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