1 /*****************************************************************************
2 * mpeg4audio.c: parse and packetize an MPEG 4 audio stream
3 *****************************************************************************
4 * Copyright (C) 2001, 2002 VideoLAN
5 * $Id: mpeg4audio.c,v 1.11 2003/10/24 17:55:14 gbazin Exp $
7 * Authors: Laurent Aimar <fenrir@via.ecp.fr>
8 * Gildas Bazin <gbazin@netcourrier.com>
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
23 *****************************************************************************/
25 /*****************************************************************************
27 *****************************************************************************/
28 #include <stdlib.h> /* malloc(), free() */
29 #include <string.h> /* strdup() */
33 #include <vlc/decoder.h>
34 #include <vlc/input.h>
38 #include "vlc_block_helper.h"
42 * AudioObjectType 5 bits
43 * samplingFrequencyIndex 4 bits
44 * if (samplingFrequencyIndex == 0xF)
45 * samplingFrequency 24 bits
46 * channelConfiguration 4 bits
48 * FrameLengthFlag 1 bit 1024 or 960
49 * DependsOnCoreCoder 1 bit (always 0)
50 * ExtensionFlag 1 bit (always 0)
53 /*****************************************************************************
54 * decoder_sys_t : decoder descriptor
55 *****************************************************************************/
64 block_bytestream_t bytestream;
67 * Packetizer output properties
69 sout_packetizer_input_t *p_sout_input;
70 sout_format_t sout_format;
71 sout_buffer_t * p_sout_buffer; /* current sout buffer */
76 audio_date_t end_date;
79 int i_frame_size, i_raw_blocks;
80 unsigned int i_channels;
81 unsigned int i_rate, i_frame_length, i_header_size;
93 static int i_sample_rates[] =
95 96000, 88200, 64000, 48000, 44100, 32000, 24000, 22050,
96 16000, 12000, 11025, 8000, 7350, 0, 0, 0
99 #define ADTS_HEADER_SIZE 9
101 /****************************************************************************
103 ****************************************************************************/
104 static int OpenPacketizer( vlc_object_t * );
105 static int InitPacketizer( decoder_t * );
106 static int RunFramePacketizer ( decoder_t *, block_t * );
107 static int RunADTSPacketizer ( decoder_t *, block_t * );
108 static int EndPacketizer ( decoder_t * );
109 static int GetSoutBuffer( decoder_t *, sout_buffer_t ** );
111 static int ADTSSyncInfo( decoder_t *, const byte_t * p_buf,
112 unsigned int * pi_channels,
113 unsigned int * pi_sample_rate,
114 unsigned int * pi_frame_length,
115 unsigned int * pi_header_size,
116 unsigned int * pi_raw_blocks );
118 /*****************************************************************************
120 *****************************************************************************/
122 set_description( _("MPEG4 Audio packetizer") );
123 set_capability( "packetizer", 50 );
124 set_callbacks( OpenPacketizer, NULL );
127 /*****************************************************************************
128 * OpenPacketizer: probe the packetizer and return score
129 *****************************************************************************/
130 static int OpenPacketizer( vlc_object_t *p_this )
132 decoder_t *p_dec = (decoder_t*)p_this;
134 if( p_dec->p_fifo->i_fourcc != VLC_FOURCC( 'm', 'p', '4', 'a' ) )
139 /* Allocate the memory needed to store the decoder's structure */
141 (decoder_sys_t *)malloc(sizeof(decoder_sys_t)) ) == NULL )
143 msg_Err( p_dec, "out of memory" );
147 p_dec->pf_init = InitPacketizer;
148 p_dec->pf_decode = RunFramePacketizer;
149 p_dec->pf_end = EndPacketizer;
154 /*****************************************************************************
155 * InitPacketizer: Initalize the packetizer
156 *****************************************************************************/
157 static int InitPacketizer( decoder_t *p_dec )
159 decoder_sys_t *p_sys = p_dec->p_sys;
162 p_sys->i_state = STATE_NOSYNC;
164 aout_DateSet( &p_sys->end_date, 0 );
166 p_sys->p_sout_input = NULL;
167 p_sys->p_sout_buffer = NULL;
168 p_sys->p_chain = NULL;
170 msg_Info( p_dec, "Running MPEG4 audio packetizer" );
172 p_wf = (WAVEFORMATEX*)p_dec->p_fifo->p_waveformatex;
174 if( p_wf && p_wf->cbSize > 0)
176 uint8_t *p_config = (uint8_t*)&p_wf[1];
179 i_index = ( ( p_config[0] << 1 ) | ( p_config[1] >> 7 ) ) & 0x0f;
180 if( i_index != 0x0f )
182 p_sys->i_rate = i_sample_rates[i_index];
183 p_sys->i_frame_length = (( p_config[1] >> 2 ) & 0x01) ? 960 : 1024;
187 p_sys->i_rate = ( ( p_config[1] & 0x7f ) << 17 ) |
188 ( p_config[2] << 9 ) | ( p_config[3] << 1 ) |
189 ( p_config[4] >> 7 );
190 p_sys->i_frame_length = (( p_config[4] >> 2 ) & 0x01) ? 960 : 1024;
193 msg_Dbg( p_dec, "AAC %dHz %d samples/frame",
194 p_sys->i_rate, p_sys->i_frame_length );
196 p_sys->i_channels = p_wf->nChannels;
197 p_sys->sout_format.i_extra_data = p_wf->cbSize;
198 p_sys->sout_format.p_extra_data = malloc( p_wf->cbSize );
199 memcpy( p_sys->sout_format.p_extra_data, &p_wf[1], p_wf->cbSize );
203 msg_Dbg( p_dec, "No decoder specific info, must be an ADTS stream" );
205 /* We will try to create a AAC Config from adts */
206 p_sys->sout_format.i_extra_data = 0;
207 p_sys->sout_format.p_extra_data = NULL;
208 p_dec->pf_decode = RunADTSPacketizer;
214 /****************************************************************************
215 * RunFramePacketizer: the whole thing
216 ****************************************************************************
217 * This function must be fed with complete frames.
218 ****************************************************************************/
219 static int RunFramePacketizer( decoder_t *p_dec, block_t *p_block )
221 decoder_sys_t *p_sys = p_dec->p_sys;
223 if( !aout_DateGet( &p_sys->end_date ) && !p_block->i_pts )
225 /* We've just started the stream, wait for the first PTS. */
226 block_Release( p_block );
230 p_sys->pts = p_block->i_pts;
231 p_sys->i_frame_size = p_block->i_buffer;
233 if( GetSoutBuffer( p_dec, &p_sys->p_sout_buffer ) != VLC_SUCCESS )
238 /* Copy the whole frame into the buffer */
239 p_dec->p_vlc->pf_memcpy( p_sys->p_sout_buffer->p_buffer,
240 p_block->p_buffer, p_block->i_buffer );
242 sout_InputSendBuffer( p_sys->p_sout_input, p_sys->p_sout_buffer );
243 p_sys->p_sout_buffer = NULL;
245 block_Release( p_block );
249 /****************************************************************************
250 * RunADTSPacketizer: the whole thing
251 ****************************************************************************/
252 static int RunADTSPacketizer( decoder_t *p_dec, block_t *p_block )
254 decoder_sys_t *p_sys = p_dec->p_sys;
255 uint8_t p_header[ADTS_HEADER_SIZE];
257 if( !aout_DateGet( &p_sys->end_date ) && !p_block->i_pts )
259 /* We've just started the stream, wait for the first PTS. */
260 block_Release( p_block );
264 if( p_block->b_discontinuity )
266 p_sys->i_state = STATE_SYNC;
271 block_ChainAppend( &p_sys->p_chain, p_block );
275 block_ChainAppend( &p_sys->p_chain, p_block );
276 p_sys->bytestream = block_BytestreamInit( p_dec, p_sys->p_chain, 0 );
281 switch( p_sys->i_state )
285 while( block_PeekBytes( &p_sys->bytestream, p_header, 2 )
288 /* Look for sync word - should be 0xfff + 2 layer bits */
289 if( p_header[0] == 0xff && (p_header[1] & 0xf6) == 0xf0 )
291 p_sys->i_state = STATE_SYNC;
294 block_SkipByte( &p_sys->bytestream );
296 if( p_sys->i_state != STATE_SYNC )
298 if( block_PeekByte( &p_sys->bytestream, p_header )
299 == VLC_SUCCESS && p_header[0] == 0xff )
301 /* Start of a sync word, need more data */
305 block_ChainRelease( p_sys->p_chain );
306 p_sys->p_chain = NULL;
313 /* New frame, set the Presentation Time Stamp */
314 p_sys->pts = p_sys->bytestream.p_block->i_pts;
315 if( p_sys->pts != 0 &&
316 p_sys->pts != aout_DateGet( &p_sys->end_date ) )
318 aout_DateSet( &p_sys->end_date, p_sys->pts );
320 p_sys->i_state = STATE_HEADER;
324 /* Get ADTS frame header (ADTS_HEADER_SIZE bytes) */
325 if( block_PeekBytes( &p_sys->bytestream, p_header,
326 ADTS_HEADER_SIZE ) != VLC_SUCCESS )
332 /* Check if frame is valid and get frame info */
333 p_sys->i_frame_size = ADTSSyncInfo( p_dec, p_header,
336 &p_sys->i_frame_length,
337 &p_sys->i_header_size,
338 &p_sys->i_raw_blocks );
339 if( p_sys->i_frame_size <= 0 )
341 msg_Dbg( p_dec, "emulated sync word" );
342 block_SkipByte( &p_sys->bytestream );
343 p_sys->i_state = STATE_NOSYNC;
347 p_sys->i_state = STATE_DATA;
350 /* TODO: If p_block == NULL, flush the buffer without checking the
353 /* Check if next expected frame contains the sync word */
354 if( block_PeekOffsetBytes( &p_sys->bytestream, p_sys->i_frame_size
355 + p_sys->i_header_size, p_header, 2 )
362 if( p_header[0] != 0xff || (p_header[1] & 0xf6) != 0xf0 )
364 msg_Dbg( p_dec, "emulated sync word "
365 "(no sync on following frame)" );
366 p_sys->i_state = STATE_NOSYNC;
367 block_SkipByte( &p_sys->bytestream );
371 if( !p_sys->p_sout_buffer )
372 if( GetSoutBuffer( p_dec, &p_sys->p_sout_buffer ) != VLC_SUCCESS )
377 /* Skip the ADTS header */
378 if( p_sys->i_header_size )
380 if( block_SkipBytes( &p_sys->bytestream,
381 p_sys->i_header_size ) != VLC_SUCCESS )
386 p_sys->i_header_size = 0;
389 /* Copy the whole frame into the buffer */
390 if( block_GetBytes( &p_sys->bytestream,
391 p_sys->p_sout_buffer->p_buffer,
392 p_sys->i_frame_size ) != VLC_SUCCESS )
398 p_sys->p_chain = block_BytestreamFlush( &p_sys->bytestream );
400 sout_InputSendBuffer( p_sys->p_sout_input, p_sys->p_sout_buffer );
402 p_sys->i_state = STATE_NOSYNC;
403 p_sys->p_sout_buffer = NULL;
405 /* Make sure we don't reuse the same pts twice */
406 if( p_sys->pts == p_sys->bytestream.p_block->i_pts )
407 p_sys->pts = p_sys->bytestream.p_block->i_pts = 0;
414 /*****************************************************************************
416 *****************************************************************************/
417 static int GetSoutBuffer( decoder_t *p_dec, sout_buffer_t **pp_buffer )
419 decoder_sys_t *p_sys = p_dec->p_sys;
421 if( p_sys->p_sout_input != NULL &&
422 ( p_sys->sout_format.i_sample_rate != (int)p_sys->i_rate
423 || p_sys->sout_format.i_channels != (int)p_sys->i_channels ) )
425 /* Parameters changed - this should not happen. */
428 /* Creating the sout input if not created yet. */
429 if( p_sys->p_sout_input == NULL )
431 p_sys->sout_format.i_cat = AUDIO_ES;
432 p_sys->sout_format.i_fourcc = VLC_FOURCC( 'm', 'p', '4', 'a' );
433 p_sys->sout_format.i_sample_rate = p_sys->i_rate;
434 p_sys->sout_format.i_channels = p_sys->i_channels;
435 p_sys->sout_format.i_block_align = 0;
436 p_sys->sout_format.i_bitrate = 0;
438 aout_DateInit( &p_sys->end_date, p_sys->i_rate );
439 aout_DateSet( &p_sys->end_date, p_sys->pts );
441 p_sys->p_sout_input = sout_InputNew( p_dec, &p_sys->sout_format );
442 if( p_sys->p_sout_input == NULL )
444 msg_Err( p_dec, "cannot add a new stream" );
448 msg_Info( p_dec, "AAC channels: %d samplerate: %d",
449 p_sys->i_channels, p_sys->i_rate );
452 *pp_buffer = sout_BufferNew( p_sys->p_sout_input->p_sout,
453 p_sys->i_frame_size );
454 if( *pp_buffer == NULL )
459 (*pp_buffer)->i_pts =
460 (*pp_buffer)->i_dts = aout_DateGet( &p_sys->end_date );
462 (*pp_buffer)->i_length =
463 aout_DateIncrement( &p_sys->end_date, p_sys->i_frame_length )
464 - (*pp_buffer)->i_pts;
469 /*****************************************************************************
470 * EndPacketizer: clean up the packetizer
471 *****************************************************************************/
472 static int EndPacketizer( decoder_t *p_dec )
474 if( p_dec->p_sys->p_sout_input != NULL )
476 if( p_dec->p_sys->p_sout_buffer )
478 sout_BufferDelete( p_dec->p_sys->p_sout_input->p_sout,
479 p_dec->p_sys->p_sout_buffer );
482 sout_InputDelete( p_dec->p_sys->p_sout_input );
485 if( p_dec->p_sys->p_chain ) block_ChainRelease( p_dec->p_sys->p_chain );
487 free( p_dec->p_sys );
492 /*****************************************************************************
493 * ADTSSyncInfo: parse MPEG 4 audio ADTS sync info
494 *****************************************************************************/
495 static int ADTSSyncInfo( decoder_t * p_dec, const byte_t * p_buf,
496 unsigned int * pi_channels,
497 unsigned int * pi_sample_rate,
498 unsigned int * pi_frame_length,
499 unsigned int * pi_header_size,
500 unsigned int * pi_raw_blocks_in_frame )
502 decoder_sys_t *p_sys = p_dec->p_sys;
503 int i_id, i_profile, i_sample_rate_idx, i_frame_size;
506 /* Fixed header between frames */
507 i_id = ( (p_buf[1] >> 3) & 0x01 ) ? 2 : 4;
508 b_crc = !(p_buf[1] & 0x01);
509 i_profile = p_buf[2] >> 6;
510 i_sample_rate_idx = (p_buf[2] >> 2) & 0x0f;
511 *pi_sample_rate = i_sample_rates[i_sample_rate_idx];
512 *pi_channels = ((p_buf[2] & 0x01) << 2) | ((p_buf[3] >> 6) & 0x03);
514 /* Variable header */
515 i_frame_size = ((p_buf[3] & 0x03) << 11) | (p_buf[4] << 3) |
516 ((p_buf[5] >> 5) & 0x7);
517 *pi_raw_blocks_in_frame = (p_buf[6] & 0x02) + 1;
519 if( !*pi_sample_rate || !*pi_channels || !i_frame_size )
525 *pi_frame_length = 1024;
527 /* Build the decoder specific info header */
528 if( !p_dec->p_sys->sout_format.i_extra_data )
530 p_sys->sout_format.i_extra_data = 2;
531 p_sys->sout_format.p_extra_data = malloc( 2 );
532 p_sys->sout_format.p_extra_data[0] =
533 (i_profile + 1) << 3 | (i_sample_rate_idx >> 1);
534 p_sys->sout_format.p_extra_data[1] =
535 ((i_sample_rate_idx & 0x01) << 7) | (*pi_channels <<3);
538 /* ADTS header length */
539 *pi_header_size = b_crc ? 9 : 7;
541 return i_frame_size - *pi_header_size;