1 /*****************************************************************************
2 * mpga.c : MPEG-I/II Audio input module for vlc
3 *****************************************************************************
4 * Copyright (C) 2001-2004 VideoLAN
7 * Authors: Laurent Aimar <fenrir@via.ecp.fr>
8 * Gildas Bazin <gbazin@videolan.org>
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.
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.
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., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
23 *****************************************************************************/
25 /*****************************************************************************
27 *****************************************************************************/
28 #include <stdlib.h> /* malloc(), free() */
31 #include <vlc/input.h>
32 #include "vlc_codec.h"
35 #define MPGA_PACKET_SIZE 4096
37 /*****************************************************************************
39 *****************************************************************************/
40 static int Open ( vlc_object_t * );
41 static void Close( vlc_object_t * );
44 set_description( _("MPEG-I/II audio demuxer" ) );
45 set_capability( "demux2", 100 );
46 set_callbacks( Open, Close );
47 add_shortcut( "mpga" );
48 add_shortcut( "mp3" );
51 /*****************************************************************************
53 *****************************************************************************/
54 static int Demux ( demux_t * );
55 static int Control( demux_t *, int, va_list );
63 decoder_t *p_packetizer;
66 mtime_t i_time_offset;
67 int i_bitrate_avg; /* extracted from Xing header */
71 int i_xing_bitrate_avg;
72 int i_xing_frame_samples;
75 static int HeaderCheck( uint32_t h )
77 if( ((( h >> 21 )&0x07FF) != 0x07FF ) /* header sync */
78 || (((h >> 17)&0x03) == 0 ) /* valid layer ?*/
79 || (((h >> 12)&0x0F) == 0x0F )
80 || (((h >> 12)&0x0F) == 0x00 ) /* valid bitrate ? */
81 || (((h >> 10) & 0x03) == 0x03 ) /* valide sampling freq ? */
82 || ((h & 0x03) == 0x02 )) /* valid emphasis ? */
89 #define MPGA_VERSION( h ) ( 1 - (((h)>>19)&0x01) )
90 #define MPGA_LAYER( h ) ( 3 - (((h)>>17)&0x03) )
91 #define MPGA_MODE(h) (((h)>> 6)&0x03)
93 static int mpga_frame_samples( uint32_t h )
95 switch( MPGA_LAYER(h) )
102 return MPGA_VERSION(h) ? 576 : 1152;
108 /*****************************************************************************
109 * Open: initializes demux structures
110 *****************************************************************************/
111 static int Open( vlc_object_t * p_this )
113 demux_t *p_demux = (demux_t*)p_this;
115 vlc_bool_t b_forced = VLC_FALSE;
120 vlc_meta_t *p_meta = NULL;
122 if( p_demux->psz_path )
124 int i_len = strlen( p_demux->psz_path );
125 if( i_len > 4 && !strcasecmp( &p_demux->psz_path[i_len - 4], ".mp3" ) )
131 /* Skip/parse possible id3 header */
132 if( ( p_id3 = module_Need( p_demux, "id3", NULL, 0 ) ) )
134 p_meta = (vlc_meta_t *)p_demux->p_private;
135 p_demux->p_private = NULL;
136 module_Unneed( p_demux, p_id3 );
139 if( stream_Peek( p_demux->s, &p_peek, 4 ) < 4 )
141 msg_Err( p_demux, "cannot peek" );
142 if( p_meta ) vlc_meta_Delete( p_meta );
146 if( !HeaderCheck( header = GetDWBE( p_peek ) ) )
148 vlc_bool_t b_ok = VLC_FALSE;
151 if( !p_demux->b_force && !b_forced )
153 if( p_meta ) vlc_meta_Delete( p_meta );
157 i_peek = stream_Peek( p_demux->s, &p_peek, 8096 );
160 if( HeaderCheck( header = GetDWBE( p_peek ) ) )
168 if( !b_ok && !p_demux->b_force )
170 msg_Warn( p_demux, "mpga module discarded" );
171 if( p_meta ) vlc_meta_Delete( p_meta );
176 p_demux->p_sys = p_sys = malloc( sizeof( demux_sys_t ) );
177 memset( p_sys, 0, sizeof( demux_sys_t ) );
179 p_sys->p_packetizer = 0;
180 p_sys->b_start = VLC_TRUE;
181 p_sys->meta = p_meta;
182 p_demux->pf_demux = Demux;
183 p_demux->pf_control = Control;
186 * Load the mpeg audio packetizer
188 p_sys->p_packetizer = vlc_object_create( p_demux, VLC_OBJECT_PACKETIZER );
189 p_sys->p_packetizer->pf_decode_audio = NULL;
190 p_sys->p_packetizer->pf_decode_video = NULL;
191 p_sys->p_packetizer->pf_decode_sub = NULL;
192 p_sys->p_packetizer->pf_packetize = NULL;
193 es_format_Init( &p_sys->p_packetizer->fmt_in, AUDIO_ES,
194 VLC_FOURCC( 'm', 'p', 'g', 'a' ) );
195 es_format_Init( &p_sys->p_packetizer->fmt_out, UNKNOWN_ES, 0 );
196 p_sys->p_packetizer->p_module =
197 module_Need( p_sys->p_packetizer, "packetizer", NULL, 0 );
199 if( p_sys->p_packetizer->p_module == NULL )
201 msg_Err( p_demux, "cannot find mpga packetizer" );
202 Close( VLC_OBJECT(p_demux ) );
207 if( HeaderCheck( header ) )
212 if( ( i_xing = stream_Peek( p_demux->s, &p_xing, 1024 ) ) < 21 )
213 return VLC_SUCCESS; /* No header */
215 if( MPGA_VERSION( header ) == 0 )
217 i_skip = MPGA_MODE( header ) != 3 ? 36 : 21;
221 i_skip = MPGA_MODE( header ) != 3 ? 21 : 13;
224 if( i_skip + 8 < i_xing && !strncmp( &p_xing[i_skip], "Xing", 4 ) )
226 unsigned int i_flags = GetDWBE( &p_xing[i_skip+4] );
228 p_xing += i_skip + 8;
229 i_xing -= i_skip + 8;
232 if( i_flags&0x01 && i_skip + 4 <= i_xing ) /* XING_FRAMES */
234 p_sys->i_xing_frames = GetDWBE( &p_xing[i_skip] );
237 if( i_flags&0x02 && i_skip + 4 <= i_xing ) /* XING_BYTES */
239 p_sys->i_xing_bytes = GetDWBE( &p_xing[i_skip] );
242 if( i_flags&0x04 ) /* XING_TOC */
247 // FIXME: doesn't return the right bitrage average, at least
249 if( i_flags&0x08 && i_skip + 4 <= i_xing ) /* XING_VBR */
251 p_sys->i_xing_bitrate_avg = GetDWBE( &p_xing[i_skip] );
252 msg_Dbg( p_demux, "xing vbr value present (%d)",
253 p_sys->i_xing_bitrate_avg );
256 if( p_sys->i_xing_frames > 0 && p_sys->i_xing_bytes > 0 )
258 p_sys->i_xing_frame_samples = mpga_frame_samples( header );
259 msg_Dbg( p_demux, "xing frames&bytes value present "
260 "(%d bytes, %d frames, %d samples/frame)",
261 p_sys->i_xing_bytes, p_sys->i_xing_frames,
262 p_sys->i_xing_frame_samples );
270 /*****************************************************************************
271 * Demux: reads and demuxes data packets
272 *****************************************************************************
273 * Returns -1 in case of error, 0 in case of EOF, 1 otherwise
274 *****************************************************************************/
275 static int Demux( demux_t *p_demux )
277 demux_sys_t *p_sys = p_demux->p_sys;
278 block_t *p_block_in, *p_block_out;
280 if( ( p_block_in = stream_Block( p_demux->s, MPGA_PACKET_SIZE ) ) == NULL )
285 p_block_in->i_pts = p_block_in->i_dts = p_sys->b_start ? 1 : 0;
286 p_sys->b_start = VLC_FALSE;
288 while( (p_block_out = p_sys->p_packetizer->pf_packetize(
289 p_sys->p_packetizer, &p_block_in )) )
293 block_t *p_next = p_block_out->p_next;
295 if( p_sys->p_es == NULL )
297 p_sys->p_packetizer->fmt_out.b_packetized = VLC_TRUE;
298 p_sys->p_es = es_out_Add( p_demux->out,
299 &p_sys->p_packetizer->fmt_out);
301 p_sys->i_bitrate_avg = p_sys->p_packetizer->fmt_out.i_bitrate;
303 if( p_sys->i_xing_bytes && p_sys->i_xing_frames &&
304 p_sys->i_xing_frame_samples )
306 p_sys->i_bitrate_avg = p_sys->i_xing_bytes * I64C(8) *
307 p_sys->p_packetizer->fmt_out.audio.i_rate /
308 p_sys->i_xing_frames / p_sys->i_xing_frame_samples;
312 es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_block_out->i_dts );
314 p_block_out->p_next = NULL;
315 p_sys->i_pts = p_block_out->i_pts;
316 es_out_Send( p_demux->out, p_sys->p_es, p_block_out );
318 p_block_out = p_next;
324 /*****************************************************************************
325 * Close: frees unused data
326 *****************************************************************************/
327 static void Close( vlc_object_t * p_this )
329 demux_t *p_demux = (demux_t*)p_this;
330 demux_sys_t *p_sys = p_demux->p_sys;
332 if( p_sys->meta ) vlc_meta_Delete( p_sys->meta );
334 if( p_sys->p_packetizer && p_sys->p_packetizer->p_module )
335 module_Unneed( p_sys->p_packetizer, p_sys->p_packetizer->p_module );
336 if( p_sys->p_packetizer )
337 vlc_object_destroy( p_sys->p_packetizer );
342 /*****************************************************************************
344 *****************************************************************************/
345 static int Control( demux_t *p_demux, int i_query, va_list args )
347 demux_sys_t *p_sys = p_demux->p_sys;
349 vlc_meta_t **pp_meta;
355 pp_meta = (vlc_meta_t **)va_arg( args, vlc_meta_t** );
356 if( p_sys->meta ) *pp_meta = vlc_meta_Duplicate( p_sys->meta );
357 else *pp_meta = NULL;
361 pi64 = (int64_t*)va_arg( args, int64_t * );
362 *pi64 = p_sys->i_pts + p_sys->i_time_offset;
366 /* FIXME TODO: implement a high precision seek (with mp3 parsing)
367 * needed for multi-input */
370 i_ret = demux2_vaControlHelper( p_demux->s, 0, -1,
371 p_sys->i_bitrate_avg, 1, i_query,
373 if( !i_ret && p_sys->i_bitrate_avg > 0 &&
374 (i_query == DEMUX_SET_POSITION || i_query == DEMUX_SET_TIME) )
376 int64_t i_time = I64C(8000000) * stream_Tell(p_demux->s) /
377 p_sys->i_bitrate_avg;
379 /* Fix time_offset */
380 if( i_time >= 0 ) p_sys->i_time_offset = i_time - p_sys->i_pts;