GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavcodec/cngdec.c Lines: 0 78 0.0 %
Date: 2019-11-22 03:34:36 Branches: 0 34 0.0 %

Line Branch Exec Source
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/*
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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 "libavutil/ffmath.h"
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#include "libavutil/intreadwrite.h"
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#include "avcodec.h"
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#include "celp_filters.h"
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#include "internal.h"
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#include "libavutil/lfg.h"
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typedef struct CNGContext {
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    float *refl_coef, *target_refl_coef;
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    float *lpc_coef;
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    int order;
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    int energy, target_energy;
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    int inited;
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    float *filter_out;
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    float *excitation;
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    AVLFG lfg;
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} CNGContext;
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static av_cold int cng_decode_close(AVCodecContext *avctx)
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{
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    CNGContext *p = avctx->priv_data;
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    av_freep(&p->refl_coef);
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    av_freep(&p->target_refl_coef);
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    av_freep(&p->lpc_coef);
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    av_freep(&p->filter_out);
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    av_freep(&p->excitation);
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    return 0;
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}
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static av_cold int cng_decode_init(AVCodecContext *avctx)
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{
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    CNGContext *p = avctx->priv_data;
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    avctx->sample_fmt  = AV_SAMPLE_FMT_S16;
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    avctx->channels    = 1;
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    avctx->sample_rate = 8000;
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    p->order            = 12;
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    avctx->frame_size   = 640;
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    p->refl_coef        = av_mallocz_array(p->order, sizeof(*p->refl_coef));
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    p->target_refl_coef = av_mallocz_array(p->order, sizeof(*p->target_refl_coef));
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    p->lpc_coef         = av_mallocz_array(p->order, sizeof(*p->lpc_coef));
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    p->filter_out       = av_mallocz_array(avctx->frame_size + p->order,
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                                     sizeof(*p->filter_out));
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    p->excitation       = av_mallocz_array(avctx->frame_size, sizeof(*p->excitation));
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    if (!p->refl_coef || !p->target_refl_coef || !p->lpc_coef ||
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        !p->filter_out || !p->excitation) {
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        return AVERROR(ENOMEM);
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    }
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    av_lfg_init(&p->lfg, 0);
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    return 0;
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}
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static void make_lpc_coefs(float *lpc, const float *refl, int order)
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{
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    float buf[100];
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    float *next, *cur;
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    int m, i;
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    next = buf;
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    cur  = lpc;
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    for (m = 0; m < order; m++) {
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        next[m] = refl[m];
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        for (i = 0; i < m; i++)
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            next[i] = cur[i] + refl[m] * cur[m - i - 1];
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        FFSWAP(float*, next, cur);
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    }
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    if (cur != lpc)
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        memcpy(lpc, cur, sizeof(*lpc) * order);
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}
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static void cng_decode_flush(AVCodecContext *avctx)
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{
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    CNGContext *p = avctx->priv_data;
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    p->inited = 0;
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}
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static int cng_decode_frame(AVCodecContext *avctx, void *data,
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                            int *got_frame_ptr, AVPacket *avpkt)
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{
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    AVFrame *frame = data;
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    CNGContext *p = avctx->priv_data;
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    int buf_size  = avpkt->size;
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    int ret, i;
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    int16_t *buf_out;
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    float e = 1.0;
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    float scaling;
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    if (avpkt->size) {
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        int dbov = -avpkt->data[0];
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        p->target_energy = 1081109975 * ff_exp10(dbov / 10.0) * 0.75;
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        memset(p->target_refl_coef, 0, p->order * sizeof(*p->target_refl_coef));
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        for (i = 0; i < FFMIN(avpkt->size - 1, p->order); i++) {
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            p->target_refl_coef[i] = (avpkt->data[1 + i] - 127) / 128.0;
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        }
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    }
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    if (avctx->internal->skip_samples > 10 * avctx->frame_size) {
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        avctx->internal->skip_samples = 0;
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        return AVERROR_INVALIDDATA;
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    }
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    if (p->inited) {
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        p->energy = p->energy / 2 + p->target_energy / 2;
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        for (i = 0; i < p->order; i++)
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            p->refl_coef[i] = 0.6 *p->refl_coef[i] + 0.4 * p->target_refl_coef[i];
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    } else {
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        p->energy = p->target_energy;
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        memcpy(p->refl_coef, p->target_refl_coef, p->order * sizeof(*p->refl_coef));
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        p->inited = 1;
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    }
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    make_lpc_coefs(p->lpc_coef, p->refl_coef, p->order);
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    for (i = 0; i < p->order; i++)
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        e *= 1.0 - p->refl_coef[i]*p->refl_coef[i];
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    scaling = sqrt(e * p->energy / 1081109975);
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    for (i = 0; i < avctx->frame_size; i++) {
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        int r = (av_lfg_get(&p->lfg) & 0xffff) - 0x8000;
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        p->excitation[i] = scaling * r;
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    }
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    ff_celp_lp_synthesis_filterf(p->filter_out + p->order, p->lpc_coef,
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                                 p->excitation, avctx->frame_size, p->order);
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    frame->nb_samples = avctx->frame_size;
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    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
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        return ret;
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    buf_out = (int16_t *)frame->data[0];
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    for (i = 0; i < avctx->frame_size; i++)
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        buf_out[i] = av_clip_int16(p->filter_out[i + p->order]);
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    memcpy(p->filter_out, p->filter_out + avctx->frame_size,
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           p->order * sizeof(*p->filter_out));
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    *got_frame_ptr = 1;
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    return buf_size;
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}
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AVCodec ff_comfortnoise_decoder = {
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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_decode_init,
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    .decode         = cng_decode_frame,
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    .flush          = cng_decode_flush,
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    .close          = cng_decode_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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    .capabilities   = AV_CODEC_CAP_DELAY | AV_CODEC_CAP_DR1,
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    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE |
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                      FF_CODEC_CAP_INIT_CLEANUP,
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};