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 *****************************************************************************/
28 #include <string.h> /* strdup() */
32 #include <vlc_codec.h>
33 #include <vlc_block.h>
35 #include <vlc_codecs.h>
36 #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 *****************************************************************************/
63 block_bytestream_t bytestream;
68 audio_date_t end_date;
72 unsigned int i_raw_blocks;
73 unsigned int i_channels;
74 unsigned int i_rate, i_frame_length, i_header_size;
89 static int i_sample_rates[] =
91 96000, 88200, 64000, 48000, 44100, 32000, 24000, 22050,
92 16000, 12000, 11025, 8000, 7350, 0, 0, 0
95 #define ADTS_HEADER_SIZE 9
97 /****************************************************************************
99 ****************************************************************************/
100 static int OpenPacketizer( vlc_object_t * );
101 static void ClosePacketizer( vlc_object_t * );
103 static block_t *PacketizeBlock ( decoder_t *, block_t ** );
104 static block_t *ADTSPacketizeBlock( decoder_t *, block_t ** );
106 static uint8_t *GetOutBuffer ( decoder_t *, void ** );
108 static int ADTSSyncInfo( decoder_t *, const byte_t * p_buf,
109 unsigned int * pi_channels,
110 unsigned int * pi_sample_rate,
111 unsigned int * pi_frame_length,
112 unsigned int * pi_header_size,
113 unsigned int * pi_raw_blocks );
115 /*****************************************************************************
117 *****************************************************************************/
119 set_category( CAT_SOUT );
120 set_subcategory( SUBCAT_SOUT_PACKETIZER );
121 set_description( _("MPEG4 audio packetizer") );
122 set_capability( "packetizer", 50 );
123 set_callbacks( OpenPacketizer, ClosePacketizer );
126 /*****************************************************************************
127 * OpenPacketizer: probe the packetizer and return score
128 *****************************************************************************/
129 static int OpenPacketizer( vlc_object_t *p_this )
131 decoder_t *p_dec = (decoder_t*)p_this;
132 decoder_sys_t *p_sys;
134 if( p_dec->fmt_in.i_codec != VLC_FOURCC( 'm', 'p', '4', 'a' ) )
139 /* Allocate the memory needed to store the decoder's structure */
140 if( ( p_dec->p_sys = p_sys =
141 (decoder_sys_t *)malloc(sizeof(decoder_sys_t)) ) == NULL )
143 msg_Err( p_dec, "out of memory" );
148 p_sys->i_state = STATE_NOSYNC;
149 aout_DateSet( &p_sys->end_date, 0 );
150 p_sys->bytestream = block_BytestreamInit( p_dec );
151 p_sys->i_input_rate = INPUT_RATE_DEFAULT;
153 /* Set output properties */
154 p_dec->fmt_out.i_cat = AUDIO_ES;
155 p_dec->fmt_out.i_codec = VLC_FOURCC('m','p','4','a');
158 p_dec->pf_packetize = PacketizeBlock;
160 msg_Dbg( p_dec, "running MPEG4 audio packetizer" );
162 if( p_dec->fmt_in.i_extra > 0 )
164 uint8_t *p_config = (uint8_t*)p_dec->fmt_in.p_extra;
167 i_index = ( ( p_config[0] << 1 ) | ( p_config[1] >> 7 ) ) & 0x0f;
168 if( i_index != 0x0f )
170 p_dec->fmt_out.audio.i_rate = i_sample_rates[i_index];
171 p_dec->fmt_out.audio.i_frame_length =
172 (( p_config[1] >> 2 ) & 0x01) ? 960 : 1024;
176 p_dec->fmt_out.audio.i_rate = ( ( p_config[1] & 0x7f ) << 17 ) |
177 ( p_config[2] << 9 ) | ( p_config[3] << 1 ) |
178 ( p_config[4] >> 7 );
179 p_dec->fmt_out.audio.i_frame_length =
180 (( p_config[4] >> 2 ) & 0x01) ? 960 : 1024;
183 msg_Dbg( p_dec, "AAC %dHz %d samples/frame",
184 p_dec->fmt_out.audio.i_rate,
185 p_dec->fmt_out.audio.i_frame_length );
187 aout_DateInit( &p_sys->end_date, p_dec->fmt_out.audio.i_rate );
189 p_dec->fmt_out.audio.i_channels = p_dec->fmt_in.audio.i_channels;
190 p_dec->fmt_out.i_extra = p_dec->fmt_in.i_extra;
191 p_dec->fmt_out.p_extra = malloc( p_dec->fmt_in.i_extra );
192 memcpy( p_dec->fmt_out.p_extra, p_dec->fmt_in.p_extra,
193 p_dec->fmt_in.i_extra );
197 msg_Dbg( p_dec, "no decoder specific info, must be an ADTS stream" );
199 aout_DateInit( &p_sys->end_date, p_dec->fmt_in.audio.i_rate );
201 /* We will try to create a AAC Config from adts */
202 p_dec->fmt_out.i_extra = 0;
203 p_dec->fmt_out.p_extra = NULL;
204 p_dec->pf_packetize = ADTSPacketizeBlock;
210 /****************************************************************************
211 * PacketizeBlock: the whole thing
212 ****************************************************************************
213 * This function must be fed with complete frames.
214 ****************************************************************************/
215 static block_t *PacketizeBlock( decoder_t *p_dec, block_t **pp_block )
217 decoder_sys_t *p_sys = p_dec->p_sys;
220 if( !pp_block || !*pp_block ) return NULL;
222 if( (*pp_block)->i_flags&(BLOCK_FLAG_DISCONTINUITY|BLOCK_FLAG_CORRUPTED) )
224 //aout_DateSet( &p_sys->end_date, 0 );
225 block_Release( *pp_block );
230 *pp_block = NULL; /* Don't reuse this block */
232 if( !aout_DateGet( &p_sys->end_date ) && !p_block->i_pts )
234 /* We've just started the stream, wait for the first PTS. */
235 block_Release( p_block );
238 else if( p_block->i_pts != 0 &&
239 p_block->i_pts != aout_DateGet( &p_sys->end_date ) )
241 aout_DateSet( &p_sys->end_date, p_block->i_pts );
244 p_block->i_pts = p_block->i_dts = aout_DateGet( &p_sys->end_date );
246 p_block->i_length = aout_DateIncrement( &p_sys->end_date,
247 p_dec->fmt_out.audio.i_frame_length * p_sys->i_input_rate / INPUT_RATE_DEFAULT ) - p_block->i_pts;
252 /****************************************************************************
253 * DTSPacketizeBlock: the whole thing
254 ****************************************************************************/
255 static block_t *ADTSPacketizeBlock( decoder_t *p_dec, block_t **pp_block )
257 decoder_sys_t *p_sys = p_dec->p_sys;
258 uint8_t p_header[ADTS_HEADER_SIZE];
262 if( !pp_block || !*pp_block ) return NULL;
264 if( (*pp_block)->i_flags&(BLOCK_FLAG_DISCONTINUITY|BLOCK_FLAG_CORRUPTED) )
266 if( (*pp_block)->i_flags&BLOCK_FLAG_CORRUPTED )
268 p_sys->i_state = STATE_NOSYNC;
269 block_BytestreamFlush( &p_sys->bytestream );
271 //aout_DateSet( &p_sys->end_date, 0 );
272 block_Release( *pp_block );
276 if( !aout_DateGet( &p_sys->end_date ) && !(*pp_block)->i_pts )
278 /* We've just started the stream, wait for the first PTS. */
279 block_Release( *pp_block );
283 if( (*pp_block)->i_rate > 0 )
284 p_sys->i_input_rate = (*pp_block)->i_rate;
286 block_BytestreamPush( &p_sys->bytestream, *pp_block );
290 switch( p_sys->i_state )
294 while( block_PeekBytes( &p_sys->bytestream, p_header, 2 )
297 /* Look for sync word - should be 0xfff + 2 layer bits */
298 if( p_header[0] == 0xff && (p_header[1] & 0xf6) == 0xf0 )
300 p_sys->i_state = STATE_SYNC;
303 block_SkipByte( &p_sys->bytestream );
305 if( p_sys->i_state != STATE_SYNC )
307 block_BytestreamFlush( &p_sys->bytestream );
314 /* New frame, set the Presentation Time Stamp */
315 p_sys->i_pts = p_sys->bytestream.p_block->i_pts;
316 if( p_sys->i_pts != 0 &&
317 p_sys->i_pts != aout_DateGet( &p_sys->end_date ) )
319 aout_DateSet( &p_sys->end_date, p_sys->i_pts );
321 p_sys->i_state = STATE_HEADER;
325 /* Get ADTS frame header (ADTS_HEADER_SIZE bytes) */
326 if( block_PeekBytes( &p_sys->bytestream, p_header,
327 ADTS_HEADER_SIZE ) != VLC_SUCCESS )
333 /* Check if frame is valid and get frame info */
334 p_sys->i_frame_size = ADTSSyncInfo( p_dec, p_header,
337 &p_sys->i_frame_length,
338 &p_sys->i_header_size,
339 &p_sys->i_raw_blocks );
340 if( p_sys->i_frame_size <= 0 )
342 msg_Dbg( p_dec, "emulated sync word" );
343 block_SkipByte( &p_sys->bytestream );
344 p_sys->i_state = STATE_NOSYNC;
348 p_sys->i_state = STATE_NEXT_SYNC;
350 case STATE_NEXT_SYNC:
351 /* TODO: If p_block == NULL, flush the buffer without checking the
354 /* Check if next expected frame contains the sync word */
355 if( block_PeekOffsetBytes( &p_sys->bytestream, p_sys->i_frame_size
356 + p_sys->i_header_size, p_header, 2 )
363 if( p_header[0] != 0xff || (p_header[1] & 0xf6) != 0xf0 )
365 msg_Dbg( p_dec, "emulated sync word "
366 "(no sync on following frame)" );
367 p_sys->i_state = STATE_NOSYNC;
368 block_SkipByte( &p_sys->bytestream );
372 p_sys->i_state = STATE_SEND_DATA;
376 /* Make sure we have enough data.
377 * (Not useful if we went through NEXT_SYNC) */
378 if( block_WaitBytes( &p_sys->bytestream, p_sys->i_frame_size +
379 p_sys->i_header_size) != VLC_SUCCESS )
384 p_sys->i_state = STATE_SEND_DATA;
386 case STATE_SEND_DATA:
387 if( !(p_buf = GetOutBuffer( p_dec, &p_out_buffer )) )
389 //p_dec->b_error = VLC_TRUE;
393 /* When we reach this point we already know we have enough
396 /* Skip the ADTS header */
397 block_SkipBytes( &p_sys->bytestream, p_sys->i_header_size );
399 /* Copy the whole frame into the buffer */
400 block_GetBytes( &p_sys->bytestream, p_buf, p_sys->i_frame_size );
402 /* Make sure we don't reuse the same pts twice */
403 if( p_sys->i_pts == p_sys->bytestream.p_block->i_pts )
404 p_sys->i_pts = p_sys->bytestream.p_block->i_pts = 0;
406 /* So p_block doesn't get re-added several times */
407 *pp_block = block_BytestreamPop( &p_sys->bytestream );
409 p_sys->i_state = STATE_NOSYNC;
418 /*****************************************************************************
420 *****************************************************************************/
421 static uint8_t *GetOutBuffer( decoder_t *p_dec, void **pp_out_buffer )
423 decoder_sys_t *p_sys = p_dec->p_sys;
426 if( p_dec->fmt_out.audio.i_rate != p_sys->i_rate )
428 msg_Info( p_dec, "AAC channels: %d samplerate: %d",
429 p_sys->i_channels, p_sys->i_rate );
431 aout_DateInit( &p_sys->end_date, p_sys->i_rate );
432 aout_DateSet( &p_sys->end_date, p_sys->i_pts );
435 p_dec->fmt_out.audio.i_rate = p_sys->i_rate;
436 p_dec->fmt_out.audio.i_channels = p_sys->i_channels;
437 p_dec->fmt_out.audio.i_bytes_per_frame = p_sys->i_frame_size;
438 p_dec->fmt_out.audio.i_frame_length = p_sys->i_frame_length;
441 p_dec->fmt_out.audio.i_original_channels = p_sys->i_channels_conf;
442 p_dec->fmt_out.audio.i_physical_channels =
443 p_sys->i_channels_conf & AOUT_CHAN_PHYSMASK;
446 p_block = block_New( p_dec, p_sys->i_frame_size );
447 if( p_block == NULL ) return NULL;
449 p_block->i_pts = p_block->i_dts = aout_DateGet( &p_sys->end_date );
451 p_block->i_length = aout_DateIncrement( &p_sys->end_date,
452 p_sys->i_frame_length * p_sys->i_input_rate / INPUT_RATE_DEFAULT ) -
455 *pp_out_buffer = p_block;
456 return p_block->p_buffer;
459 /*****************************************************************************
460 * ClosePacketizer: clean up the packetizer
461 *****************************************************************************/
462 static void ClosePacketizer( vlc_object_t *p_this )
464 decoder_t *p_dec = (decoder_t *)p_this;
465 decoder_sys_t *p_sys = p_dec->p_sys;
467 block_BytestreamRelease( &p_sys->bytestream );
469 free( p_dec->p_sys );
472 /*****************************************************************************
473 * ADTSSyncInfo: parse MPEG 4 audio ADTS sync info
474 *****************************************************************************/
475 static int ADTSSyncInfo( decoder_t * p_dec, const byte_t * p_buf,
476 unsigned int * pi_channels,
477 unsigned int * pi_sample_rate,
478 unsigned int * pi_frame_length,
479 unsigned int * pi_header_size,
480 unsigned int * pi_raw_blocks_in_frame )
482 int i_id, i_profile, i_sample_rate_idx, i_frame_size;
485 /* Fixed header between frames */
486 i_id = ( (p_buf[1] >> 3) & 0x01 ) ? 2 : 4;
487 b_crc = !(p_buf[1] & 0x01);
488 i_profile = p_buf[2] >> 6;
489 i_sample_rate_idx = (p_buf[2] >> 2) & 0x0f;
490 *pi_sample_rate = i_sample_rates[i_sample_rate_idx];
491 *pi_channels = ((p_buf[2] & 0x01) << 2) | ((p_buf[3] >> 6) & 0x03);
493 /* Variable header */
494 i_frame_size = ((p_buf[3] & 0x03) << 11) | (p_buf[4] << 3) |
495 ((p_buf[5] >> 5) & 0x7);
496 *pi_raw_blocks_in_frame = (p_buf[6] & 0x02) + 1;
498 if( !*pi_sample_rate || !*pi_channels || !i_frame_size )
504 *pi_frame_length = 1024;
506 /* Build the decoder specific info header */
507 if( !p_dec->fmt_out.i_extra )
509 p_dec->fmt_out.i_extra = 2;
510 p_dec->fmt_out.p_extra = malloc( 2 );
511 ((uint8_t *)p_dec->fmt_out.p_extra)[0] =
512 (i_profile + 1) << 3 | (i_sample_rate_idx >> 1);
513 ((uint8_t *)p_dec->fmt_out.p_extra)[1] =
514 ((i_sample_rate_idx & 0x01) << 7) | (*pi_channels <<3);
517 /* ADTS header length */
518 *pi_header_size = b_crc ? 9 : 7;
520 return i_frame_size - *pi_header_size;