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authorMichael Niedermayer <michaelni@gmx.at>2012-10-30 14:40:22 +0100
committerMichael Niedermayer <michaelni@gmx.at>2012-10-30 14:40:22 +0100
commite79c3858b35fcc77c68c33b627958e736686957e (patch)
tree5f933517c2909def4e2930a409b0a460eb4f41fd /libavcodec/cngdec.c
parentcd37963684d8ee9819af15ccebe09d84839101dd (diff)
parent14f031d7ecfabba0ef02776d4516aa3dcb7c40d8 (diff)
downloadffmpeg-e79c3858b35fcc77c68c33b627958e736686957e.tar.gz
Merge commit '14f031d7ecfabba0ef02776d4516aa3dcb7c40d8'
* commit '14f031d7ecfabba0ef02776d4516aa3dcb7c40d8': dv: use AVStream.index instead of abusing AVStream.id lavfi: add ashowinfo filter avcodec: Add a RFC 3389 comfort noise codec lpc: Add a function for calculating reflection coefficients from samples lpc: Add a function for calculating reflection coefficients from autocorrelation coefficients lavr: document upper bound on number of output samples. lavr: add general API usage doxy indeo3: remove duplicate capabilities line. fate: ac3: Add dependencies Conflicts: Changelog doc/filters.texi libavcodec/Makefile libavcodec/allcodecs.c libavcodec/avcodec.h libavcodec/codec_desc.c libavcodec/version.h libavfilter/Makefile libavfilter/af_ashowinfo.c libavfilter/allfilters.c libavfilter/version.h libavutil/avutil.h Merged-by: Michael Niedermayer <michaelni@gmx.at>
Diffstat (limited to 'libavcodec/cngdec.c')
-rw-r--r--libavcodec/cngdec.c162
1 files changed, 162 insertions, 0 deletions
diff --git a/libavcodec/cngdec.c b/libavcodec/cngdec.c
new file mode 100644
index 0000000000..0daeb9b969
--- /dev/null
+++ b/libavcodec/cngdec.c
@@ -0,0 +1,162 @@
+/*
+ * RFC 3389 comfort noise generator
+ * Copyright (c) 2012 Martin Storsjo
+ *
+ * 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 <math.h>
+
+#include "libavutil/common.h"
+#include "avcodec.h"
+#include "celp_filters.h"
+#include "libavutil/lfg.h"
+
+typedef struct CNGContext {
+ AVFrame avframe;
+ float *refl_coef, *target_refl_coef;
+ float *lpc_coef;
+ int order;
+ int energy, target_energy;
+ float *filter_out;
+ float *excitation;
+ AVLFG lfg;
+} CNGContext;
+
+static av_cold int cng_decode_close(AVCodecContext *avctx)
+{
+ CNGContext *p = avctx->priv_data;
+ av_free(p->refl_coef);
+ av_free(p->target_refl_coef);
+ av_free(p->lpc_coef);
+ av_free(p->filter_out);
+ av_free(p->excitation);
+ return 0;
+}
+
+static av_cold int cng_decode_init(AVCodecContext *avctx)
+{
+ CNGContext *p = avctx->priv_data;
+
+ avctx->sample_fmt = AV_SAMPLE_FMT_S16;
+ avctx->channels = 1;
+ avctx->sample_rate = 8000;
+
+ avcodec_get_frame_defaults(&p->avframe);
+ avctx->coded_frame = &p->avframe;
+ p->order = 12;
+ avctx->frame_size = 640;
+ p->refl_coef = av_mallocz(p->order * sizeof(*p->refl_coef));
+ p->target_refl_coef = av_mallocz(p->order * sizeof(*p->target_refl_coef));
+ p->lpc_coef = av_mallocz(p->order * sizeof(*p->lpc_coef));
+ p->filter_out = av_mallocz((avctx->frame_size + p->order) *
+ sizeof(*p->filter_out));
+ p->excitation = av_mallocz(avctx->frame_size * sizeof(*p->excitation));
+ if (!p->refl_coef || !p->target_refl_coef || !p->lpc_coef ||
+ !p->filter_out || !p->excitation) {
+ cng_decode_close(avctx);
+ return AVERROR(ENOMEM);
+ }
+
+ av_lfg_init(&p->lfg, 0);
+
+ return 0;
+}
+
+static void make_lpc_coefs(float *lpc, const float *refl, int order)
+{
+ float buf[100];
+ float *next, *cur;
+ int m, i;
+ next = buf;
+ cur = lpc;
+ for (m = 0; m < order; m++) {
+ next[m] = refl[m];
+ for (i = 0; i < m; i++)
+ next[i] = cur[i] + refl[m] * cur[m - i - 1];
+ FFSWAP(float*, next, cur);
+ }
+ if (cur != lpc)
+ memcpy(lpc, cur, sizeof(*lpc) * order);
+}
+
+static int cng_decode_frame(AVCodecContext *avctx, void *data,
+ int *got_frame_ptr, AVPacket *avpkt)
+{
+
+ CNGContext *p = avctx->priv_data;
+ int buf_size = avpkt->size;
+ int ret, i;
+ int16_t *buf_out;
+ float e = 1.0;
+ float scaling;
+
+ if (avpkt->size) {
+ float dbov = -avpkt->data[0] / 10.0;
+ p->target_energy = 1081109975 * pow(10, dbov) * 0.75;
+ memset(p->target_refl_coef, 0, sizeof(p->refl_coef));
+ for (i = 0; i < FFMIN(avpkt->size - 1, p->order); i++) {
+ p->target_refl_coef[i] = (avpkt->data[1 + i] - 127) / 128.0;
+ }
+ make_lpc_coefs(p->lpc_coef, p->refl_coef, p->order);
+ }
+
+ p->energy = p->energy / 2 + p->target_energy / 2;
+ for (i = 0; i < p->order; i++)
+ p->refl_coef[i] = 0.6 *p->refl_coef[i] + 0.4 * p->target_refl_coef[i];
+
+ for (i = 0; i < p->order; i++)
+ e *= 1.0 - p->refl_coef[i]*p->refl_coef[i];
+
+ scaling = sqrt(e * p->energy / 1081109975);
+ for (i = 0; i < avctx->frame_size; i++) {
+ int r = (av_lfg_get(&p->lfg) & 0xffff) - 0x8000;
+ p->excitation[i] = scaling * r;
+ }
+ ff_celp_lp_synthesis_filterf(p->filter_out + p->order, p->lpc_coef,
+ p->excitation, avctx->frame_size, p->order);
+
+ p->avframe.nb_samples = avctx->frame_size;
+ if ((ret = avctx->get_buffer(avctx, &p->avframe)) < 0) {
+ av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
+ return ret;
+ }
+ buf_out = (int16_t *)p->avframe.data[0];
+ for (i = 0; i < avctx->frame_size; i++)
+ buf_out[i] = p->filter_out[i + p->order];
+ memcpy(p->filter_out, p->filter_out + avctx->frame_size,
+ p->order * sizeof(*p->filter_out));
+
+ *got_frame_ptr = 1;
+ *(AVFrame *)data = p->avframe;
+
+ return buf_size;
+}
+
+AVCodec ff_comfortnoise_decoder = {
+ .name = "comfortnoise",
+ .type = AVMEDIA_TYPE_AUDIO,
+ .id = AV_CODEC_ID_COMFORT_NOISE,
+ .priv_data_size = sizeof(CNGContext),
+ .init = cng_decode_init,
+ .decode = cng_decode_frame,
+ .close = cng_decode_close,
+ .long_name = NULL_IF_CONFIG_SMALL("RFC 3389 comfort noise generator"),
+ .sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
+ AV_SAMPLE_FMT_NONE },
+ .capabilities = CODEC_CAP_DELAY | CODEC_CAP_DR1,
+};