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 *****************************************************************************/
58 block_bytestream_t bytestream
;
64 unsigned int i_current_layer
;
68 int i_frame_size
, i_free_frame_size
;
69 unsigned int i_channels_conf
, i_channels
;
70 unsigned int i_rate
, i_max_frame_size
, i_frame_length
;
71 unsigned int i_layer
, i_bit_rate
;
76 /* This isn't the place to put mad-specific stuff. However, it makes the
77 * mad plug-in's life much easier if we put 8 extra bytes at the end of the
78 * buffer, because that way it doesn't have to copy the block_t to a bigger
79 * buffer. This has no implication on other plug-ins, and we only lose 8 bytes
80 * per frame. --Meuuh */
81 #define MAD_BUFFER_GUARD 8
82 #define MPGA_HEADER_SIZE 4
84 /****************************************************************************
86 ****************************************************************************/
87 static int OpenDecoder ( vlc_object_t
* );
88 static int OpenPacketizer( vlc_object_t
* );
89 static void CloseDecoder ( vlc_object_t
* );
90 static block_t
*DecodeBlock ( decoder_t
*, block_t
** );
92 static uint8_t *GetOutBuffer ( decoder_t
*, block_t
** );
93 static block_t
*GetAoutBuffer( decoder_t
* );
94 static block_t
*GetSoutBuffer( decoder_t
* );
96 static int SyncInfo( uint32_t i_header
, unsigned int * pi_channels
,
97 unsigned int * pi_channels_conf
,
98 unsigned int * pi_sample_rate
, unsigned int * pi_bit_rate
,
99 unsigned int * pi_frame_length
,
100 unsigned int * pi_max_frame_size
,
101 unsigned int * pi_layer
);
103 /*****************************************************************************
105 *****************************************************************************/
107 set_description( N_("MPEG audio layer I/II/III decoder") )
108 set_category( CAT_INPUT
)
109 set_subcategory( SUBCAT_INPUT_ACODEC
)
110 set_capability( "decoder", 100 )
111 set_callbacks( OpenDecoder
, CloseDecoder
)
114 set_description( N_("MPEG audio layer I/II/III packetizer") )
115 set_capability( "packetizer", 10 )
116 set_callbacks( OpenPacketizer
, CloseDecoder
)
119 /*****************************************************************************
120 * Open: probe the decoder and return score
121 *****************************************************************************/
122 static int Open( vlc_object_t
*p_this
)
124 decoder_t
*p_dec
= (decoder_t
*)p_this
;
125 decoder_sys_t
*p_sys
;
127 if(( p_dec
->fmt_in
.i_codec
!= VLC_CODEC_MPGA
) &&
128 ( p_dec
->fmt_in
.i_codec
!= VLC_CODEC_MP3
) )
133 /* Allocate the memory needed to store the decoder's structure */
134 if( ( p_dec
->p_sys
= p_sys
=
135 (decoder_sys_t
*)malloc(sizeof(decoder_sys_t
)) ) == NULL
)
139 p_sys
->b_packetizer
= false;
140 p_sys
->i_state
= STATE_NOSYNC
;
141 date_Set( &p_sys
->end_date
, 0 );
142 block_BytestreamInit( &p_sys
->bytestream
);
143 p_sys
->i_pts
= VLC_TS_INVALID
;
144 p_sys
->b_discontinuity
= false;
146 /* Set output properties */
147 p_dec
->fmt_out
.i_cat
= AUDIO_ES
;
148 p_dec
->fmt_out
.i_codec
= VLC_CODEC_MPGA
;
149 p_dec
->fmt_out
.audio
.i_rate
= 0; /* So end_date gets initialized */
152 p_dec
->pf_decode_audio
= DecodeBlock
;
153 p_dec
->pf_packetize
= DecodeBlock
;
155 /* Start with the minimum size for a free bitrate frame */
156 p_sys
->i_free_frame_size
= MPGA_HEADER_SIZE
;
161 static int OpenDecoder( vlc_object_t
*p_this
)
163 /* HACK: Don't use this codec if we don't have an mpga audio filter */
164 if( !module_exists( "mpgatofixed32" ) )
167 return Open( p_this
);
170 static int OpenPacketizer( vlc_object_t
*p_this
)
172 decoder_t
*p_dec
= (decoder_t
*)p_this
;
174 int i_ret
= Open( p_this
);
176 if( i_ret
== VLC_SUCCESS
) p_dec
->p_sys
->b_packetizer
= true;
181 /****************************************************************************
182 * DecodeBlock: the whole thing
183 ****************************************************************************
184 * This function is called just after the thread is launched.
185 ****************************************************************************/
186 static block_t
*DecodeBlock( decoder_t
*p_dec
, block_t
**pp_block
)
188 decoder_sys_t
*p_sys
= p_dec
->p_sys
;
189 uint8_t p_header
[MAD_BUFFER_GUARD
];
192 block_t
*p_out_buffer
;
194 block_t
*p_block
= pp_block
? *pp_block
: NULL
;
197 if( p_block
->i_flags
&(BLOCK_FLAG_DISCONTINUITY
|BLOCK_FLAG_CORRUPTED
) )
199 if( p_block
->i_flags
&BLOCK_FLAG_CORRUPTED
)
201 p_sys
->i_state
= STATE_NOSYNC
;
202 block_BytestreamEmpty( &p_sys
->bytestream
);
204 date_Set( &p_sys
->end_date
, 0 );
205 block_Release( p_block
);
206 p_sys
->b_discontinuity
= true;
210 if( !date_Get( &p_sys
->end_date
) && p_block
->i_pts
<= VLC_TS_INVALID
)
212 /* We've just started the stream, wait for the first PTS. */
213 msg_Dbg( p_dec
, "waiting for PTS" );
214 block_Release( p_block
);
218 block_BytestreamPush( &p_sys
->bytestream
, p_block
);
220 p_sys
->i_state
= STATE_SEND_DATA
; /* return all the data we have left */
224 switch( p_sys
->i_state
)
228 while( block_PeekBytes( &p_sys
->bytestream
, p_header
, 2 )
231 /* Look for sync word - should be 0xffe */
232 if( p_header
[0] == 0xff && (p_header
[1] & 0xe0) == 0xe0 )
234 p_sys
->i_state
= STATE_SYNC
;
237 block_SkipByte( &p_sys
->bytestream
);
239 if( p_sys
->i_state
!= STATE_SYNC
)
241 block_BytestreamFlush( &p_sys
->bytestream
);
248 /* New frame, set the Presentation Time Stamp */
249 p_sys
->i_pts
= p_sys
->bytestream
.p_block
->i_pts
;
250 if( p_sys
->i_pts
> VLC_TS_INVALID
&&
251 p_sys
->i_pts
!= date_Get( &p_sys
->end_date
) )
253 date_Set( &p_sys
->end_date
, p_sys
->i_pts
);
255 p_sys
->i_state
= STATE_HEADER
;
258 /* Get MPGA frame header (MPGA_HEADER_SIZE bytes) */
259 if( block_PeekBytes( &p_sys
->bytestream
, p_header
,
260 MPGA_HEADER_SIZE
) != VLC_SUCCESS
)
266 /* Build frame header */
267 i_header
= GetDWBE(p_header
);
269 /* Check if frame is valid and get frame info */
270 p_sys
->i_frame_size
= SyncInfo( i_header
,
272 &p_sys
->i_channels_conf
,
275 &p_sys
->i_frame_length
,
276 &p_sys
->i_max_frame_size
,
279 p_dec
->fmt_in
.i_profile
= p_sys
->i_layer
;
281 if( p_sys
->i_frame_size
== -1 )
283 msg_Dbg( p_dec
, "emulated startcode" );
284 block_SkipByte( &p_sys
->bytestream
);
285 p_sys
->i_state
= STATE_NOSYNC
;
286 p_sys
->b_discontinuity
= true;
290 if( p_sys
->i_bit_rate
== 0 )
292 /* Free bitrate, but 99% emulated startcode :( */
293 if( p_dec
->p_sys
->i_free_frame_size
== MPGA_HEADER_SIZE
)
295 msg_Dbg( p_dec
, "free bitrate mode");
297 /* The -1 below is to account for the frame padding */
298 p_sys
->i_frame_size
= p_sys
->i_free_frame_size
- 1;
301 p_sys
->i_state
= STATE_NEXT_SYNC
;
303 case STATE_NEXT_SYNC
:
304 /* TODO: If p_block == NULL, flush the buffer without checking the
307 /* Check if next expected frame contains the sync word */
308 if( block_PeekOffsetBytes( &p_sys
->bytestream
,
309 p_sys
->i_frame_size
, p_header
,
310 MAD_BUFFER_GUARD
) != VLC_SUCCESS
)
316 if( p_header
[0] == 0xff && (p_header
[1] & 0xe0) == 0xe0 )
318 /* Startcode is fine, let's try the header as an extra check */
319 int i_next_frame_size
;
320 unsigned int i_next_channels
, i_next_channels_conf
;
321 unsigned int i_next_rate
, i_next_bit_rate
;
322 unsigned int i_next_frame_length
, i_next_max_frame_size
;
323 unsigned int i_next_layer
;
325 /* Build frame header */
326 i_header
= GetDWBE(p_header
);
328 i_next_frame_size
= SyncInfo( i_header
,
330 &i_next_channels_conf
,
333 &i_next_frame_length
,
334 &i_next_max_frame_size
,
337 /* Free bitrate only */
338 if( p_sys
->i_bit_rate
== 0 && i_next_frame_size
== -1 )
340 if( (unsigned int)p_sys
->i_frame_size
>
341 p_sys
->i_max_frame_size
)
343 msg_Dbg( p_dec
, "frame too big %d > %d "
344 "(emulated startcode ?)", p_sys
->i_frame_size
,
345 p_sys
->i_max_frame_size
);
346 block_SkipByte( &p_sys
->bytestream
);
347 p_sys
->i_state
= STATE_NOSYNC
;
348 p_sys
->i_free_frame_size
= MPGA_HEADER_SIZE
;
352 p_sys
->i_frame_size
++;
356 if( i_next_frame_size
== -1 )
358 msg_Dbg( p_dec
, "emulated startcode on next frame" );
359 block_SkipByte( &p_sys
->bytestream
);
360 p_sys
->i_state
= STATE_NOSYNC
;
361 p_sys
->b_discontinuity
= true;
365 /* Check info is in sync with previous one */
366 if( i_next_channels_conf
!= p_sys
->i_channels_conf
||
367 i_next_rate
!= p_sys
->i_rate
||
368 i_next_layer
!= p_sys
->i_layer
||
369 i_next_frame_length
!= p_sys
->i_frame_length
)
371 /* Free bitrate only */
372 if( p_sys
->i_bit_rate
== 0 )
374 p_sys
->i_frame_size
++;
378 msg_Dbg( p_dec
, "parameters changed unexpectedly "
379 "(emulated startcode ?)" );
380 block_SkipByte( &p_sys
->bytestream
);
381 p_sys
->i_state
= STATE_NOSYNC
;
385 /* Free bitrate only */
386 if( p_sys
->i_bit_rate
== 0 )
388 if( i_next_bit_rate
!= 0 )
390 p_sys
->i_frame_size
++;
398 /* Free bitrate only */
399 if( p_sys
->i_bit_rate
== 0 )
401 if( (unsigned int)p_sys
->i_frame_size
>
402 p_sys
->i_max_frame_size
)
404 msg_Dbg( p_dec
, "frame too big %d > %d "
405 "(emulated startcode ?)", p_sys
->i_frame_size
,
406 p_sys
->i_max_frame_size
);
407 block_SkipByte( &p_sys
->bytestream
);
408 p_sys
->i_state
= STATE_NOSYNC
;
409 p_sys
->i_free_frame_size
= MPGA_HEADER_SIZE
;
413 p_sys
->i_frame_size
++;
417 msg_Dbg( p_dec
, "emulated startcode "
418 "(no startcode on following frame)" );
419 p_sys
->i_state
= STATE_NOSYNC
;
420 block_SkipByte( &p_sys
->bytestream
);
424 p_sys
->i_state
= STATE_SEND_DATA
;
428 /* Make sure we have enough data.
429 * (Not useful if we went through NEXT_SYNC) */
430 if( block_WaitBytes( &p_sys
->bytestream
,
431 p_sys
->i_frame_size
) != VLC_SUCCESS
)
436 p_sys
->i_state
= STATE_SEND_DATA
;
438 case STATE_SEND_DATA
:
439 if( !(p_buf
= GetOutBuffer( p_dec
, &p_out_buffer
)) )
441 //p_dec->b_error = true;
445 /* Free bitrate only */
446 if( p_sys
->i_bit_rate
== 0 )
448 p_sys
->i_free_frame_size
= p_sys
->i_frame_size
;
451 /* Copy the whole frame into the buffer. */
452 if (block_GetBytes( &p_sys
->bytestream
,
453 p_buf
, __MIN( (unsigned)p_sys
->i_frame_size
, p_out_buffer
->i_buffer
) )) {
454 block_Release(p_out_buffer
);
458 /* Get beginning of next frame for libmad */
459 if( !p_sys
->b_packetizer
)
461 assert( p_out_buffer
->i_buffer
>= (unsigned)p_sys
->i_frame_size
+ MAD_BUFFER_GUARD
);
462 memcpy( p_buf
+ p_sys
->i_frame_size
,
463 p_header
, MAD_BUFFER_GUARD
);
466 p_sys
->i_state
= STATE_NOSYNC
;
468 /* Make sure we don't reuse the same pts twice */
469 if( p_sys
->i_pts
== p_sys
->bytestream
.p_block
->i_pts
)
470 p_sys
->i_pts
= p_sys
->bytestream
.p_block
->i_pts
= VLC_TS_INVALID
;
472 /* So p_block doesn't get re-added several times */
473 p_block
= block_BytestreamPop( &p_sys
->bytestream
);
477 block_Release(p_block
);
486 /*****************************************************************************
488 *****************************************************************************/
489 static uint8_t *GetOutBuffer( decoder_t
*p_dec
, block_t
**pp_out_buffer
)
491 decoder_sys_t
*p_sys
= p_dec
->p_sys
;
494 if( p_dec
->fmt_out
.audio
.i_rate
!= p_sys
->i_rate
)
496 msg_Dbg( p_dec
, "MPGA channels:%d samplerate:%d bitrate:%d",
497 p_sys
->i_channels
, p_sys
->i_rate
, p_sys
->i_bit_rate
);
499 date_Init( &p_sys
->end_date
, p_sys
->i_rate
, 1 );
500 date_Set( &p_sys
->end_date
, p_sys
->i_pts
);
503 p_dec
->fmt_out
.audio
.i_rate
= p_sys
->i_rate
;
504 p_dec
->fmt_out
.audio
.i_channels
= p_sys
->i_channels
;
505 p_dec
->fmt_out
.audio
.i_frame_length
= p_sys
->i_frame_length
;
506 p_dec
->fmt_out
.audio
.i_bytes_per_frame
=
507 p_sys
->i_max_frame_size
+ MAD_BUFFER_GUARD
;
509 p_dec
->fmt_out
.audio
.i_original_channels
= p_sys
->i_channels_conf
;
510 p_dec
->fmt_out
.audio
.i_physical_channels
=
511 p_sys
->i_channels_conf
& AOUT_CHAN_PHYSMASK
;
513 p_dec
->fmt_out
.i_bitrate
= p_sys
->i_bit_rate
* 1000;
515 if( p_sys
->b_packetizer
)
517 block_t
*p_sout_buffer
= GetSoutBuffer( p_dec
);
518 p_buf
= p_sout_buffer
? p_sout_buffer
->p_buffer
: NULL
;
519 *pp_out_buffer
= p_sout_buffer
;
523 block_t
*p_aout_buffer
= GetAoutBuffer( p_dec
);
524 p_buf
= p_aout_buffer
? p_aout_buffer
->p_buffer
: NULL
;
525 *pp_out_buffer
= p_aout_buffer
;
531 /*****************************************************************************
533 *****************************************************************************/
534 static block_t
*GetAoutBuffer( decoder_t
*p_dec
)
536 decoder_sys_t
*p_sys
= p_dec
->p_sys
;
539 p_buf
= decoder_NewAudioBuffer( p_dec
, p_sys
->i_frame_length
);
540 if( p_buf
== NULL
) return NULL
;
542 p_buf
->i_pts
= date_Get( &p_sys
->end_date
);
543 p_buf
->i_length
= date_Increment( &p_sys
->end_date
, p_sys
->i_frame_length
)
545 if( p_sys
->b_discontinuity
)
546 p_buf
->i_flags
|= BLOCK_FLAG_DISCONTINUITY
;
547 p_sys
->b_discontinuity
= false;
549 /* Hack for libmad filter */
550 p_buf
= block_Realloc( p_buf
, 0, p_sys
->i_frame_size
+ MAD_BUFFER_GUARD
);
555 /*****************************************************************************
557 *****************************************************************************/
558 static block_t
*GetSoutBuffer( decoder_t
*p_dec
)
560 decoder_sys_t
*p_sys
= p_dec
->p_sys
;
563 p_block
= block_Alloc( p_sys
->i_frame_size
);
564 if( p_block
== NULL
) return NULL
;
566 p_block
->i_pts
= p_block
->i_dts
= date_Get( &p_sys
->end_date
);
569 date_Increment( &p_sys
->end_date
, p_sys
->i_frame_length
) - p_block
->i_pts
;
574 /*****************************************************************************
575 * CloseDecoder: clean up the decoder
576 *****************************************************************************/
577 static void CloseDecoder( vlc_object_t
*p_this
)
579 decoder_t
*p_dec
= (decoder_t
*)p_this
;
580 decoder_sys_t
*p_sys
= p_dec
->p_sys
;
582 block_BytestreamRelease( &p_sys
->bytestream
);
587 /*****************************************************************************
588 * SyncInfo: parse MPEG audio sync info
589 *****************************************************************************/
590 static int SyncInfo( uint32_t i_header
, unsigned int * pi_channels
,
591 unsigned int * pi_channels_conf
,
592 unsigned int * pi_sample_rate
, unsigned int * pi_bit_rate
,
593 unsigned int * pi_frame_length
,
594 unsigned int * pi_max_frame_size
, unsigned int * pi_layer
)
596 static const int ppi_bitrate
[2][3][16] =
600 { 0, 32, 64, 96, 128, 160, 192, 224, 256, 288, 320, 352, 384,
603 { 0, 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256,
606 { 0, 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224,
612 { 0, 32, 48, 56, 64, 80, 96, 112, 128, 144, 160, 176, 192,
615 { 0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128,
618 { 0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128,
623 static const int ppi_samplerate
[2][4] = /* version 1 then 2 */
625 { 44100, 48000, 32000, 0 },
626 { 22050, 24000, 16000, 0 }
629 int i_version
, i_mode
, i_emphasis
;
630 bool b_padding
, b_mpeg_2_5
;
631 int i_frame_size
= 0;
632 int i_bitrate_index
, i_samplerate_index
;
635 b_mpeg_2_5
= 1 - ((i_header
& 0x100000) >> 20);
636 i_version
= 1 - ((i_header
& 0x80000) >> 19);
637 *pi_layer
= 4 - ((i_header
& 0x60000) >> 17);
638 //bool b_crc = !((i_header >> 16) & 0x01);
639 i_bitrate_index
= (i_header
& 0xf000) >> 12;
640 i_samplerate_index
= (i_header
& 0xc00) >> 10;
641 b_padding
= (i_header
& 0x200) >> 9;
643 i_mode
= (i_header
& 0xc0) >> 6;
644 /* Modeext, copyright & original */
645 i_emphasis
= i_header
& 0x3;
647 if( *pi_layer
!= 4 &&
648 i_bitrate_index
< 0x0f &&
649 i_samplerate_index
!= 0x03 &&
655 case 1: /* joint stereo */
657 *pi_channels_conf
= AOUT_CHAN_LEFT
| AOUT_CHAN_RIGHT
;
659 case 2: /* dual-mono */
661 *pi_channels_conf
= AOUT_CHAN_LEFT
| AOUT_CHAN_RIGHT
662 | AOUT_CHAN_DUALMONO
;
666 *pi_channels_conf
= AOUT_CHAN_CENTER
;
669 *pi_bit_rate
= ppi_bitrate
[i_version
][*pi_layer
-1][i_bitrate_index
];
670 i_max_bit_rate
= ppi_bitrate
[i_version
][*pi_layer
-1][14];
671 *pi_sample_rate
= ppi_samplerate
[i_version
][i_samplerate_index
];
675 *pi_sample_rate
>>= 1;
681 i_frame_size
= ( 12000 * *pi_bit_rate
/ *pi_sample_rate
+
683 *pi_max_frame_size
= ( 12000 * i_max_bit_rate
/
684 *pi_sample_rate
+ 1 ) * 4;
685 *pi_frame_length
= 384;
689 i_frame_size
= 144000 * *pi_bit_rate
/ *pi_sample_rate
+ b_padding
;
690 *pi_max_frame_size
= 144000 * i_max_bit_rate
/ *pi_sample_rate
+ 1;
691 *pi_frame_length
= 1152;
695 i_frame_size
= ( i_version
? 72000 : 144000 ) *
696 *pi_bit_rate
/ *pi_sample_rate
+ b_padding
;
697 *pi_max_frame_size
= ( i_version
? 72000 : 144000 ) *
698 i_max_bit_rate
/ *pi_sample_rate
+ 1;
699 *pi_frame_length
= i_version
? 576 : 1152;
706 /* Free bitrate mode can support higher bitrates */
707 if( !*pi_bit_rate
) *pi_max_frame_size
*= 2;