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a247ac640d
Given that the AVCodec.next pointer has now been removed, most of the AVCodecs are not modified at all any more and can therefore be made const (as this patch does); the only exceptions are the very few codecs for external libraries that have a init_static_data callback. Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com> Signed-off-by: James Almer <jamrial@gmail.com>
116 lines
3.5 KiB
C
116 lines
3.5 KiB
C
/*
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* RFC 3389 comfort noise generator
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* Copyright (c) 2012 Martin Storsjo
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include <math.h>
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#include "libavutil/common.h"
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#include "avcodec.h"
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#include "internal.h"
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#include "lpc.h"
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typedef struct CNGContext {
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LPCContext lpc;
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int order;
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int32_t *samples32;
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double *ref_coef;
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} CNGContext;
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static av_cold int cng_encode_close(AVCodecContext *avctx)
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{
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CNGContext *p = avctx->priv_data;
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ff_lpc_end(&p->lpc);
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av_freep(&p->samples32);
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av_freep(&p->ref_coef);
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return 0;
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}
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static av_cold int cng_encode_init(AVCodecContext *avctx)
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{
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CNGContext *p = avctx->priv_data;
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int ret;
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if (avctx->channels != 1) {
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av_log(avctx, AV_LOG_ERROR, "Only mono supported\n");
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return AVERROR(EINVAL);
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}
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avctx->frame_size = 640;
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p->order = 10;
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if ((ret = ff_lpc_init(&p->lpc, avctx->frame_size, p->order, FF_LPC_TYPE_LEVINSON)) < 0)
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return ret;
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p->samples32 = av_malloc_array(avctx->frame_size, sizeof(*p->samples32));
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p->ref_coef = av_malloc_array(p->order, sizeof(*p->ref_coef));
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if (!p->samples32 || !p->ref_coef)
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return AVERROR(ENOMEM);
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return 0;
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}
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static int cng_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
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const AVFrame *frame, int *got_packet_ptr)
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{
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CNGContext *p = avctx->priv_data;
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int ret, i;
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double energy = 0;
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int qdbov;
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int16_t *samples = (int16_t*) frame->data[0];
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if ((ret = ff_alloc_packet2(avctx, avpkt, 1 + p->order, 1 + p->order))) {
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av_log(avctx, AV_LOG_ERROR, "Error getting output packet\n");
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return ret;
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}
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for (i = 0; i < frame->nb_samples; i++) {
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p->samples32[i] = samples[i];
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energy += samples[i] * samples[i];
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}
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energy /= frame->nb_samples;
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if (energy > 0) {
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double dbov = 10 * log10(energy / 1081109975);
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qdbov = av_clip_uintp2(-floor(dbov), 7);
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} else {
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qdbov = 127;
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}
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ff_lpc_calc_ref_coefs(&p->lpc, p->samples32, p->order, p->ref_coef);
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avpkt->data[0] = qdbov;
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for (i = 0; i < p->order; i++)
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avpkt->data[1 + i] = p->ref_coef[i] * 127 + 127;
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*got_packet_ptr = 1;
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av_assert1(avpkt->size == 1 + p->order);
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return 0;
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}
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const AVCodec ff_comfortnoise_encoder = {
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.name = "comfortnoise",
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.long_name = NULL_IF_CONFIG_SMALL("RFC 3389 comfort noise generator"),
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.type = AVMEDIA_TYPE_AUDIO,
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.id = AV_CODEC_ID_COMFORT_NOISE,
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.priv_data_size = sizeof(CNGContext),
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.init = cng_encode_init,
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.encode2 = cng_encode_frame,
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.close = cng_encode_close,
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.sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
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AV_SAMPLE_FMT_NONE },
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.caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
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};
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