1 /*****************************************************************************
2 * mpeg_audio.c: parse MPEG audio sync info and packetize the stream
3 *****************************************************************************
4 * Copyright (C) 2001-2003 VLC authors and VideoLAN
7 * Authors: Laurent Aimar <fenrir@via.ecp.fr>
8 * Eric Petit <titer@videolan.org>
9 * Christophe Massiot <massiot@via.ecp.fr>
10 * Gildas Bazin <gbazin@videolan.org>
12 * This program is free software; you can redistribute it and/or modify it
13 * under the terms of the GNU Lesser General Public License as published by
14 * the Free Software Foundation; either version 2.1 of the License, or
15 * (at your option) any later version.
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU Lesser General Public License for more details.
22 * You should have received a copy of the GNU Lesser General Public License
23 * along with this program; if not, write to the Free Software Foundation,
24 * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
25 *****************************************************************************/
27 /*****************************************************************************
29 *****************************************************************************/
34 #include <vlc_common.h>
35 #include <vlc_plugin.h>
36 #include <vlc_codec.h>
38 #include <vlc_modules.h>
41 #include <vlc_block_helper.h>
43 #include "../packetizer/packetizer_helper.h"
45 /*****************************************************************************
46 * decoder_sys_t : decoder descriptor
47 *****************************************************************************/
50 #ifdef HAVE_MPGA_FILTER
59 block_bytestream_t bytestream;
65 unsigned int i_current_layer;
69 int i_frame_size, i_free_frame_size;
70 unsigned int i_channels_conf, i_channels;
71 unsigned int i_rate, i_max_frame_size, i_frame_length;
72 unsigned int i_layer, i_bit_rate;
77 /* This isn't the place to put mad-specific stuff. However, it makes the
78 * mad plug-in's life much easier if we put 8 extra bytes at the end of the
79 * buffer, because that way it doesn't have to copy the block_t to a bigger
80 * buffer. This has no implication on other plug-ins, and we only lose 8 bytes
81 * per frame. --Meuuh */
82 #define MAD_BUFFER_GUARD 8
83 #define MPGA_HEADER_SIZE 4
85 /****************************************************************************
87 ****************************************************************************/
89 #ifdef HAVE_MPGA_FILTER
90 static int OpenDecoder ( vlc_object_t * );
91 static block_t *GetAoutBuffer( decoder_t * );
93 static int Open( vlc_object_t * );
94 static block_t *DecodeBlock ( decoder_t *, block_t ** );
95 static uint8_t *GetOutBuffer ( decoder_t *, block_t ** );
96 static block_t *GetSoutBuffer( decoder_t * );
97 static void Close( vlc_object_t * );
98 static int SyncInfo( uint32_t i_header, unsigned int * pi_channels,
99 unsigned int * pi_channels_conf,
100 unsigned int * pi_sample_rate, unsigned int * pi_bit_rate,
101 unsigned int * pi_frame_length,
102 unsigned int * pi_max_frame_size,
103 unsigned int * pi_layer );
105 /*****************************************************************************
107 *****************************************************************************/
109 set_category( CAT_INPUT )
110 set_subcategory( SUBCAT_INPUT_ACODEC )
111 set_description( N_("MPEG audio layer I/II/III packetizer") )
112 set_capability( "packetizer", 10 )
113 set_callbacks( Open, Close )
114 #ifdef HAVE_MPGA_FILTER
116 set_description( N_("MPEG audio layer I/II/III decoder") )
117 set_capability( "decoder", 100 )
118 set_callbacks( OpenDecoder, Close )
122 /*****************************************************************************
123 * Open: probe the decoder and return score
124 *****************************************************************************/
125 static int Open( vlc_object_t *p_this )
127 decoder_t *p_dec = (decoder_t*)p_this;
128 decoder_sys_t *p_sys;
130 if(( p_dec->fmt_in.i_codec != VLC_CODEC_MPGA ) &&
131 ( p_dec->fmt_in.i_codec != VLC_CODEC_MP3 ) )
136 /* Allocate the memory needed to store the decoder's structure */
137 if( ( p_dec->p_sys = p_sys =
138 (decoder_sys_t *)malloc(sizeof(decoder_sys_t)) ) == NULL )
142 #ifdef HAVE_MPGA_FILTER
143 p_sys->b_packetizer = true;
145 p_sys->i_state = STATE_NOSYNC;
146 date_Set( &p_sys->end_date, 0 );
147 block_BytestreamInit( &p_sys->bytestream );
148 p_sys->i_pts = VLC_TS_INVALID;
149 p_sys->b_discontinuity = false;
151 /* Set output properties */
152 p_dec->fmt_out.i_cat = AUDIO_ES;
153 p_dec->fmt_out.i_codec = VLC_CODEC_MPGA;
154 p_dec->fmt_out.audio.i_rate = 0; /* So end_date gets initialized */
157 p_dec->pf_decode_audio = DecodeBlock;
158 p_dec->pf_packetize = DecodeBlock;
160 /* Start with the minimum size for a free bitrate frame */
161 p_sys->i_free_frame_size = MPGA_HEADER_SIZE;
166 #ifdef HAVE_MPGA_FILTER
167 static int OpenDecoder( vlc_object_t *p_this )
169 decoder_t *p_dec = (decoder_t *)p_this;
171 /* HACK: Don't use this codec if we don't have an mpga audio filter */
172 if( !module_exists( "mad" ) )
175 int i_ret = Open( p_this );
176 if( i_ret != VLC_SUCCESS )
179 p_dec->p_sys->b_packetizer = false;
184 /****************************************************************************
185 * DecodeBlock: the whole thing
186 ****************************************************************************
187 * This function is called just after the thread is launched.
188 ****************************************************************************/
189 static block_t *DecodeBlock( decoder_t *p_dec, block_t **pp_block )
191 decoder_sys_t *p_sys = p_dec->p_sys;
192 uint8_t p_header[MAD_BUFFER_GUARD];
195 block_t *p_out_buffer;
197 block_t *p_block = pp_block ? *pp_block : NULL;
200 if( p_block->i_flags&(BLOCK_FLAG_DISCONTINUITY|BLOCK_FLAG_CORRUPTED) )
202 if( p_block->i_flags&BLOCK_FLAG_CORRUPTED )
204 p_sys->i_state = STATE_NOSYNC;
205 block_BytestreamEmpty( &p_sys->bytestream );
207 date_Set( &p_sys->end_date, 0 );
208 block_Release( p_block );
209 p_sys->b_discontinuity = true;
213 if( !date_Get( &p_sys->end_date ) && p_block->i_pts <= VLC_TS_INVALID )
215 /* We've just started the stream, wait for the first PTS. */
216 msg_Dbg( p_dec, "waiting for PTS" );
217 block_Release( p_block );
221 block_BytestreamPush( &p_sys->bytestream, p_block );
223 p_sys->i_state = STATE_SEND_DATA; /* return all the data we have left */
227 switch( p_sys->i_state )
231 while( block_PeekBytes( &p_sys->bytestream, p_header, 2 )
234 /* Look for sync word - should be 0xffe */
235 if( p_header[0] == 0xff && (p_header[1] & 0xe0) == 0xe0 )
237 p_sys->i_state = STATE_SYNC;
240 block_SkipByte( &p_sys->bytestream );
242 if( p_sys->i_state != STATE_SYNC )
244 block_BytestreamFlush( &p_sys->bytestream );
251 /* New frame, set the Presentation Time Stamp */
252 p_sys->i_pts = p_sys->bytestream.p_block->i_pts;
253 if( p_sys->i_pts > VLC_TS_INVALID &&
254 p_sys->i_pts > date_Get( &p_sys->end_date ) )
256 date_Set( &p_sys->end_date, p_sys->i_pts );
258 p_sys->i_state = STATE_HEADER;
261 /* Get MPGA frame header (MPGA_HEADER_SIZE bytes) */
262 if( block_PeekBytes( &p_sys->bytestream, p_header,
263 MPGA_HEADER_SIZE ) != VLC_SUCCESS )
269 /* Build frame header */
270 i_header = GetDWBE(p_header);
272 /* Check if frame is valid and get frame info */
273 p_sys->i_frame_size = SyncInfo( i_header,
275 &p_sys->i_channels_conf,
278 &p_sys->i_frame_length,
279 &p_sys->i_max_frame_size,
282 p_dec->fmt_in.i_profile = p_sys->i_layer;
284 if( p_sys->i_frame_size == -1 )
286 msg_Dbg( p_dec, "emulated startcode" );
287 block_SkipByte( &p_sys->bytestream );
288 p_sys->i_state = STATE_NOSYNC;
289 p_sys->b_discontinuity = true;
293 if( p_sys->i_bit_rate == 0 )
295 /* Free bitrate, but 99% emulated startcode :( */
296 if( p_dec->p_sys->i_free_frame_size == MPGA_HEADER_SIZE )
298 msg_Dbg( p_dec, "free bitrate mode");
300 /* The -1 below is to account for the frame padding */
301 p_sys->i_frame_size = p_sys->i_free_frame_size - 1;
304 p_sys->i_state = STATE_NEXT_SYNC;
306 case STATE_NEXT_SYNC:
307 /* TODO: If p_block == NULL, flush the buffer without checking the
310 /* Check if next expected frame contains the sync word */
311 if( block_PeekOffsetBytes( &p_sys->bytestream,
312 p_sys->i_frame_size, p_header,
313 MAD_BUFFER_GUARD ) != VLC_SUCCESS )
319 if( p_header[0] == 0xff && (p_header[1] & 0xe0) == 0xe0 )
321 /* Startcode is fine, let's try the header as an extra check */
322 int i_next_frame_size;
323 unsigned int i_next_channels, i_next_channels_conf;
324 unsigned int i_next_rate, i_next_bit_rate;
325 unsigned int i_next_frame_length, i_next_max_frame_size;
326 unsigned int i_next_layer;
328 /* Build frame header */
329 i_header = GetDWBE(p_header);
331 i_next_frame_size = SyncInfo( i_header,
333 &i_next_channels_conf,
336 &i_next_frame_length,
337 &i_next_max_frame_size,
340 /* Free bitrate only */
341 if( p_sys->i_bit_rate == 0 && i_next_frame_size == -1 )
343 if( (unsigned int)p_sys->i_frame_size >
344 p_sys->i_max_frame_size )
346 msg_Dbg( p_dec, "frame too big %d > %d "
347 "(emulated startcode ?)", p_sys->i_frame_size,
348 p_sys->i_max_frame_size );
349 block_SkipByte( &p_sys->bytestream );
350 p_sys->i_state = STATE_NOSYNC;
351 p_sys->i_free_frame_size = MPGA_HEADER_SIZE;
355 p_sys->i_frame_size++;
359 if( i_next_frame_size == -1 )
361 msg_Dbg( p_dec, "emulated startcode on next frame" );
362 block_SkipByte( &p_sys->bytestream );
363 p_sys->i_state = STATE_NOSYNC;
364 p_sys->b_discontinuity = true;
368 /* Check info is in sync with previous one */
369 if( i_next_channels_conf != p_sys->i_channels_conf ||
370 i_next_rate != p_sys->i_rate ||
371 i_next_layer != p_sys->i_layer ||
372 i_next_frame_length != p_sys->i_frame_length )
374 /* Free bitrate only */
375 if( p_sys->i_bit_rate == 0 )
377 p_sys->i_frame_size++;
381 msg_Dbg( p_dec, "parameters changed unexpectedly "
382 "(emulated startcode ?)" );
383 block_SkipByte( &p_sys->bytestream );
384 p_sys->i_state = STATE_NOSYNC;
388 /* Free bitrate only */
389 if( p_sys->i_bit_rate == 0 )
391 if( i_next_bit_rate != 0 )
393 p_sys->i_frame_size++;
401 /* Free bitrate only */
402 if( p_sys->i_bit_rate == 0 )
404 if( (unsigned int)p_sys->i_frame_size >
405 p_sys->i_max_frame_size )
407 msg_Dbg( p_dec, "frame too big %d > %d "
408 "(emulated startcode ?)", p_sys->i_frame_size,
409 p_sys->i_max_frame_size );
410 block_SkipByte( &p_sys->bytestream );
411 p_sys->i_state = STATE_NOSYNC;
412 p_sys->i_free_frame_size = MPGA_HEADER_SIZE;
416 p_sys->i_frame_size++;
420 msg_Dbg( p_dec, "emulated startcode "
421 "(no startcode on following frame)" );
422 p_sys->i_state = STATE_NOSYNC;
423 block_SkipByte( &p_sys->bytestream );
427 p_sys->i_state = STATE_SEND_DATA;
431 /* Make sure we have enough data.
432 * (Not useful if we went through NEXT_SYNC) */
433 if( block_WaitBytes( &p_sys->bytestream,
434 p_sys->i_frame_size ) != VLC_SUCCESS )
439 p_sys->i_state = STATE_SEND_DATA;
441 case STATE_SEND_DATA:
442 if( !(p_buf = GetOutBuffer( p_dec, &p_out_buffer )) )
444 //p_dec->b_error = true;
448 /* Free bitrate only */
449 if( p_sys->i_bit_rate == 0 )
451 p_sys->i_free_frame_size = p_sys->i_frame_size;
454 /* Copy the whole frame into the buffer. */
455 if (block_GetBytes( &p_sys->bytestream,
456 p_buf, __MIN( (unsigned)p_sys->i_frame_size, p_out_buffer->i_buffer ) )) {
457 block_Release(p_out_buffer);
461 #ifdef HAVE_MPGA_FILTER
462 /* Get beginning of next frame for libmad */
463 if( !p_sys->b_packetizer )
465 assert( p_out_buffer->i_buffer >= (unsigned)p_sys->i_frame_size + MAD_BUFFER_GUARD );
466 memcpy( p_buf + p_sys->i_frame_size,
467 p_header, MAD_BUFFER_GUARD );
470 p_sys->i_state = STATE_NOSYNC;
472 /* Make sure we don't reuse the same pts twice */
473 if( p_sys->i_pts == p_sys->bytestream.p_block->i_pts )
474 p_sys->i_pts = p_sys->bytestream.p_block->i_pts = VLC_TS_INVALID;
476 /* So p_block doesn't get re-added several times */
477 p_block = block_BytestreamPop( &p_sys->bytestream );
481 block_Release(p_block);
490 /*****************************************************************************
492 *****************************************************************************/
493 static uint8_t *GetOutBuffer( decoder_t *p_dec, block_t **pp_out_buffer )
495 decoder_sys_t *p_sys = p_dec->p_sys;
498 if( p_dec->fmt_out.audio.i_rate != p_sys->i_rate )
500 msg_Dbg( p_dec, "MPGA channels:%d samplerate:%d bitrate:%d",
501 p_sys->i_channels, p_sys->i_rate, p_sys->i_bit_rate );
503 date_Init( &p_sys->end_date, p_sys->i_rate, 1 );
504 date_Set( &p_sys->end_date, p_sys->i_pts );
507 p_dec->fmt_out.audio.i_rate = p_sys->i_rate;
508 p_dec->fmt_out.audio.i_channels = p_sys->i_channels;
509 p_dec->fmt_out.audio.i_frame_length = p_sys->i_frame_length;
510 p_dec->fmt_out.audio.i_bytes_per_frame =
511 p_sys->i_max_frame_size + MAD_BUFFER_GUARD;
513 p_dec->fmt_out.audio.i_original_channels = p_sys->i_channels_conf;
514 p_dec->fmt_out.audio.i_physical_channels =
515 p_sys->i_channels_conf & AOUT_CHAN_PHYSMASK;
517 p_dec->fmt_out.i_bitrate = p_sys->i_bit_rate * 1000;
519 #ifdef HAVE_MPGA_FILTER
520 if( !p_sys->b_packetizer )
522 block_t *p_aout_buffer = GetAoutBuffer( p_dec );
523 p_buf = p_aout_buffer ? p_aout_buffer->p_buffer : NULL;
524 *pp_out_buffer = p_aout_buffer;
529 block_t *p_sout_buffer = GetSoutBuffer( p_dec );
530 p_buf = p_sout_buffer ? p_sout_buffer->p_buffer : NULL;
531 *pp_out_buffer = p_sout_buffer;
536 #ifdef HAVE_MPGA_FILTER
537 /*****************************************************************************
539 *****************************************************************************/
540 static block_t *GetAoutBuffer( decoder_t *p_dec )
542 decoder_sys_t *p_sys = p_dec->p_sys;
545 p_buf = decoder_NewAudioBuffer( p_dec, p_sys->i_frame_length );
546 if( p_buf == NULL ) return NULL;
548 p_buf->i_pts = date_Get( &p_sys->end_date );
549 p_buf->i_length = date_Increment( &p_sys->end_date, p_sys->i_frame_length )
551 if( p_sys->b_discontinuity )
552 p_buf->i_flags |= BLOCK_FLAG_DISCONTINUITY;
553 p_sys->b_discontinuity = false;
555 /* Hack for libmad filter */
556 p_buf = block_Realloc( p_buf, 0, p_sys->i_frame_size + MAD_BUFFER_GUARD );
562 /*****************************************************************************
564 *****************************************************************************/
565 static block_t *GetSoutBuffer( decoder_t *p_dec )
567 decoder_sys_t *p_sys = p_dec->p_sys;
570 p_block = block_Alloc( p_sys->i_frame_size );
571 if( p_block == NULL ) return NULL;
573 p_block->i_pts = p_block->i_dts = date_Get( &p_sys->end_date );
576 date_Increment( &p_sys->end_date, p_sys->i_frame_length ) - p_block->i_pts;
581 /*****************************************************************************
582 * Close: clean up the decoder
583 *****************************************************************************/
584 static void Close( vlc_object_t *p_this )
586 decoder_t *p_dec = (decoder_t *)p_this;
587 decoder_sys_t *p_sys = p_dec->p_sys;
589 block_BytestreamRelease( &p_sys->bytestream );
594 /*****************************************************************************
595 * SyncInfo: parse MPEG audio sync info
596 *****************************************************************************/
597 static int SyncInfo( uint32_t i_header, unsigned int * pi_channels,
598 unsigned int * pi_channels_conf,
599 unsigned int * pi_sample_rate, unsigned int * pi_bit_rate,
600 unsigned int * pi_frame_length,
601 unsigned int * pi_max_frame_size, unsigned int * pi_layer)
603 static const int ppi_bitrate[2][3][16] =
607 { 0, 32, 64, 96, 128, 160, 192, 224, 256, 288, 320, 352, 384,
610 { 0, 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256,
613 { 0, 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224,
619 { 0, 32, 48, 56, 64, 80, 96, 112, 128, 144, 160, 176, 192,
622 { 0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128,
625 { 0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128,
630 static const int ppi_samplerate[2][4] = /* version 1 then 2 */
632 { 44100, 48000, 32000, 0 },
633 { 22050, 24000, 16000, 0 }
636 int i_version, i_mode, i_emphasis;
637 bool b_padding, b_mpeg_2_5;
638 int i_frame_size = 0;
639 int i_bitrate_index, i_samplerate_index;
642 b_mpeg_2_5 = 1 - ((i_header & 0x100000) >> 20);
643 i_version = 1 - ((i_header & 0x80000) >> 19);
644 *pi_layer = 4 - ((i_header & 0x60000) >> 17);
645 //bool b_crc = !((i_header >> 16) & 0x01);
646 i_bitrate_index = (i_header & 0xf000) >> 12;
647 i_samplerate_index = (i_header & 0xc00) >> 10;
648 b_padding = (i_header & 0x200) >> 9;
650 i_mode = (i_header & 0xc0) >> 6;
651 /* Modeext, copyright & original */
652 i_emphasis = i_header & 0x3;
654 if( *pi_layer != 4 &&
655 i_bitrate_index < 0x0f &&
656 i_samplerate_index != 0x03 &&
662 case 1: /* joint stereo */
664 *pi_channels_conf = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT;
666 case 2: /* dual-mono */
668 *pi_channels_conf = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
669 | AOUT_CHAN_DUALMONO;
673 *pi_channels_conf = AOUT_CHAN_CENTER;
676 *pi_bit_rate = ppi_bitrate[i_version][*pi_layer-1][i_bitrate_index];
677 i_max_bit_rate = ppi_bitrate[i_version][*pi_layer-1][14];
678 *pi_sample_rate = ppi_samplerate[i_version][i_samplerate_index];
682 *pi_sample_rate >>= 1;
688 i_frame_size = ( 12000 * *pi_bit_rate / *pi_sample_rate +
690 *pi_max_frame_size = ( 12000 * i_max_bit_rate /
691 *pi_sample_rate + 1 ) * 4;
692 *pi_frame_length = 384;
696 i_frame_size = 144000 * *pi_bit_rate / *pi_sample_rate + b_padding;
697 *pi_max_frame_size = 144000 * i_max_bit_rate / *pi_sample_rate + 1;
698 *pi_frame_length = 1152;
702 i_frame_size = ( i_version ? 72000 : 144000 ) *
703 *pi_bit_rate / *pi_sample_rate + b_padding;
704 *pi_max_frame_size = ( i_version ? 72000 : 144000 ) *
705 i_max_bit_rate / *pi_sample_rate + 1;
706 *pi_frame_length = i_version ? 576 : 1152;
713 /* Free bitrate mode can support higher bitrates */
714 if( !*pi_bit_rate ) *pi_max_frame_size *= 2;