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Move AMR-NB frame unpacking code to a common file so it can be reused in

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the AMR-WB decoder.

Patch by Marcelo Galvăo Póvoa.

Originally committed as revision 25100 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Marcelo Galvăo Póvoa 2010-09-10 19:51:08 +00:00 committed by Vitor Sessak
parent 6f9932476d
commit c7bb7eff81
2 changed files with 70 additions and 18 deletions
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66
libavcodec/amr.h Normal file
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@ -0,0 +1,66 @@
/*
* Shared functions between AMR codecs
*
* Copyright (c) 2010 Marcelo Galvao Povoa
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef AVCODEC_AMR_H
#define AVCODEC_AMR_H
#ifdef AMR_USE_16BIT_TABLES
#define R_TABLE_TYPE uint16_t
#else
#define R_TABLE_TYPE uint8_t
#endif
/**
* Fill the frame structure variables from bitstream by parsing the
* given reordering table that uses the following format:
*
* Each field (16 bits) in the AMR Frame is stored as:
* - one byte for the number of bits in the field
* - one byte for the field index
* - then, one byte for each bit of the field (from most-significant to least)
* of the position of that bit in the AMR frame.
*
* @param out pointer to the frame struct
* @param size the size in bytes of the frame struct
* @param data input bitstream after the frame header
* @param ord_table the reordering table as above
*/
static inline void ff_amr_bit_reorder(uint16_t *out, int size,
const uint8_t *data,
const R_TABLE_TYPE *ord_table)
{
int field_size;
memset(out, 0, size);
while ((field_size = *ord_table++)) {
int field = 0;
int field_offset = *ord_table++;
while (field_size--) {
int bit = *ord_table++;
field <<= 1;
field |= data[bit >> 3] >> (bit & 7) & 1;
}
out[field_offset] = field;
}
}
#endif /* AVCODEC_AMR_H */

22
libavcodec/amrnbdec.c
View File

@ -52,6 +52,7 @@
#include "acelp_vectors.h"
#include "acelp_pitch_delay.h"
#include "lsp.h"
#include "amr.h"
#include "amrnbdata.h"
@ -195,24 +196,9 @@ static enum Mode unpack_bitstream(AMRContext *p, const uint8_t *buf,
p->bad_frame_indicator = !get_bits1(&gb); // quality bit
skip_bits(&gb, 2); // two padding bits
if (mode < MODE_DTX) {
uint16_t *data = (uint16_t *)&p->frame;
const uint8_t *order = amr_unpacking_bitmaps_per_mode[mode];
int field_size;
memset(&p->frame, 0, sizeof(AMRNBFrame));
buf++;
while ((field_size = *order++)) {
int field = 0;
int field_offset = *order++;
while (field_size--) {
int bit = *order++;
field <<= 1;
field |= buf[bit >> 3] >> (bit & 7) & 1;
}
data[field_offset] = field;
}
}
if (mode < MODE_DTX)
ff_amr_bit_reorder((uint16_t *) &p->frame, sizeof(AMRNBFrame), buf + 1,
amr_unpacking_bitmaps_per_mode[mode]);
return mode;
}