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;
77 static int HeaderCheck( uint32_t h )
79 if( ((( h >> 21 )&0x07FF) != 0x07FF ) /* header sync */
80 || (((h >> 17)&0x03) == 0 ) /* valid layer ?*/
81 || (((h >> 12)&0x0F) == 0x0F )
82 || (((h >> 12)&0x0F) == 0x00 ) /* valid bitrate ? */
83 || (((h >> 10) & 0x03) == 0x03 ) /* valide sampling freq ? */
84 || ((h & 0x03) == 0x02 )) /* valid emphasis ? */
91 #define MPGA_VERSION( h ) ( 1 - (((h)>>19)&0x01) )
92 #define MPGA_LAYER( h ) ( 3 - (((h)>>17)&0x03) )
93 #define MPGA_MODE(h) (((h)>> 6)&0x03)
95 static int mpga_frame_samples( uint32_t h )
97 switch( MPGA_LAYER(h) )
104 return MPGA_VERSION(h) ? 576 : 1152;
110 /*****************************************************************************
111 * Open: initializes demux structures
112 *****************************************************************************/
113 static int Open( vlc_object_t * p_this )
115 demux_t *p_demux = (demux_t*)p_this;
117 vlc_bool_t b_forced = VLC_FALSE;
122 vlc_meta_t *p_meta = NULL;
124 if( p_demux->psz_path )
126 int i_len = strlen( p_demux->psz_path );
127 if( i_len > 4 && !strcasecmp( &p_demux->psz_path[i_len - 4], ".mp3" ) )
133 /* Skip/parse possible id3 header */
134 if( ( p_id3 = module_Need( p_demux, "id3", NULL, 0 ) ) )
136 p_meta = (vlc_meta_t *)p_demux->p_private;
137 p_demux->p_private = NULL;
138 module_Unneed( p_demux, p_id3 );
141 if( stream_Peek( p_demux->s, &p_peek, 4 ) < 4 )
143 msg_Err( p_demux, "cannot peek" );
144 if( p_meta ) vlc_meta_Delete( p_meta );
148 if( !HeaderCheck( header = GetDWBE( p_peek ) ) )
150 vlc_bool_t b_ok = VLC_FALSE;
153 if( !p_demux->b_force && !b_forced )
155 if( p_meta ) vlc_meta_Delete( p_meta );
159 i_peek = stream_Peek( p_demux->s, &p_peek, 8096 );
162 if( HeaderCheck( header = GetDWBE( p_peek ) ) )
170 if( !b_ok && !p_demux->b_force )
172 msg_Warn( p_demux, "mpga module discarded" );
173 if( p_meta ) vlc_meta_Delete( p_meta );
178 p_demux->p_sys = p_sys = malloc( sizeof( demux_sys_t ) );
179 memset( p_sys, 0, sizeof( demux_sys_t ) );
181 p_sys->p_packetizer = 0;
182 p_sys->b_start = VLC_TRUE;
183 p_sys->meta = p_meta;
184 p_demux->pf_demux = Demux;
185 p_demux->pf_control = Control;
188 * Load the mpeg audio packetizer
190 p_sys->p_packetizer = vlc_object_create( p_demux, VLC_OBJECT_PACKETIZER );
191 p_sys->p_packetizer->pf_decode_audio = NULL;
192 p_sys->p_packetizer->pf_decode_video = NULL;
193 p_sys->p_packetizer->pf_decode_sub = NULL;
194 p_sys->p_packetizer->pf_packetize = NULL;
195 es_format_Init( &p_sys->p_packetizer->fmt_in, AUDIO_ES,
196 VLC_FOURCC( 'm', 'p', 'g', 'a' ) );
197 es_format_Init( &p_sys->p_packetizer->fmt_out, UNKNOWN_ES, 0 );
198 p_sys->p_packetizer->p_module =
199 module_Need( p_sys->p_packetizer, "packetizer", NULL, 0 );
201 if( p_sys->p_packetizer->p_module == NULL )
203 msg_Err( p_demux, "cannot find mpga packetizer" );
204 Close( VLC_OBJECT(p_demux ) );
209 if( HeaderCheck( header ) )
214 if( ( i_xing = stream_Peek( p_demux->s, &p_xing, 1024 ) ) < 21 )
215 return VLC_SUCCESS; /* No header */
217 if( MPGA_VERSION( header ) == 0 )
219 i_skip = MPGA_MODE( header ) != 3 ? 36 : 21;
223 i_skip = MPGA_MODE( header ) != 3 ? 21 : 13;
226 if( i_skip + 8 < i_xing && !strncmp( &p_xing[i_skip], "Xing", 4 ) )
228 unsigned int i_flags = GetDWBE( &p_xing[i_skip+4] );
230 p_xing += i_skip + 8;
231 i_xing -= i_skip + 8;
234 if( i_flags&0x01 && i_skip + 4 <= i_xing ) /* XING_FRAMES */
236 p_sys->i_xing_frames = GetDWBE( &p_xing[i_skip] );
239 if( i_flags&0x02 && i_skip + 4 <= i_xing ) /* XING_BYTES */
241 p_sys->i_xing_bytes = GetDWBE( &p_xing[i_skip] );
244 if( i_flags&0x04 ) /* XING_TOC */
249 // FIXME: doesn't return the right bitrage average, at least
251 if( i_flags&0x08 && i_skip + 4 <= i_xing ) /* XING_VBR */
253 p_sys->i_xing_bitrate_avg = GetDWBE( &p_xing[i_skip] );
254 msg_Dbg( p_demux, "xing vbr value present (%d)",
255 p_sys->i_xing_bitrate_avg );
258 if( p_sys->i_xing_frames > 0 && p_sys->i_xing_bytes > 0 )
260 p_sys->i_xing_frame_samples = mpga_frame_samples( header );
261 msg_Dbg( p_demux, "xing frames&bytes value present "
262 "(%d bytes, %d frames, %d samples/frame)",
263 p_sys->i_xing_bytes, p_sys->i_xing_frames,
264 p_sys->i_xing_frame_samples );
272 /*****************************************************************************
273 * Demux: reads and demuxes data packets
274 *****************************************************************************
275 * Returns -1 in case of error, 0 in case of EOF, 1 otherwise
276 *****************************************************************************/
277 static int Demux( demux_t *p_demux )
279 demux_sys_t *p_sys = p_demux->p_sys;
280 block_t *p_block_in, *p_block_out;
282 if( ( p_block_in = stream_Block( p_demux->s, MPGA_PACKET_SIZE ) ) == NULL )
287 p_block_in->i_pts = p_block_in->i_dts = p_sys->b_start ? 1 : 0;
288 p_sys->b_start = VLC_FALSE;
290 while( (p_block_out = p_sys->p_packetizer->pf_packetize(
291 p_sys->p_packetizer, &p_block_in )) )
295 block_t *p_next = p_block_out->p_next;
297 if( p_sys->p_es == NULL )
299 p_sys->p_packetizer->fmt_out.b_packetized = VLC_TRUE;
300 p_sys->p_es = es_out_Add( p_demux->out,
301 &p_sys->p_packetizer->fmt_out);
303 p_sys->i_bitrate_avg = p_sys->p_packetizer->fmt_out.i_bitrate;
305 if( p_sys->i_xing_bytes && p_sys->i_xing_frames &&
306 p_sys->i_xing_frame_samples )
308 p_sys->i_bitrate_avg = p_sys->i_xing_bytes * I64C(8) *
309 p_sys->p_packetizer->fmt_out.audio.i_rate /
310 p_sys->i_xing_frames / p_sys->i_xing_frame_samples;
314 es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_block_out->i_dts );
316 p_block_out->p_next = NULL;
317 p_sys->i_pts = p_block_out->i_pts;
318 es_out_Send( p_demux->out, p_sys->p_es, p_block_out );
320 p_block_out = p_next;
326 /*****************************************************************************
327 * Close: frees unused data
328 *****************************************************************************/
329 static void Close( vlc_object_t * p_this )
331 demux_t *p_demux = (demux_t*)p_this;
332 demux_sys_t *p_sys = p_demux->p_sys;
334 if( p_sys->meta ) vlc_meta_Delete( p_sys->meta );
336 if( p_sys->p_packetizer && p_sys->p_packetizer->p_module )
337 module_Unneed( p_sys->p_packetizer, p_sys->p_packetizer->p_module );
338 if( p_sys->p_packetizer )
339 vlc_object_destroy( p_sys->p_packetizer );
344 /*****************************************************************************
346 *****************************************************************************/
347 static int Control( demux_t *p_demux, int i_query, va_list args )
349 demux_sys_t *p_sys = p_demux->p_sys;
351 vlc_meta_t **pp_meta;
357 pp_meta = (vlc_meta_t **)va_arg( args, vlc_meta_t** );
358 if( p_sys->meta ) *pp_meta = vlc_meta_Duplicate( p_sys->meta );
359 else *pp_meta = NULL;
363 pi64 = (int64_t*)va_arg( args, int64_t * );
364 *pi64 = p_sys->i_pts + p_sys->i_time_offset;
368 /* FIXME TODO: implement a high precision seek (with mp3 parsing)
369 * needed for multi-input */
372 i_ret = demux2_vaControlHelper( p_demux->s, 0, -1,
373 p_sys->i_bitrate_avg, 1, i_query,
375 if( !i_ret && p_sys->i_bitrate_avg > 0 &&
376 (i_query == DEMUX_SET_POSITION || i_query == DEMUX_SET_TIME) )
378 int64_t i_time = I64C(8000000) * stream_Tell(p_demux->s) /
379 p_sys->i_bitrate_avg;
381 /* Fix time_offset */
382 if( i_time >= 0 ) p_sys->i_time_offset = i_time - p_sys->i_pts;