1 /*****************************************************************************
2 * mpegaudio.c: parse MPEG audio sync info and packetize the stream
3 *****************************************************************************
4 * Copyright (C) 2001-2016 VLC authors and VideoLAN
6 * Authors: Laurent Aimar <fenrir@via.ecp.fr>
7 * Eric Petit <titer@videolan.org>
8 * Christophe Massiot <massiot@via.ecp.fr>
9 * Gildas Bazin <gbazin@videolan.org>
11 * This program is free software; you can redistribute it and/or modify it
12 * under the terms of the GNU Lesser General Public License as published by
13 * the Free Software Foundation; either version 2.1 of the License, or
14 * (at your option) any later version.
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU Lesser General Public License for more details.
21 * You should have received a copy of the GNU Lesser General Public License
22 * along with this program; if not, write to the Free Software Foundation,
23 * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
24 *****************************************************************************/
26 /*****************************************************************************
28 *****************************************************************************/
33 #include <vlc_common.h>
34 #include <vlc_plugin.h>
35 #include <vlc_codec.h>
37 #include <vlc_modules.h>
40 #include <vlc_block_helper.h>
42 #include "packetizer_helper.h"
44 /*****************************************************************************
45 * decoder_sys_t : decoder descriptor
46 *****************************************************************************/
54 block_bytestream_t bytestream
;
63 int i_frame_size
, i_free_frame_size
;
64 unsigned int i_channels_conf
, i_chan_mode
, i_channels
;
65 unsigned int i_rate
, i_max_frame_size
, i_frame_length
;
66 unsigned int i_layer
, i_bit_rate
;
71 #define MAD_BUFFER_GUARD 8
72 #define MPGA_HEADER_SIZE 4
74 /****************************************************************************
76 ****************************************************************************/
78 static int Open( vlc_object_t
* );
79 static void Close( vlc_object_t
* );
81 /*****************************************************************************
83 *****************************************************************************/
85 set_category( CAT_INPUT
)
86 set_subcategory( SUBCAT_INPUT_ACODEC
)
87 set_description( N_("MPEG audio layer I/II/III packetizer") )
88 set_capability( "packetizer", 10 )
89 set_callbacks( Open
, Close
)
92 /*****************************************************************************
94 *****************************************************************************/
95 static void Flush( decoder_t
*p_dec
)
97 decoder_sys_t
*p_sys
= p_dec
->p_sys
;
99 date_Set( &p_sys
->end_date
, VLC_TICK_INVALID
);
100 p_sys
->i_state
= STATE_NOSYNC
;
101 block_BytestreamEmpty( &p_sys
->bytestream
);
102 p_sys
->b_discontinuity
= true;
105 /*****************************************************************************
107 *****************************************************************************/
108 static uint8_t *GetOutBuffer( decoder_t
*p_dec
, block_t
**pp_out_buffer
)
110 decoder_sys_t
*p_sys
= p_dec
->p_sys
;
112 if( p_dec
->fmt_out
.audio
.i_rate
!= p_sys
->i_rate
||
113 date_Get( &p_sys
->end_date
) == VLC_TICK_INVALID
)
115 msg_Dbg( p_dec
, "MPGA channels:%d samplerate:%d bitrate:%d",
116 p_sys
->i_channels
, p_sys
->i_rate
, p_sys
->i_bit_rate
);
118 if( p_sys
->end_date
.i_divider_num
== 0 )
119 date_Init( &p_sys
->end_date
, p_sys
->i_rate
, 1 );
121 date_Change( &p_sys
->end_date
, p_sys
->i_rate
, 1 );
122 date_Set( &p_sys
->end_date
, p_sys
->i_pts
);
125 p_dec
->fmt_out
.i_profile
= p_sys
->i_layer
;
126 p_dec
->fmt_out
.audio
.i_rate
= p_sys
->i_rate
;
127 p_dec
->fmt_out
.audio
.i_channels
= p_sys
->i_channels
;
128 p_dec
->fmt_out
.audio
.i_frame_length
= p_sys
->i_frame_length
;
129 p_dec
->fmt_out
.audio
.i_bytes_per_frame
= p_sys
->i_max_frame_size
;
131 p_dec
->fmt_out
.audio
.i_physical_channels
= p_sys
->i_channels_conf
;
132 p_dec
->fmt_out
.audio
.i_chan_mode
= p_sys
->i_chan_mode
;
134 p_dec
->fmt_out
.i_bitrate
= p_sys
->i_bit_rate
* 1000;
136 block_t
*p_block
= block_Alloc( p_sys
->i_frame_size
);
137 if( p_block
== NULL
)
140 p_block
->i_pts
= p_block
->i_dts
= date_Get( &p_sys
->end_date
);
142 date_Increment( &p_sys
->end_date
, p_sys
->i_frame_length
) - p_block
->i_pts
;
144 *pp_out_buffer
= p_block
;
145 return p_block
->p_buffer
;
148 /*****************************************************************************
149 * SyncInfo: parse MPEG audio sync info
150 *****************************************************************************/
151 static int SyncInfo( uint32_t i_header
, unsigned int * pi_channels
,
152 unsigned int * pi_channels_conf
,
153 unsigned int * pi_chan_mode
,
154 unsigned int * pi_sample_rate
, unsigned int * pi_bit_rate
,
155 unsigned int * pi_frame_length
,
156 unsigned int * pi_max_frame_size
, unsigned int * pi_layer
)
158 static const int ppi_bitrate
[2][3][16] =
162 { 0, 32, 64, 96, 128, 160, 192, 224, 256, 288, 320, 352, 384,
165 { 0, 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256,
168 { 0, 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224,
174 { 0, 32, 48, 56, 64, 80, 96, 112, 128, 144, 160, 176, 192,
177 { 0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128,
180 { 0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128,
185 static const int ppi_samplerate
[2][4] = /* version 1 then 2 */
187 { 44100, 48000, 32000, 0 },
188 { 22050, 24000, 16000, 0 }
191 int i_version
, i_mode
, i_emphasis
;
192 bool b_padding
, b_mpeg_2_5
;
193 int i_frame_size
= 0;
194 int i_bitrate_index
, i_samplerate_index
;
197 b_mpeg_2_5
= 1 - ((i_header
& 0x100000) >> 20);
198 i_version
= 1 - ((i_header
& 0x80000) >> 19);
199 *pi_layer
= 4 - ((i_header
& 0x60000) >> 17);
200 //bool b_crc = !((i_header >> 16) & 0x01);
201 i_bitrate_index
= (i_header
& 0xf000) >> 12;
202 i_samplerate_index
= (i_header
& 0xc00) >> 10;
203 b_padding
= (i_header
& 0x200) >> 9;
205 i_mode
= (i_header
& 0xc0) >> 6;
206 /* Modeext, copyright & original */
207 i_emphasis
= i_header
& 0x3;
210 if( *pi_layer
!= 4 &&
211 i_bitrate_index
< 0x0f &&
212 i_samplerate_index
!= 0x03 &&
217 case 2: /* dual-mono */
218 *pi_chan_mode
= AOUT_CHANMODE_DUALMONO
;
221 case 1: /* joint stereo */
223 *pi_channels_conf
= AOUT_CHAN_LEFT
| AOUT_CHAN_RIGHT
;
227 *pi_channels_conf
= AOUT_CHAN_CENTER
;
230 *pi_bit_rate
= ppi_bitrate
[i_version
][*pi_layer
-1][i_bitrate_index
];
231 i_max_bit_rate
= ppi_bitrate
[i_version
][*pi_layer
-1][14];
232 *pi_sample_rate
= ppi_samplerate
[i_version
][i_samplerate_index
];
236 *pi_sample_rate
>>= 1;
242 i_frame_size
= ( 12000 * *pi_bit_rate
/ *pi_sample_rate
+
244 *pi_max_frame_size
= ( 12000 * i_max_bit_rate
/
245 *pi_sample_rate
+ 1 ) * 4;
246 *pi_frame_length
= 384;
250 i_frame_size
= 144000 * *pi_bit_rate
/ *pi_sample_rate
+ b_padding
;
251 *pi_max_frame_size
= 144000 * i_max_bit_rate
/ *pi_sample_rate
+ 1;
252 *pi_frame_length
= 1152;
256 i_frame_size
= ( i_version
? 72000 : 144000 ) *
257 *pi_bit_rate
/ *pi_sample_rate
+ b_padding
;
258 *pi_max_frame_size
= ( i_version
? 72000 : 144000 ) *
259 i_max_bit_rate
/ *pi_sample_rate
+ 1;
260 *pi_frame_length
= i_version
? 576 : 1152;
267 /* Free bitrate mode can support higher bitrates */
268 if( !*pi_bit_rate
) *pi_max_frame_size
*= 2;
278 /****************************************************************************
279 * DecodeBlock: the whole thing
280 ****************************************************************************
281 * This function is called just after the thread is launched.
282 ****************************************************************************/
283 static block_t
*DecodeBlock( decoder_t
*p_dec
, block_t
**pp_block
)
285 decoder_sys_t
*p_sys
= p_dec
->p_sys
;
286 uint8_t p_header
[MAD_BUFFER_GUARD
];
289 block_t
*p_out_buffer
;
291 block_t
*p_block
= pp_block
? *pp_block
: NULL
;
295 if( p_block
->i_flags
& (BLOCK_FLAG_DISCONTINUITY
|BLOCK_FLAG_CORRUPTED
) )
297 /* First always drain complete blocks before discontinuity */
298 block_t
*p_drain
= DecodeBlock( p_dec
, NULL
);
304 if( p_block
->i_flags
& BLOCK_FLAG_CORRUPTED
)
306 block_Release( p_block
);
311 if( p_block
->i_pts
== VLC_TICK_INVALID
&&
312 date_Get( &p_sys
->end_date
) == VLC_TICK_INVALID
)
314 /* We've just started the stream, wait for the first PTS. */
315 msg_Dbg( p_dec
, "waiting for PTS" );
316 block_Release( p_block
);
320 block_BytestreamPush( &p_sys
->bytestream
, p_block
);
325 switch( p_sys
->i_state
)
329 while( block_PeekBytes( &p_sys
->bytestream
, p_header
, 2 )
332 /* Look for sync word - should be 0xffe */
333 if( p_header
[0] == 0xff && (p_header
[1] & 0xe0) == 0xe0 )
335 p_sys
->i_state
= STATE_SYNC
;
338 block_SkipByte( &p_sys
->bytestream
);
340 if( p_sys
->i_state
!= STATE_SYNC
)
342 block_BytestreamFlush( &p_sys
->bytestream
);
350 /* New frame, set the Presentation Time Stamp */
351 p_sys
->i_pts
= p_sys
->bytestream
.p_block
->i_pts
;
352 if( p_sys
->i_pts
!= VLC_TICK_INVALID
&&
353 p_sys
->i_pts
!= date_Get( &p_sys
->end_date
) )
355 if( p_dec
->fmt_in
.i_original_fourcc
== VLC_FOURCC( 'D','V','R',' ') )
357 if( date_Get( &p_sys
->end_date
) == VLC_TICK_INVALID
)
358 date_Set( &p_sys
->end_date
, p_sys
->i_pts
);
360 else if ( p_sys
->i_pts
!= date_Get( &p_sys
->end_date
) )
362 date_Set( &p_sys
->end_date
, p_sys
->i_pts
);
365 p_sys
->i_state
= STATE_HEADER
;
369 /* Get MPGA frame header (MPGA_HEADER_SIZE bytes) */
370 if( block_PeekBytes( &p_sys
->bytestream
, p_header
,
371 MPGA_HEADER_SIZE
) != VLC_SUCCESS
)
377 /* Build frame header */
378 i_header
= GetDWBE(p_header
);
380 /* Check if frame is valid and get frame info */
381 p_sys
->i_frame_size
= SyncInfo( i_header
,
383 &p_sys
->i_channels_conf
,
387 &p_sys
->i_frame_length
,
388 &p_sys
->i_max_frame_size
,
391 if( p_sys
->i_frame_size
== -1 )
393 msg_Dbg( p_dec
, "emulated startcode" );
394 block_SkipByte( &p_sys
->bytestream
);
395 p_sys
->i_state
= STATE_NOSYNC
;
399 if( p_sys
->i_bit_rate
== 0 )
401 /* Free bitrate, but 99% emulated startcode :( */
402 if( p_sys
->i_free_frame_size
== MPGA_HEADER_SIZE
)
404 msg_Dbg( p_dec
, "free bitrate mode");
406 /* The -1 below is to account for the frame padding */
407 p_sys
->i_frame_size
= p_sys
->i_free_frame_size
- 1;
410 p_sys
->i_state
= STATE_NEXT_SYNC
;
413 case STATE_NEXT_SYNC
:
414 /* Check if next expected frame contains the sync word */
415 if( block_PeekOffsetBytes( &p_sys
->bytestream
,
416 p_sys
->i_frame_size
, p_header
,
417 MAD_BUFFER_GUARD
) != VLC_SUCCESS
)
419 if( p_block
== NULL
) /* drain */
421 p_sys
->i_state
= STATE_SEND_DATA
;
428 if( p_header
[0] == 0xff && (p_header
[1] & 0xe0) == 0xe0 )
430 /* Startcode is fine, let's try the header as an extra check */
431 int i_next_frame_size
;
432 unsigned int i_next_channels
, i_next_stereo_mode
, i_next_channels_conf
;
433 unsigned int i_next_rate
, i_next_bit_rate
;
434 unsigned int i_next_frame_length
, i_next_max_frame_size
;
435 unsigned int i_next_layer
;
437 /* Build frame header */
438 i_header
= GetDWBE(p_header
);
440 i_next_frame_size
= SyncInfo( i_header
,
442 &i_next_channels_conf
,
446 &i_next_frame_length
,
447 &i_next_max_frame_size
,
450 /* Free bitrate only */
451 if( p_sys
->i_bit_rate
== 0 && i_next_frame_size
== -1 )
453 if( (unsigned int)p_sys
->i_frame_size
>
454 p_sys
->i_max_frame_size
)
456 msg_Dbg( p_dec
, "frame too big %d > %d "
457 "(emulated startcode ?)", p_sys
->i_frame_size
,
458 p_sys
->i_max_frame_size
);
459 block_SkipByte( &p_sys
->bytestream
);
460 p_sys
->i_state
= STATE_NOSYNC
;
461 p_sys
->i_free_frame_size
= MPGA_HEADER_SIZE
;
465 p_sys
->i_frame_size
++;
469 if( i_next_frame_size
== -1 )
471 msg_Dbg( p_dec
, "emulated startcode on next frame" );
472 block_SkipByte( &p_sys
->bytestream
);
473 p_sys
->i_state
= STATE_NOSYNC
;
477 /* Check info is in sync with previous one */
478 if( i_next_channels_conf
!= p_sys
->i_channels_conf
||
479 i_next_stereo_mode
!= p_sys
->i_chan_mode
||
480 i_next_rate
!= p_sys
->i_rate
||
481 i_next_layer
!= p_sys
->i_layer
||
482 i_next_frame_length
!= p_sys
->i_frame_length
)
484 /* Free bitrate only */
485 if( p_sys
->i_bit_rate
== 0 )
487 p_sys
->i_frame_size
++;
491 msg_Dbg( p_dec
, "parameters changed unexpectedly "
492 "(emulated startcode ?)" );
493 block_SkipByte( &p_sys
->bytestream
);
494 p_sys
->i_state
= STATE_NOSYNC
;
498 /* Free bitrate only */
499 if( p_sys
->i_bit_rate
== 0 )
501 if( i_next_bit_rate
!= 0 )
503 p_sys
->i_frame_size
++;
511 /* Free bitrate only */
512 if( p_sys
->i_bit_rate
== 0 )
514 if( (unsigned int)p_sys
->i_frame_size
>
515 p_sys
->i_max_frame_size
)
517 msg_Dbg( p_dec
, "frame too big %d > %d "
518 "(emulated startcode ?)", p_sys
->i_frame_size
,
519 p_sys
->i_max_frame_size
);
520 block_SkipByte( &p_sys
->bytestream
);
521 p_sys
->i_state
= STATE_NOSYNC
;
522 p_sys
->i_free_frame_size
= MPGA_HEADER_SIZE
;
526 p_sys
->i_frame_size
++;
530 msg_Dbg( p_dec
, "emulated startcode "
531 "(no startcode on following frame)" );
532 p_sys
->i_state
= STATE_NOSYNC
;
533 block_SkipByte( &p_sys
->bytestream
);
537 p_sys
->i_state
= STATE_GET_DATA
;
541 /* Make sure we have enough data.
542 * (Not useful if we went through NEXT_SYNC) */
543 if( block_WaitBytes( &p_sys
->bytestream
,
544 p_sys
->i_frame_size
) != VLC_SUCCESS
)
549 p_sys
->i_state
= STATE_SEND_DATA
;
552 case STATE_SEND_DATA
:
553 if( !(p_buf
= GetOutBuffer( p_dec
, &p_out_buffer
)) )
558 /* Free bitrate only */
559 if( p_sys
->i_bit_rate
== 0 )
561 p_sys
->i_free_frame_size
= p_sys
->i_frame_size
;
564 /* Copy the whole frame into the buffer. */
565 if (block_GetBytes( &p_sys
->bytestream
,
566 p_buf
, __MIN( (unsigned)p_sys
->i_frame_size
, p_out_buffer
->i_buffer
) )) {
567 block_Release(p_out_buffer
);
571 p_sys
->i_state
= STATE_NOSYNC
;
573 /* Make sure we don't reuse the same pts twice */
574 if( p_sys
->i_pts
== p_sys
->bytestream
.p_block
->i_pts
)
575 p_sys
->i_pts
= p_sys
->bytestream
.p_block
->i_pts
= VLC_TICK_INVALID
;
577 if( p_sys
->b_discontinuity
)
579 p_out_buffer
->i_flags
|= BLOCK_FLAG_DISCONTINUITY
;
580 p_sys
->b_discontinuity
= false;
583 /* So p_block doesn't get re-added several times */
584 p_block
= block_BytestreamPop( &p_sys
->bytestream
);
588 block_Release(p_block
);
597 /*****************************************************************************
598 * Close: clean up the decoder
599 *****************************************************************************/
600 static void Close( vlc_object_t
*p_this
)
602 decoder_t
*p_dec
= (decoder_t
*)p_this
;
603 decoder_sys_t
*p_sys
= p_dec
->p_sys
;
605 block_BytestreamRelease( &p_sys
->bytestream
);
610 /*****************************************************************************
611 * Open: probe the decoder and return score
612 *****************************************************************************/
613 static int Open( vlc_object_t
*p_this
)
615 decoder_t
*p_dec
= (decoder_t
*)p_this
;
616 decoder_sys_t
*p_sys
;
618 if(( p_dec
->fmt_in
.i_codec
!= VLC_CODEC_MPGA
) &&
619 ( p_dec
->fmt_in
.i_codec
!= VLC_CODEC_MP3
) )
624 /* Allocate the memory needed to store the decoder's structure */
625 if( ( p_dec
->p_sys
= p_sys
=
626 (decoder_sys_t
*)malloc(sizeof(decoder_sys_t
)) ) == NULL
)
630 p_sys
->i_state
= STATE_NOSYNC
;
631 date_Init( &p_sys
->end_date
, 1, 1 );
632 block_BytestreamInit( &p_sys
->bytestream
);
633 p_sys
->i_pts
= VLC_TICK_INVALID
;
634 p_sys
->b_discontinuity
= false;
635 p_sys
->i_frame_size
= 0;
637 p_sys
->i_channels_conf
= p_sys
->i_chan_mode
= p_sys
->i_channels
=
638 p_sys
->i_rate
= p_sys
->i_max_frame_size
= p_sys
->i_frame_length
=
639 p_sys
->i_layer
= p_sys
->i_bit_rate
= 0;
641 /* Set output properties */
642 p_dec
->fmt_out
.i_codec
= VLC_CODEC_MPGA
;
643 p_dec
->fmt_out
.audio
.i_rate
= 0; /* So end_date gets initialized */
646 p_dec
->pf_packetize
= DecodeBlock
;
647 p_dec
->pf_flush
= Flush
;
648 p_dec
->pf_get_cc
= NULL
;
650 /* Start with the minimum size for a free bitrate frame */
651 p_sys
->i_free_frame_size
= MPGA_HEADER_SIZE
;