LCOV - code coverage report
Current view: top level - src/libavfilter - af_flanger.c (source / functions) Hit Total Coverage
Test: coverage.info Lines: 0 90 0.0 %
Date: 2017-01-24 04:42:20 Functions: 0 5 0.0 %

          Line data    Source code
       1             : /*
       2             :  * Copyright (c) 2006 Rob Sykes <robs@users.sourceforge.net>
       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/avstring.h"
      22             : #include "libavutil/opt.h"
      23             : #include "libavutil/samplefmt.h"
      24             : #include "avfilter.h"
      25             : #include "audio.h"
      26             : #include "internal.h"
      27             : #include "generate_wave_table.h"
      28             : 
      29             : #define INTERPOLATION_LINEAR    0
      30             : #define INTERPOLATION_QUADRATIC 1
      31             : 
      32             : typedef struct FlangerContext {
      33             :     const AVClass *class;
      34             :     double delay_min;
      35             :     double delay_depth;
      36             :     double feedback_gain;
      37             :     double delay_gain;
      38             :     double speed;
      39             :     int wave_shape;
      40             :     double channel_phase;
      41             :     int interpolation;
      42             :     double in_gain;
      43             :     int max_samples;
      44             :     uint8_t **delay_buffer;
      45             :     int delay_buf_pos;
      46             :     double *delay_last;
      47             :     float *lfo;
      48             :     int lfo_length;
      49             :     int lfo_pos;
      50             : } FlangerContext;
      51             : 
      52             : #define OFFSET(x) offsetof(FlangerContext, x)
      53             : #define A AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
      54             : 
      55             : static const AVOption flanger_options[] = {
      56             :     { "delay", "base delay in milliseconds",        OFFSET(delay_min),   AV_OPT_TYPE_DOUBLE, {.dbl=0}, 0, 30, A },
      57             :     { "depth", "added swept delay in milliseconds", OFFSET(delay_depth), AV_OPT_TYPE_DOUBLE, {.dbl=2}, 0, 10, A },
      58             :     { "regen", "percentage regeneration (delayed signal feedback)", OFFSET(feedback_gain), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -95, 95, A },
      59             :     { "width", "percentage of delayed signal mixed with original", OFFSET(delay_gain), AV_OPT_TYPE_DOUBLE, {.dbl=71}, 0, 100, A },
      60             :     { "speed", "sweeps per second (Hz)", OFFSET(speed), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0.1, 10, A },
      61             :     { "shape", "swept wave shape", OFFSET(wave_shape), AV_OPT_TYPE_INT, {.i64=WAVE_SIN}, WAVE_SIN, WAVE_NB-1, A, "type" },
      62             :     { "triangular",  NULL, 0, AV_OPT_TYPE_CONST,  {.i64=WAVE_TRI}, 0, 0, A, "type" },
      63             :     { "t",           NULL, 0, AV_OPT_TYPE_CONST,  {.i64=WAVE_TRI}, 0, 0, A, "type" },
      64             :     { "sinusoidal",  NULL, 0, AV_OPT_TYPE_CONST,  {.i64=WAVE_SIN}, 0, 0, A, "type" },
      65             :     { "s",           NULL, 0, AV_OPT_TYPE_CONST,  {.i64=WAVE_SIN}, 0, 0, A, "type" },
      66             :     { "phase", "swept wave percentage phase-shift for multi-channel", OFFSET(channel_phase), AV_OPT_TYPE_DOUBLE, {.dbl=25}, 0, 100, A },
      67             :     { "interp", "delay-line interpolation", OFFSET(interpolation), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, A, "itype" },
      68             :     { "linear",     NULL, 0, AV_OPT_TYPE_CONST,  {.i64=INTERPOLATION_LINEAR},    0, 0, A, "itype" },
      69             :     { "quadratic",  NULL, 0, AV_OPT_TYPE_CONST,  {.i64=INTERPOLATION_QUADRATIC}, 0, 0, A, "itype" },
      70             :     { NULL }
      71             : };
      72             : 
      73             : AVFILTER_DEFINE_CLASS(flanger);
      74             : 
      75           0 : static int init(AVFilterContext *ctx)
      76             : {
      77           0 :     FlangerContext *s = ctx->priv;
      78             : 
      79           0 :     s->feedback_gain /= 100;
      80           0 :     s->delay_gain    /= 100;
      81           0 :     s->channel_phase /= 100;
      82           0 :     s->delay_min     /= 1000;
      83           0 :     s->delay_depth   /= 1000;
      84           0 :     s->in_gain        = 1 / (1 + s->delay_gain);
      85           0 :     s->delay_gain    /= 1 + s->delay_gain;
      86           0 :     s->delay_gain    *= 1 - fabs(s->feedback_gain);
      87             : 
      88           0 :     return 0;
      89             : }
      90             : 
      91           0 : static int query_formats(AVFilterContext *ctx)
      92             : {
      93             :     AVFilterChannelLayouts *layouts;
      94             :     AVFilterFormats *formats;
      95             :     static const enum AVSampleFormat sample_fmts[] = {
      96             :         AV_SAMPLE_FMT_DBLP, AV_SAMPLE_FMT_NONE
      97             :     };
      98             :     int ret;
      99             : 
     100           0 :     layouts = ff_all_channel_counts();
     101           0 :     if (!layouts)
     102           0 :         return AVERROR(ENOMEM);
     103           0 :     ret = ff_set_common_channel_layouts(ctx, layouts);
     104           0 :     if (ret < 0)
     105           0 :         return ret;
     106             : 
     107           0 :     formats = ff_make_format_list(sample_fmts);
     108           0 :     if (!formats)
     109           0 :         return AVERROR(ENOMEM);
     110           0 :     ret = ff_set_common_formats(ctx, formats);
     111           0 :     if (ret < 0)
     112           0 :         return ret;
     113             : 
     114           0 :     formats = ff_all_samplerates();
     115           0 :     if (!formats)
     116           0 :         return AVERROR(ENOMEM);
     117           0 :     return ff_set_common_samplerates(ctx, formats);
     118             : }
     119             : 
     120           0 : static int config_input(AVFilterLink *inlink)
     121             : {
     122           0 :     AVFilterContext *ctx = inlink->dst;
     123           0 :     FlangerContext *s = ctx->priv;
     124             : 
     125           0 :     s->max_samples = (s->delay_min + s->delay_depth) * inlink->sample_rate + 2.5;
     126           0 :     s->lfo_length  = inlink->sample_rate / s->speed;
     127           0 :     s->delay_last  = av_calloc(inlink->channels, sizeof(*s->delay_last));
     128           0 :     s->lfo         = av_calloc(s->lfo_length, sizeof(*s->lfo));
     129           0 :     if (!s->lfo || !s->delay_last)
     130           0 :         return AVERROR(ENOMEM);
     131             : 
     132           0 :     ff_generate_wave_table(s->wave_shape, AV_SAMPLE_FMT_FLT, s->lfo, s->lfo_length,
     133           0 :                            rint(s->delay_min * inlink->sample_rate),
     134           0 :                            s->max_samples - 2., 3 * M_PI_2);
     135             : 
     136           0 :     return av_samples_alloc_array_and_samples(&s->delay_buffer, NULL,
     137             :                                               inlink->channels, s->max_samples,
     138           0 :                                               inlink->format, 0);
     139             : }
     140             : 
     141           0 : static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
     142             : {
     143           0 :     AVFilterContext *ctx = inlink->dst;
     144           0 :     FlangerContext *s = ctx->priv;
     145             :     AVFrame *out_frame;
     146             :     int chan, i;
     147             : 
     148           0 :     if (av_frame_is_writable(frame)) {
     149           0 :         out_frame = frame;
     150             :     } else {
     151           0 :         out_frame = ff_get_audio_buffer(inlink, frame->nb_samples);
     152           0 :         if (!out_frame) {
     153           0 :             av_frame_free(&frame);
     154           0 :             return AVERROR(ENOMEM);
     155             :         }
     156           0 :         av_frame_copy_props(out_frame, frame);
     157             :     }
     158             : 
     159           0 :     for (i = 0; i < frame->nb_samples; i++) {
     160             : 
     161           0 :         s->delay_buf_pos = (s->delay_buf_pos + s->max_samples - 1) % s->max_samples;
     162             : 
     163           0 :         for (chan = 0; chan < inlink->channels; chan++) {
     164           0 :             double *src = (double *)frame->extended_data[chan];
     165           0 :             double *dst = (double *)out_frame->extended_data[chan];
     166             :             double delayed_0, delayed_1;
     167             :             double delayed;
     168             :             double in, out;
     169           0 :             int channel_phase = chan * s->lfo_length * s->channel_phase + .5;
     170           0 :             double delay = s->lfo[(s->lfo_pos + channel_phase) % s->lfo_length];
     171           0 :             int int_delay = (int)delay;
     172           0 :             double frac_delay = modf(delay, &delay);
     173           0 :             double *delay_buffer = (double *)s->delay_buffer[chan];
     174             : 
     175           0 :             in = src[i];
     176           0 :             delay_buffer[s->delay_buf_pos] = in + s->delay_last[chan] *
     177           0 :                                                            s->feedback_gain;
     178           0 :             delayed_0 = delay_buffer[(s->delay_buf_pos + int_delay++) % s->max_samples];
     179           0 :             delayed_1 = delay_buffer[(s->delay_buf_pos + int_delay++) % s->max_samples];
     180             : 
     181           0 :             if (s->interpolation == INTERPOLATION_LINEAR) {
     182           0 :                 delayed = delayed_0 + (delayed_1 - delayed_0) * frac_delay;
     183             :             } else {
     184             :                 double a, b;
     185           0 :                 double delayed_2 = delay_buffer[(s->delay_buf_pos + int_delay++) % s->max_samples];
     186           0 :                 delayed_2 -= delayed_0;
     187           0 :                 delayed_1 -= delayed_0;
     188           0 :                 a = delayed_2 * .5 - delayed_1;
     189           0 :                 b = delayed_1 *  2 - delayed_2 *.5;
     190           0 :                 delayed = delayed_0 + (a * frac_delay + b) * frac_delay;
     191             :             }
     192             : 
     193           0 :             s->delay_last[chan] = delayed;
     194           0 :             out = in * s->in_gain + delayed * s->delay_gain;
     195           0 :             dst[i] = out;
     196             :         }
     197           0 :         s->lfo_pos = (s->lfo_pos + 1) % s->lfo_length;
     198             :     }
     199             : 
     200           0 :     if (frame != out_frame)
     201           0 :         av_frame_free(&frame);
     202             : 
     203           0 :     return ff_filter_frame(ctx->outputs[0], out_frame);
     204             : }
     205             : 
     206           0 : static av_cold void uninit(AVFilterContext *ctx)
     207             : {
     208           0 :     FlangerContext *s = ctx->priv;
     209             : 
     210           0 :     av_freep(&s->lfo);
     211           0 :     av_freep(&s->delay_last);
     212             : 
     213           0 :     if (s->delay_buffer)
     214           0 :         av_freep(&s->delay_buffer[0]);
     215           0 :     av_freep(&s->delay_buffer);
     216           0 : }
     217             : 
     218             : static const AVFilterPad flanger_inputs[] = {
     219             :     {
     220             :         .name         = "default",
     221             :         .type         = AVMEDIA_TYPE_AUDIO,
     222             :         .config_props = config_input,
     223             :         .filter_frame = filter_frame,
     224             :     },
     225             :     { NULL }
     226             : };
     227             : 
     228             : static const AVFilterPad flanger_outputs[] = {
     229             :     {
     230             :         .name          = "default",
     231             :         .type          = AVMEDIA_TYPE_AUDIO,
     232             :     },
     233             :     { NULL }
     234             : };
     235             : 
     236             : AVFilter ff_af_flanger = {
     237             :     .name          = "flanger",
     238             :     .description   = NULL_IF_CONFIG_SMALL("Apply a flanging effect to the audio."),
     239             :     .query_formats = query_formats,
     240             :     .priv_size     = sizeof(FlangerContext),
     241             :     .priv_class    = &flanger_class,
     242             :     .init          = init,
     243             :     .uninit        = uninit,
     244             :     .inputs        = flanger_inputs,
     245             :     .outputs       = flanger_outputs,
     246             : };

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