1 /*****************************************************************************
2 * mpeg4audio.c: parse and packetize an MPEG 4 audio stream
3 *****************************************************************************
4 * Copyright (C) 2001, 2002, 2006 the VideoLAN team
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., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
23 *****************************************************************************/
25 /*****************************************************************************
27 *****************************************************************************/
31 #include <vlc_codec.h>
32 #include <vlc_block.h>
34 #include <vlc_codecs.h>
35 #include <vlc_input.h>
37 #include "vlc_block_helper.h"
41 * AudioObjectType 5 bits
42 * samplingFrequencyIndex 4 bits
43 * if (samplingFrequencyIndex == 0xF)
44 * samplingFrequency 24 bits
45 * channelConfiguration 4 bits
47 * FrameLengthFlag 1 bit 1024 or 960
48 * DependsOnCoreCoder 1 bit (always 0)
49 * ExtensionFlag 1 bit (always 0)
52 /*****************************************************************************
53 * decoder_sys_t : decoder descriptor
54 *****************************************************************************/
62 block_bytestream_t bytestream;
67 audio_date_t end_date;
71 unsigned int i_raw_blocks;
72 unsigned int i_channels;
73 unsigned int i_rate, i_frame_length, i_header_size;
88 static int i_sample_rates[] =
90 96000, 88200, 64000, 48000, 44100, 32000, 24000, 22050,
91 16000, 12000, 11025, 8000, 7350, 0, 0, 0
94 #define ADTS_HEADER_SIZE 9
96 /****************************************************************************
98 ****************************************************************************/
99 static int OpenPacketizer( vlc_object_t * );
100 static void ClosePacketizer( vlc_object_t * );
102 static block_t *PacketizeBlock ( decoder_t *, block_t ** );
103 static block_t *ADTSPacketizeBlock( decoder_t *, block_t ** );
105 static uint8_t *GetOutBuffer ( decoder_t *, void ** );
107 static int ADTSSyncInfo( decoder_t *, const byte_t * p_buf,
108 unsigned int * pi_channels,
109 unsigned int * pi_sample_rate,
110 unsigned int * pi_frame_length,
111 unsigned int * pi_header_size,
112 unsigned int * pi_raw_blocks );
114 /*****************************************************************************
116 *****************************************************************************/
118 set_category( CAT_SOUT );
119 set_subcategory( SUBCAT_SOUT_PACKETIZER );
120 set_description( _("MPEG4 audio packetizer") );
121 set_capability( "packetizer", 50 );
122 set_callbacks( OpenPacketizer, ClosePacketizer );
125 /*****************************************************************************
126 * OpenPacketizer: probe the packetizer and return score
127 *****************************************************************************/
128 static int OpenPacketizer( vlc_object_t *p_this )
130 decoder_t *p_dec = (decoder_t*)p_this;
131 decoder_sys_t *p_sys;
133 if( p_dec->fmt_in.i_codec != VLC_FOURCC( 'm', 'p', '4', 'a' ) )
138 /* Allocate the memory needed to store the decoder's structure */
139 if( ( p_dec->p_sys = p_sys =
140 (decoder_sys_t *)malloc(sizeof(decoder_sys_t)) ) == NULL )
142 msg_Err( p_dec, "out of memory" );
147 p_sys->i_state = STATE_NOSYNC;
148 aout_DateSet( &p_sys->end_date, 0 );
149 p_sys->bytestream = block_BytestreamInit( p_dec );
150 p_sys->i_input_rate = INPUT_RATE_DEFAULT;
152 /* Set output properties */
153 p_dec->fmt_out.i_cat = AUDIO_ES;
154 p_dec->fmt_out.i_codec = VLC_FOURCC('m','p','4','a');
157 p_dec->pf_packetize = PacketizeBlock;
159 msg_Dbg( p_dec, "running MPEG4 audio packetizer" );
161 if( p_dec->fmt_in.i_extra > 0 )
163 uint8_t *p_config = (uint8_t*)p_dec->fmt_in.p_extra;
166 i_index = ( ( p_config[0] << 1 ) | ( p_config[1] >> 7 ) ) & 0x0f;
167 if( i_index != 0x0f )
169 p_dec->fmt_out.audio.i_rate = i_sample_rates[i_index];
170 p_dec->fmt_out.audio.i_frame_length =
171 (( p_config[1] >> 2 ) & 0x01) ? 960 : 1024;
175 p_dec->fmt_out.audio.i_rate = ( ( p_config[1] & 0x7f ) << 17 ) |
176 ( p_config[2] << 9 ) | ( p_config[3] << 1 ) |
177 ( p_config[4] >> 7 );
178 p_dec->fmt_out.audio.i_frame_length =
179 (( p_config[4] >> 2 ) & 0x01) ? 960 : 1024;
182 msg_Dbg( p_dec, "AAC %dHz %d samples/frame",
183 p_dec->fmt_out.audio.i_rate,
184 p_dec->fmt_out.audio.i_frame_length );
186 aout_DateInit( &p_sys->end_date, p_dec->fmt_out.audio.i_rate );
188 p_dec->fmt_out.audio.i_channels = p_dec->fmt_in.audio.i_channels;
189 p_dec->fmt_out.i_extra = p_dec->fmt_in.i_extra;
190 p_dec->fmt_out.p_extra = malloc( p_dec->fmt_in.i_extra );
191 memcpy( p_dec->fmt_out.p_extra, p_dec->fmt_in.p_extra,
192 p_dec->fmt_in.i_extra );
196 msg_Dbg( p_dec, "no decoder specific info, must be an ADTS stream" );
198 aout_DateInit( &p_sys->end_date, p_dec->fmt_in.audio.i_rate );
200 /* We will try to create a AAC Config from adts */
201 p_dec->fmt_out.i_extra = 0;
202 p_dec->fmt_out.p_extra = NULL;
203 p_dec->pf_packetize = ADTSPacketizeBlock;
209 /****************************************************************************
210 * PacketizeBlock: the whole thing
211 ****************************************************************************
212 * This function must be fed with complete frames.
213 ****************************************************************************/
214 static block_t *PacketizeBlock( decoder_t *p_dec, block_t **pp_block )
216 decoder_sys_t *p_sys = p_dec->p_sys;
219 if( !pp_block || !*pp_block ) return NULL;
221 if( (*pp_block)->i_flags&(BLOCK_FLAG_DISCONTINUITY|BLOCK_FLAG_CORRUPTED) )
223 //aout_DateSet( &p_sys->end_date, 0 );
224 block_Release( *pp_block );
229 *pp_block = NULL; /* Don't reuse this block */
231 if( !aout_DateGet( &p_sys->end_date ) && !p_block->i_pts )
233 /* We've just started the stream, wait for the first PTS. */
234 block_Release( p_block );
237 else if( p_block->i_pts != 0 &&
238 p_block->i_pts != aout_DateGet( &p_sys->end_date ) )
240 aout_DateSet( &p_sys->end_date, p_block->i_pts );
243 p_block->i_pts = p_block->i_dts = aout_DateGet( &p_sys->end_date );
245 p_block->i_length = aout_DateIncrement( &p_sys->end_date,
246 p_dec->fmt_out.audio.i_frame_length * p_sys->i_input_rate / INPUT_RATE_DEFAULT ) - p_block->i_pts;
251 /****************************************************************************
252 * DTSPacketizeBlock: the whole thing
253 ****************************************************************************/
254 static block_t *ADTSPacketizeBlock( decoder_t *p_dec, block_t **pp_block )
256 decoder_sys_t *p_sys = p_dec->p_sys;
257 uint8_t p_header[ADTS_HEADER_SIZE];
261 if( !pp_block || !*pp_block ) return NULL;
263 if( (*pp_block)->i_flags&(BLOCK_FLAG_DISCONTINUITY|BLOCK_FLAG_CORRUPTED) )
265 if( (*pp_block)->i_flags&BLOCK_FLAG_CORRUPTED )
267 p_sys->i_state = STATE_NOSYNC;
268 block_BytestreamFlush( &p_sys->bytestream );
270 //aout_DateSet( &p_sys->end_date, 0 );
271 block_Release( *pp_block );
275 if( !aout_DateGet( &p_sys->end_date ) && !(*pp_block)->i_pts )
277 /* We've just started the stream, wait for the first PTS. */
278 block_Release( *pp_block );
282 if( (*pp_block)->i_rate > 0 )
283 p_sys->i_input_rate = (*pp_block)->i_rate;
285 block_BytestreamPush( &p_sys->bytestream, *pp_block );
289 switch( p_sys->i_state )
293 while( block_PeekBytes( &p_sys->bytestream, p_header, 2 )
296 /* Look for sync word - should be 0xfff + 2 layer bits */
297 if( p_header[0] == 0xff && (p_header[1] & 0xf6) == 0xf0 )
299 p_sys->i_state = STATE_SYNC;
302 block_SkipByte( &p_sys->bytestream );
304 if( p_sys->i_state != STATE_SYNC )
306 block_BytestreamFlush( &p_sys->bytestream );
313 /* New frame, set the Presentation Time Stamp */
314 p_sys->i_pts = p_sys->bytestream.p_block->i_pts;
315 if( p_sys->i_pts != 0 &&
316 p_sys->i_pts != aout_DateGet( &p_sys->end_date ) )
318 aout_DateSet( &p_sys->end_date, p_sys->i_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_NEXT_SYNC;
349 case STATE_NEXT_SYNC:
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 p_sys->i_state = STATE_SEND_DATA;
375 /* Make sure we have enough data.
376 * (Not useful if we went through NEXT_SYNC) */
377 if( block_WaitBytes( &p_sys->bytestream, p_sys->i_frame_size +
378 p_sys->i_header_size) != VLC_SUCCESS )
383 p_sys->i_state = STATE_SEND_DATA;
385 case STATE_SEND_DATA:
386 if( !(p_buf = GetOutBuffer( p_dec, &p_out_buffer )) )
388 //p_dec->b_error = VLC_TRUE;
392 /* When we reach this point we already know we have enough
395 /* Skip the ADTS header */
396 block_SkipBytes( &p_sys->bytestream, p_sys->i_header_size );
398 /* Copy the whole frame into the buffer */
399 block_GetBytes( &p_sys->bytestream, p_buf, p_sys->i_frame_size );
401 /* Make sure we don't reuse the same pts twice */
402 if( p_sys->i_pts == p_sys->bytestream.p_block->i_pts )
403 p_sys->i_pts = p_sys->bytestream.p_block->i_pts = 0;
405 /* So p_block doesn't get re-added several times */
406 *pp_block = block_BytestreamPop( &p_sys->bytestream );
408 p_sys->i_state = STATE_NOSYNC;
417 /*****************************************************************************
419 *****************************************************************************/
420 static uint8_t *GetOutBuffer( decoder_t *p_dec, void **pp_out_buffer )
422 decoder_sys_t *p_sys = p_dec->p_sys;
425 if( p_dec->fmt_out.audio.i_rate != p_sys->i_rate )
427 msg_Info( p_dec, "AAC channels: %d samplerate: %d",
428 p_sys->i_channels, p_sys->i_rate );
430 aout_DateInit( &p_sys->end_date, p_sys->i_rate );
431 aout_DateSet( &p_sys->end_date, p_sys->i_pts );
434 p_dec->fmt_out.audio.i_rate = p_sys->i_rate;
435 p_dec->fmt_out.audio.i_channels = p_sys->i_channels;
436 p_dec->fmt_out.audio.i_bytes_per_frame = p_sys->i_frame_size;
437 p_dec->fmt_out.audio.i_frame_length = p_sys->i_frame_length;
440 p_dec->fmt_out.audio.i_original_channels = p_sys->i_channels_conf;
441 p_dec->fmt_out.audio.i_physical_channels =
442 p_sys->i_channels_conf & AOUT_CHAN_PHYSMASK;
445 p_block = block_New( p_dec, p_sys->i_frame_size );
446 if( p_block == NULL ) return NULL;
448 p_block->i_pts = p_block->i_dts = aout_DateGet( &p_sys->end_date );
450 p_block->i_length = aout_DateIncrement( &p_sys->end_date,
451 p_sys->i_frame_length * p_sys->i_input_rate / INPUT_RATE_DEFAULT ) -
454 *pp_out_buffer = p_block;
455 return p_block->p_buffer;
458 /*****************************************************************************
459 * ClosePacketizer: clean up the packetizer
460 *****************************************************************************/
461 static void ClosePacketizer( vlc_object_t *p_this )
463 decoder_t *p_dec = (decoder_t *)p_this;
464 decoder_sys_t *p_sys = p_dec->p_sys;
466 block_BytestreamRelease( &p_sys->bytestream );
468 free( p_dec->p_sys );
471 /*****************************************************************************
472 * ADTSSyncInfo: parse MPEG 4 audio ADTS sync info
473 *****************************************************************************/
474 static int ADTSSyncInfo( decoder_t * p_dec, const byte_t * p_buf,
475 unsigned int * pi_channels,
476 unsigned int * pi_sample_rate,
477 unsigned int * pi_frame_length,
478 unsigned int * pi_header_size,
479 unsigned int * pi_raw_blocks_in_frame )
481 int i_id, i_profile, i_sample_rate_idx, i_frame_size;
484 /* Fixed header between frames */
485 i_id = ( (p_buf[1] >> 3) & 0x01 ) ? 2 : 4;
486 b_crc = !(p_buf[1] & 0x01);
487 i_profile = p_buf[2] >> 6;
488 i_sample_rate_idx = (p_buf[2] >> 2) & 0x0f;
489 *pi_sample_rate = i_sample_rates[i_sample_rate_idx];
490 *pi_channels = ((p_buf[2] & 0x01) << 2) | ((p_buf[3] >> 6) & 0x03);
492 /* Variable header */
493 i_frame_size = ((p_buf[3] & 0x03) << 11) | (p_buf[4] << 3) |
494 ((p_buf[5] >> 5) & 0x7);
495 *pi_raw_blocks_in_frame = (p_buf[6] & 0x02) + 1;
497 if( !*pi_sample_rate || !*pi_channels || !i_frame_size )
503 *pi_frame_length = 1024;
505 /* Build the decoder specific info header */
506 if( !p_dec->fmt_out.i_extra )
508 p_dec->fmt_out.i_extra = 2;
509 p_dec->fmt_out.p_extra = malloc( 2 );
510 ((uint8_t *)p_dec->fmt_out.p_extra)[0] =
511 (i_profile + 1) << 3 | (i_sample_rate_idx >> 1);
512 ((uint8_t *)p_dec->fmt_out.p_extra)[1] =
513 ((i_sample_rate_idx & 0x01) << 7) | (*pi_channels <<3);
516 /* ADTS header length */
517 *pi_header_size = b_crc ? 9 : 7;
519 return i_frame_size - *pi_header_size;