GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavfilter/af_crossfeed.c Lines: 0 67 0.0 %
Date: 2020-10-23 17:01:47 Branches: 0 22 0.0 %

Line Branch Exec Source
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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/channel_layout.h"
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#include "libavutil/ffmath.h"
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#include "libavutil/opt.h"
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#include "avfilter.h"
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#include "audio.h"
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#include "formats.h"
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typedef struct CrossfeedContext {
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    const AVClass *class;
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    double range;
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    double strength;
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    double slope;
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    double level_in;
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    double level_out;
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    double a0, a1, a2;
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    double b0, b1, b2;
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    double w1, w2;
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} CrossfeedContext;
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static int query_formats(AVFilterContext *ctx)
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{
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    AVFilterFormats *formats = NULL;
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    AVFilterChannelLayouts *layout = NULL;
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    int ret;
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    if ((ret = ff_add_format                 (&formats, AV_SAMPLE_FMT_DBL  )) < 0 ||
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        (ret = ff_set_common_formats         (ctx     , formats            )) < 0 ||
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        (ret = ff_add_channel_layout         (&layout , AV_CH_LAYOUT_STEREO)) < 0 ||
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        (ret = ff_set_common_channel_layouts (ctx     , layout             )) < 0 ||
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        (ret = ff_set_common_samplerates     (ctx     , ff_all_samplerates())) < 0)
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        return ret;
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    return 0;
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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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    CrossfeedContext *s = ctx->priv;
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    double A = ff_exp10(s->strength * -30 / 40);
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    double w0 = 2 * M_PI * (1. - s->range) * 2100 / inlink->sample_rate;
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    double alpha;
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    alpha = sin(w0) / 2 * sqrt((A + 1 / A) * (1 / s->slope - 1) + 2);
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    s->a0 =          (A + 1) + (A - 1) * cos(w0) + 2 * sqrt(A) * alpha;
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    s->a1 =    -2 * ((A - 1) + (A + 1) * cos(w0));
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    s->a2 =          (A + 1) + (A - 1) * cos(w0) - 2 * sqrt(A) * alpha;
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    s->b0 =     A * ((A + 1) - (A - 1) * cos(w0) + 2 * sqrt(A) * alpha);
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    s->b1 = 2 * A * ((A - 1) - (A + 1) * cos(w0));
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    s->b2 =     A * ((A + 1) - (A - 1) * cos(w0) - 2 * sqrt(A) * alpha);
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    s->a1 /= s->a0;
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    s->a2 /= s->a0;
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    s->b0 /= s->a0;
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    s->b1 /= s->a0;
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    s->b2 /= s->a0;
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    return 0;
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}
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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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    CrossfeedContext *s = ctx->priv;
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    const double *src = (const double *)in->data[0];
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    const double level_in = s->level_in;
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    const double level_out = s->level_out;
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    const double b0 = s->b0;
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    const double b1 = s->b1;
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    const double b2 = s->b2;
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    const double a1 = -s->a1;
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    const double a2 = -s->a2;
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    AVFrame *out;
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    double *dst;
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    int n;
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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 < out->nb_samples; n++, src += 2, dst += 2) {
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        double mid = (src[0] + src[1]) * level_in * .5;
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        double side = (src[0] - src[1]) * level_in * .5;
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        double oside = side * b0 + s->w1;
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        s->w1 = b1 * side + s->w2 + a1 * oside;
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        s->w2 = b2 * side + a2 * oside;
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        if (ctx->is_disabled) {
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            dst[0] = src[0];
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            dst[1] = src[1];
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        } else {
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            dst[0] = (mid + oside) * level_out;
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            dst[1] = (mid - oside) * level_out;
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        }
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    }
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    if (out != in)
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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 process_command(AVFilterContext *ctx, const char *cmd, const char *args,
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                           char *res, int res_len, int flags)
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{
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    int ret;
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    ret = ff_filter_process_command(ctx, cmd, args, res, res_len, flags);
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    if (ret < 0)
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        return ret;
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    return config_input(ctx->inputs[0]);
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}
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#define OFFSET(x) offsetof(CrossfeedContext, x)
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#define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_RUNTIME_PARAM
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static const AVOption crossfeed_options[] = {
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    { "strength",  "set crossfeed strength",  OFFSET(strength),  AV_OPT_TYPE_DOUBLE, {.dbl=.2}, 0, 1, FLAGS },
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    { "range",     "set soundstage wideness", OFFSET(range),     AV_OPT_TYPE_DOUBLE, {.dbl=.5}, 0, 1, FLAGS },
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    { "slope",     "set curve slope",         OFFSET(slope),     AV_OPT_TYPE_DOUBLE, {.dbl=.5}, .01, 1, FLAGS },
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    { "level_in",  "set level in",            OFFSET(level_in),  AV_OPT_TYPE_DOUBLE, {.dbl=.9}, 0, 1, FLAGS },
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    { "level_out", "set level out",           OFFSET(level_out), AV_OPT_TYPE_DOUBLE, {.dbl=1.}, 0, 1, FLAGS },
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    { NULL }
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};
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AVFILTER_DEFINE_CLASS(crossfeed);
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static const AVFilterPad inputs[] = {
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    {
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        .name         = "default",
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        .type         = AVMEDIA_TYPE_AUDIO,
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        .filter_frame = filter_frame,
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        .config_props = config_input,
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    },
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    { NULL }
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};
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static const AVFilterPad 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_crossfeed = {
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    .name           = "crossfeed",
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    .description    = NULL_IF_CONFIG_SMALL("Apply headphone crossfeed filter."),
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    .query_formats  = query_formats,
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    .priv_size      = sizeof(CrossfeedContext),
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    .priv_class     = &crossfeed_class,
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    .inputs         = inputs,
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    .outputs        = outputs,
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    .flags          = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL,
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    .process_command = process_command,
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};