1 /*****************************************************************************
2 * a52.c: parse A/52 audio sync info and packetize the stream
3 *****************************************************************************
4 * Copyright (C) 2001-2002 the VideoLAN team
7 * Authors: Stéphane Borel <stef@via.ecp.fr>
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
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 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 General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, 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_input.h>
38 #include <vlc_block_helper.h>
40 #define A52_HEADER_SIZE 7
42 /*****************************************************************************
43 * decoder_sys_t : decoder descriptor
44 *****************************************************************************/
55 block_bytestream_t bytestream;
60 audio_date_t end_date;
63 int i_frame_size, i_bit_rate;
64 unsigned int i_rate, i_channels, i_channels_conf;
79 /****************************************************************************
81 ****************************************************************************/
82 static int OpenDecoder ( vlc_object_t * );
83 static int OpenPacketizer( vlc_object_t * );
84 static void CloseDecoder ( vlc_object_t * );
85 static void *DecodeBlock ( decoder_t *, block_t ** );
87 static int SyncInfo ( const uint8_t *, unsigned int *, unsigned int *,
88 unsigned int *, int * );
90 static uint8_t *GetOutBuffer ( decoder_t *, void ** );
91 static aout_buffer_t *GetAoutBuffer( decoder_t * );
92 static block_t *GetSoutBuffer( decoder_t * );
94 /*****************************************************************************
96 *****************************************************************************/
98 set_description( N_("A/52 parser") );
99 set_capability( "decoder", 100 );
100 set_callbacks( OpenDecoder, CloseDecoder );
101 set_category( CAT_INPUT );
102 set_subcategory( SUBCAT_INPUT_ACODEC );
105 set_description( N_("A/52 audio packetizer") );
106 set_capability( "packetizer", 10 );
107 set_callbacks( OpenPacketizer, CloseDecoder );
110 /*****************************************************************************
111 * OpenDecoder: probe the decoder and return score
112 *****************************************************************************/
113 static int OpenDecoder( vlc_object_t *p_this )
115 decoder_t *p_dec = (decoder_t*)p_this;
116 decoder_sys_t *p_sys;
118 if( p_dec->fmt_in.i_codec != VLC_FOURCC('a','5','2',' ')
119 && p_dec->fmt_in.i_codec != VLC_FOURCC('a','5','2','b') )
124 /* Allocate the memory needed to store the decoder's structure */
125 if( ( p_dec->p_sys = p_sys =
126 (decoder_sys_t *)malloc(sizeof(decoder_sys_t)) ) == NULL )
130 p_sys->b_packetizer = false;
131 p_sys->i_state = STATE_NOSYNC;
132 aout_DateSet( &p_sys->end_date, 0 );
134 p_sys->bytestream = block_BytestreamInit();
135 p_sys->i_input_rate = INPUT_RATE_DEFAULT;
137 /* Set output properties */
138 p_dec->fmt_out.i_cat = AUDIO_ES;
139 p_dec->fmt_out.i_codec = VLC_FOURCC('a','5','2',' ');
140 p_dec->fmt_out.audio.i_rate = 0; /* So end_date gets initialized */
143 p_dec->pf_decode_audio = (aout_buffer_t *(*)(decoder_t *, block_t **))
145 p_dec->pf_packetize = (block_t *(*)(decoder_t *, block_t **))
151 static int OpenPacketizer( vlc_object_t *p_this )
153 decoder_t *p_dec = (decoder_t*)p_this;
155 int i_ret = OpenDecoder( p_this );
157 if( i_ret == VLC_SUCCESS ) p_dec->p_sys->b_packetizer = true;
162 /****************************************************************************
163 * DecodeBlock: the whole thing
164 ****************************************************************************
165 * This function is called just after the thread is launched.
166 ****************************************************************************/
167 static void *DecodeBlock( decoder_t *p_dec, block_t **pp_block )
169 decoder_sys_t *p_sys = p_dec->p_sys;
170 uint8_t p_header[A52_HEADER_SIZE];
174 if( !pp_block || !*pp_block ) return NULL;
176 if( (*pp_block)->i_flags&(BLOCK_FLAG_DISCONTINUITY|BLOCK_FLAG_CORRUPTED) )
178 if( (*pp_block)->i_flags&BLOCK_FLAG_CORRUPTED )
180 p_sys->i_state = STATE_NOSYNC;
181 block_BytestreamFlush( &p_sys->bytestream );
183 // aout_DateSet( &p_sys->end_date, 0 );
184 block_Release( *pp_block );
188 if( !aout_DateGet( &p_sys->end_date ) && !(*pp_block)->i_pts )
190 /* We've just started the stream, wait for the first PTS. */
191 block_Release( *pp_block );
195 if( (*pp_block)->i_rate > 0 )
196 p_sys->i_input_rate = (*pp_block)->i_rate;
198 block_BytestreamPush( &p_sys->bytestream, *pp_block );
202 switch( p_sys->i_state )
205 while( block_PeekBytes( &p_sys->bytestream, p_header, 2 )
208 if( p_header[0] == 0x0b && p_header[1] == 0x77 )
210 p_sys->i_state = STATE_SYNC;
213 block_SkipByte( &p_sys->bytestream );
215 if( p_sys->i_state != STATE_SYNC )
217 block_BytestreamFlush( &p_sys->bytestream );
224 /* New frame, set the Presentation Time Stamp */
225 p_sys->i_pts = p_sys->bytestream.p_block->i_pts;
226 if( p_sys->i_pts != 0 &&
227 p_sys->i_pts != aout_DateGet( &p_sys->end_date ) )
229 aout_DateSet( &p_sys->end_date, p_sys->i_pts );
231 p_sys->i_state = STATE_HEADER;
234 /* Get A/52 frame header (A52_HEADER_SIZE bytes) */
235 if( block_PeekBytes( &p_sys->bytestream, p_header,
236 A52_HEADER_SIZE ) != VLC_SUCCESS )
242 /* Check if frame is valid and get frame info */
243 p_sys->i_frame_size = SyncInfo( p_header,
245 &p_sys->i_channels_conf,
247 &p_sys->i_bit_rate );
248 if( !p_sys->i_frame_size )
250 msg_Dbg( p_dec, "emulated sync word" );
251 block_SkipByte( &p_sys->bytestream );
252 p_sys->i_state = STATE_NOSYNC;
255 p_sys->i_state = STATE_NEXT_SYNC;
257 case STATE_NEXT_SYNC:
258 /* TODO: If pp_block == NULL, flush the buffer without checking the
261 /* Check if next expected frame contains the sync word */
262 if( block_PeekOffsetBytes( &p_sys->bytestream,
263 p_sys->i_frame_size, p_header, 2 )
270 if( p_sys->b_packetizer &&
271 p_header[0] == 0 && p_header[1] == 0 )
273 /* A52 wav files and audio CD's use stuffing */
274 p_sys->i_state = STATE_GET_DATA;
278 if( p_header[0] != 0x0b || p_header[1] != 0x77 )
280 msg_Dbg( p_dec, "emulated sync word "
281 "(no sync on following frame)" );
282 p_sys->i_state = STATE_NOSYNC;
283 block_SkipByte( &p_sys->bytestream );
286 p_sys->i_state = STATE_SEND_DATA;
290 /* Make sure we have enough data.
291 * (Not useful if we went through NEXT_SYNC) */
292 if( block_WaitBytes( &p_sys->bytestream,
293 p_sys->i_frame_size ) != VLC_SUCCESS )
298 p_sys->i_state = STATE_SEND_DATA;
300 case STATE_SEND_DATA:
301 if( !(p_buf = GetOutBuffer( p_dec, &p_out_buffer )) )
303 //p_dec->b_error = true;
307 /* Copy the whole frame into the buffer. When we reach this point
308 * we already know we have enough data available. */
309 block_GetBytes( &p_sys->bytestream, p_buf, p_sys->i_frame_size );
311 /* Make sure we don't reuse the same pts twice */
312 if( p_sys->i_pts == p_sys->bytestream.p_block->i_pts )
313 p_sys->i_pts = p_sys->bytestream.p_block->i_pts = 0;
315 /* So p_block doesn't get re-added several times */
316 *pp_block = block_BytestreamPop( &p_sys->bytestream );
318 p_sys->i_state = STATE_NOSYNC;
327 /*****************************************************************************
328 * CloseDecoder: clean up the decoder
329 *****************************************************************************/
330 static void CloseDecoder( vlc_object_t *p_this )
332 decoder_t *p_dec = (decoder_t*)p_this;
333 decoder_sys_t *p_sys = p_dec->p_sys;
335 block_BytestreamRelease( &p_sys->bytestream );
340 /*****************************************************************************
342 *****************************************************************************/
343 static uint8_t *GetOutBuffer( decoder_t *p_dec, void **pp_out_buffer )
345 decoder_sys_t *p_sys = p_dec->p_sys;
348 if( p_dec->fmt_out.audio.i_rate != p_sys->i_rate )
350 msg_Info( p_dec, "A/52 channels:%d samplerate:%d bitrate:%d",
351 p_sys->i_channels, p_sys->i_rate, p_sys->i_bit_rate );
353 aout_DateInit( &p_sys->end_date, p_sys->i_rate );
354 aout_DateSet( &p_sys->end_date, p_sys->i_pts );
357 p_dec->fmt_out.audio.i_rate = p_sys->i_rate;
358 p_dec->fmt_out.audio.i_channels = p_sys->i_channels;
359 p_dec->fmt_out.audio.i_bytes_per_frame = p_sys->i_frame_size;
360 p_dec->fmt_out.audio.i_frame_length = A52_FRAME_NB;
362 p_dec->fmt_out.audio.i_original_channels = p_sys->i_channels_conf;
363 p_dec->fmt_out.audio.i_physical_channels =
364 p_sys->i_channels_conf & AOUT_CHAN_PHYSMASK;
366 p_dec->fmt_out.i_bitrate = p_sys->i_bit_rate;
368 if( p_sys->b_packetizer )
370 block_t *p_sout_buffer = GetSoutBuffer( p_dec );
371 p_buf = p_sout_buffer ? p_sout_buffer->p_buffer : NULL;
372 *pp_out_buffer = p_sout_buffer;
376 aout_buffer_t *p_aout_buffer = GetAoutBuffer( p_dec );
377 p_buf = p_aout_buffer ? p_aout_buffer->p_buffer : NULL;
378 *pp_out_buffer = p_aout_buffer;
384 /*****************************************************************************
386 *****************************************************************************/
387 static aout_buffer_t *GetAoutBuffer( decoder_t *p_dec )
389 decoder_sys_t *p_sys = p_dec->p_sys;
390 aout_buffer_t *p_buf;
392 p_buf = p_dec->pf_aout_buffer_new( p_dec, A52_FRAME_NB );
393 if( p_buf == NULL ) return NULL;
395 p_buf->start_date = aout_DateGet( &p_sys->end_date );
396 p_buf->end_date = aout_DateIncrement( &p_sys->end_date,
397 A52_FRAME_NB * p_sys->i_input_rate / INPUT_RATE_DEFAULT );
402 /*****************************************************************************
404 *****************************************************************************/
405 static block_t *GetSoutBuffer( decoder_t *p_dec )
407 decoder_sys_t *p_sys = p_dec->p_sys;
410 p_block = block_New( p_dec, p_sys->i_frame_size );
411 if( p_block == NULL ) return NULL;
413 p_block->i_pts = p_block->i_dts = aout_DateGet( &p_sys->end_date );
416 aout_DateIncrement( &p_sys->end_date,
417 A52_FRAME_NB * p_sys->i_input_rate / INPUT_RATE_DEFAULT ) -
423 /*****************************************************************************
424 * SyncInfo: parse A/52 sync info
425 *****************************************************************************
426 * This code is borrowed from liba52 by Aaron Holtzman & Michel Lespinasse,
427 * since we don't want to oblige S/PDIF people to use liba52 just to get
429 *****************************************************************************/
430 static int SyncInfo( const uint8_t * p_buf,
431 unsigned int * pi_channels,
432 unsigned int * pi_channels_conf,
433 unsigned int * pi_sample_rate, int * pi_bit_rate )
435 static const uint8_t halfrate[12] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3 };
436 static const int rate[] = { 32, 40, 48, 56, 64, 80, 96, 112,
437 128, 160, 192, 224, 256, 320, 384, 448,
439 static const uint8_t lfeon[8] = { 0x10, 0x10, 0x04, 0x04,
440 0x04, 0x01, 0x04, 0x01 };
446 if ((p_buf[0] != 0x0b) || (p_buf[1] != 0x77)) /* syncword */
449 if (p_buf[5] >= 0x60) /* bsid >= 12 */
451 half = halfrate[p_buf[5] >> 3];
453 /* acmod, dsurmod and lfeon */
454 acmod = p_buf[6] >> 5;
455 if ( (p_buf[6] & 0xf8) == 0x50 )
457 /* Dolby surround = stereo + Dolby */
459 *pi_channels_conf = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
460 | AOUT_CHAN_DOLBYSTEREO;
462 else switch ( acmod )
465 /* Dual-mono = stereo + dual-mono */
467 *pi_channels_conf = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
468 | AOUT_CHAN_DUALMONO;
473 *pi_channels_conf = AOUT_CHAN_CENTER;
478 *pi_channels_conf = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT;
483 *pi_channels_conf = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
489 *pi_channels_conf = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
490 | AOUT_CHAN_REARCENTER;
495 *pi_channels_conf = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
496 | AOUT_CHAN_REARCENTER;
501 *pi_channels_conf = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
502 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT;
507 *pi_channels_conf = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
508 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT;
514 if ( p_buf[6] & lfeon[acmod] )
517 *pi_channels_conf |= AOUT_CHAN_LFE;
520 frmsizecod = p_buf[4] & 63;
521 if (frmsizecod >= 38)
523 bitrate = rate [frmsizecod >> 1];
524 *pi_bit_rate = (bitrate * 1000) >> half;
526 switch (p_buf[4] & 0xc0) {
528 *pi_sample_rate = 48000 >> half;
531 *pi_sample_rate = 44100 >> half;
532 return 2 * (320 * bitrate / 147 + (frmsizecod & 1));
534 *pi_sample_rate = 32000 >> half;