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FFmpeg/libavcodec/cngenc.c
Andreas Rheinhardt 20f9727018 avcodec/codec_internal: Add FFCodec, hide internal part of AVCodec
Up until now, codec.h contains both public and private parts
of AVCodec. This exposes the internals of AVCodec to users
and leads them into the temptation of actually using them
and forces us to forward-declare structures and types that
users can't use at all.

This commit changes this by adding a new structure FFCodec to
codec_internal.h that extends AVCodec, i.e. contains the public
AVCodec as first member; the private fields of AVCodec are moved
to this structure, leaving codec.h clean.

Reviewed-by: Anton Khirnov <anton@khirnov.net>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2022-03-21 01:33:09 +01:00

114 lines
3.5 KiB
C

/*
* 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 "codec_internal.h"
#include "encode.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_freep(&p->samples32);
av_freep(&p->ref_coef);
return 0;
}
static av_cold int cng_encode_init(AVCodecContext *avctx)
{
CNGContext *p = avctx->priv_data;
int ret;
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_array(avctx->frame_size, sizeof(*p->samples32));
p->ref_coef = av_malloc_array(p->order, sizeof(*p->ref_coef));
if (!p->samples32 || !p->ref_coef)
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_get_encode_buffer(avctx, avpkt, 1 + p->order, 0))) {
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_uintp2(-floor(dbov), 7);
} else {
qdbov = 127;
}
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;
av_assert1(avpkt->size == 1 + p->order);
return 0;
}
const FFCodec ff_comfortnoise_encoder = {
.p.name = "comfortnoise",
.p.long_name = NULL_IF_CONFIG_SMALL("RFC 3389 comfort noise generator"),
.p.type = AVMEDIA_TYPE_AUDIO,
.p.id = AV_CODEC_ID_COMFORT_NOISE,
.p.capabilities = AV_CODEC_CAP_DR1,
.priv_data_size = sizeof(CNGContext),
.init = cng_encode_init,
.encode2 = cng_encode_frame,
.close = cng_encode_close,
.p.sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
AV_SAMPLE_FMT_NONE },
.p.ch_layouts = (const AVChannelLayout[]){ AV_CHANNEL_LAYOUT_MONO, { 0 } },
.caps_internal = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
};