From 645e75992d8876a5e0aa056739885d3afd08d431 Mon Sep 17 00:00:00 2001 From: Reimar Döffinger Date: Sat, 2 Oct 2010 09:51:26 +0000 Subject: Fix GSM decoding: regular GSM and MSGSM do not use the same bitstream endianness, so they cannot reuse the same code without a lot of function call overhead. Thus use templating to compile two different binaries. Originally committed as revision 25312 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavcodec/gsmdec_template.c | 150 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 150 insertions(+) create mode 100644 libavcodec/gsmdec_template.c (limited to 'libavcodec/gsmdec_template.c') diff --git a/libavcodec/gsmdec_template.c b/libavcodec/gsmdec_template.c new file mode 100644 index 0000000000..b63ec9ed27 --- /dev/null +++ b/libavcodec/gsmdec_template.c @@ -0,0 +1,150 @@ +/* + * gsm 06.10 decoder + * Copyright (c) 2010 Reimar Döffinger + * + * 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 + */ + +/** + * @file + * GSM decoder + */ + +#include "get_bits.h" +#include "gsmdec_data.h" + +static void apcm_dequant_add(GetBitContext *gb, int16_t *dst) +{ + int i; + int maxidx = get_bits(gb, 6); + const int16_t *tab = ff_gsm_dequant_tab[maxidx]; + for (i = 0; i < 13; i++) + dst[3*i] += tab[get_bits(gb, 3)]; +} + +static inline int gsm_mult(int a, int b) +{ + return (a * b + (1 << 14)) >> 15; +} + +static void long_term_synth(int16_t *dst, int lag, int gain_idx) +{ + int i; + const int16_t *src = dst - lag; + uint16_t gain = ff_gsm_long_term_gain_tab[gain_idx]; + for (i = 0; i < 40; i++) + dst[i] = gsm_mult(gain, src[i]); +} + +static inline int decode_log_area(int coded, int factor, int offset) +{ + coded <<= 10; + coded -= offset; + return gsm_mult(coded, factor) << 1; +} + +static av_noinline int get_rrp(int filtered) +{ + int abs = FFABS(filtered); + if (abs < 11059) abs <<= 1; + else if (abs < 20070) abs += 11059; + else abs = (abs >> 2) + 26112; + return filtered < 0 ? -abs : abs; +} + +static int filter_value(int in, int rrp[8], int v[9]) +{ + int i; + for (i = 7; i >= 0; i--) { + in -= gsm_mult(rrp[i], v[i]); + v[i + 1] = v[i] + gsm_mult(rrp[i], in); + } + v[0] = in; + return in; +} + +static void short_term_synth(GSMContext *ctx, int16_t *dst, const int16_t *src) +{ + int i; + int rrp[8]; + int *lar = ctx->lar[ctx->lar_idx]; + int *lar_prev = ctx->lar[ctx->lar_idx ^ 1]; + for (i = 0; i < 8; i++) + rrp[i] = get_rrp((lar_prev[i] >> 2) + (lar_prev[i] >> 1) + (lar[i] >> 2)); + for (i = 0; i < 13; i++) + dst[i] = filter_value(src[i], rrp, ctx->v); + + for (i = 0; i < 8; i++) + rrp[i] = get_rrp((lar_prev[i] >> 1) + (lar [i] >> 1)); + for (i = 13; i < 27; i++) + dst[i] = filter_value(src[i], rrp, ctx->v); + + for (i = 0; i < 8; i++) + rrp[i] = get_rrp((lar_prev[i] >> 2) + (lar [i] >> 1) + (lar[i] >> 2)); + for (i = 27; i < 40; i++) + dst[i] = filter_value(src[i], rrp, ctx->v); + + for (i = 0; i < 8; i++) + rrp[i] = get_rrp(lar[i]); + for (i = 40; i < 160; i++) + dst[i] = filter_value(src[i], rrp, ctx->v); + + ctx->lar_idx ^= 1; +} + +static int postprocess(int16_t *data, int msr) +{ + int i; + for (i = 0; i < 160; i++) { + msr = av_clip_int16(data[i] + gsm_mult(msr, 28180)); + data[i] = av_clip_int16(msr << 1) & ~7; + } + return msr; +} + +static int gsm_decode_block(AVCodecContext *avctx, int16_t *samples, + GetBitContext *gb) +{ + GSMContext *ctx = avctx->priv_data; + int i; + int16_t *ref_dst = ctx->ref_buf + 120; + int *lar = ctx->lar[ctx->lar_idx]; + lar[0] = decode_log_area(get_bits(gb, 6), 13107, 1 << 15); + lar[1] = decode_log_area(get_bits(gb, 6), 13107, 1 << 15); + lar[2] = decode_log_area(get_bits(gb, 5), 13107, (1 << 14) + 2048*2); + lar[3] = decode_log_area(get_bits(gb, 5), 13107, (1 << 14) - 2560*2); + lar[4] = decode_log_area(get_bits(gb, 4), 19223, (1 << 13) + 94*2); + lar[5] = decode_log_area(get_bits(gb, 4), 17476, (1 << 13) - 1792*2); + lar[6] = decode_log_area(get_bits(gb, 3), 31454, (1 << 12) - 341*2); + lar[7] = decode_log_area(get_bits(gb, 3), 29708, (1 << 12) - 1144*2); + + for (i = 0; i < 4; i++) { + int lag = get_bits(gb, 7); + int gain_idx = get_bits(gb, 2); + int offset = get_bits(gb, 2); + lag = av_clip(lag, 40, 120); + long_term_synth(ref_dst, lag, gain_idx); + apcm_dequant_add(gb, ref_dst + offset); + ref_dst += 40; + } + memcpy(ctx->ref_buf, ctx->ref_buf + 160, 120 * sizeof(*ctx->ref_buf)); + short_term_synth(ctx, samples, ctx->ref_buf + 120); + // for optimal speed this could be merged with short_term_synth, + // not done yet because it is a bit ugly + ctx->msr = postprocess(samples, ctx->msr); + return 0; +} -- cgit v1.2.3