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avcodec: Add a RFC 3389 comfort noise codec

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This isn't too useful as a normal codec, but can be used in
voip style applications. The decoder updates the noise
generator parameters when a packet is given to it for decoding,
but if called with an empty packet, it generates more noise
according to the last parameters.

Signed-off-by: Martin Storsjö <martin@martin.st>
This commit is contained in:
Martin Storsjö 2012-10-23 00:02:41 +03:00
parent 8b25a20efb
commit 9b500b8f6c
8 changed files with 291 additions and 1 deletions
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1
configure vendored
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@ -1440,6 +1440,7 @@ atrac3_decoder_select="mdct"
binkaudio_dct_decoder_select="mdct rdft dct sinewin"
binkaudio_rdft_decoder_select="mdct rdft sinewin"
cavs_decoder_select="golomb mpegvideo"
comfortnoise_encoder_select="lpc"
cook_decoder_select="mdct sinewin"
cscd_decoder_select="lzo"
cscd_decoder_suggest="zlib"

2
libavcodec/Makefile
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@ -129,6 +129,8 @@ OBJS-$(CONFIG_CLJR_DECODER) += cljr.o
OBJS-$(CONFIG_CLJR_ENCODER) += cljr.o
OBJS-$(CONFIG_CLLC_DECODER) += cllc.o
OBJS-$(CONFIG_COOK_DECODER) += cook.o
OBJS-$(CONFIG_COMFORTNOISE_DECODER) += cngdec.o celp_filters.o
OBJS-$(CONFIG_COMFORTNOISE_ENCODER) += cngenc.o
OBJS-$(CONFIG_CSCD_DECODER) += cscd.o
OBJS-$(CONFIG_CYUV_DECODER) += cyuv.o
OBJS-$(CONFIG_DCA_DECODER) += dcadec.o dca.o dcadsp.o \

1
libavcodec/allcodecs.c
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@ -91,6 +91,7 @@ void avcodec_register_all(void)
REGISTER_DECODER (CINEPAK, cinepak);
REGISTER_ENCDEC (CLJR, cljr);
REGISTER_DECODER (CLLC, cllc);
REGISTER_ENCDEC (COMFORTNOISE, comfortnoise);
REGISTER_DECODER (CSCD, cscd);
REGISTER_DECODER (CYUV, cyuv);
REGISTER_DECODER (DFA, dfa);

1
libavcodec/avcodec.h
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@ -406,6 +406,7 @@ enum AVCodecID {
AV_CODEC_ID_IAC,
AV_CODEC_ID_ILBC,
AV_CODEC_ID_OPUS,
AV_CODEC_ID_COMFORT_NOISE,
/* subtitle codecs */
AV_CODEC_ID_FIRST_SUBTITLE = 0x17000, ///< A dummy ID pointing at the start of subtitle codecs.

162
libavcodec/cngdec.c Normal file
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@ -0,0 +1,162 @@
/*
* RFC 3389 comfort noise generator
* Copyright (c) 2012 Martin Storsjo
*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; 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,
};

116
libavcodec/cngenc.c Normal file
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@ -0,0 +1,116 @@
/*
* RFC 3389 comfort noise generator
* Copyright (c) 2012 Martin Storsjo
*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; 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 "internal.h"
#include "lpc.h"
typedef struct CNGContext {
LPCContext lpc;
int order;
int32_t *samples32;
double *ref_coef;
} CNGContext;
static av_cold int cng_encode_close(AVCodecContext *avctx)
{
CNGContext *p = avctx->priv_data;
ff_lpc_end(&p->lpc);
av_free(p->samples32);
av_free(p->ref_coef);
return 0;
}
static av_cold int cng_encode_init(AVCodecContext *avctx)
{
CNGContext *p = avctx->priv_data;
int ret;
if (avctx->channels != 1) {
av_log(avctx, AV_LOG_ERROR, "Only mono supported\n");
return AVERROR(EINVAL);
}
avctx->frame_size = 640;
p->order = 10;
if ((ret = ff_lpc_init(&p->lpc, avctx->frame_size, p->order, FF_LPC_TYPE_LEVINSON)) < 0)
return ret;
p->samples32 = av_malloc(avctx->frame_size * sizeof(*p->samples32));
p->ref_coef = av_malloc(p->order * sizeof(*p->ref_coef));
if (!p->samples32 || !p->ref_coef) {
cng_encode_close(avctx);
return AVERROR(ENOMEM);
}
return 0;
}
static int cng_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
const AVFrame *frame, int *got_packet_ptr)
{
CNGContext *p = avctx->priv_data;
int ret, i;
double energy = 0;
int qdbov;
int16_t *samples = (int16_t*) frame->data[0];
if ((ret = ff_alloc_packet(avpkt, 1 + p->order))) {
av_log(avctx, AV_LOG_ERROR, "Error getting output packet\n");
return ret;
}
for (i = 0; i < frame->nb_samples; i++) {
p->samples32[i] = samples[i];
energy += samples[i] * samples[i];
}
energy /= frame->nb_samples;
if (energy > 0) {
double dbov = 10 * log10(energy / 1081109975);
qdbov = av_clip(-floor(dbov), 0, 127);
} else {
qdbov = 127;
}
ret = ff_lpc_calc_ref_coefs(&p->lpc, p->samples32, p->order, p->ref_coef);
avpkt->data[0] = qdbov;
for (i = 0; i < p->order; i++)
avpkt->data[1 + i] = p->ref_coef[i] * 127 + 127;
*got_packet_ptr = 1;
avpkt->size = 1 + p->order;
return 0;
}
AVCodec ff_comfortnoise_encoder = {
.name = "comfortnoise",
.type = AVMEDIA_TYPE_AUDIO,
.id = AV_CODEC_ID_COMFORT_NOISE,
.priv_data_size = sizeof(CNGContext),
.init = cng_encode_init,
.encode2 = cng_encode_frame,
.close = cng_encode_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 },
};

7
libavcodec/codec_desc.c
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@ -2112,6 +2112,13 @@ static const AVCodecDescriptor codec_descriptors[] = {
.long_name = NULL_IF_CONFIG_SMALL("Opus (Opus Interactive Audio Codec)"),
.props = AV_CODEC_PROP_LOSSY,
},
{
.id = AV_CODEC_ID_COMFORT_NOISE,
.type = AVMEDIA_TYPE_AUDIO,
.name = "comfortnoise",
.long_name = NULL_IF_CONFIG_SMALL("RFC 3389 Comfort Noise"),
.props = AV_CODEC_PROP_LOSSY,
},
/* subtitle codecs */
{

2
libavcodec/version.h
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@ -27,7 +27,7 @@
*/
#define LIBAVCODEC_VERSION_MAJOR 54
#define LIBAVCODEC_VERSION_MINOR 31
#define LIBAVCODEC_VERSION_MINOR 32
#define LIBAVCODEC_VERSION_MICRO 0
#define LIBAVCODEC_VERSION_INT AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \