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 <stdlib.h> /* malloc(), free() */
29 #include <string.h> /* strdup() */
33 #include <vlc_codec.h>
34 #include <vlc_block.h>
36 #include <vlc_codecs.h>
37 #include <vlc_input.h>
39 #include "vlc_block_helper.h"
43 * AudioObjectType 5 bits
44 * samplingFrequencyIndex 4 bits
45 * if (samplingFrequencyIndex == 0xF)
46 * samplingFrequency 24 bits
47 * channelConfiguration 4 bits
49 * FrameLengthFlag 1 bit 1024 or 960
50 * DependsOnCoreCoder 1 bit (always 0)
51 * ExtensionFlag 1 bit (always 0)
54 /*****************************************************************************
55 * decoder_sys_t : decoder descriptor
56 *****************************************************************************/
64 block_bytestream_t bytestream;
69 audio_date_t end_date;
73 unsigned int i_raw_blocks;
74 unsigned int i_channels;
75 unsigned int i_rate, i_frame_length, i_header_size;
90 static int i_sample_rates[] =
92 96000, 88200, 64000, 48000, 44100, 32000, 24000, 22050,
93 16000, 12000, 11025, 8000, 7350, 0, 0, 0
96 #define ADTS_HEADER_SIZE 9
98 /****************************************************************************
100 ****************************************************************************/
101 static int OpenPacketizer( vlc_object_t * );
102 static void ClosePacketizer( vlc_object_t * );
104 static block_t *PacketizeBlock ( decoder_t *, block_t ** );
105 static block_t *ADTSPacketizeBlock( decoder_t *, block_t ** );
107 static uint8_t *GetOutBuffer ( decoder_t *, void ** );
109 static int ADTSSyncInfo( decoder_t *, const byte_t * p_buf,
110 unsigned int * pi_channels,
111 unsigned int * pi_sample_rate,
112 unsigned int * pi_frame_length,
113 unsigned int * pi_header_size,
114 unsigned int * pi_raw_blocks );
116 /*****************************************************************************
118 *****************************************************************************/
120 set_category( CAT_SOUT );
121 set_subcategory( SUBCAT_SOUT_PACKETIZER );
122 set_description( _("MPEG4 audio packetizer") );
123 set_capability( "packetizer", 50 );
124 set_callbacks( OpenPacketizer, ClosePacketizer );
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;
133 decoder_sys_t *p_sys;
135 if( p_dec->fmt_in.i_codec != VLC_FOURCC( 'm', 'p', '4', 'a' ) )
140 /* Allocate the memory needed to store the decoder's structure */
141 if( ( p_dec->p_sys = p_sys =
142 (decoder_sys_t *)malloc(sizeof(decoder_sys_t)) ) == NULL )
144 msg_Err( p_dec, "out of memory" );
149 p_sys->i_state = STATE_NOSYNC;
150 aout_DateSet( &p_sys->end_date, 0 );
151 p_sys->bytestream = block_BytestreamInit( p_dec );
152 p_sys->i_input_rate = INPUT_RATE_DEFAULT;
154 /* Set output properties */
155 p_dec->fmt_out.i_cat = AUDIO_ES;
156 p_dec->fmt_out.i_codec = VLC_FOURCC('m','p','4','a');
159 p_dec->pf_packetize = PacketizeBlock;
161 msg_Dbg( p_dec, "running MPEG4 audio packetizer" );
163 if( p_dec->fmt_in.i_extra > 0 )
165 uint8_t *p_config = (uint8_t*)p_dec->fmt_in.p_extra;
168 i_index = ( ( p_config[0] << 1 ) | ( p_config[1] >> 7 ) ) & 0x0f;
169 if( i_index != 0x0f )
171 p_dec->fmt_out.audio.i_rate = i_sample_rates[i_index];
172 p_dec->fmt_out.audio.i_frame_length =
173 (( p_config[1] >> 2 ) & 0x01) ? 960 : 1024;
177 p_dec->fmt_out.audio.i_rate = ( ( p_config[1] & 0x7f ) << 17 ) |
178 ( p_config[2] << 9 ) | ( p_config[3] << 1 ) |
179 ( p_config[4] >> 7 );
180 p_dec->fmt_out.audio.i_frame_length =
181 (( p_config[4] >> 2 ) & 0x01) ? 960 : 1024;
184 msg_Dbg( p_dec, "AAC %dHz %d samples/frame",
185 p_dec->fmt_out.audio.i_rate,
186 p_dec->fmt_out.audio.i_frame_length );
188 aout_DateInit( &p_sys->end_date, p_dec->fmt_out.audio.i_rate );
190 p_dec->fmt_out.audio.i_channels = p_dec->fmt_in.audio.i_channels;
191 p_dec->fmt_out.i_extra = p_dec->fmt_in.i_extra;
192 p_dec->fmt_out.p_extra = malloc( p_dec->fmt_in.i_extra );
193 memcpy( p_dec->fmt_out.p_extra, p_dec->fmt_in.p_extra,
194 p_dec->fmt_in.i_extra );
198 msg_Dbg( p_dec, "no decoder specific info, must be an ADTS stream" );
200 aout_DateInit( &p_sys->end_date, p_dec->fmt_in.audio.i_rate );
202 /* We will try to create a AAC Config from adts */
203 p_dec->fmt_out.i_extra = 0;
204 p_dec->fmt_out.p_extra = NULL;
205 p_dec->pf_packetize = ADTSPacketizeBlock;
211 /****************************************************************************
212 * PacketizeBlock: the whole thing
213 ****************************************************************************
214 * This function must be fed with complete frames.
215 ****************************************************************************/
216 static block_t *PacketizeBlock( decoder_t *p_dec, block_t **pp_block )
218 decoder_sys_t *p_sys = p_dec->p_sys;
221 if( !pp_block || !*pp_block ) return NULL;
223 if( (*pp_block)->i_flags&(BLOCK_FLAG_DISCONTINUITY|BLOCK_FLAG_CORRUPTED) )
225 //aout_DateSet( &p_sys->end_date, 0 );
226 block_Release( *pp_block );
231 *pp_block = NULL; /* Don't reuse this block */
233 if( !aout_DateGet( &p_sys->end_date ) && !p_block->i_pts )
235 /* We've just started the stream, wait for the first PTS. */
236 block_Release( p_block );
239 else if( p_block->i_pts != 0 &&
240 p_block->i_pts != aout_DateGet( &p_sys->end_date ) )
242 aout_DateSet( &p_sys->end_date, p_block->i_pts );
245 p_block->i_pts = p_block->i_dts = aout_DateGet( &p_sys->end_date );
247 p_block->i_length = aout_DateIncrement( &p_sys->end_date,
248 p_dec->fmt_out.audio.i_frame_length * p_sys->i_input_rate / INPUT_RATE_DEFAULT ) - p_block->i_pts;
253 /****************************************************************************
254 * DTSPacketizeBlock: the whole thing
255 ****************************************************************************/
256 static block_t *ADTSPacketizeBlock( decoder_t *p_dec, block_t **pp_block )
258 decoder_sys_t *p_sys = p_dec->p_sys;
259 uint8_t p_header[ADTS_HEADER_SIZE];
263 if( !pp_block || !*pp_block ) return NULL;
265 if( (*pp_block)->i_flags&(BLOCK_FLAG_DISCONTINUITY|BLOCK_FLAG_CORRUPTED) )
267 if( (*pp_block)->i_flags&BLOCK_FLAG_CORRUPTED )
269 p_sys->i_state = STATE_NOSYNC;
270 block_BytestreamFlush( &p_sys->bytestream );
272 //aout_DateSet( &p_sys->end_date, 0 );
273 block_Release( *pp_block );
277 if( !aout_DateGet( &p_sys->end_date ) && !(*pp_block)->i_pts )
279 /* We've just started the stream, wait for the first PTS. */
280 block_Release( *pp_block );
284 if( (*pp_block)->i_rate > 0 )
285 p_sys->i_input_rate = (*pp_block)->i_rate;
287 block_BytestreamPush( &p_sys->bytestream, *pp_block );
291 switch( p_sys->i_state )
295 while( block_PeekBytes( &p_sys->bytestream, p_header, 2 )
298 /* Look for sync word - should be 0xfff + 2 layer bits */
299 if( p_header[0] == 0xff && (p_header[1] & 0xf6) == 0xf0 )
301 p_sys->i_state = STATE_SYNC;
304 block_SkipByte( &p_sys->bytestream );
306 if( p_sys->i_state != STATE_SYNC )
308 block_BytestreamFlush( &p_sys->bytestream );
315 /* New frame, set the Presentation Time Stamp */
316 p_sys->i_pts = p_sys->bytestream.p_block->i_pts;
317 if( p_sys->i_pts != 0 &&
318 p_sys->i_pts != aout_DateGet( &p_sys->end_date ) )
320 aout_DateSet( &p_sys->end_date, p_sys->i_pts );
322 p_sys->i_state = STATE_HEADER;
326 /* Get ADTS frame header (ADTS_HEADER_SIZE bytes) */
327 if( block_PeekBytes( &p_sys->bytestream, p_header,
328 ADTS_HEADER_SIZE ) != VLC_SUCCESS )
334 /* Check if frame is valid and get frame info */
335 p_sys->i_frame_size = ADTSSyncInfo( p_dec, p_header,
338 &p_sys->i_frame_length,
339 &p_sys->i_header_size,
340 &p_sys->i_raw_blocks );
341 if( p_sys->i_frame_size <= 0 )
343 msg_Dbg( p_dec, "emulated sync word" );
344 block_SkipByte( &p_sys->bytestream );
345 p_sys->i_state = STATE_NOSYNC;
349 p_sys->i_state = STATE_NEXT_SYNC;
351 case STATE_NEXT_SYNC:
352 /* TODO: If p_block == NULL, flush the buffer without checking the
355 /* Check if next expected frame contains the sync word */
356 if( block_PeekOffsetBytes( &p_sys->bytestream, p_sys->i_frame_size
357 + p_sys->i_header_size, p_header, 2 )
364 if( p_header[0] != 0xff || (p_header[1] & 0xf6) != 0xf0 )
366 msg_Dbg( p_dec, "emulated sync word "
367 "(no sync on following frame)" );
368 p_sys->i_state = STATE_NOSYNC;
369 block_SkipByte( &p_sys->bytestream );
373 p_sys->i_state = STATE_SEND_DATA;
377 /* Make sure we have enough data.
378 * (Not useful if we went through NEXT_SYNC) */
379 if( block_WaitBytes( &p_sys->bytestream, p_sys->i_frame_size +
380 p_sys->i_header_size) != VLC_SUCCESS )
385 p_sys->i_state = STATE_SEND_DATA;
387 case STATE_SEND_DATA:
388 if( !(p_buf = GetOutBuffer( p_dec, &p_out_buffer )) )
390 //p_dec->b_error = VLC_TRUE;
394 /* When we reach this point we already know we have enough
397 /* Skip the ADTS header */
398 block_SkipBytes( &p_sys->bytestream, p_sys->i_header_size );
400 /* Copy the whole frame into the buffer */
401 block_GetBytes( &p_sys->bytestream, p_buf, p_sys->i_frame_size );
403 /* Make sure we don't reuse the same pts twice */
404 if( p_sys->i_pts == p_sys->bytestream.p_block->i_pts )
405 p_sys->i_pts = p_sys->bytestream.p_block->i_pts = 0;
407 /* So p_block doesn't get re-added several times */
408 *pp_block = block_BytestreamPop( &p_sys->bytestream );
410 p_sys->i_state = STATE_NOSYNC;
419 /*****************************************************************************
421 *****************************************************************************/
422 static uint8_t *GetOutBuffer( decoder_t *p_dec, void **pp_out_buffer )
424 decoder_sys_t *p_sys = p_dec->p_sys;
427 if( p_dec->fmt_out.audio.i_rate != p_sys->i_rate )
429 msg_Info( p_dec, "AAC channels: %d samplerate: %d",
430 p_sys->i_channels, p_sys->i_rate );
432 aout_DateInit( &p_sys->end_date, p_sys->i_rate );
433 aout_DateSet( &p_sys->end_date, p_sys->i_pts );
436 p_dec->fmt_out.audio.i_rate = p_sys->i_rate;
437 p_dec->fmt_out.audio.i_channels = p_sys->i_channels;
438 p_dec->fmt_out.audio.i_bytes_per_frame = p_sys->i_frame_size;
439 p_dec->fmt_out.audio.i_frame_length = p_sys->i_frame_length;
442 p_dec->fmt_out.audio.i_original_channels = p_sys->i_channels_conf;
443 p_dec->fmt_out.audio.i_physical_channels =
444 p_sys->i_channels_conf & AOUT_CHAN_PHYSMASK;
447 p_block = block_New( p_dec, p_sys->i_frame_size );
448 if( p_block == NULL ) return NULL;
450 p_block->i_pts = p_block->i_dts = aout_DateGet( &p_sys->end_date );
452 p_block->i_length = aout_DateIncrement( &p_sys->end_date,
453 p_sys->i_frame_length * p_sys->i_input_rate / INPUT_RATE_DEFAULT ) -
456 *pp_out_buffer = p_block;
457 return p_block->p_buffer;
460 /*****************************************************************************
461 * ClosePacketizer: clean up the packetizer
462 *****************************************************************************/
463 static void ClosePacketizer( vlc_object_t *p_this )
465 decoder_t *p_dec = (decoder_t *)p_this;
466 decoder_sys_t *p_sys = p_dec->p_sys;
468 block_BytestreamRelease( &p_sys->bytestream );
470 free( p_dec->p_sys );
473 /*****************************************************************************
474 * ADTSSyncInfo: parse MPEG 4 audio ADTS sync info
475 *****************************************************************************/
476 static int ADTSSyncInfo( decoder_t * p_dec, const byte_t * p_buf,
477 unsigned int * pi_channels,
478 unsigned int * pi_sample_rate,
479 unsigned int * pi_frame_length,
480 unsigned int * pi_header_size,
481 unsigned int * pi_raw_blocks_in_frame )
483 int i_id, i_profile, i_sample_rate_idx, i_frame_size;
486 /* Fixed header between frames */
487 i_id = ( (p_buf[1] >> 3) & 0x01 ) ? 2 : 4;
488 b_crc = !(p_buf[1] & 0x01);
489 i_profile = p_buf[2] >> 6;
490 i_sample_rate_idx = (p_buf[2] >> 2) & 0x0f;
491 *pi_sample_rate = i_sample_rates[i_sample_rate_idx];
492 *pi_channels = ((p_buf[2] & 0x01) << 2) | ((p_buf[3] >> 6) & 0x03);
494 /* Variable header */
495 i_frame_size = ((p_buf[3] & 0x03) << 11) | (p_buf[4] << 3) |
496 ((p_buf[5] >> 5) & 0x7);
497 *pi_raw_blocks_in_frame = (p_buf[6] & 0x02) + 1;
499 if( !*pi_sample_rate || !*pi_channels || !i_frame_size )
505 *pi_frame_length = 1024;
507 /* Build the decoder specific info header */
508 if( !p_dec->fmt_out.i_extra )
510 p_dec->fmt_out.i_extra = 2;
511 p_dec->fmt_out.p_extra = malloc( 2 );
512 ((uint8_t *)p_dec->fmt_out.p_extra)[0] =
513 (i_profile + 1) << 3 | (i_sample_rate_idx >> 1);
514 ((uint8_t *)p_dec->fmt_out.p_extra)[1] =
515 ((i_sample_rate_idx & 0x01) << 7) | (*pi_channels <<3);
518 /* ADTS header length */
519 *pi_header_size = b_crc ? 9 : 7;
521 return i_frame_size - *pi_header_size;