1 /*****************************************************************************
2 * mpga.c : MPEG-I/II Audio input module for vlc
3 *****************************************************************************
4 * Copyright (C) 2001-2004 VideoLAN
5 * $Id: mpga.c,v 1.18 2004/03/03 20:39:52 gbazin Exp $
7 * Authors: Laurent Aimar <fenrir@via.ecp.fr>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
22 *****************************************************************************/
24 /*****************************************************************************
26 *****************************************************************************/
27 #include <stdlib.h> /* malloc(), free() */
30 #include <vlc/input.h>
32 /*****************************************************************************
34 *****************************************************************************/
35 static int Open ( vlc_object_t * );
36 static void Close( vlc_object_t * );
39 set_description( _("MPEG-I/II audio demuxer" ) );
40 set_capability( "demux2", 100 );
41 set_callbacks( Open, Close );
42 add_shortcut( "mpga" );
43 add_shortcut( "mp3" );
50 /*****************************************************************************
52 *****************************************************************************/
53 static int Demux ( demux_t * );
54 static int Control( demux_t *, int, va_list );
60 int i_bitrate_avg; /* extracted from Xing header */
65 static int HeaderCheck( uint32_t h )
67 if( ((( h >> 21 )&0x07FF) != 0x07FF ) /* header sync */
68 || (((h >> 17)&0x03) == 0 ) /* valid layer ?*/
69 || (((h >> 12)&0x0F) == 0x0F )
70 || (((h >> 12)&0x0F) == 0x00 ) /* valid bitrate ? */
71 || (((h >> 10) & 0x03) == 0x03 ) /* valide sampling freq ? */
72 || ((h & 0x03) == 0x02 )) /* valid emphasis ? */
79 static int mpga_sample_rate[2][4] =
81 { 44100, 48000, 32000, 0 },
82 { 22050, 24000, 16000, 0 }
85 static int mpga_bitrate[2][3][16] =
88 { 0, 32, 64, 96, 128, 160, 192, 224, 256, 288, 320, 352, 384, 416, 448, 0},
89 { 0, 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384, 0},
90 { 0, 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 0}
93 { 0, 32, 48, 56, 64, 80, 96, 112, 128, 144, 160, 176, 192, 224, 256, 0},
94 { 0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, 0},
95 { 0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, 0}
100 #define MPGA_VERSION( h ) ( 1 - (((h)>>19)&0x01) )
101 #define MPGA_LAYER( h ) ( 3 - (((h)>>17)&0x03) )
102 #define MPGA_SAMPLE_RATE(h) \
103 ( mpga_sample_rate[MPGA_VERSION(h)][((h)>>10)&0x03] / ( ((h>>20)&0x01) ? 1 : 2) )
104 #define MPGA_CHANNELS(h) ( (((h)>>6)&0x03) == 3 ? 1 : 2)
105 #define MPGA_BITRATE(h) mpga_bitrate[MPGA_VERSION(h)][MPGA_LAYER(h)][((h)>>12)&0x0f]
106 #define MPGA_PADDING(h) ( ((h)>>9)&0x01 )
107 #define MPGA_MODE(h) (((h)>> 6)&0x03)
109 static int mpga_frame_size( uint32_t h )
111 switch( MPGA_LAYER(h) )
114 return ( ( 12000 * MPGA_BITRATE(h) ) / MPGA_SAMPLE_RATE(h) + MPGA_PADDING(h) ) * 4;
116 return ( 144000 * MPGA_BITRATE(h) ) / MPGA_SAMPLE_RATE(h) + MPGA_PADDING(h);
118 return ( ( MPGA_VERSION(h) ? 72000 : 144000 ) * MPGA_BITRATE(h) ) / MPGA_SAMPLE_RATE(h) + MPGA_PADDING(h);
124 static int mpga_frame_samples( uint32_t h )
126 switch( MPGA_LAYER(h) )
133 return MPGA_VERSION(h) ? 576 : 1152;
139 /*****************************************************************************
140 * Open: initializes demux structures
141 *****************************************************************************/
142 static int Open( vlc_object_t * p_this )
144 demux_t *p_demux = (demux_t*)p_this;
146 vlc_bool_t b_forced = VLC_FALSE;
147 vlc_bool_t b_extention = VLC_FALSE;
154 if( !strncmp( p_demux->psz_demux, "mpga", 4 ) ||
155 !strncmp( p_demux->psz_demux, "mp3", 3 ) )
159 if( p_demux->psz_path )
161 int i_len = strlen( p_demux->psz_path );
162 if( i_len > 4 && !strcasecmp( &p_demux->psz_path[i_len - 4], ".mp3" ) )
164 b_extention = VLC_TRUE;
168 /* skip possible id3 header */
169 if( ( p_id3 = module_Need( p_demux, "id3", NULL, 0 ) ) )
171 module_Unneed( p_demux, p_id3 );
174 if( stream_Peek( p_demux->s, &p_peek, 4 ) < 4 )
176 msg_Err( p_demux, "cannot peek" );
180 if( !HeaderCheck( header = GetDWBE( p_peek ) ) )
182 vlc_bool_t b_ok = VLC_FALSE;
185 if( !b_forced && !b_extention )
187 msg_Warn( p_demux, "mpga module discarded" );
191 i_peek = stream_Peek( p_demux->s, &p_peek, 8096 );
195 if( HeaderCheck( header = GetDWBE( p_peek ) ) )
203 if( !b_ok && !b_forced )
205 msg_Warn( p_demux, "mpga module discarded" );
210 p_demux->pf_demux = Demux;
211 p_demux->pf_control = Control;
212 p_demux->p_sys = p_sys = malloc( sizeof( demux_sys_t ) );
214 p_sys->i_bitrate_avg = 0;
216 es_format_Init( &fmt, AUDIO_ES, VLC_FOURCC( 'm', 'p', 'g', 'a' ) );
218 if( HeaderCheck( header ) )
222 char psz_description[50];
224 p_sys->i_bitrate_avg = MPGA_BITRATE( header ) * 1000;
225 if( ( i_xing = stream_Peek( p_demux->s, &p_xing, 1024 ) ) >= 21 )
229 if( MPGA_VERSION( header) == 0 )
231 i_skip = MPGA_MODE( header ) != 3 ? 36 : 21;
235 i_skip = MPGA_MODE( header ) != 3 ? 21 : 13;
237 if( i_skip + 8 < i_xing &&
238 !strncmp( &p_xing[i_skip], "Xing", 4 ) )
240 unsigned int i_flags = GetDWBE( &p_xing[i_skip+4] );
241 unsigned int i_bytes = 0, i_frames = 0;
243 p_xing += i_skip + 8;
244 i_xing -= i_skip + 8;
247 if( i_flags&0x01 && i_skip + 4 <= i_xing ) /* XING_FRAMES */
249 i_frames = GetDWBE( &p_xing[i_skip] );
252 if( i_flags&0x02 && i_skip + 4 <= i_xing ) /* XING_BYTES */
254 i_bytes = GetDWBE( &p_xing[i_skip] );
257 if( i_flags&0x04 ) /* XING_TOC */
262 // FIXME: doesn't return the right bitrage average, at least with some MP3's
263 if( i_flags&0x08 && i_skip + 4 <= i_xing ) /* XING_VBR */
265 p_sys->i_bitrate_avg = GetDWBE( &p_xing[i_skip] );
266 fprintf(stderr,"rate2 %d\n", p_sys->i_bitrate_avg);
267 msg_Dbg( p_input, "xing vbr value present (%d)", p_sys->i_bitrate_avg );
271 if( i_frames > 0 && i_bytes > 0 )
273 p_sys->i_bitrate_avg = (int64_t)i_bytes *
275 (int64_t)MPGA_SAMPLE_RATE( header ) /
277 (int64_t)mpga_frame_samples( header );
278 msg_Dbg( p_demux, "xing frames&bytes value present (%db/s)", p_sys->i_bitrate_avg );
283 msg_Dbg( p_demux, "version=%d layer=%d channels=%d samplerate=%d",
284 MPGA_VERSION( header ) + 1,
285 MPGA_LAYER( header ) + 1,
286 MPGA_CHANNELS( header ),
287 MPGA_SAMPLE_RATE( header ) );
289 fmt.audio.i_channels = MPGA_CHANNELS( header );
290 fmt.audio.i_rate = MPGA_SAMPLE_RATE( header );
291 fmt.i_bitrate = p_sys->i_bitrate_avg;
292 sprintf( psz_description, "MPEG Audio Layer %d, version %d",
293 MPGA_LAYER ( header ) + 1, MPGA_VERSION ( header ) + 1 );
294 fmt.psz_description = strdup( psz_description );
297 p_sys->p_es = es_out_Add( p_demux->out, &fmt );
298 if( fmt.psz_description ) free( fmt.psz_description );
304 /*****************************************************************************
305 * Demux: reads and demuxes data packets
306 *****************************************************************************
307 * Returns -1 in case of error, 0 in case of EOF, 1 otherwise
308 *****************************************************************************/
309 static int Demux( demux_t *p_demux )
311 demux_sys_t *p_sys = p_demux->p_sys;
317 if( stream_Peek( p_demux->s, &p_peek, 4 ) < 4 )
319 msg_Warn( p_demux, "cannot peek" );
323 if( !HeaderCheck( header = GetDWBE( p_peek ) ) )
325 /* we need to resynch */
326 vlc_bool_t b_ok = VLC_FALSE;
330 i_peek = stream_Peek( p_demux->s, &p_peek, 8096 );
333 msg_Warn( p_demux, "cannot peek" );
339 if( HeaderCheck( header = GetDWBE( p_peek ) ) )
350 msg_Warn( p_demux, "garbage=%d bytes", i_skip );
351 stream_Read( p_demux->s, NULL, i_skip );
355 if( ( p_frame = stream_Block( p_demux->s,
356 mpga_frame_size( header ) ) ) == NULL )
358 msg_Warn( p_demux, "cannot read data" );
361 p_frame->i_dts = p_frame->i_pts = p_sys->i_time;
364 es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_sys->i_time );
366 es_out_Send( p_demux->out, p_sys->p_es, p_frame );
368 p_sys->i_time += (mtime_t)1000000 *
369 (mtime_t)mpga_frame_samples( header ) /
370 (mtime_t)MPGA_SAMPLE_RATE( header );
374 /*****************************************************************************
375 * Close: frees unused data
376 *****************************************************************************/
377 static void Close( vlc_object_t * p_this )
379 demux_t *p_demux = (demux_t*)p_this;
380 demux_sys_t *p_sys = p_demux->p_sys;
385 /*****************************************************************************
387 *****************************************************************************/
388 static int Control( demux_t *p_demux, int i_query, va_list args )
390 demux_sys_t *p_sys = p_demux->p_sys;
391 return demux2_vaControlHelper( p_demux->s,
393 p_sys->i_bitrate_avg, 1, i_query, args );