LCOV - code coverage report
Current view: top level - src/libavfilter - af_tremolo.c (source / functions) Hit Total Coverage
Test: coverage.info Lines: 48 60 80.0 %
Date: 2017-01-24 04:42:20 Functions: 4 4 100.0 %

          Line data    Source code
       1             : /*
       2             :  * Copyright (c) 2015 Kyle Swanson <k@ylo.ph>.
       3             :  *
       4             :  * This file is part of FFmpeg.
       5             :  *
       6             :  * FFmpeg is free software; you can redistribute it and/or
       7             :  * modify it under the terms of the GNU Lesser General Public
       8             :  * License as published by the Free Software Foundation; either
       9             :  * version 2.1 of the License, or (at your option) any later version.
      10             :  *
      11             :  * FFmpeg is distributed in the hope that it will be useful,
      12             :  * but WITHOUT ANY WARRANTY; without even the implied warranty of
      13             :  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      14             :  * Lesser General Public License for more details.
      15             :  *
      16             :  * You should have received a copy of the GNU Lesser General Public
      17             :  * License along with FFmpeg; if not, write to the Free Software
      18             :  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
      19             :  */
      20             : 
      21             : #include "libavutil/opt.h"
      22             : #include "avfilter.h"
      23             : #include "internal.h"
      24             : #include "audio.h"
      25             : 
      26             : typedef struct TremoloContext {
      27             :     const AVClass *class;
      28             :     double freq;
      29             :     double depth;
      30             :     double *table;
      31             :     int index;
      32             : } TremoloContext;
      33             : 
      34             : #define OFFSET(x) offsetof(TremoloContext, x)
      35             : #define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
      36             : 
      37             : static const AVOption tremolo_options[] = {
      38             :     { "f", "set frequency in hertz",    OFFSET(freq),    AV_OPT_TYPE_DOUBLE,   {.dbl = 5.0},   0.1,   20000.0, FLAGS },
      39             :     { "d", "set depth as percentage",   OFFSET(depth),   AV_OPT_TYPE_DOUBLE,   {.dbl = 0.5},   0.0,   1.0,     FLAGS },
      40             :     { NULL }
      41             : };
      42             : 
      43             : AVFILTER_DEFINE_CLASS(tremolo);
      44             : 
      45          20 : static int filter_frame(AVFilterLink *inlink, AVFrame *in)
      46             : {
      47          20 :     AVFilterContext *ctx = inlink->dst;
      48          20 :     AVFilterLink *outlink = ctx->outputs[0];
      49          20 :     TremoloContext *s = ctx->priv;
      50          20 :     const double *src = (const double *)in->data[0];
      51          20 :     const int channels = inlink->channels;
      52          20 :     const int nb_samples = in->nb_samples;
      53             :     AVFrame *out;
      54             :     double *dst;
      55             :     int n, c;
      56             : 
      57          20 :     if (av_frame_is_writable(in)) {
      58          20 :         out = in;
      59             :     } else {
      60           0 :         out = ff_get_audio_buffer(inlink, in->nb_samples);
      61           0 :         if (!out) {
      62           0 :             av_frame_free(&in);
      63           0 :             return AVERROR(ENOMEM);
      64             :         }
      65           0 :         av_frame_copy_props(out, in);
      66             :     }
      67          20 :     dst = (double *)out->data[0];
      68             : 
      69       20500 :     for (n = 0; n < nb_samples; n++) {
      70       61440 :         for (c = 0; c < channels; c++)
      71       40960 :             dst[c] = src[c] * s->table[s->index];
      72       20480 :         dst += channels;
      73       20480 :         src += channels;
      74       20480 :         s->index++;
      75       20480 :         if (s->index >= inlink->sample_rate / s->freq)
      76           2 :             s->index = 0;
      77             :     }
      78             : 
      79          20 :     if (in != out)
      80           0 :         av_frame_free(&in);
      81             : 
      82          20 :     return ff_filter_frame(outlink, out);
      83             : }
      84             : 
      85           1 : static int query_formats(AVFilterContext *ctx)
      86             : {
      87             :     AVFilterFormats *formats;
      88             :     AVFilterChannelLayouts *layouts;
      89             :     static const enum AVSampleFormat sample_fmts[] = {
      90             :         AV_SAMPLE_FMT_DBL,
      91             :         AV_SAMPLE_FMT_NONE
      92             :     };
      93             :     int ret;
      94             : 
      95           1 :     layouts = ff_all_channel_counts();
      96           1 :     if (!layouts)
      97           0 :         return AVERROR(ENOMEM);
      98           1 :     ret = ff_set_common_channel_layouts(ctx, layouts);
      99           1 :     if (ret < 0)
     100           0 :         return ret;
     101             : 
     102           1 :     formats = ff_make_format_list(sample_fmts);
     103           1 :     if (!formats)
     104           0 :         return AVERROR(ENOMEM);
     105           1 :     ret = ff_set_common_formats(ctx, formats);
     106           1 :     if (ret < 0)
     107           0 :         return ret;
     108             : 
     109           1 :     formats = ff_all_samplerates();
     110           1 :     if (!formats)
     111           0 :         return AVERROR(ENOMEM);
     112           1 :     return ff_set_common_samplerates(ctx, formats);
     113             : }
     114             : 
     115           1 : static av_cold void uninit(AVFilterContext *ctx)
     116             : {
     117           1 :     TremoloContext *s = ctx->priv;
     118           1 :     av_freep(&s->table);
     119           1 : }
     120             : 
     121           1 : static int config_input(AVFilterLink *inlink)
     122             : {
     123           1 :     AVFilterContext *ctx = inlink->dst;
     124           1 :     TremoloContext *s = ctx->priv;
     125           1 :     const double offset = 1. - s->depth / 2.;
     126             :     int i;
     127             : 
     128           1 :     s->table = av_malloc_array(inlink->sample_rate / s->freq, sizeof(*s->table));
     129           1 :     if (!s->table)
     130           0 :         return AVERROR(ENOMEM);
     131             : 
     132        8821 :     for (i = 0; i < inlink->sample_rate / s->freq; i++) {
     133        8820 :         double env = s->freq * i / inlink->sample_rate;
     134        8820 :         env = sin(2 * M_PI * fmod(env + 0.25, 1.0));
     135        8820 :         s->table[i] = env * (1 - fabs(offset)) + offset;
     136             :     }
     137             : 
     138           1 :     s->index = 0;
     139             : 
     140           1 :     return 0;
     141             : }
     142             : 
     143             : static const AVFilterPad avfilter_af_tremolo_inputs[] = {
     144             :     {
     145             :         .name         = "default",
     146             :         .type         = AVMEDIA_TYPE_AUDIO,
     147             :         .config_props = config_input,
     148             :         .filter_frame = filter_frame,
     149             :     },
     150             :     { NULL }
     151             : };
     152             : 
     153             : static const AVFilterPad avfilter_af_tremolo_outputs[] = {
     154             :     {
     155             :         .name = "default",
     156             :         .type = AVMEDIA_TYPE_AUDIO,
     157             :     },
     158             :     { NULL }
     159             : };
     160             : 
     161             : AVFilter ff_af_tremolo = {
     162             :     .name          = "tremolo",
     163             :     .description   = NULL_IF_CONFIG_SMALL("Apply tremolo effect."),
     164             :     .priv_size     = sizeof(TremoloContext),
     165             :     .priv_class    = &tremolo_class,
     166             :     .uninit        = uninit,
     167             :     .query_formats = query_formats,
     168             :     .inputs        = avfilter_af_tremolo_inputs,
     169             :     .outputs       = avfilter_af_tremolo_outputs,
     170             : };

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