GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavfilter/af_tremolo.c Lines: 49 61 80.3 %
Date: 2020-10-23 17:01:47 Branches: 16 26 61.5 %

Line Branch Exec Source
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/*
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 * Copyright (c) 2015 Kyle Swanson <k@ylo.ph>.
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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 "libavutil/opt.h"
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#include "avfilter.h"
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#include "internal.h"
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#include "audio.h"
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typedef struct TremoloContext {
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    const AVClass *class;
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    double freq;
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    double depth;
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    double *table;
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    int table_size;
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    int index;
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} TremoloContext;
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#define OFFSET(x) offsetof(TremoloContext, x)
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#define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
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static const AVOption tremolo_options[] = {
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    { "f", "set frequency in hertz",    OFFSET(freq),    AV_OPT_TYPE_DOUBLE,   {.dbl = 5.0},   0.1,   20000.0, FLAGS },
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    { "d", "set depth as percentage",   OFFSET(depth),   AV_OPT_TYPE_DOUBLE,   {.dbl = 0.5},   0.0,   1.0,     FLAGS },
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    { NULL }
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};
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AVFILTER_DEFINE_CLASS(tremolo);
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static int filter_frame(AVFilterLink *inlink, AVFrame *in)
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{
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    AVFilterContext *ctx = inlink->dst;
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    AVFilterLink *outlink = ctx->outputs[0];
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    TremoloContext *s = ctx->priv;
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    const double *src = (const double *)in->data[0];
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    const int channels = inlink->channels;
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    const int nb_samples = in->nb_samples;
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    AVFrame *out;
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    double *dst;
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    int n, c;
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    if (av_frame_is_writable(in)) {
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        out = in;
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    } else {
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        out = ff_get_audio_buffer(outlink, in->nb_samples);
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        if (!out) {
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            av_frame_free(&in);
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            return AVERROR(ENOMEM);
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        }
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        av_frame_copy_props(out, in);
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    }
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    dst = (double *)out->data[0];
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    for (n = 0; n < nb_samples; n++) {
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61440
        for (c = 0; c < channels; c++)
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40960
            dst[c] = src[c] * s->table[s->index];
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        dst += channels;
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        src += channels;
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        s->index++;
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        if (s->index >= s->table_size)
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2
            s->index = 0;
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    }
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    if (in != out)
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        av_frame_free(&in);
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    return ff_filter_frame(outlink, out);
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}
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static int query_formats(AVFilterContext *ctx)
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{
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    AVFilterFormats *formats;
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    AVFilterChannelLayouts *layouts;
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    static const enum AVSampleFormat sample_fmts[] = {
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        AV_SAMPLE_FMT_DBL,
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        AV_SAMPLE_FMT_NONE
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    };
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    int ret;
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    layouts = ff_all_channel_counts();
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1
    if (!layouts)
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        return AVERROR(ENOMEM);
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1
    ret = ff_set_common_channel_layouts(ctx, layouts);
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    if (ret < 0)
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        return ret;
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    formats = ff_make_format_list(sample_fmts);
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1
    if (!formats)
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        return AVERROR(ENOMEM);
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1
    ret = ff_set_common_formats(ctx, formats);
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1
    if (ret < 0)
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        return ret;
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    formats = ff_all_samplerates();
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1
    if (!formats)
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        return AVERROR(ENOMEM);
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    return ff_set_common_samplerates(ctx, formats);
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}
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static av_cold void uninit(AVFilterContext *ctx)
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{
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    TremoloContext *s = ctx->priv;
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    av_freep(&s->table);
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}
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static int config_input(AVFilterLink *inlink)
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{
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    AVFilterContext *ctx = inlink->dst;
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    TremoloContext *s = ctx->priv;
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    const double offset = 1. - s->depth / 2.;
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    int i;
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    s->table_size = inlink->sample_rate / s->freq;
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    s->table = av_malloc_array(s->table_size, sizeof(*s->table));
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    if (!s->table)
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        return AVERROR(ENOMEM);
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    for (i = 0; i < s->table_size; i++) {
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        double env = s->freq * i / inlink->sample_rate;
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        env = sin(2 * M_PI * fmod(env + 0.25, 1.0));
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        s->table[i] = env * (1 - fabs(offset)) + offset;
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    }
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    s->index = 0;
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    return 0;
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}
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static const AVFilterPad avfilter_af_tremolo_inputs[] = {
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    {
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        .name         = "default",
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        .type         = AVMEDIA_TYPE_AUDIO,
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        .config_props = config_input,
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        .filter_frame = filter_frame,
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    },
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    { NULL }
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};
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static const AVFilterPad avfilter_af_tremolo_outputs[] = {
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    {
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        .name = "default",
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        .type = AVMEDIA_TYPE_AUDIO,
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    },
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    { NULL }
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};
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AVFilter ff_af_tremolo = {
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    .name          = "tremolo",
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    .description   = NULL_IF_CONFIG_SMALL("Apply tremolo effect."),
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    .priv_size     = sizeof(TremoloContext),
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    .priv_class    = &tremolo_class,
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    .uninit        = uninit,
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    .query_formats = query_formats,
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    .inputs        = avfilter_af_tremolo_inputs,
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    .outputs       = avfilter_af_tremolo_outputs,
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};