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_category( CAT_INPUT );
45 set_subcategory( SUBCAT_INPUT_DEMUX );
46 set_description( _("MPEG-I/II audio demuxer" ) );
47 set_capability( "demux2", 100 );
48 set_callbacks( Open, Close );
49 add_shortcut( "mpga" );
50 add_shortcut( "mp3" );
53 /*****************************************************************************
55 *****************************************************************************/
56 static int Demux ( demux_t * );
57 static int Control( demux_t *, int, va_list );
65 decoder_t *p_packetizer;
68 mtime_t i_time_offset;
69 int i_bitrate_avg; /* extracted from Xing header */
73 int i_xing_bitrate_avg;
74 int i_xing_frame_samples;
75 block_t *p_block_in, *p_block_out;
78 static int HeaderCheck( uint32_t h )
80 if( ((( h >> 21 )&0x07FF) != 0x07FF ) /* header sync */
81 || (((h >> 17)&0x03) == 0 ) /* valid layer ?*/
82 || (((h >> 12)&0x0F) == 0x0F )
83 || (((h >> 12)&0x0F) == 0x00 ) /* valid bitrate ? */
84 || (((h >> 10) & 0x03) == 0x03 ) /* valide sampling freq ? */
85 || ((h & 0x03) == 0x02 )) /* valid emphasis ? */
92 #define MPGA_VERSION( h ) ( 1 - (((h)>>19)&0x01) )
93 #define MPGA_LAYER( h ) ( 3 - (((h)>>17)&0x03) )
94 #define MPGA_MODE(h) (((h)>> 6)&0x03)
96 static int mpga_frame_samples( uint32_t h )
98 switch( MPGA_LAYER(h) )
105 return MPGA_VERSION(h) ? 576 : 1152;
111 /*****************************************************************************
112 * Open: initializes demux structures
113 *****************************************************************************/
114 static int Open( vlc_object_t * p_this )
116 demux_t *p_demux = (demux_t*)p_this;
118 vlc_bool_t b_forced = VLC_FALSE;
123 vlc_meta_t *p_meta = NULL;
124 block_t *p_block_in, *p_block_out;
126 if( p_demux->psz_path )
128 int i_len = strlen( p_demux->psz_path );
129 if( i_len > 4 && !strcasecmp( &p_demux->psz_path[i_len - 4], ".mp3" ) )
135 /* Skip/parse possible id3 header */
136 if( ( p_id3 = module_Need( p_demux, "id3", NULL, 0 ) ) )
138 p_meta = (vlc_meta_t *)p_demux->p_private;
139 p_demux->p_private = NULL;
140 module_Unneed( p_demux, p_id3 );
143 if( stream_Peek( p_demux->s, &p_peek, 4 ) < 4 )
145 msg_Err( p_demux, "cannot peek" );
146 if( p_meta ) vlc_meta_Delete( p_meta );
150 if( !HeaderCheck( header = GetDWBE( p_peek ) ) )
152 vlc_bool_t b_ok = VLC_FALSE;
155 if( !p_demux->b_force && !b_forced )
157 if( p_meta ) vlc_meta_Delete( p_meta );
161 i_peek = stream_Peek( p_demux->s, &p_peek, 8096 );
164 if( HeaderCheck( header = GetDWBE( p_peek ) ) )
172 if( !b_ok && !p_demux->b_force )
174 msg_Warn( p_demux, "mpga module discarded" );
175 if( p_meta ) vlc_meta_Delete( p_meta );
180 p_demux->p_sys = p_sys = malloc( sizeof( demux_sys_t ) );
181 memset( p_sys, 0, sizeof( demux_sys_t ) );
183 p_sys->p_packetizer = 0;
184 p_sys->b_start = VLC_TRUE;
185 p_sys->meta = p_meta;
186 p_demux->pf_demux = Demux;
187 p_demux->pf_control = Control;
190 * Load the mpeg audio packetizer
192 p_sys->p_packetizer = vlc_object_create( p_demux, VLC_OBJECT_PACKETIZER );
193 p_sys->p_packetizer->pf_decode_audio = NULL;
194 p_sys->p_packetizer->pf_decode_video = NULL;
195 p_sys->p_packetizer->pf_decode_sub = NULL;
196 p_sys->p_packetizer->pf_packetize = NULL;
197 es_format_Init( &p_sys->p_packetizer->fmt_in, AUDIO_ES,
198 VLC_FOURCC( 'm', 'p', 'g', 'a' ) );
199 es_format_Init( &p_sys->p_packetizer->fmt_out, UNKNOWN_ES, 0 );
200 p_sys->p_packetizer->p_module =
201 module_Need( p_sys->p_packetizer, "packetizer", NULL, 0 );
203 if( p_sys->p_packetizer->p_module == NULL )
205 msg_Err( p_demux, "cannot find mpga packetizer" );
206 Close( VLC_OBJECT(p_demux ) );
211 if( HeaderCheck( header ) )
216 if( ( i_xing = stream_Peek( p_demux->s, &p_xing, 1024 ) ) < 21 )
217 return VLC_SUCCESS; /* No header */
219 if( MPGA_VERSION( header ) == 0 )
221 i_skip = MPGA_MODE( header ) != 3 ? 36 : 21;
225 i_skip = MPGA_MODE( header ) != 3 ? 21 : 13;
228 if( i_skip + 8 < i_xing && !strncmp( &p_xing[i_skip], "Xing", 4 ) )
230 unsigned int i_flags = GetDWBE( &p_xing[i_skip+4] );
232 p_xing += i_skip + 8;
233 i_xing -= i_skip + 8;
236 if( i_flags&0x01 && i_skip + 4 <= i_xing ) /* XING_FRAMES */
238 p_sys->i_xing_frames = GetDWBE( &p_xing[i_skip] );
241 if( i_flags&0x02 && i_skip + 4 <= i_xing ) /* XING_BYTES */
243 p_sys->i_xing_bytes = GetDWBE( &p_xing[i_skip] );
246 if( i_flags&0x04 ) /* XING_TOC */
251 // FIXME: doesn't return the right bitrage average, at least
253 if( i_flags&0x08 && i_skip + 4 <= i_xing ) /* XING_VBR */
255 p_sys->i_xing_bitrate_avg = GetDWBE( &p_xing[i_skip] );
256 msg_Dbg( p_demux, "xing vbr value present (%d)",
257 p_sys->i_xing_bitrate_avg );
260 if( p_sys->i_xing_frames > 0 && p_sys->i_xing_bytes > 0 )
262 p_sys->i_xing_frame_samples = mpga_frame_samples( header );
263 msg_Dbg( p_demux, "xing frames&bytes value present "
264 "(%d bytes, %d frames, %d samples/frame)",
265 p_sys->i_xing_bytes, p_sys->i_xing_frames,
266 p_sys->i_xing_frame_samples );
271 if( ( p_block_in = stream_Block( p_demux->s, MPGA_PACKET_SIZE ) ) == NULL )
275 p_block_in->i_pts = p_block_in->i_dts = 1;
276 p_block_out = p_sys->p_packetizer->pf_packetize(
277 p_sys->p_packetizer, &p_block_in );
279 p_sys->p_packetizer->fmt_out.b_packetized = VLC_TRUE;
280 p_sys->p_es = es_out_Add( p_demux->out,
281 &p_sys->p_packetizer->fmt_out);
282 p_sys->i_bitrate_avg = p_sys->p_packetizer->fmt_out.i_bitrate;
284 if( p_sys->i_xing_bytes && p_sys->i_xing_frames &&
285 p_sys->i_xing_frame_samples )
287 p_sys->i_bitrate_avg = p_sys->i_xing_bytes * I64C(8) *
288 p_sys->p_packetizer->fmt_out.audio.i_rate /
289 p_sys->i_xing_frames / p_sys->i_xing_frame_samples;
292 p_sys->p_block_in = p_block_in;
293 p_sys->p_block_out = p_block_out;
298 /*****************************************************************************
299 * Demux: reads and demuxes data packets
300 *****************************************************************************
301 * Returns -1 in case of error, 0 in case of EOF, 1 otherwise
302 *****************************************************************************/
303 static int Demux( demux_t *p_demux )
305 demux_sys_t *p_sys = p_demux->p_sys;
306 block_t *p_block_in, *p_block_out;
309 p_sys->b_start = VLC_FALSE;
310 p_block_in = p_sys->p_block_in;
311 p_block_out = p_sys->p_block_out;
315 if( ( p_block_in = stream_Block( p_demux->s, MPGA_PACKET_SIZE ) )
320 p_block_in->i_pts = p_block_in->i_dts = 0;
321 p_block_out = p_sys->p_packetizer->pf_packetize(
322 p_sys->p_packetizer, &p_block_in );
330 block_t *p_next = p_block_out->p_next;
332 es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_block_out->i_dts );
334 p_block_out->p_next = NULL;
335 p_sys->i_pts = p_block_out->i_pts;
336 es_out_Send( p_demux->out, p_sys->p_es, p_block_out );
338 p_block_out = p_next;
340 p_block_out = p_sys->p_packetizer->pf_packetize(
341 p_sys->p_packetizer, &p_block_in );
346 /*****************************************************************************
347 * Close: frees unused data
348 *****************************************************************************/
349 static void Close( vlc_object_t * p_this )
351 demux_t *p_demux = (demux_t*)p_this;
352 demux_sys_t *p_sys = p_demux->p_sys;
354 if( p_sys->meta ) vlc_meta_Delete( p_sys->meta );
356 if( p_sys->p_packetizer && p_sys->p_packetizer->p_module )
357 module_Unneed( p_sys->p_packetizer, p_sys->p_packetizer->p_module );
358 if( p_sys->p_packetizer )
359 vlc_object_destroy( p_sys->p_packetizer );
364 /*****************************************************************************
366 *****************************************************************************/
367 static int Control( demux_t *p_demux, int i_query, va_list args )
369 demux_sys_t *p_sys = p_demux->p_sys;
371 vlc_meta_t **pp_meta;
377 pp_meta = (vlc_meta_t **)va_arg( args, vlc_meta_t** );
378 if( p_sys->meta ) *pp_meta = vlc_meta_Duplicate( p_sys->meta );
379 else *pp_meta = NULL;
383 pi64 = (int64_t*)va_arg( args, int64_t * );
384 *pi64 = p_sys->i_pts + p_sys->i_time_offset;
388 /* FIXME TODO: implement a high precision seek (with mp3 parsing)
389 * needed for multi-input */
392 i_ret = demux2_vaControlHelper( p_demux->s, 0, -1,
393 p_sys->i_bitrate_avg, 1, i_query,
395 if( !i_ret && p_sys->i_bitrate_avg > 0 &&
396 (i_query == DEMUX_SET_POSITION || i_query == DEMUX_SET_TIME) )
398 int64_t i_time = I64C(8000000) * stream_Tell(p_demux->s) /
399 p_sys->i_bitrate_avg;
401 /* Fix time_offset */
402 if( i_time >= 0 ) p_sys->i_time_offset = i_time - p_sys->i_pts;