GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavfilter/af_earwax.c Lines: 35 39 89.7 %
Date: 2020-08-14 10:39:37 Branches: 11 18 61.1 %

Line Branch Exec Source
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/*
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 * Copyright (c) 2011 Mina Nagy Zaki
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 * Copyright (c) 2000 Edward Beingessner And Sundry Contributors.
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 * This source code is freely redistributable and may be used for any purpose.
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 * This copyright notice must be maintained.  Edward Beingessner And Sundry
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 * Contributors are not responsible for the consequences of using this
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 * software.
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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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/**
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 * @file
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 * Stereo Widening Effect. Adds audio cues to move stereo image in
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 * front of the listener. Adapted from the libsox earwax effect.
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 */
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#include "libavutil/channel_layout.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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#define NUMTAPS 64
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static const int8_t filt[NUMTAPS] = {
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/* 30°  330° */
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    4,   -6,     /* 32 tap stereo FIR filter. */
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    4,  -11,     /* One side filters as if the */
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   -1,   -5,     /* signal was from 30 degrees */
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    3,    3,     /* from the ear, the other as */
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   -2,    5,     /* if 330 degrees. */
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   -5,    0,
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    9,    1,
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    6,    3,     /*                         Input                         */
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   -4,   -1,     /*                   Left         Right                  */
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   -5,   -3,     /*                __________   __________                */
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   -2,   -5,     /*               |          | |          |               */
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   -7,    1,     /*           .---|  Hh,0(f) | |  Hh,0(f) |---.           */
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    6,   -7,     /*          /    |__________| |__________|    \          */
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   30,  -29,     /*         /                \ /                \         */
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   12,   -3,     /*        /                  X                  \        */
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  -11,    4,     /*       /                  / \                  \       */
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   -3,    7,     /*  ____V_____   __________V   V__________   _____V____  */
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  -20,   23,     /* |          | |          |   |          | |          | */
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    2,    0,     /* | Hh,30(f) | | Hh,330(f)|   | Hh,330(f)| | Hh,30(f) | */
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    1,   -6,     /* |__________| |__________|   |__________| |__________| */
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  -14,   -5,     /*      \     ___      /           \      ___     /      */
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   15,  -18,     /*       \   /   \    /    _____    \    /   \   /       */
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    6,    7,     /*        `->| + |<--'    /     \    `-->| + |<-'        */
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   15,  -10,     /*           \___/      _/       \_      \___/           */
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  -14,   22,     /*               \     / \       / \     /               */
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   -7,   -2,     /*                `--->| |       | |<---'                */
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   -4,    9,     /*                     \_/       \_/                     */
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    6,  -12,     /*                                                       */
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    6,   -6,     /*                       Headphones                      */
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    0,  -11,
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    0,   -5,
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    4,    0};
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typedef struct EarwaxContext {
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    int16_t taps[NUMTAPS * 2];
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} EarwaxContext;
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static int query_formats(AVFilterContext *ctx)
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{
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    static const int sample_rates[] = { 44100, -1 };
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    int ret;
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    AVFilterFormats *formats = NULL;
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    AVFilterChannelLayouts *layout = NULL;
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    if ((ret = ff_add_format                 (&formats, AV_SAMPLE_FMT_S16                 )) < 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_make_format_list(sample_rates) )) < 0)
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        return ret;
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    return 0;
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}
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//FIXME: replace with DSPContext.scalarproduct_int16
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static inline int16_t *scalarproduct(const int16_t *in, const int16_t *endin, int16_t *out)
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{
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    int32_t sample;
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    int16_t j;
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    while (in < endin) {
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        sample = 0;
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        for (j = 0; j < NUMTAPS; j++)
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2621440
            sample += in[j] * filt[j];
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40960
        *out = av_clip_int16(sample >> 6);
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40960
        out++;
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        in++;
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    }
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    return out;
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}
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static int filter_frame(AVFilterLink *inlink, AVFrame *insamples)
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{
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    AVFilterLink *outlink = inlink->dst->outputs[0];
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    int16_t *taps, *endin, *in, *out;
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    AVFrame *outsamples = ff_get_audio_buffer(outlink, insamples->nb_samples);
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    int len;
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    if (!outsamples) {
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        av_frame_free(&insamples);
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        return AVERROR(ENOMEM);
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    }
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    av_frame_copy_props(outsamples, insamples);
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    taps  = ((EarwaxContext *)inlink->dst->priv)->taps;
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    out   = (int16_t *)outsamples->data[0];
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    in    = (int16_t *)insamples ->data[0];
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    len = FFMIN(NUMTAPS, 2*insamples->nb_samples);
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    // copy part of new input and process with saved input
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    memcpy(taps+NUMTAPS, in, len * sizeof(*taps));
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    out   = scalarproduct(taps, taps + len, out);
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    // process current input
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    if (2*insamples->nb_samples >= NUMTAPS ){
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        endin = in + insamples->nb_samples * 2 - NUMTAPS;
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        scalarproduct(in, endin, out);
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        // save part of input for next round
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        memcpy(taps, endin, NUMTAPS * sizeof(*taps));
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    } else
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        memmove(taps, taps + 2*insamples->nb_samples, NUMTAPS * sizeof(*taps));
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    av_frame_free(&insamples);
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    return ff_filter_frame(outlink, outsamples);
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}
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static const AVFilterPad earwax_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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    },
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    { NULL }
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};
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static const AVFilterPad earwax_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_earwax = {
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    .name           = "earwax",
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    .description    = NULL_IF_CONFIG_SMALL("Widen the stereo image."),
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    .query_formats  = query_formats,
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    .priv_size      = sizeof(EarwaxContext),
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    .inputs         = earwax_inputs,
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    .outputs        = earwax_outputs,
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};