From 0b42463aecff38fda35982141ccd095c9445f78f Mon Sep 17 00:00:00 2001 From: Vladimir Voroshilov Date: Sat, 13 Jun 2009 00:32:54 +0700 Subject: Gain pitch and gain code for G729D --- libavcodec/g729dec.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) (limited to 'libavcodec/g729dec.c') diff --git a/libavcodec/g729dec.c b/libavcodec/g729dec.c index cc1948b2f8..c5deab94a5 100644 --- a/libavcodec/g729dec.c +++ b/libavcodec/g729dec.c @@ -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); -- cgit v1.2.1