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Gain pitch and gain code for G729D

This commit is contained in:
Vladimir Voroshilov 2009-06-13 00:32:54 +07:00 committed by Michael Niedermayer
parent 12081d0599
commit 0b42463aec
2 changed files with 60 additions and 0 deletions
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30
libavcodec/g729data.h
View File

@ -245,6 +245,36 @@ static const int16_t cb_gain_2nd_8k[1<<GC_2ND_IDX_BITS_8K][2] = { /*(1.14) (1.13
{ 13260 , 3256 },
};
/**
* gain codebook (first stage), 6.4k mode (D.3.9.2 of G.729)
*/
static const int16_t cb_gain_1st_6k4[1<<GC_1ST_IDX_BITS_6K4][2] =
{ /*(0.14) (1.14)*/
{ 5849, 0 },
{ 3171, 9280 },
{ 3617, 6747 },
{ 4987, 22294 },
{ 2929, 1078 },
{ 6068, 6093 },
{ 9425, 2731 },
{ 3915, 12872 },
};
/**
* gain codebook (second stage), 6.4k mode (D.3.9.2 of G.729)
*/
static const int16_t cb_gain_2nd_6k4[1<<GC_2ND_IDX_BITS_6K4][2] =
{ /*(1.14) (1.14)*/
{ 0, 4175 },
{10828, 27602 },
{16423, 15724 },
{ 4478, 7324 },
{ 3988, 0 },
{10291, 11385 },
{11956, 10735 },
{ 7876, 7821 },
};
/**
* 4th order Moving Average (MA) Predictor codebook (3.2.4 of G.729)
*

30
libavcodec/g729dec.c
View File

@ -419,10 +419,25 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *data_size,
gain_corr_factor = 0;
} else {
if (packet_type == FORMAT_G729D_6K4) {
ctx->past_gain_pitch[0] = cb_gain_1st_6k4[gc_1st_index][0] +
cb_gain_2nd_6k4[gc_2nd_index][0];
gain_corr_factor = cb_gain_1st_6k4[gc_1st_index][1] +
cb_gain_2nd_6k4[gc_2nd_index][1];
/* Without check below overflow can occure in ff_acelp_update_past_gain.
It is not issue for G.729, because gain_corr_factor in it's case is always
greater than 1024, while in G.729D it can be even zero. */
gain_corr_factor = FFMAX(gain_corr_factor, 1024);
#ifndef G729_BITEXACT
gain_corr_factor >>= 1;
#endif
} else {
ctx->past_gain_pitch[0] = cb_gain_1st_8k[gc_1st_index][0] +
cb_gain_2nd_8k[gc_2nd_index][0];
gain_corr_factor = cb_gain_1st_8k[gc_1st_index][1] +
cb_gain_2nd_8k[gc_2nd_index][1];
}
/* Decode the fixed-codebook gain. */
ctx->past_gain_code[0] = ff_acelp_decode_gain_code(&ctx->dsp, gain_corr_factor,
@ -430,6 +445,21 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *data_size,
ctx->quant_energy,
ma_prediction_coeff,
SUBFRAME_SIZE, 4);
#ifdef G729_BITEXACT
/*
This correction required to get bit-exact result with
reference code, because gain_corr_factor in G.729D is
two times larger than in original G.729.
If bit-exact result is not issue then gain_corr_factor
can be simpler devided by 2 before call to g729_get_gain_code
instead of using correction below.
*/
if (packet_type == FORMAT_G729D_6K4) {
gain_corr_factor >>= 1;
ctx->past_gain_code[0] >>= 1;
}
#endif
}
ff_acelp_update_past_gain(ctx->quant_energy, gain_corr_factor, 2, frame_erasure);