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FFmpeg/libavcodec/g729dec.c

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/*
* G.729 decoder
* Copyright (c) 2008 Vladimir Voroshilov
*
* 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
*/
#include <stdlib.h>
#include <inttypes.h>
#include <limits.h>
#include <stdio.h>
#include <string.h>
#include <math.h>
#include <assert.h>
#include "avcodec.h"
#include "libavutil/avutil.h"
#include "bitstream.h"
#include "g729.h"
#include "lsp.h"
#include "celp_math.h"
#include "acelp_filters.h"
#include "acelp_pitch_delay.h"
#include "acelp_vectors.h"
#include "g729data.h"
/**
* minimum quantized LSF value (3.2.4)
* 0.005 in Q13
*/
#define LSFQ_MIN 40
/**
* maximum quantized LSF value (3.2.4)
* 3.135 in Q13
*/
#define LSFQ_MAX 25681
/**
* minimum LSF distance (3.2.4)
* 0.0391 in Q13
*/
#define LSFQ_DIFF_MIN 321
/**
* minimum gain pitch value (3.8, Equation 47)
* 0.2 in (1.14)
*/
#define SHARP_MIN 3277
/**
* maximum gain pitch value (3.8, Equation 47)
* (EE) This does not comply with the specification.
* Specification says about 0.8, which should be
* 13107 in (1.14), but reference C code uses
* 13017 (equals to 0.7945) instead of it.
*/
#define SHARP_MAX 13017
typedef struct
{
int sample_rate;
uint8_t packed_frame_size; ///< input frame size(in bytes)
uint8_t unpacked_frame_size;///< output frame size (in bytes)
uint8_t fc_indexes_bits; ///< size (in bits) of fixed-codebook index entry
/// mr_energy = mean_energy + 10 * log10(2^26 * subframe_size) in (7.13)
int mr_energy;
} G729_format_description;
/**
* \brief pseudo random number generator
*/
static inline uint16_t g729_random(uint16_t value)
{
return 31821 * value + 13849;
}
/**
* Get parity bit of bit 2..7
*/
static inline int g729_get_parity(uint8_t value)
{
return (0x6996966996696996ULL >> (value >> 2)) & 1;
}
if(avctx->channels != 1)
{
av_log(avctx, AV_LOG_ERROR, "Only mono sound is supported (requested channels: %d).\n", avctx->channels);
return AVERROR_NOFMT;
}
ff_acelp_weighted_vector_sum(
fc + pitch_delay_int[i],
fc + pitch_delay_int[i],
fc,
1 << 14,
av_clip(ctx->gain_pitch, SHARP_MIN, SHARP_MAX),
0,
14,
ctx->subframe_size - pitch_delay_int[i]);
if(ctx->frame_erasure)
{
ctx->gain_pitch = (29491 * ctx->gain_pitch) >> 15; // 0.9 (0.15)
ctx->gain_code = (2007 * ctx->gain_code) >> 11; // 0.98 in (0.11)
gain_corr_factor = 0;
}
else
{
ctx->gain_pitch = cb_gain_1st_8k[parm->gc_1st_index[i]][0] +
cb_gain_2nd_8k[parm->gc_2nd_index[i]][0];
gain_corr_factor = cb_gain_1st_8k[parm->gc_1st_index[i]][1] +
cb_gain_2nd_8k[parm->gc_2nd_index[i]][1];
ff_acelp_weighted_vector_sum(
ctx->exc + i * ctx->subframe_size,
ctx->exc + i * ctx->subframe_size,
fc,
(!voicing && ctx->frame_erasure) ? 0 : ctx->gain_pitch,
( voicing && ctx->frame_erasure) ? 0 : ctx->gain_code,
1<<13,
14,
ctx->subframe_size);
if (buf_size<packed_frame_size)
{
av_log(avctx, AV_LOG_ERROR, "Error processing packet: packet size too small\n");
return AVERROR(EIO);
}
if (*data_size<unpacked_frame_size)
{
av_log(avctx, AV_LOG_ERROR, "Error processing packet: output buffer too small\n");
return AVERROR(EIO);
}
AVCodec g729_decoder =
{
"g729",
CODEC_TYPE_AUDIO,
CODEC_ID_G729,
sizeof(G729_Context),
ff_g729_decoder_init,
NULL,
NULL,
ff_g729_decode_frame,
.long_name = NULL_IF_CONFIG_SMALL("G.729"),
};