }
 196
 197 /*****************************************************************************
 198  * Demux: reads and demuxes data packets
 199  *****************************************************************************
 200  * Returns -1 in case of error, 0 in case of EOF, 1 otherwise
 201  *****************************************************************************/
 202 static int Demux( demux_t *p_demux )
 203 {
 204     demux_sys_t *p_sys = p_demux->p_sys;
 205     block_t     *p_block_in, *p_block_out;
 206
 207     if( !( p_block_in = stream_Block( p_demux->s, FLAC_PACKET_SIZE ) ) )
 208         return 0;
 209
 210     p_block_in->i_pts = p_block_in->i_dts = p_sys->b_start ? VLC_TS_0 : VLC_TS_INVALID;
 211     p_sys->b_start = false;
 212
 213     while( (p_block_out = p_sys->p_packetizer->pf_packetize(
 214                 p_sys->p_packetizer, &p_block_in )) )
 215     {
 216         while( p_block_out )
 217         {
 218             block_t *p_next = p_block_out->p_next;
 219
 220             p_block_out->p_next = NULL;
 221
 222             if( p_sys->p_es == NULL )
 223             {
 224                 p_sys->p_packetizer->fmt_out.b_packetized = true;
 225                 p_sys->p_es = es_out_Add( p_demux->out, &p_sys->p_packetizer->fmt_out);
 226             }
 227
 228             p_sys->i_pts = p_block_out->i_dts - VLC_TS_0;
 229
 230             /* Correct timestamp */
 231             p_block_out->i_pts += p_sys->i_time_offset;
 232             p_block_out->i_dts += p_sys->i_time_offset;
 233
 234             /* set PCR */
 235             es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_block_out->i_dts );
 236
 237             es_out_Send( p_demux->out, p_sys->p_es, p_block_out );
 238
 239             p_block_out = p_next;
 240         }
 241     }
 242     return 1;
 243 }
 244
 245 /*****************************************************************************
 246  * Control:
 247  *****************************************************************************/
 248 static int64_t ControlGetLength( demux_t *p_demux )
 249 {
 250     demux_sys_t *p_sys = p_demux->p_sys;
 251     const int64_t i_size = stream_Size(p_demux->s) - p_sys->i_data_pos;
 252     int64_t i_length = p_sys->i_length;
 253     int i;
 254
 255     /* Try to fix length using seekpoint and current size for truncated file */
 256     for( i = p_sys->i_seekpoint-1; i >= 0; i-- )
 257     {
 258         seekpoint_t *s = p_sys->seekpoint[i];
 259         if( s->i_byte_offset <= i_size )
 260         {
 261             if( i+1 < p_sys->i_seekpoint )
 262             {
 263                 /* Broken file */
 264                 seekpoint_t *n = p_sys->seekpoint[i+1];
 265                 assert( n->i_byte_offset != s->i_byte_offset); /* Should be ensured by ParseSeekTable */
 266                 i_length = s->i_time_offset + (n->i_time_offset-s->i_time_offset) * (i_size-s->i_byte_offset) / (n->i_byte_offset-s->i_byte_offset);
 267             }
 268             break;
 269         }
 270     }
 271     return i_length;
 272 }
 273
 274 static int64_t ControlGetTime( demux_t *p_demux )
 275 {
 276     demux_sys_t *p_sys = p_demux->p_sys;
 277     return __MAX(p_sys->i_pts, p_sys->i_pts_start) + p_sys->i_time_offset;
 278 }
 279
 280 static int ControlSetTime( demux_t *p_demux, int64_t i_time )
 281 {
 282     demux_sys_t *p_sys = p_demux->p_sys;
 283     int64_t i_delta_time;
 284     bool b_seekable;
 285     int i;
 286
 287     /* */
 288     stream_Control( p_demux->s, STREAM_CAN_SEEK, &b_seekable );
 289     if( !b_seekable )
 290         return VLC_EGENERIC;
 291
 292     /* */
 293     assert( p_sys->i_seekpoint > 0 );   /* ReadMeta ensure at least (0,0) */
 294     for( i = p_sys->i_seekpoint-1; i >= 0; i-- )
 295     {
 296         if( p_sys->seekpoint[i]->i_time_offset <= i_time )
 297             break;
 298     }
 299     i_delta_time = i_time - p_sys->seekpoint[i]->i_time_offset;
 300
 301     /* XXX We do exact seek if it's not too far away(45s) */
 302     if( i_delta_time < 45*INT64_C(1000000) )
 303     {
 304         if( stream_Seek( p_demux->s, p_sys->seekpoint[i]->i_byte_offset+p_sys->i_data_pos ) )
 305             return VLC_EGENERIC;
 306
 307         p_sys->i_time_offset = p_sys->seekpoint[i]->i_time_offset - p_sys->i_pts;
 308         p_sys->i_pts_start = p_sys->i_pts+i_delta_time;
 309         es_out_Control( p_demux->out, ES_OUT_SET_NEXT_DISPLAY_TIME, p_sys->i_pts_start + p_sys->i_time_offset );
 310     }
 311     else
 312     {
 313         int64_t i_delta_offset;
 314         int64_t i_next_time;
 315         int64_t i_next_offset;
 316
 317         if( i+1 < p_sys->i_seekpoint )
 318         {
 319             i_next_time   = p_sys->seekpoint[i+1]->i_time_offset;
 320             i_next_offset = p_sys->seekpoint[i+1]->i_byte_offset;
 321         }
 322         else
 323         {
 324             i_next_time   = p_sys->i_length;
 325             i_next_offset = stream_Size(p_demux->s)-p_sys->i_data_pos;
 326         }
 327
 328         i_delta_offset = 0;
 329         if( i_next_time-p_sys->seekpoint[i]->i_time_offset > 0 )
 330             i_delta_offset = (i_next_offset - p_sys->seekpoint[i]->i_byte_offset) * i_delta_time /
 331                              (i_next_time-p_sys->seekpoint[i]->i_time_offset);
 332
 333         if( stream_Seek( p_demux->s, p_sys->seekpoint[i]->i_byte_offset+p_sys->i_data_pos + i_delta_offset ) )
 334             return VLC_EGENERIC;
 335
 336         p_sys->i_pts_start = p_sys->i_pts;
 337         p_sys->i_time_offset = (p_sys->seekpoint[i]->i_time_offset+i_delta_time) - p_sys->i_pts;
 338     }
 339     return VLC_SUCCESS;
 340 }
 341
 342 static int Control( demux_t *p_demux, int i_query, va_list args )
 343 {
 344     demux_sys_t *p_sys = p_demux->p_sys;
 345
 346     if( i_query == DEMUX_GET_META )
 347     {
 348         vlc_meta_t *p_meta = (vlc_meta_t *)va_arg( args, vlc_meta_t* );
 349         if( p_demux->p_sys->p_meta )
 350             vlc_meta_Merge( p_meta, p_demux->p_sys->p_meta );
 351         return VLC_SUCCESS;
 352     }
 353     else if( i_query == DEMUX_HAS_UNSUPPORTED_META )
 354     {
 355         bool *pb_bool = (bool*)va_arg( args, bool* );
 356         *pb_bool = true;
 357         return VLC_SUCCESS;
 358     }
 359     else if( i_query == DEMUX_GET_LENGTH )
 360     {
 361         int64_t *pi64 = (int64_t*)va_arg( args, int64_t * );
 362         *pi64 = ControlGetLength( p_demux );
 363         return VLC_SUCCESS;
 364     }
 365     else if( i_query == DEMUX_SET_TIME )
 366     {
 367         int64_t i_time = (int64_t)va_arg( args, int64_t );
 368         return ControlSetTime( p_demux, i_time );
 369     }
 370     else if( i_query == DEMUX_SET_POSITION )
 371     {
 372         const double f = (double)va_arg( args, double );
 373         int64_t i_time = f * ControlGetLength( p_demux );
 374         return ControlSetTime( p_demux, i_time );
 375     }
 376     else if( i_query == DEMUX_GET_TIME )
 377     {
 378         int64_t *pi64 = (int64_t*)va_arg( args, int64_t * );
 379         *pi64 = ControlGetTime( p_demux );
 380         return VLC_SUCCESS;
 381     }
 382     else if( i_query == DEMUX_GET_POSITION )
 383     {
 384         double *pf = (double*)va_arg( args, double * );
 385         const int64_t i_length = ControlGetLength(p_demux);
 386         if( i_length > 0 )
 387         {
 388             double current = ControlGetTime(p_demux);
 389             *pf = current / (double)i_length;
 390         }
 391         else
 392             *pf= 0.0;
 393         return VLC_SUCCESS;
 394     }
 395     else if( i_query == DEMUX_GET_ATTACHMENTS )
 396     {
 397         input_attachment_t ***ppp_attach =
 398             (input_attachment_t***)va_arg( args, input_attachment_t*** );
 399         int *pi_int = (int*)va_arg( args, int * );
 400
 401         if( p_sys->i_attachments <= 0 )
 402             return VLC_EGENERIC;
 403
 404         *pi_int = p_sys->i_attachments;
 405         *ppp_attach = xmalloc( sizeof(input_attachment_t**) * p_sys->i_attachments );
 406         for( int i = 0; i < p_sys->i_attachments; i++ )
 407             (*ppp_attach)[i] = vlc_input_attachment_Duplicate( p_sys->attachments[i] );
 408         return VLC_SUCCESS;
 409     }
 410
 411     return demux_vaControlHelper( p_demux->s, p_sys->i_data_pos, -1,
 412                                    8*0, 1, i_query, args );
 413 }
 414
 415 enum
 416 {
 417     META_STREAMINFO = 0,
 418     META_SEEKTABLE = 3,
 419     META_COMMENT = 4,
 420     META_PICTURE = 6,
 421 };
 422
 423 static inline int Get24bBE( const uint8_t *p )
 424 {
 425     return (p[0] << 16)|(p[1] << 8)|(p[2]);
 426 }
 427
 428 static void ParseStreamInfo( int *pi_rate, int64_t *pi_count, uint8_t *p_data );
 429 static void ParseSeekTable( demux_t *p_demux, const uint8_t *p_data, int i_data,
 430                             int i_sample_rate );
 431 static void ParseComment( demux_t *, const uint8_t *p_data, int i_data );
 432 static void ParsePicture( demux_t *, const uint8_t *p_data, int i_data );
 433
 434 static int  ReadMeta( demux_t *p_demux, uint8_t **pp_streaminfo, int *pi_streaminfo )
 435 {
 436     demux_sys_t *p_sys = p_demux->p_sys;
 437     int     i_peek;
 438     const uint8_t *p_peek;
 439     bool b_last;
 440     int i_sample_rate = 0;
 441     int64_t i_sample_count;
 442
 443     *pp_streaminfo = NULL;
 444
 445     /* Be sure we have seekpoint 0 */
 446     seekpoint_t *s = vlc_seekpoint_New();
 447     s->i_time_offset = 0;
 448     s->i_byte_offset = 0;
 449     TAB_APPEND( p_sys->i_seekpoint, p_sys->seekpoint, s );
 450
 451     static const uint8_t marker[4] = { 'f', 'L', 'a', 'C' };
 452     uint8_t header[4];
 453     if( stream_Read( p_demux->s, header, 4) < 4)
 454         return VLC_EGENERIC;
 455
 456     if (memcmp(header, marker, 4))
 457         return VLC_EGENERIC;
 458
 459     b_last = 0;
 460     while( !b_last )
 461     {
 462         int i_len;
 463         int i_type;
 464
 465         i_peek = stream_Peek( p_demux->s, &p_peek, 4 );
 466         if( i_peek < 4 )
 467             break;
 468         b_last = p_peek[0]&0x80;
 469         i_type = p_peek[0]&0x7f;
 470         i_len  = Get24bBE( &p_peek[1] );
 471
 472         if( i_type == META_STREAMINFO && !*pp_streaminfo )
 473         {
 474             if( i_len != (STREAMINFO_SIZE - 4) ) {
 475                 msg_Err( p_demux, "invalid size %d for a STREAMINFO metadata block", i_len );
 476                 return VLC_EGENERIC;
 477             }
 478             i_peek = stream_Peek( p_demux->s, &p_peek, STREAMINFO_SIZE);
 479             if( i_peek == STREAMINFO_SIZE)
 480
 481             *pi_streaminfo = STREAMINFO_SIZE + 4;
 482             *pp_streaminfo = malloc( STREAMINFO_SIZE + 4 );
 483             if( *pp_streaminfo == NULL )
 484                 return VLC_EGENERIC;
 485
 486             if( stream_Read( p_demux->s, &(*pp_streaminfo)[4], STREAMINFO_SIZE ) != STREAMINFO_SIZE )
 487             {
 488                 msg_Err( p_demux, "failed to read STREAMINFO metadata block" );
 489                 free( *pp_streaminfo );
 490                 return VLC_EGENERIC;
 491             }
 492
 493             memcpy(*pp_streaminfo, marker, 4);
 494
 495             /* */
 496             ParseStreamInfo( &i_sample_rate, &i_sample_count, *pp_streaminfo );
 497             if( i_sample_rate > 0 )
 498                 p_sys->i_length = i_sample_count * INT64_C(1000000)/i_sample_rate;
 499         }
 500         else if( i_type == META_SEEKTABLE )
 501         {
 502             i_peek = stream_Peek( p_demux->s, &p_peek, 4+i_len );
 503             if( i_peek == 4+i_len )
 504                 ParseSeekTable( p_demux, p_peek, i_peek, i_sample_rate );
 505         }
 506         else if( i_type == META_COMMENT )
 507         {
 508             i_peek = stream_Peek( p_demux->s, &p_peek, 4+i_len );
 509             if( i_peek == 4+i_len )
 510                 ParseComment( p_demux, p_peek, i_peek );
 511         }
 512         else if( i_type == META_PICTURE )
 513         {
 514             i_peek = stream_Peek( p_demux->s, &p_peek, 4+i_len );
 515             if( i_peek == 4+i_len )
 516                 ParsePicture( p_demux, p_peek, i_peek );
 517         }
 518
 519         if( stream_Read( p_demux->s, NULL, 4+i_len ) < 4+i_len )
 520             break;
 521     }
 522
 523     /* */
 524     p_sys->i_data_pos = stream_Tell( p_demux->s );
 525
 526     if (!*pp_streaminfo)
 527         return VLC_EGENERIC;
 528
 529     return VLC_SUCCESS;
 530 }
 531 static void ParseStreamInfo( int *pi_rate, int64_t *pi_count, uint8_t *p_data )
 532 {
 533     const int i_skip = 4+4;
 534
 535     *pi_rate = GetDWBE(&p_data[i_skip+4+6]) >> 12;
 536     *pi_count = GetQWBE(&p_data[i_skip+4+6]) &  ((INT64_C(1)<<36)-1);
 537 }
 538
 539 static void ParseSeekTable( demux_t *p_demux, const uint8_t *p_data, int i_data,
 540                             int i_sample_rate )
 541 {
 542     demux_sys_t *p_sys = p_demux->p_sys;
 543     seekpoint_t *s;
 544     int i;
 545
 546     if( i_sample_rate <= 0 )
 547         return;
 548
 549     /* */
 550     for( i = 0; i < (i_data-4)/18; i++ )
 551     {
 552         const int64_t i_sample = GetQWBE( &p_data[4+18*i+0] );
 553         int j;
 554
 555         if( i_sample < 0 || i_sample >= INT64_MAX )
 556             continue;
 557
 558         s = vlc_seekpoint_New();
 559         s->i_time_offset = i_sample * INT64_C(1000000)/i_sample_rate;
 560         s->i_byte_offset = GetQWBE( &p_data[4+18*i+8] );
 561
 562         /* Check for duplicate entry */
 563         for( j = 0; j < p_sys->i_seekpoint; j++ )
 564         {
 565             if( p_sys->seekpoint[j]->i_time_offset == s->i_time_offset ||
 566                 p_sys->seekpoint[j]->i_byte_offset == s->i_byte_offset )
 567             {
 568                 vlc_seekpoint_Delete( s );
 569                 s = NULL;
 570                 break;
 571             }
 572         }
 573         if( s )
 574         {
 575             TAB_APPEND( p_sys->i_seekpoint, p_sys->seekpoint, s );
 576         }
 577     }
 578     /* TODO sort it by size and remove wrong seek entry (time not increasing) */
 579 }
 580
 581 static void ParseComment( demux_t *p_demux, const uint8_t *p_data, int i_data )
 582 {
 583     demux_sys_t *p_sys = p_demux->p_sys;
 584
 585     if( i_data < 4 )
 586         return;
 587
 588     vorbis_ParseComment( &p_sys->p_meta, &p_data[4], i_data - 4,
 589         &p_sys->i_attachments, &p_sys->attachments,
 590         &p_sys->i_cover_score, &p_sys->i_cover_idx, NULL, NULL );
 591 }
 592
 593 static void ParsePicture( demux_t *p_demux, const uint8_t *p_data, int i_data )
 594 {
 595     demux_sys_t *p_sys = p_demux->p_sys;
 596
 597     i_data -= 4; p_data += 4;
 598
 599     input_attachment_t *p_attachment = ParseFlacPicture( p_data, i_data,
 600         p_sys->i_attachments, &p_sys->i_cover_score, &p_sys->i_cover_idx );
 601     if( p_attachment == NULL )
 602         return;
 603
 604     TAB_APPEND( p_sys->i_attachments, p_sys->attachments, p_attachment );
 605 }
 606