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

   1 /*****************************************************************************
   2  * mpga.c : MPEG-I/II Audio input module for vlc
   3  *****************************************************************************
   4  * Copyright (C) 2001-2004 the VideoLAN team
   5  * $Id$
   6  *
   7  * Authors: Laurent Aimar <fenrir@via.ecp.fr>
   8  *          Gildas Bazin <gbazin@videolan.org>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 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 General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  23  *****************************************************************************/
  24
  25 /*****************************************************************************
  26  * Preamble
  27  *****************************************************************************/
  28
  29 #include <vlc/vlc.h>
  30 #include <vlc_demux.h>
  31 #include <vlc_meta.h>
  32 #include <vlc_codec.h>
  33 #include <vlc_input.h>
  34
  35 #define MPGA_PACKET_SIZE 1024
  36
  37 /*****************************************************************************
  38  * Module descriptor
  39  *****************************************************************************/
  40 static int  Open ( vlc_object_t * );
  41 static void Close( vlc_object_t * );
  42
  43 vlc_module_begin();
  44     set_category( CAT_INPUT );
  45     set_subcategory( SUBCAT_INPUT_DEMUX );
  46     set_description( _("MPEG audio / MP3 demuxer" ) );
  47     set_capability( "demux2", 100 );
  48     set_callbacks( Open, Close );
  49     add_shortcut( "mpga" );
  50     add_shortcut( "mp3" );
  51 vlc_module_end();
  52
  53 /*****************************************************************************
  54  * Local prototypes
  55  *****************************************************************************/
  56 static int Demux  ( demux_t * );
  57 static int Control( demux_t *, int, va_list );
  58
  59 struct demux_sys_t
  60 {
  61     es_out_id_t *p_es;
  62     vlc_meta_t  *meta;
  63
  64     vlc_bool_t  b_start;
  65     decoder_t   *p_packetizer;
  66
  67     mtime_t     i_pts;
  68     mtime_t     i_time_offset;
  69     int         i_bitrate_avg;  /* extracted from Xing header */
  70
  71     vlc_bool_t b_initial_sync_failed;
  72
  73     int i_xing_frames;
  74     int i_xing_bytes;
  75     int i_xing_bitrate_avg;
  76     int i_xing_frame_samples;
  77     block_t *p_block_in, *p_block_out;
  78
  79     int                i_attachments;
  80     input_attachment_t **attachments;
  81 };
  82
  83 static int HeaderCheck( uint32_t h )
  84 {
  85     if( ((( h >> 21 )&0x07FF) != 0x07FF )   /* header sync */
  86         || (((h >> 17)&0x03) == 0 )         /* valid layer ?*/
  87         || (((h >> 12)&0x0F) == 0x0F )
  88         || (((h >> 12)&0x0F) == 0x00 )      /* valid bitrate ? */
  89         || (((h >> 10) & 0x03) == 0x03 )    /* valide sampling freq ? */
  90         || ((h & 0x03) == 0x02 ))           /* valid emphasis ? */
  91     {
  92         return VLC_FALSE;
  93     }
  94     return VLC_TRUE;
  95 }
  96
  97 #define MPGA_VERSION( h )   ( 1 - (((h)>>19)&0x01) )
  98 #define MPGA_LAYER( h )     ( 3 - (((h)>>17)&0x03) )
  99 #define MPGA_MODE(h)        (((h)>> 6)&0x03)
 100
 101 static int mpga_frame_samples( uint32_t h )
 102 {
 103     switch( MPGA_LAYER(h) )
 104     {
 105         case 0:
 106             return 384;
 107         case 1:
 108             return 1152;
 109         case 2:
 110             return MPGA_VERSION(h) ? 576 : 1152;
 111         default:
 112             return 0;
 113     }
 114 }
 115
 116
 117 /*****************************************************************************
 118  * Open: initializes demux structures
 119  *****************************************************************************/
 120 static int Open( vlc_object_t * p_this )
 121 {
 122     demux_t     *p_demux = (demux_t*)p_this;
 123     demux_sys_t *p_sys;
 124     vlc_bool_t   b_forced = VLC_FALSE;
 125
 126     uint32_t     header;
 127     const uint8_t     *p_peek;
 128     module_t    *p_id3;
 129     block_t     *p_block_in, *p_block_out;
 130
 131     if( demux2_IsPathExtension( p_demux, ".mp3" ) )
 132         b_forced = VLC_TRUE;
 133
 134     if( stream_Peek( p_demux->s, &p_peek, 4 ) < 4 ) return VLC_EGENERIC;
 135
 136     if( !HeaderCheck( header = GetDWBE( p_peek ) ) )
 137     {
 138         vlc_bool_t b_ok = VLC_FALSE;
 139         int i_peek;
 140
 141         if( !p_demux->b_force && !b_forced ) return VLC_EGENERIC;
 142
 143         i_peek = stream_Peek( p_demux->s, &p_peek, 8096 );
 144         while( i_peek > 4 )
 145         {
 146             if( HeaderCheck( header = GetDWBE( p_peek ) ) )
 147             {
 148                 b_ok = VLC_TRUE;
 149                 break;
 150             }
 151             p_peek += 1;
 152             i_peek -= 1;
 153         }
 154         if( !b_ok && !p_demux->b_force ) return VLC_EGENERIC;
 155     }
 156
 157     DEMUX_INIT_COMMON(); p_sys = p_demux->p_sys;
 158     memset( p_sys, 0, sizeof( demux_sys_t ) );
 159     p_sys->p_es = 0;
 160     p_sys->b_start = VLC_TRUE;
 161     p_sys->meta = 0;
 162
 163     /* Load the mpeg audio packetizer */
 164     INIT_APACKETIZER( p_sys->p_packetizer, 'm', 'p', 'g', 'a' );
 165     es_format_Init( &p_sys->p_packetizer->fmt_out, UNKNOWN_ES, 0 );
 166     LOAD_PACKETIZER_OR_FAIL( p_sys->p_packetizer, "mpga" );
 167
 168     /* Xing header */
 169     if( HeaderCheck( header ) )
 170     {
 171         int i_xing, i_skip;
 172         const uint8_t *p_xing;
 173
 174         if( ( i_xing = stream_Peek( p_demux->s, &p_xing, 1024 ) ) < 21 )
 175             return VLC_SUCCESS; /* No header */
 176
 177         if( MPGA_VERSION( header ) == 0 )
 178         {
 179             i_skip = MPGA_MODE( header ) != 3 ? 36 : 21;
 180         }
 181         else
 182         {
 183             i_skip = MPGA_MODE( header ) != 3 ? 21 : 13;
 184         }
 185
 186         if( i_skip + 8 < i_xing && !strncmp( (char *)&p_xing[i_skip], "Xing", 4 ) )
 187         {
 188             unsigned int i_flags = GetDWBE( &p_xing[i_skip+4] );
 189
 190             p_xing += i_skip + 8;
 191             i_xing -= i_skip + 8;
 192
 193             i_skip = 0;
 194             if( i_flags&0x01 && i_skip + 4 <= i_xing )   /* XING_FRAMES */
 195             {
 196                 p_sys->i_xing_frames = GetDWBE( &p_xing[i_skip] );
 197                 i_skip += 4;
 198             }
 199             if( i_flags&0x02 && i_skip + 4 <= i_xing )   /* XING_BYTES */
 200             {
 201                 p_sys->i_xing_bytes = GetDWBE( &p_xing[i_skip] );
 202                 i_skip += 4;
 203             }
 204             if( i_flags&0x04 )   /* XING_TOC */
 205             {
 206                 i_skip += 100;
 207             }
 208
 209             // FIXME: doesn't return the right bitrage average, at least
 210             // with some MP3's
 211             if( i_flags&0x08 && i_skip + 4 <= i_xing )   /* XING_VBR */
 212             {
 213                 p_sys->i_xing_bitrate_avg = GetDWBE( &p_xing[i_skip] );
 214                 msg_Dbg( p_demux, "xing vbr value present (%d)",
 215                          p_sys->i_xing_bitrate_avg );
 216             }
 217
 218             if( p_sys->i_xing_frames > 0 && p_sys->i_xing_bytes > 0 )
 219             {
 220                 p_sys->i_xing_frame_samples = mpga_frame_samples( header );
 221                 msg_Dbg( p_demux, "xing frames&bytes value present "
 222                          "(%d bytes, %d frames, %d samples/frame)",
 223                          p_sys->i_xing_bytes, p_sys->i_xing_frames,
 224                          p_sys->i_xing_frame_samples );
 225             }
 226         }
 227     }
 228
 229     if( ( p_block_in = stream_Block( p_demux->s, MPGA_PACKET_SIZE ) ) == NULL )
 230     {
 231         return VLC_EGENERIC;
 232     }
 233     p_block_in->i_pts = p_block_in->i_dts = 1;
 234     p_block_out = p_sys->p_packetizer->pf_packetize(
 235         p_sys->p_packetizer, &p_block_in );
 236
 237     if( p_block_out == NULL )
 238     {
 239         msg_Dbg( p_demux, "did not sync on first block" );
 240         p_sys->b_initial_sync_failed = VLC_TRUE;
 241     }
 242     else
 243         p_sys->b_initial_sync_failed = VLC_FALSE;
 244
 245     p_sys->i_bitrate_avg = p_sys->p_packetizer->fmt_out.i_bitrate;
 246
 247     if( p_sys->i_xing_bytes && p_sys->i_xing_frames &&
 248         p_sys->i_xing_frame_samples )
 249     {
 250         p_sys->i_bitrate_avg = p_sys->i_xing_bytes * I64C(8) *
 251             p_sys->p_packetizer->fmt_out.audio.i_rate /
 252             p_sys->i_xing_frames / p_sys->i_xing_frame_samples;
 253     }
 254
 255     p_sys->p_block_in = p_block_in;
 256     p_sys->p_block_out = p_block_out;
 257
 258     /* Parse possible id3 header */
 259     if( !var_CreateGetBool( p_demux, "meta-preparsed" ) )
 260     {
 261         p_demux->p_private = malloc( sizeof( demux_meta_t ) );
 262         if( !p_demux->p_private )
 263             return VLC_ENOMEM;
 264         if( ( p_id3 = module_Need( p_demux, "meta reader", NULL, 0 ) ) )
 265         {
 266             module_Unneed( p_demux, p_id3 );
 267             demux_meta_t *p_demux_meta = (demux_meta_t *)p_demux->p_private;
 268             p_sys->meta = p_demux_meta->p_meta;
 269             p_sys->i_attachments = p_demux_meta->i_attachments;
 270             p_sys->attachments = p_demux_meta->attachments;
 271         }
 272         free( p_demux->p_private );
 273     }
 274     else printf("SKIP\n");
 275     /* */
 276     p_sys->p_packetizer->fmt_out.b_packetized = VLC_TRUE;
 277     vlc_audio_replay_gain_MergeFromMeta( &p_sys->p_packetizer->fmt_out.audio_replay_gain,
 278                                          p_sys->meta );
 279     p_sys->p_es = es_out_Add( p_demux->out,
 280                               &p_sys->p_packetizer->fmt_out);
 281     return VLC_SUCCESS;
 282 }
 283
 284 /*****************************************************************************
 285  * Demux: reads and demuxes data packets
 286  *****************************************************************************
 287  * Returns -1 in case of error, 0 in case of EOF, 1 otherwise
 288  *****************************************************************************/
 289 static int Demux( demux_t *p_demux )
 290 {
 291     demux_sys_t *p_sys = p_demux->p_sys;
 292     block_t *p_block_in, *p_block_out;
 293     if( p_sys->b_start )
 294     {
 295         p_sys->b_start = VLC_FALSE;
 296         p_block_in = p_sys->p_block_in;
 297         p_sys->p_block_in = NULL;
 298         p_block_out = p_sys->p_block_out;
 299         p_sys->p_block_out = NULL;
 300     }
 301     else
 302     {
 303         if( ( p_block_in = stream_Block( p_demux->s, MPGA_PACKET_SIZE ) )
 304             == NULL )
 305         {
 306             return 0;
 307         }
 308         if( p_demux->p_sys->b_initial_sync_failed == VLC_TRUE )
 309         {
 310             p_block_in->i_pts = p_block_in->i_dts = 1;
 311             /* Only try to resync once */
 312             p_demux->p_sys->b_initial_sync_failed = 0;
 313         }
 314         else
 315             p_block_in->i_pts = p_block_in->i_dts = 0;
 316         p_block_out = p_sys->p_packetizer->pf_packetize(
 317             p_sys->p_packetizer, &p_block_in );
 318     }
 319
 320
 321     while( p_block_out )
 322     {
 323         while( p_block_out )
 324         {
 325             block_t *p_next = p_block_out->p_next;
 326
 327             es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_block_out->i_dts );
 328
 329             p_block_out->p_next = NULL;
 330             p_sys->i_pts = p_block_out->i_pts;
 331             es_out_Send( p_demux->out, p_sys->p_es, p_block_out );
 332
 333             p_block_out = p_next;
 334         }
 335         p_block_out = p_sys->p_packetizer->pf_packetize(
 336             p_sys->p_packetizer, &p_block_in );
 337     }
 338     return 1;
 339 }
 340
 341 /*****************************************************************************
 342  * Close: frees unused data
 343  *****************************************************************************/
 344 static void Close( vlc_object_t * p_this )
 345 {
 346     demux_t     *p_demux = (demux_t*)p_this;
 347     demux_sys_t *p_sys = p_demux->p_sys;
 348
 349     var_Destroy( p_demux, "meta-preparsed" );
 350
 351     DESTROY_PACKETIZER( p_sys->p_packetizer );
 352     if( p_sys->meta ) vlc_meta_Delete( p_sys->meta );
 353     if( p_sys->p_block_out ) block_Release( p_sys->p_block_out );
 354
 355     int i;
 356     for( i = 0; i < p_sys->i_attachments; i++ )
 357         free( p_sys->attachments[i] );
 358     TAB_CLEAN( p_sys->i_attachments, p_sys->attachments);
 359
 360     free( p_sys );
 361 }
 362
 363 /*****************************************************************************
 364  * Control:
 365  *****************************************************************************/
 366 static int Control( demux_t *p_demux, int i_query, va_list args )
 367 {
 368     demux_sys_t *p_sys  = p_demux->p_sys;
 369     int64_t *pi64;
 370     vlc_meta_t *p_meta;
 371     int i_ret;
 372
 373     input_attachment_t ***ppp_attach;
 374     int *pi_int, i;
 375
 376     switch( i_query )
 377     {
 378         case DEMUX_GET_META:
 379             p_meta = (vlc_meta_t *)va_arg( args, vlc_meta_t* );
 380             vlc_meta_Merge( p_meta, p_sys->meta );
 381             return VLC_SUCCESS;
 382
 383         case DEMUX_GET_ATTACHMENTS:
 384             ppp_attach =
 385                 (input_attachment_t***)va_arg( args, input_attachment_t*** );
 386             pi_int = (int*)va_arg( args, int * );
 387
 388             if( p_sys->i_attachments <= 0 )
 389                 return VLC_EGENERIC;
 390
 391             *pi_int = p_sys->i_attachments;
 392             *ppp_attach = malloc( sizeof(input_attachment_t**) * p_sys->i_attachments );
 393             for( i = 0; i < p_sys->i_attachments; i++ )
 394                 (*ppp_attach)[i] = vlc_input_attachment_Duplicate( p_sys->attachments[i] );
 395             return VLC_SUCCESS;
 396
 397         case DEMUX_GET_TIME:
 398             pi64 = (int64_t*)va_arg( args, int64_t * );
 399             *pi64 = p_sys->i_pts + p_sys->i_time_offset;
 400             return VLC_SUCCESS;
 401
 402         case DEMUX_SET_TIME:
 403             /* FIXME TODO: implement a high precision seek (with mp3 parsing)
 404              * needed for multi-input */
 405
 406         default:
 407             i_ret = demux2_vaControlHelper( p_demux->s, 0, -1,
 408                                             p_sys->i_bitrate_avg, 1, i_query,
 409                                             args );
 410             /* No bitrate, we can't have it precisely, but we can compute
 411              * a raw approximation with time/position */
 412             if( i_ret && i_query == DEMUX_GET_LENGTH &&!p_sys->i_bitrate_avg )
 413             {
 414                 float f_pos = (double)( stream_Tell( p_demux->s ) ) /
 415                               (double)( stream_Size( p_demux->s ) );
 416                 /* The first few seconds are guaranteed to be very whacky,
 417                  * don't bother trying ... Too bad */
 418                 if( f_pos < 0.01 ||
 419                     (p_sys->i_pts + p_sys->i_time_offset) < 8000000 )
 420                     return VLC_EGENERIC;
 421
 422                 pi64 = (int64_t *)va_arg( args, int64_t * );
 423                 *pi64 = (p_sys->i_pts + p_sys->i_time_offset) / f_pos;
 424                 return VLC_SUCCESS;
 425             }
 426             if( !i_ret && p_sys->i_bitrate_avg > 0 &&
 427                 (i_query == DEMUX_SET_POSITION || i_query == DEMUX_SET_TIME) )
 428             {
 429                 int64_t i_time = I64C(8000000) * stream_Tell(p_demux->s) /
 430                     p_sys->i_bitrate_avg;
 431
 432                 /* Fix time_offset */
 433                 if( i_time >= 0 ) p_sys->i_time_offset = i_time - p_sys->i_pts;
 434             }
 435             return i_ret;
 436     }
 437 }