1 /*****************************************************************************
2 * mpeg_audio.c: parse MPEG audio sync info and packetize the stream
3 *****************************************************************************
4 * Copyright (C) 2001-2003 VideoLAN
5 * $Id: mpeg_audio.c,v 1.18 2003/10/04 12:04:06 gbazin Exp $
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@netcourrier.com>
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 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 General Public License for more details.
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
25 *****************************************************************************/
27 /*****************************************************************************
29 *****************************************************************************/
30 #include <stdlib.h> /* malloc(), free() */
31 #include <string.h> /* strdup() */
34 #include <vlc/decoder.h>
35 #include <vlc/input.h>
39 #include "vlc_block_helper.h"
41 /*****************************************************************************
42 * decoder_sys_t : decoder descriptor
43 *****************************************************************************/
47 vlc_bool_t b_packetizer;
55 block_bytestream_t bytestream;
58 * Decoder output properties
60 aout_instance_t * p_aout; /* opaque */
61 aout_input_t * p_aout_input; /* opaque */
62 audio_sample_format_t aout_format;
63 aout_buffer_t * p_aout_buffer; /* current aout buffer being filled */
66 * Packetizer output properties
68 sout_packetizer_input_t *p_sout_input;
69 sout_format_t sout_format;
70 sout_buffer_t * p_sout_buffer; /* current sout buffer */
75 uint8_t *p_out_buffer; /* output buffer */
76 audio_date_t end_date;
77 unsigned int i_current_layer;
81 int i_frame_size, i_free_frame_size;
82 unsigned int i_channels_conf, i_channels;
83 unsigned int i_rate, i_max_frame_size, i_frame_length;
84 unsigned int i_layer, i_bit_rate;
96 #define MAX_FRAME_SIZE 10000
97 /* This isn't the place to put mad-specific stuff. However, it makes the
98 * mad plug-in's life much easier if we put 8 extra bytes at the end of the
99 * buffer, because that way it doesn't have to copy the aout_buffer_t to a
100 * bigger buffer. This has no implication on other plug-ins, and we only
101 * lose 8 bytes per frame. --Meuuh */
102 #define MAD_BUFFER_GUARD 8
103 #define MPGA_HEADER_SIZE 4
105 /****************************************************************************
107 ****************************************************************************/
108 static int OpenDecoder ( vlc_object_t * );
109 static int OpenPacketizer( vlc_object_t * );
111 static int InitDecoder ( decoder_t * );
112 static int RunDecoder ( decoder_t *, block_t * );
113 static int EndDecoder ( decoder_t * );
115 static int GetOutBuffer ( decoder_t *, uint8_t ** );
116 static int GetAoutBuffer( decoder_t *, aout_buffer_t ** );
117 static int GetSoutBuffer( decoder_t *, sout_buffer_t ** );
118 static int SendOutBuffer( decoder_t * );
120 static int SyncInfo( uint32_t i_header, unsigned int * pi_channels,
121 unsigned int * pi_sample_rate, unsigned int * pi_bit_rate,
122 unsigned int * pi_frame_length,
123 unsigned int * pi_current_frame_length,
124 unsigned int * pi_layer );
126 /*****************************************************************************
128 *****************************************************************************/
130 set_description( _("MPEG audio layer I/II/III parser") );
131 set_capability( "decoder", 100 );
132 set_callbacks( OpenDecoder, NULL );
135 set_description( _("MPEG audio layer I/II/III packetizer") );
136 set_capability( "packetizer", 10 );
137 set_callbacks( OpenPacketizer, NULL );
140 /*****************************************************************************
141 * OpenDecoder: probe the decoder and return score
142 *****************************************************************************/
143 static int OpenDecoder( vlc_object_t *p_this )
145 decoder_t *p_dec = (decoder_t*)p_this;
147 if( p_dec->p_fifo->i_fourcc != VLC_FOURCC( 'm', 'p', 'g', 'a') )
152 p_dec->pf_init = InitDecoder;
153 p_dec->pf_decode = RunDecoder;
154 p_dec->pf_end = EndDecoder;
156 /* Allocate the memory needed to store the decoder's structure */
158 (decoder_sys_t *)malloc(sizeof(decoder_sys_t)) ) == NULL )
160 msg_Err( p_dec, "out of memory" );
163 p_dec->p_sys->b_packetizer = VLC_FALSE;
168 static int OpenPacketizer( vlc_object_t *p_this )
170 decoder_t *p_dec = (decoder_t*)p_this;
172 int i_ret = OpenDecoder( p_this );
174 if( i_ret == VLC_SUCCESS ) p_dec->p_sys->b_packetizer = VLC_TRUE;
179 /*****************************************************************************
180 * InitDecoder: Initalize the decoder
181 *****************************************************************************/
182 static int InitDecoder( decoder_t *p_dec )
184 p_dec->p_sys->i_state = STATE_NOSYNC;
186 p_dec->p_sys->p_out_buffer = NULL;
187 aout_DateSet( &p_dec->p_sys->end_date, 0 );
189 p_dec->p_sys->p_aout = NULL;
190 p_dec->p_sys->p_aout_input = NULL;
191 p_dec->p_sys->p_aout_buffer = NULL;
192 p_dec->p_sys->aout_format.i_format = VLC_FOURCC('m','p','g','a');
194 p_dec->p_sys->p_sout_input = NULL;
195 p_dec->p_sys->p_sout_buffer = NULL;
196 p_dec->p_sys->sout_format.i_cat = AUDIO_ES;
197 p_dec->p_sys->sout_format.i_fourcc = VLC_FOURCC('m','p','g','a');
199 /* Start with the inimum size for a free bitrate frame */
200 p_dec->p_sys->i_free_frame_size = MPGA_HEADER_SIZE;
202 p_dec->p_sys->p_chain = NULL;
207 /****************************************************************************
208 * RunDecoder: the whole thing
209 ****************************************************************************
210 * This function is called just after the thread is launched.
211 ****************************************************************************/
212 static int RunDecoder( decoder_t *p_dec, block_t *p_block )
214 decoder_sys_t *p_sys = p_dec->p_sys;
215 uint8_t p_header[MAD_BUFFER_GUARD];
218 if( !aout_DateGet( &p_sys->end_date ) && !p_block->i_pts )
220 /* We've just started the stream, wait for the first PTS. */
221 block_Release( p_block );
227 block_ChainAppend( &p_sys->p_chain, p_block );
231 block_ChainAppend( &p_sys->p_chain, p_block );
232 p_sys->bytestream = block_BytestreamInit( p_dec, p_sys->p_chain, 0 );
237 switch( p_sys->i_state )
241 while( block_PeekBytes( &p_sys->bytestream, p_header, 2 )
244 /* Look for sync word - should be 0xffe */
245 if( p_header[0] == 0xff && (p_header[1] & 0xe0) == 0xe0 )
247 p_sys->i_state = STATE_SYNC;
250 block_SkipByte( &p_sys->bytestream );
252 if( p_sys->i_state != STATE_SYNC )
254 block_ChainRelease( p_sys->p_chain );
255 p_sys->p_chain = NULL;
262 /* New frame, set the Presentation Time Stamp */
263 p_sys->pts = p_sys->bytestream.p_block->i_pts;
264 if( p_sys->pts != 0 &&
265 p_sys->pts != aout_DateGet( &p_sys->end_date ) )
267 aout_DateSet( &p_sys->end_date, p_sys->pts );
269 p_sys->i_state = STATE_HEADER;
273 /* Get MPGA frame header (MPGA_HEADER_SIZE bytes) */
274 if( block_PeekBytes( &p_sys->bytestream, p_header,
275 MPGA_HEADER_SIZE ) != VLC_SUCCESS )
281 /* Build frame header */
282 i_header = (p_header[0]<<24)|(p_header[1]<<16)|(p_header[2]<<8)
285 /* Check if frame is valid and get frame info */
286 p_sys->i_frame_size = SyncInfo( i_header,
287 &p_sys->i_channels_conf,
290 &p_sys->i_frame_length,
291 &p_sys->i_frame_size,
294 if( p_sys->i_frame_size == -1 )
296 msg_Dbg( p_dec, "emulated start code" );
297 block_SkipByte( &p_sys->bytestream );
298 p_sys->i_state = STATE_NOSYNC;
302 if( p_sys->i_bit_rate == 0 )
304 /* Free birate, but 99% emulated startcode :( */
305 if( p_dec->p_sys->i_free_frame_size == MPGA_HEADER_SIZE )
307 msg_Dbg( p_dec, "free bitrate mode");
309 p_sys->i_frame_size = p_sys->i_free_frame_size;
312 p_sys->i_state = STATE_NEXT_SYNC;
314 case STATE_NEXT_SYNC:
315 /* TODO: If p_block == NULL, flush the buffer without checking the
318 /* Check if next expected frame contains the sync word */
319 if( block_PeekOffsetBytes( &p_sys->bytestream,
320 p_sys->i_frame_size, p_header,
321 MAD_BUFFER_GUARD ) != VLC_SUCCESS )
327 if( p_header[0] == 0xff && (p_header[1] & 0xe0) == 0xe0 )
329 /* Startcode is fine, let's try the header as an extra check */
330 int i_next_frame_size;
331 unsigned int i_next_channels, i_next_rate, i_next_bit_rate;
332 unsigned int i_next_frame_length, i_next_max_frame_size;
333 unsigned int i_next_layer;
335 /* Build frame header */
336 i_header = (p_header[0]<<24)|(p_header[1]<<16)|(p_header[2]<<8)
339 i_next_frame_size = SyncInfo( i_header,
343 &i_next_frame_length,
344 &i_next_max_frame_size,
347 if( i_next_frame_size == -1 )
349 msg_Dbg( p_dec, "emulated start code on next frame" );
350 block_SkipByte( &p_sys->bytestream );
351 p_sys->i_state = STATE_NOSYNC;
355 /* Free bitrate only */
356 if( p_sys->i_bit_rate == 0 )
358 if( i_next_bit_rate != 0 )
360 p_sys->i_frame_size++;
364 if( (unsigned int)p_sys->i_frame_size >
365 p_sys->i_max_frame_size )
367 msg_Dbg( p_dec, "frame too big %d > %d "
368 "(emulated startcode ?)", p_sys->i_frame_size,
369 p_sys->i_max_frame_size );
370 block_SkipByte( &p_sys->bytestream );
371 p_sys->i_state = STATE_NOSYNC;
372 p_sys->i_free_frame_size = MPGA_HEADER_SIZE;
377 /* Check info is in sync with previous one */
378 if( i_next_channels != p_sys->i_channels_conf ||
379 i_next_rate != p_sys->i_rate ||
380 i_next_layer != p_sys->i_layer ||
381 i_next_frame_length != p_sys->i_frame_length )
383 /* Free bitrate only */
384 if( p_sys->i_bit_rate == 0 )
386 p_sys->i_frame_size++;
390 msg_Dbg( p_dec, "parameters changed unexpectedly "
391 "(emulated startcode ?)" );
392 block_SkipByte( &p_sys->bytestream );
393 p_sys->i_state = STATE_NOSYNC;
399 msg_Dbg( p_dec, "emulated startcode "
400 "(no startcode on following frame)" );
401 p_sys->i_state = STATE_NOSYNC;
402 block_SkipByte( &p_sys->bytestream );
406 if( GetOutBuffer( p_dec, &p_sys->p_out_buffer ) != VLC_SUCCESS )
411 /* Free bitrate only */
412 if( p_sys->i_bit_rate == 0 )
414 p_sys->i_free_frame_size = p_sys->i_frame_size;
417 p_sys->i_state = STATE_DATA;
420 /* Copy the whole frame into the buffer */
421 if( block_GetBytes( &p_sys->bytestream, p_sys->p_out_buffer,
422 p_sys->i_frame_size ) != VLC_SUCCESS )
428 p_sys->p_chain = block_BytestreamFlush( &p_sys->bytestream );
430 /* Get beginning of next frame for libmad */
431 if( !p_sys->b_packetizer )
433 memcpy( p_sys->p_out_buffer + p_sys->i_frame_size,
434 p_header, MAD_BUFFER_GUARD );
437 SendOutBuffer( p_dec );
438 p_sys->i_state = STATE_NOSYNC;
440 /* Make sure we don't reuse the same pts twice */
441 if( p_sys->pts == p_sys->bytestream.p_block->i_pts )
442 p_sys->pts = p_sys->bytestream.p_block->i_pts = 0;
449 /*****************************************************************************
451 *****************************************************************************/
452 static int GetOutBuffer( decoder_t *p_dec, uint8_t **pp_out_buffer )
454 decoder_sys_t *p_sys = p_dec->p_sys;
457 if( p_sys->b_packetizer )
459 i_ret = GetSoutBuffer( p_dec, &p_sys->p_sout_buffer );
461 p_sys->p_sout_buffer ? p_sys->p_sout_buffer->p_buffer : NULL;
465 i_ret = GetAoutBuffer( p_dec, &p_sys->p_aout_buffer );
467 p_sys->p_aout_buffer ? p_sys->p_aout_buffer->p_buffer : NULL;
473 /*****************************************************************************
475 *****************************************************************************/
476 static int GetAoutBuffer( decoder_t *p_dec, aout_buffer_t **pp_buffer )
478 decoder_sys_t *p_sys = p_dec->p_sys;
480 if( p_sys->p_aout_input != NULL &&
481 ( p_sys->aout_format.i_rate != p_sys->i_rate
482 || p_sys->aout_format.i_original_channels != p_sys->i_channels_conf
483 || (int)p_sys->aout_format.i_bytes_per_frame !=
484 p_sys->i_max_frame_size + MAD_BUFFER_GUARD
485 || p_sys->aout_format.i_frame_length != p_sys->i_frame_length
486 || p_sys->i_current_layer != p_sys->i_layer ) )
488 /* Parameters changed - this should not happen. */
489 aout_DecDelete( p_sys->p_aout, p_sys->p_aout_input );
490 p_sys->p_aout_input = NULL;
493 /* Creating the audio input if not created yet. */
494 if( p_sys->p_aout_input == NULL )
496 p_sys->i_current_layer = p_sys->i_layer;
497 if( p_sys->i_layer == 3 )
499 p_sys->aout_format.i_format = VLC_FOURCC('m','p','g','3');
503 p_sys->aout_format.i_format = VLC_FOURCC('m','p','g','a');
506 p_sys->aout_format.i_rate = p_sys->i_rate;
507 p_sys->aout_format.i_original_channels = p_sys->i_channels_conf;
508 p_sys->aout_format.i_physical_channels
509 = p_sys->i_channels_conf & AOUT_CHAN_PHYSMASK;
510 p_sys->aout_format.i_bytes_per_frame = p_sys->i_max_frame_size
512 p_sys->aout_format.i_frame_length = p_sys->i_frame_length;
513 aout_DateInit( &p_sys->end_date, p_sys->i_rate );
514 aout_DateSet( &p_sys->end_date, p_sys->pts );
515 p_sys->p_aout_input = aout_DecNew( p_dec,
517 &p_sys->aout_format );
518 if( p_sys->p_aout_input == NULL )
525 *pp_buffer = aout_DecNewBuffer( p_sys->p_aout, p_sys->p_aout_input,
526 p_sys->i_frame_length );
527 if( *pp_buffer == NULL )
532 (*pp_buffer)->start_date = aout_DateGet( &p_sys->end_date );
533 (*pp_buffer)->end_date =
534 aout_DateIncrement( &p_sys->end_date, p_sys->i_frame_length );
539 /*****************************************************************************
541 *****************************************************************************/
542 static int GetSoutBuffer( decoder_t *p_dec, sout_buffer_t **pp_buffer )
544 decoder_sys_t *p_sys = p_dec->p_sys;
546 if( p_sys->p_sout_input != NULL &&
547 ( p_sys->sout_format.i_sample_rate != (int)p_sys->i_rate
548 || p_sys->sout_format.i_channels != (int)p_sys->i_channels ) )
550 /* Parameters changed - this should not happen. */
553 /* Creating the sout input if not created yet. */
554 if( p_sys->p_sout_input == NULL )
556 p_sys->sout_format.i_sample_rate = p_sys->i_rate;
557 p_sys->sout_format.i_channels = p_sys->i_channels;
558 p_sys->sout_format.i_block_align = 0;
559 p_sys->sout_format.i_bitrate = p_sys->i_bit_rate;
560 p_sys->sout_format.i_extra_data = 0;
561 p_sys->sout_format.p_extra_data = NULL;
563 aout_DateInit( &p_sys->end_date, p_sys->i_rate );
564 aout_DateSet( &p_sys->end_date, p_sys->pts );
566 p_sys->p_sout_input = sout_InputNew( p_dec, &p_sys->sout_format );
567 if( p_sys->p_sout_input == NULL )
569 msg_Err( p_dec, "cannot add a new stream" );
573 msg_Info( p_dec, "A/52 channels:%d samplerate:%d bitrate:%d",
574 p_sys->i_channels, p_sys->i_rate, p_sys->i_bit_rate );
577 *pp_buffer = sout_BufferNew( p_sys->p_sout_input->p_sout,
578 p_sys->i_frame_size );
579 if( *pp_buffer == NULL )
584 (*pp_buffer)->i_pts =
585 (*pp_buffer)->i_dts = aout_DateGet( &p_sys->end_date );
587 (*pp_buffer)->i_length =
588 aout_DateIncrement( &p_sys->end_date, p_sys->i_frame_length )
589 - (*pp_buffer)->i_pts;
594 /*****************************************************************************
596 *****************************************************************************/
597 static int SendOutBuffer( decoder_t *p_dec )
599 decoder_sys_t *p_sys = p_dec->p_sys;
601 if( p_sys->b_packetizer )
603 sout_InputSendBuffer( p_sys->p_sout_input, p_sys->p_sout_buffer );
604 p_sys->p_sout_buffer = NULL;
608 /* We have all we need, send the buffer to the aout core. */
609 aout_DecPlay( p_sys->p_aout, p_sys->p_aout_input,
610 p_sys->p_aout_buffer );
611 p_sys->p_aout_buffer = NULL;
614 p_sys->p_out_buffer = NULL;
619 /*****************************************************************************
620 * EndDecoder: clean up the decoder
621 *****************************************************************************/
622 static int EndDecoder( decoder_t *p_dec )
624 if( p_dec->p_sys->p_aout_input != NULL )
626 if( p_dec->p_sys->p_aout_buffer )
628 aout_DecDeleteBuffer( p_dec->p_sys->p_aout,
629 p_dec->p_sys->p_aout_input,
630 p_dec->p_sys->p_aout_buffer );
633 aout_DecDelete( p_dec->p_sys->p_aout, p_dec->p_sys->p_aout_input );
636 if( p_dec->p_sys->p_sout_input != NULL )
638 if( p_dec->p_sys->p_sout_buffer )
640 sout_BufferDelete( p_dec->p_sys->p_sout_input->p_sout,
641 p_dec->p_sys->p_sout_buffer );
644 sout_InputDelete( p_dec->p_sys->p_sout_input );
647 if( p_dec->p_sys->p_chain ) block_ChainRelease( p_dec->p_sys->p_chain );
649 free( p_dec->p_sys );
654 /*****************************************************************************
655 * SyncInfo: parse MPEG audio sync info
656 *****************************************************************************/
657 static int SyncInfo( uint32_t i_header, unsigned int * pi_channels,
658 unsigned int * pi_sample_rate, unsigned int * pi_bit_rate,
659 unsigned int * pi_frame_length,
660 unsigned int * pi_frame_size, unsigned int * pi_layer )
662 static const int pppi_mpegaudio_bitrate[2][3][16] =
666 { 0, 32, 64, 96, 128, 160, 192, 224, 256, 288, 320, 352, 384,
669 { 0, 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256,
672 { 0, 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224,
678 { 0, 32, 48, 56, 64, 80, 96, 112, 128, 144, 160, 176, 192,
681 { 0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128,
684 { 0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128,
689 static const int ppi_mpegaudio_samplerate[2][4] = /* version 1 then 2 */
691 { 44100, 48000, 32000, 0 },
692 { 22050, 24000, 16000, 0 }
695 int i_version, i_mode, i_emphasis;
696 vlc_bool_t b_padding, b_mpeg_2_5;
697 int i_current_frame_size = 0;
698 int i_bitrate_index, i_samplerate_index;
701 b_mpeg_2_5 = 1 - ((i_header & 0x100000) >> 20);
702 i_version = 1 - ((i_header & 0x80000) >> 19);
703 *pi_layer = 4 - ((i_header & 0x60000) >> 17);
705 i_bitrate_index = (i_header & 0xf000) >> 12;
706 i_samplerate_index = (i_header & 0xc00) >> 10;
707 b_padding = (i_header & 0x200) >> 9;
709 i_mode = (i_header & 0xc0) >> 6;
710 /* Modeext, copyright & original */
711 i_emphasis = i_header & 0x3;
713 if( *pi_layer != 4 &&
714 i_bitrate_index < 0x0f &&
715 i_samplerate_index != 0x03 &&
721 case 1: /* joint stereo */
722 *pi_channels = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT;
724 case 2: /* dual-mono */
725 *pi_channels = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
726 | AOUT_CHAN_DUALMONO;
729 *pi_channels = AOUT_CHAN_CENTER;
732 *pi_bit_rate = pppi_mpegaudio_bitrate[i_version][*pi_layer-1][i_bitrate_index];
733 i_max_bit_rate = pppi_mpegaudio_bitrate[i_version][*pi_layer-1][14];
734 *pi_sample_rate = ppi_mpegaudio_samplerate[i_version][i_samplerate_index];
738 *pi_sample_rate >>= 1;
744 i_current_frame_size = ( 12000 * *pi_bit_rate /
745 *pi_sample_rate + b_padding ) * 4;
746 *pi_frame_size = ( 12000 * i_max_bit_rate /
747 *pi_sample_rate + 1 ) * 4;
748 *pi_frame_length = 384;
752 i_current_frame_size = 144000 * *pi_bit_rate /
753 *pi_sample_rate + b_padding;
754 *pi_frame_size = 144000 * i_max_bit_rate / *pi_sample_rate + 1;
755 *pi_frame_length = 1152;
759 i_current_frame_size = ( i_version ? 72000 : 144000 ) *
760 *pi_bit_rate / *pi_sample_rate + b_padding;
761 *pi_frame_size = ( i_version ? 72000 : 144000 ) *
762 i_max_bit_rate / *pi_sample_rate + 1;
763 *pi_frame_length = i_version ? 576 : 1152;
775 return i_current_frame_size;