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This is possible, because every given FFCodec has to implement exactly one of these. Doing so decreases sizeof(FFCodec) and therefore decreases the size of the binary. Notice that in case of position-independent code the decrease is in .data.rel.ro, so that this translates to decreased memory consumption. Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
114 lines
3.6 KiB
C
114 lines
3.6 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 "codec_internal.h"
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#include "encode.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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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_get_encode_buffer(avctx, avpkt, 1 + p->order, 0))) {
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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 FFCodec ff_comfortnoise_encoder = {
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.p.name = "comfortnoise",
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.p.long_name = NULL_IF_CONFIG_SMALL("RFC 3389 comfort noise generator"),
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.p.type = AVMEDIA_TYPE_AUDIO,
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.p.id = AV_CODEC_ID_COMFORT_NOISE,
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.p.capabilities = AV_CODEC_CAP_DR1,
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.priv_data_size = sizeof(CNGContext),
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.init = cng_encode_init,
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FF_CODEC_ENCODE_CB(cng_encode_frame),
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.close = cng_encode_close,
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.p.sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
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AV_SAMPLE_FMT_NONE },
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.p.ch_layouts = (const AVChannelLayout[]){ AV_CHANNEL_LAYOUT_MONO, { 0 } },
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.caps_internal = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
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};
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