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>
41 /*****************************************************************************
43 *****************************************************************************/
44 static int OpenDecoder ( vlc_object_t * );
45 static int OpenPacketizer( vlc_object_t * );
46 static void CloseCommon ( vlc_object_t * );
49 set_description( N_("A/52 parser") )
50 set_capability( "decoder", 100 )
51 set_callbacks( OpenDecoder, CloseCommon )
52 set_category( CAT_INPUT )
53 set_subcategory( SUBCAT_INPUT_ACODEC )
56 set_description( N_("A/52 audio packetizer") )
57 set_capability( "packetizer", 10 )
58 set_callbacks( OpenPacketizer, CloseCommon )
61 /*****************************************************************************
62 * decoder_sys_t : decoder descriptor
63 *****************************************************************************/
75 block_bytestream_t bytestream;
80 audio_date_t end_date;
84 vlc_a52_header_t frame;
97 /****************************************************************************
99 ****************************************************************************/
100 static void *DecodeBlock ( decoder_t *, block_t ** );
102 static uint8_t *GetOutBuffer ( decoder_t *, void ** );
103 static aout_buffer_t *GetAoutBuffer( decoder_t * );
104 static block_t *GetSoutBuffer( decoder_t * );
106 /*****************************************************************************
107 * OpenCommon: probe the decoder/packetizer and return score
108 *****************************************************************************/
109 static int OpenCommon( vlc_object_t *p_this, bool b_packetizer )
111 decoder_t *p_dec = (decoder_t*)p_this;
112 decoder_sys_t *p_sys;
113 vlc_fourcc_t i_codec;
115 switch( p_dec->fmt_in.i_codec )
118 i_codec = VLC_CODEC_A52;
121 /* XXX ugly hack, a52 does not support eac3 so no eac3 pass-through
125 i_codec = VLC_CODEC_EAC3;
131 /* Allocate the memory needed to store the decoder's structure */
132 if( ( p_dec->p_sys = p_sys =
133 (decoder_sys_t *)malloc(sizeof(decoder_sys_t)) ) == NULL )
137 p_sys->b_packetizer = b_packetizer;
138 p_sys->i_state = STATE_NOSYNC;
139 aout_DateSet( &p_sys->end_date, 0 );
141 p_sys->bytestream = block_BytestreamInit();
143 /* Set output properties */
144 p_dec->fmt_out.i_cat = AUDIO_ES;
145 p_dec->fmt_out.i_codec = i_codec;
146 p_dec->fmt_out.audio.i_rate = 0; /* So end_date gets initialized */
147 p_dec->fmt_out.audio.i_bytes_per_frame = 0;
151 p_dec->pf_packetize = (block_t *(*)(decoder_t *, block_t **))
154 p_dec->pf_decode_audio = (aout_buffer_t *(*)(decoder_t *, block_t **))
159 static int OpenDecoder( vlc_object_t *p_this )
161 return OpenCommon( p_this, false );
164 static int OpenPacketizer( vlc_object_t *p_this )
166 return OpenCommon( p_this, true );
169 /****************************************************************************
170 * DecodeBlock: the whole thing
171 ****************************************************************************
172 * This function is called just after the thread is launched.
173 ****************************************************************************/
174 static void *DecodeBlock( decoder_t *p_dec, block_t **pp_block )
176 decoder_sys_t *p_sys = p_dec->p_sys;
177 uint8_t p_header[VLC_A52_HEADER_SIZE];
181 if( !pp_block || !*pp_block ) return NULL;
183 if( (*pp_block)->i_flags&(BLOCK_FLAG_DISCONTINUITY|BLOCK_FLAG_CORRUPTED) )
185 if( (*pp_block)->i_flags&BLOCK_FLAG_CORRUPTED )
187 p_sys->i_state = STATE_NOSYNC;
188 block_BytestreamEmpty( &p_sys->bytestream );
190 aout_DateSet( &p_sys->end_date, 0 );
191 block_Release( *pp_block );
195 if( !aout_DateGet( &p_sys->end_date ) && !(*pp_block)->i_pts )
197 /* We've just started the stream, wait for the first PTS. */
198 block_Release( *pp_block );
202 block_BytestreamPush( &p_sys->bytestream, *pp_block );
206 switch( p_sys->i_state )
209 while( block_PeekBytes( &p_sys->bytestream, p_header, 2 )
212 if( p_header[0] == 0x0b && p_header[1] == 0x77 )
214 p_sys->i_state = STATE_SYNC;
217 block_SkipByte( &p_sys->bytestream );
219 if( p_sys->i_state != STATE_SYNC )
221 block_BytestreamFlush( &p_sys->bytestream );
228 /* New frame, set the Presentation Time Stamp */
229 p_sys->i_pts = p_sys->bytestream.p_block->i_pts;
230 if( p_sys->i_pts != 0 &&
231 p_sys->i_pts != aout_DateGet( &p_sys->end_date ) )
233 aout_DateSet( &p_sys->end_date, p_sys->i_pts );
235 p_sys->i_state = STATE_HEADER;
238 /* Get A/52 frame header (VLC_A52_HEADER_SIZE bytes) */
239 if( block_PeekBytes( &p_sys->bytestream, p_header,
240 VLC_A52_HEADER_SIZE ) != VLC_SUCCESS )
246 /* Check if frame is valid and get frame info */
247 if( vlc_a52_header_Parse( &p_sys->frame, p_header, VLC_A52_HEADER_SIZE ) )
249 msg_Dbg( p_dec, "emulated sync word" );
250 block_SkipByte( &p_sys->bytestream );
251 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->frame.i_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->frame.i_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->frame.i_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 * CloseCommon: clean up the decoder
329 *****************************************************************************/
330 static void CloseCommon( 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->frame.i_rate )
350 msg_Info( p_dec, "A/52 channels:%d samplerate:%d bitrate:%d",
351 p_sys->frame.i_channels, p_sys->frame.i_rate, p_sys->frame.i_bitrate );
353 aout_DateInit( &p_sys->end_date, p_sys->frame.i_rate );
354 aout_DateSet( &p_sys->end_date, p_sys->i_pts );
357 p_dec->fmt_out.audio.i_rate = p_sys->frame.i_rate;
358 p_dec->fmt_out.audio.i_channels = p_sys->frame.i_channels;
359 if( p_dec->fmt_out.audio.i_bytes_per_frame < p_sys->frame.i_size )
360 p_dec->fmt_out.audio.i_bytes_per_frame = p_sys->frame.i_size;
361 p_dec->fmt_out.audio.i_frame_length = p_sys->frame.i_samples;
363 p_dec->fmt_out.audio.i_original_channels = p_sys->frame.i_channels_conf;
364 p_dec->fmt_out.audio.i_physical_channels =
365 p_sys->frame.i_channels_conf & AOUT_CHAN_PHYSMASK;
367 p_dec->fmt_out.i_bitrate = p_sys->frame.i_bitrate;
369 if( p_sys->b_packetizer )
371 block_t *p_sout_buffer = GetSoutBuffer( p_dec );
372 p_buf = p_sout_buffer ? p_sout_buffer->p_buffer : NULL;
373 *pp_out_buffer = p_sout_buffer;
377 aout_buffer_t *p_aout_buffer = GetAoutBuffer( p_dec );
378 p_buf = p_aout_buffer ? p_aout_buffer->p_buffer : NULL;
379 *pp_out_buffer = p_aout_buffer;
385 /*****************************************************************************
387 *****************************************************************************/
388 static aout_buffer_t *GetAoutBuffer( decoder_t *p_dec )
390 decoder_sys_t *p_sys = p_dec->p_sys;
391 aout_buffer_t *p_buf;
393 p_buf = decoder_NewAudioBuffer( p_dec, p_sys->frame.i_samples );
394 if( p_buf == NULL ) return NULL;
396 p_buf->start_date = aout_DateGet( &p_sys->end_date );
397 p_buf->end_date = aout_DateIncrement( &p_sys->end_date, p_sys->frame.i_samples );
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->frame.i_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, p_sys->frame.i_samples ) - p_block->i_pts;