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 *****************************************************************************/
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( _("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( _("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 )
128 msg_Err( p_dec, "out of memory" );
133 p_sys->b_packetizer = false;
134 p_sys->i_state = STATE_NOSYNC;
135 aout_DateSet( &p_sys->end_date, 0 );
137 p_sys->bytestream = block_BytestreamInit();
138 p_sys->i_input_rate = INPUT_RATE_DEFAULT;
140 /* Set output properties */
141 p_dec->fmt_out.i_cat = AUDIO_ES;
142 p_dec->fmt_out.i_codec = VLC_FOURCC('a','5','2',' ');
143 p_dec->fmt_out.audio.i_rate = 0; /* So end_date gets initialized */
146 p_dec->pf_decode_audio = (aout_buffer_t *(*)(decoder_t *, block_t **))
148 p_dec->pf_packetize = (block_t *(*)(decoder_t *, block_t **))
154 static int OpenPacketizer( vlc_object_t *p_this )
156 decoder_t *p_dec = (decoder_t*)p_this;
158 int i_ret = OpenDecoder( p_this );
160 if( i_ret == VLC_SUCCESS ) p_dec->p_sys->b_packetizer = true;
165 /****************************************************************************
166 * DecodeBlock: the whole thing
167 ****************************************************************************
168 * This function is called just after the thread is launched.
169 ****************************************************************************/
170 static void *DecodeBlock( decoder_t *p_dec, block_t **pp_block )
172 decoder_sys_t *p_sys = p_dec->p_sys;
173 uint8_t p_header[A52_HEADER_SIZE];
177 if( !pp_block || !*pp_block ) return NULL;
179 if( (*pp_block)->i_flags&(BLOCK_FLAG_DISCONTINUITY|BLOCK_FLAG_CORRUPTED) )
181 if( (*pp_block)->i_flags&BLOCK_FLAG_CORRUPTED )
183 p_sys->i_state = STATE_NOSYNC;
184 block_BytestreamFlush( &p_sys->bytestream );
186 // aout_DateSet( &p_sys->end_date, 0 );
187 block_Release( *pp_block );
191 if( !aout_DateGet( &p_sys->end_date ) && !(*pp_block)->i_pts )
193 /* We've just started the stream, wait for the first PTS. */
194 block_Release( *pp_block );
198 if( (*pp_block)->i_rate > 0 )
199 p_sys->i_input_rate = (*pp_block)->i_rate;
201 block_BytestreamPush( &p_sys->bytestream, *pp_block );
205 switch( p_sys->i_state )
208 while( block_PeekBytes( &p_sys->bytestream, p_header, 2 )
211 if( p_header[0] == 0x0b && p_header[1] == 0x77 )
213 p_sys->i_state = STATE_SYNC;
216 block_SkipByte( &p_sys->bytestream );
218 if( p_sys->i_state != STATE_SYNC )
220 block_BytestreamFlush( &p_sys->bytestream );
227 /* New frame, set the Presentation Time Stamp */
228 p_sys->i_pts = p_sys->bytestream.p_block->i_pts;
229 if( p_sys->i_pts != 0 &&
230 p_sys->i_pts != aout_DateGet( &p_sys->end_date ) )
232 aout_DateSet( &p_sys->end_date, p_sys->i_pts );
234 p_sys->i_state = STATE_HEADER;
237 /* Get A/52 frame header (A52_HEADER_SIZE bytes) */
238 if( block_PeekBytes( &p_sys->bytestream, p_header,
239 A52_HEADER_SIZE ) != VLC_SUCCESS )
245 /* Check if frame is valid and get frame info */
246 p_sys->i_frame_size = SyncInfo( p_header,
248 &p_sys->i_channels_conf,
250 &p_sys->i_bit_rate );
251 if( !p_sys->i_frame_size )
253 msg_Dbg( p_dec, "emulated sync word" );
254 block_SkipByte( &p_sys->bytestream );
255 p_sys->i_state = STATE_NOSYNC;
258 p_sys->i_state = STATE_NEXT_SYNC;
260 case STATE_NEXT_SYNC:
261 /* TODO: If pp_block == NULL, flush the buffer without checking the
264 /* Check if next expected frame contains the sync word */
265 if( block_PeekOffsetBytes( &p_sys->bytestream,
266 p_sys->i_frame_size, p_header, 2 )
273 if( p_sys->b_packetizer &&
274 p_header[0] == 0 && p_header[1] == 0 )
276 /* A52 wav files and audio CD's use stuffing */
277 p_sys->i_state = STATE_GET_DATA;
281 if( p_header[0] != 0x0b || p_header[1] != 0x77 )
283 msg_Dbg( p_dec, "emulated sync word "
284 "(no sync on following frame)" );
285 p_sys->i_state = STATE_NOSYNC;
286 block_SkipByte( &p_sys->bytestream );
289 p_sys->i_state = STATE_SEND_DATA;
293 /* Make sure we have enough data.
294 * (Not useful if we went through NEXT_SYNC) */
295 if( block_WaitBytes( &p_sys->bytestream,
296 p_sys->i_frame_size ) != VLC_SUCCESS )
301 p_sys->i_state = STATE_SEND_DATA;
303 case STATE_SEND_DATA:
304 if( !(p_buf = GetOutBuffer( p_dec, &p_out_buffer )) )
306 //p_dec->b_error = true;
310 /* Copy the whole frame into the buffer. When we reach this point
311 * we already know we have enough data available. */
312 block_GetBytes( &p_sys->bytestream, p_buf, p_sys->i_frame_size );
314 /* Make sure we don't reuse the same pts twice */
315 if( p_sys->i_pts == p_sys->bytestream.p_block->i_pts )
316 p_sys->i_pts = p_sys->bytestream.p_block->i_pts = 0;
318 /* So p_block doesn't get re-added several times */
319 *pp_block = block_BytestreamPop( &p_sys->bytestream );
321 p_sys->i_state = STATE_NOSYNC;
330 /*****************************************************************************
331 * CloseDecoder: clean up the decoder
332 *****************************************************************************/
333 static void CloseDecoder( vlc_object_t *p_this )
335 decoder_t *p_dec = (decoder_t*)p_this;
336 decoder_sys_t *p_sys = p_dec->p_sys;
338 block_BytestreamRelease( &p_sys->bytestream );
343 /*****************************************************************************
345 *****************************************************************************/
346 static uint8_t *GetOutBuffer( decoder_t *p_dec, void **pp_out_buffer )
348 decoder_sys_t *p_sys = p_dec->p_sys;
351 if( p_dec->fmt_out.audio.i_rate != p_sys->i_rate )
353 msg_Info( p_dec, "A/52 channels:%d samplerate:%d bitrate:%d",
354 p_sys->i_channels, p_sys->i_rate, p_sys->i_bit_rate );
356 aout_DateInit( &p_sys->end_date, p_sys->i_rate );
357 aout_DateSet( &p_sys->end_date, p_sys->i_pts );
360 p_dec->fmt_out.audio.i_rate = p_sys->i_rate;
361 p_dec->fmt_out.audio.i_channels = p_sys->i_channels;
362 p_dec->fmt_out.audio.i_bytes_per_frame = p_sys->i_frame_size;
363 p_dec->fmt_out.audio.i_frame_length = A52_FRAME_NB;
365 p_dec->fmt_out.audio.i_original_channels = p_sys->i_channels_conf;
366 p_dec->fmt_out.audio.i_physical_channels =
367 p_sys->i_channels_conf & AOUT_CHAN_PHYSMASK;
369 p_dec->fmt_out.i_bitrate = p_sys->i_bit_rate;
371 if( p_sys->b_packetizer )
373 block_t *p_sout_buffer = GetSoutBuffer( p_dec );
374 p_buf = p_sout_buffer ? p_sout_buffer->p_buffer : NULL;
375 *pp_out_buffer = p_sout_buffer;
379 aout_buffer_t *p_aout_buffer = GetAoutBuffer( p_dec );
380 p_buf = p_aout_buffer ? p_aout_buffer->p_buffer : NULL;
381 *pp_out_buffer = p_aout_buffer;
387 /*****************************************************************************
389 *****************************************************************************/
390 static aout_buffer_t *GetAoutBuffer( decoder_t *p_dec )
392 decoder_sys_t *p_sys = p_dec->p_sys;
393 aout_buffer_t *p_buf;
395 p_buf = p_dec->pf_aout_buffer_new( p_dec, A52_FRAME_NB );
396 if( p_buf == NULL ) return NULL;
398 p_buf->start_date = aout_DateGet( &p_sys->end_date );
399 p_buf->end_date = aout_DateIncrement( &p_sys->end_date,
400 A52_FRAME_NB * p_sys->i_input_rate / INPUT_RATE_DEFAULT );
405 /*****************************************************************************
407 *****************************************************************************/
408 static block_t *GetSoutBuffer( decoder_t *p_dec )
410 decoder_sys_t *p_sys = p_dec->p_sys;
413 p_block = block_New( p_dec, p_sys->i_frame_size );
414 if( p_block == NULL ) return NULL;
416 p_block->i_pts = p_block->i_dts = aout_DateGet( &p_sys->end_date );
419 aout_DateIncrement( &p_sys->end_date,
420 A52_FRAME_NB * p_sys->i_input_rate / INPUT_RATE_DEFAULT ) -
426 /*****************************************************************************
427 * SyncInfo: parse A/52 sync info
428 *****************************************************************************
429 * This code is borrowed from liba52 by Aaron Holtzman & Michel Lespinasse,
430 * since we don't want to oblige S/PDIF people to use liba52 just to get
432 *****************************************************************************/
433 static int SyncInfo( const uint8_t * p_buf,
434 unsigned int * pi_channels,
435 unsigned int * pi_channels_conf,
436 unsigned int * pi_sample_rate, int * pi_bit_rate )
438 static const uint8_t halfrate[12] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3 };
439 static const int rate[] = { 32, 40, 48, 56, 64, 80, 96, 112,
440 128, 160, 192, 224, 256, 320, 384, 448,
442 static const uint8_t lfeon[8] = { 0x10, 0x10, 0x04, 0x04,
443 0x04, 0x01, 0x04, 0x01 };
449 if ((p_buf[0] != 0x0b) || (p_buf[1] != 0x77)) /* syncword */
452 if (p_buf[5] >= 0x60) /* bsid >= 12 */
454 half = halfrate[p_buf[5] >> 3];
456 /* acmod, dsurmod and lfeon */
457 acmod = p_buf[6] >> 5;
458 if ( (p_buf[6] & 0xf8) == 0x50 )
460 /* Dolby surround = stereo + Dolby */
462 *pi_channels_conf = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
463 | AOUT_CHAN_DOLBYSTEREO;
465 else switch ( acmod )
468 /* Dual-mono = stereo + dual-mono */
470 *pi_channels_conf = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
471 | AOUT_CHAN_DUALMONO;
476 *pi_channels_conf = AOUT_CHAN_CENTER;
481 *pi_channels_conf = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT;
486 *pi_channels_conf = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
492 *pi_channels_conf = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
493 | AOUT_CHAN_REARCENTER;
498 *pi_channels_conf = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
499 | AOUT_CHAN_REARCENTER;
504 *pi_channels_conf = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
505 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT;
510 *pi_channels_conf = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
511 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT;
517 if ( p_buf[6] & lfeon[acmod] )
520 *pi_channels_conf |= AOUT_CHAN_LFE;
523 frmsizecod = p_buf[4] & 63;
524 if (frmsizecod >= 38)
526 bitrate = rate [frmsizecod >> 1];
527 *pi_bit_rate = (bitrate * 1000) >> half;
529 switch (p_buf[4] & 0xc0) {
531 *pi_sample_rate = 48000 >> half;
534 *pi_sample_rate = 44100 >> half;
535 return 2 * (320 * bitrate / 147 + (frmsizecod & 1));
537 *pi_sample_rate = 32000 >> half;