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_block_helper.h>
38 #include <vlc_modules.h>
42 /*****************************************************************************
44 *****************************************************************************/
45 static int OpenDecoder ( vlc_object_t * );
46 static int OpenPacketizer( vlc_object_t * );
47 static void CloseCommon ( vlc_object_t * );
50 set_description( N_("A/52 parser") )
51 set_capability( "decoder", 100 )
52 set_callbacks( OpenDecoder, CloseCommon )
53 set_category( CAT_INPUT )
54 set_subcategory( SUBCAT_INPUT_ACODEC )
57 set_description( N_("A/52 audio packetizer") )
58 set_capability( "packetizer", 10 )
59 set_callbacks( OpenPacketizer, CloseCommon )
62 /*****************************************************************************
63 * decoder_sys_t : decoder descriptor
64 *****************************************************************************/
76 block_bytestream_t bytestream;
85 vlc_a52_header_t frame;
98 /****************************************************************************
100 ****************************************************************************/
101 static block_t *DecodeBlock ( decoder_t *, block_t ** );
103 static uint8_t *GetOutBuffer ( decoder_t *, block_t ** );
104 static aout_buffer_t *GetAoutBuffer( decoder_t * );
105 static block_t *GetSoutBuffer( decoder_t * );
107 /*****************************************************************************
108 * OpenCommon: probe the decoder/packetizer and return score
109 *****************************************************************************/
110 static int OpenCommon( vlc_object_t *p_this, bool b_packetizer )
112 decoder_t *p_dec = (decoder_t*)p_this;
113 decoder_sys_t *p_sys;
114 vlc_fourcc_t i_codec;
116 switch( p_dec->fmt_in.i_codec )
119 i_codec = VLC_CODEC_A52;
122 /* XXX ugly hack, a52 does not support eac3 so no eac3 pass-through
126 i_codec = VLC_CODEC_EAC3;
132 /* Allocate the memory needed to store the decoder's structure */
133 if( ( p_dec->p_sys = p_sys =
134 (decoder_sys_t *)malloc(sizeof(decoder_sys_t)) ) == NULL )
138 p_sys->b_packetizer = b_packetizer;
139 p_sys->i_state = STATE_NOSYNC;
140 date_Set( &p_sys->end_date, 0 );
141 p_sys->i_pts = VLC_TS_INVALID;
143 block_BytestreamInit( &p_sys->bytestream );
145 /* Set output properties */
146 p_dec->fmt_out.i_cat = AUDIO_ES;
147 p_dec->fmt_out.i_codec = i_codec;
148 p_dec->fmt_out.audio.i_rate = 0; /* So end_date gets initialized */
149 p_dec->fmt_out.audio.i_bytes_per_frame = 0;
153 p_dec->pf_packetize = DecodeBlock;
155 p_dec->pf_decode_audio = DecodeBlock;
159 static int OpenDecoder( vlc_object_t *p_this )
161 /* HACK: Don't use this codec if we don't have an a52 audio filter */
162 if( !module_exists( "a52tofloat32" ) )
164 return OpenCommon( p_this, false );
167 static int OpenPacketizer( vlc_object_t *p_this )
169 return OpenCommon( p_this, true );
172 /****************************************************************************
173 * DecodeBlock: the whole thing
174 ****************************************************************************
175 * This function is called just after the thread is launched.
176 ****************************************************************************/
177 static block_t *DecodeBlock( decoder_t *p_dec, block_t **pp_block )
179 decoder_sys_t *p_sys = p_dec->p_sys;
180 uint8_t p_header[VLC_A52_HEADER_SIZE];
182 block_t *p_out_buffer;
184 if( !pp_block || !*pp_block ) return NULL;
186 if( (*pp_block)->i_flags&(BLOCK_FLAG_DISCONTINUITY|BLOCK_FLAG_CORRUPTED) )
188 if( (*pp_block)->i_flags&BLOCK_FLAG_CORRUPTED )
190 p_sys->i_state = STATE_NOSYNC;
191 block_BytestreamEmpty( &p_sys->bytestream );
193 date_Set( &p_sys->end_date, 0 );
194 block_Release( *pp_block );
198 if( !date_Get( &p_sys->end_date ) && (*pp_block)->i_pts <= VLC_TS_INVALID)
200 /* We've just started the stream, wait for the first PTS. */
201 block_Release( *pp_block );
205 block_BytestreamPush( &p_sys->bytestream, *pp_block );
209 switch( p_sys->i_state )
212 while( block_PeekBytes( &p_sys->bytestream, p_header, 2 )
215 if( p_header[0] == 0x0b && p_header[1] == 0x77 )
217 p_sys->i_state = STATE_SYNC;
220 block_SkipByte( &p_sys->bytestream );
222 if( p_sys->i_state != STATE_SYNC )
224 block_BytestreamFlush( &p_sys->bytestream );
231 /* New frame, set the Presentation Time Stamp */
232 p_sys->i_pts = p_sys->bytestream.p_block->i_pts;
233 if( p_sys->i_pts > VLC_TS_INVALID &&
234 p_sys->i_pts != date_Get( &p_sys->end_date ) )
236 date_Set( &p_sys->end_date, p_sys->i_pts );
238 p_sys->i_state = STATE_HEADER;
241 /* Get A/52 frame header (VLC_A52_HEADER_SIZE bytes) */
242 if( block_PeekBytes( &p_sys->bytestream, p_header,
243 VLC_A52_HEADER_SIZE ) != VLC_SUCCESS )
249 /* Check if frame is valid and get frame info */
250 if( vlc_a52_header_Parse( &p_sys->frame, p_header, VLC_A52_HEADER_SIZE ) )
252 msg_Dbg( p_dec, "emulated sync word" );
253 block_SkipByte( &p_sys->bytestream );
254 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->frame.i_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->frame.i_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,
313 p_buf, __MIN( p_sys->frame.i_size, p_out_buffer->i_buffer ) );
315 /* Make sure we don't reuse the same pts twice */
316 if( p_sys->i_pts == p_sys->bytestream.p_block->i_pts )
317 p_sys->i_pts = p_sys->bytestream.p_block->i_pts = VLC_TS_INVALID;
319 /* So p_block doesn't get re-added several times */
320 *pp_block = block_BytestreamPop( &p_sys->bytestream );
322 p_sys->i_state = STATE_NOSYNC;
331 /*****************************************************************************
332 * CloseCommon: clean up the decoder
333 *****************************************************************************/
334 static void CloseCommon( vlc_object_t *p_this )
336 decoder_t *p_dec = (decoder_t*)p_this;
337 decoder_sys_t *p_sys = p_dec->p_sys;
339 block_BytestreamRelease( &p_sys->bytestream );
344 /*****************************************************************************
346 *****************************************************************************/
347 static uint8_t *GetOutBuffer( decoder_t *p_dec, block_t **pp_out_buffer )
349 decoder_sys_t *p_sys = p_dec->p_sys;
352 if( p_dec->fmt_out.audio.i_rate != p_sys->frame.i_rate )
354 msg_Dbg( p_dec, "A/52 channels:%d samplerate:%d bitrate:%d",
355 p_sys->frame.i_channels, p_sys->frame.i_rate, p_sys->frame.i_bitrate );
357 date_Init( &p_sys->end_date, p_sys->frame.i_rate, 1 );
358 date_Set( &p_sys->end_date, p_sys->i_pts );
361 p_dec->fmt_out.audio.i_rate = p_sys->frame.i_rate;
362 p_dec->fmt_out.audio.i_channels = p_sys->frame.i_channels;
363 if( p_dec->fmt_out.audio.i_bytes_per_frame < p_sys->frame.i_size )
364 p_dec->fmt_out.audio.i_bytes_per_frame = p_sys->frame.i_size;
365 p_dec->fmt_out.audio.i_frame_length = p_sys->frame.i_samples;
367 p_dec->fmt_out.audio.i_original_channels = p_sys->frame.i_channels_conf;
368 p_dec->fmt_out.audio.i_physical_channels =
369 p_sys->frame.i_channels_conf & AOUT_CHAN_PHYSMASK;
371 p_dec->fmt_out.i_bitrate = p_sys->frame.i_bitrate;
373 if( p_sys->b_packetizer )
375 block_t *p_sout_buffer = GetSoutBuffer( p_dec );
376 p_buf = p_sout_buffer ? p_sout_buffer->p_buffer : NULL;
377 *pp_out_buffer = p_sout_buffer;
381 aout_buffer_t *p_aout_buffer = GetAoutBuffer( p_dec );
382 p_buf = p_aout_buffer ? p_aout_buffer->p_buffer : NULL;
383 *pp_out_buffer = p_aout_buffer;
389 /*****************************************************************************
391 *****************************************************************************/
392 static aout_buffer_t *GetAoutBuffer( decoder_t *p_dec )
394 decoder_sys_t *p_sys = p_dec->p_sys;
395 aout_buffer_t *p_buf;
397 p_buf = decoder_NewAudioBuffer( p_dec, p_sys->frame.i_samples );
398 if( p_buf == NULL ) return NULL;
400 p_buf->i_pts = date_Get( &p_sys->end_date );
401 p_buf->i_length = date_Increment( &p_sys->end_date,
402 p_sys->frame.i_samples ) - p_buf->i_pts;
407 /*****************************************************************************
409 *****************************************************************************/
410 static block_t *GetSoutBuffer( decoder_t *p_dec )
412 decoder_sys_t *p_sys = p_dec->p_sys;
415 p_block = block_New( p_dec, p_sys->frame.i_size );
416 if( p_block == NULL ) return NULL;
418 p_block->i_pts = p_block->i_dts = date_Get( &p_sys->end_date );
421 date_Increment( &p_sys->end_date, p_sys->frame.i_samples ) - p_block->i_pts;