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Subroutine to copy an AAC Program Config Element (PCE)

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Originally committed as revision 18817 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Alex Converse 2009-05-13 22:57:30 +00:00
parent f2e5c8b96a
commit 107815de42
2 changed files with 49 additions and 0 deletions
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42
libavcodec/mpeg4audio.c
View File

@ -1,6 +1,7 @@
/*
* MPEG-4 Audio common code
* Copyright (c) 2008 Baptiste Coudurier <baptiste.coudurier@free.fr>
* Copyright (c) 2009 Alex Converse <alex.converse@gmail.com>
*
* This file is part of FFmpeg.
*
@ -20,6 +21,7 @@
*/
#include "get_bits.h"
#include "put_bits.h"
#include "mpeg4audio.h"
const int ff_mpeg4audio_sample_rates[16] = {
@ -84,3 +86,43 @@ int ff_mpeg4audio_get_config(MPEG4AudioConfig *c, const uint8_t *buf, int buf_si
}
return specific_config_bitindex;
}
static av_always_inline unsigned int copy_bits(PutBitContext *pb,
GetBitContext *gb,
int bits)
{
unsigned int el = get_bits(gb, bits);
put_bits(pb, bits, el);
return el;
}
int ff_copy_pce_data(PutBitContext *pb, GetBitContext *gb)
{
int five_bit_ch, four_bit_ch, comment_size, bits;
int offset = put_bits_count(pb);
copy_bits(pb, gb, 10); //Tag, Object Type, Frequency
five_bit_ch = copy_bits(pb, gb, 4); //Front
five_bit_ch += copy_bits(pb, gb, 4); //Side
five_bit_ch += copy_bits(pb, gb, 4); //Back
four_bit_ch = copy_bits(pb, gb, 2); //LFE
four_bit_ch += copy_bits(pb, gb, 3); //Data
five_bit_ch += copy_bits(pb, gb, 4); //Coupling
if (copy_bits(pb, gb, 1)) //Mono Mixdown
copy_bits(pb, gb, 4);
if (copy_bits(pb, gb, 1)) //Stereo Mixdown
copy_bits(pb, gb, 4);
if (copy_bits(pb, gb, 1)) //Matrix Mixdown
copy_bits(pb, gb, 3);
for (bits = five_bit_ch*5+four_bit_ch*4; bits > 16; bits -= 16)
copy_bits(pb, gb, 16);
if (bits)
copy_bits(pb, gb, bits);
align_put_bits(pb);
align_get_bits(gb);
comment_size = copy_bits(pb, gb, 8);
for (; comment_size > 0; comment_size--)
copy_bits(pb, gb, 8);
return put_bits_count(pb) - offset;
}

7
libavcodec/mpeg4audio.h
View File

@ -23,6 +23,8 @@
#define AVCODEC_MPEG4AUDIO_H
#include <stdint.h>
#include "get_bits.h"
#include "put_bits.h"
typedef struct {
int object_type;
@ -90,4 +92,9 @@ enum AudioObjectType {
AOT_SMR_MAIN, ///< N Symbolic Music Representation Main
};
#define MAX_PCE_SIZE 304 ///<Maximum size of a PCE including the 3-bit ID_PCE
///<marker and the comment
int ff_copy_pce_data(PutBitContext *pb, GetBitContext *gb);
#endif /* AVCODEC_MPEG4AUDIO_H */