LCOV - code coverage report
Current view: top level - src/libavfilter - af_dcshift.c (source / functions) Hit Total Coverage
Test: coverage.info Lines: 35 58 60.3 %
Date: 2017-09-22 00:04:37 Functions: 3 3 100.0 %

          Line data    Source code
       1             : /*
       2             :  * Copyright (c) 2000 Chris Ausbrooks <weed@bucket.pp.ualr.edu>
       3             :  * Copyright (c) 2000 Fabien COELHO <fabien@coelho.net>
       4             :  *
       5             :  * This file is part of FFmpeg.
       6             :  *
       7             :  * FFmpeg is free software; you can redistribute it and/or
       8             :  * modify it under the terms of the GNU Lesser General Public
       9             :  * License as published by the Free Software Foundation; either
      10             :  * version 2.1 of the License, or (at your option) any later version.
      11             :  *
      12             :  * FFmpeg is distributed in the hope that it will be useful,
      13             :  * but WITHOUT ANY WARRANTY; without even the implied warranty of
      14             :  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      15             :  * Lesser General Public License for more details.
      16             :  *
      17             :  * You should have received a copy of the GNU Lesser General Public
      18             :  * License along with FFmpeg; if not, write to the Free Software
      19             :  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
      20             :  */
      21             : 
      22             : #include "libavutil/opt.h"
      23             : #include "libavutil/samplefmt.h"
      24             : #include "avfilter.h"
      25             : #include "audio.h"
      26             : #include "internal.h"
      27             : 
      28             : typedef struct DCShiftContext {
      29             :     const AVClass *class;
      30             :     double dcshift;
      31             :     double limiterthreshhold;
      32             :     double limitergain;
      33             : } DCShiftContext;
      34             : 
      35             : #define OFFSET(x) offsetof(DCShiftContext, x)
      36             : #define A AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
      37             : 
      38             : static const AVOption dcshift_options[] = {
      39             :     { "shift",       "set DC shift",     OFFSET(dcshift),       AV_OPT_TYPE_DOUBLE, {.dbl=0}, -1, 1, A },
      40             :     { "limitergain", "set limiter gain", OFFSET(limitergain), AV_OPT_TYPE_DOUBLE, {.dbl=0}, 0, 1, A },
      41             :     { NULL }
      42             : };
      43             : 
      44             : AVFILTER_DEFINE_CLASS(dcshift);
      45             : 
      46           1 : static av_cold int init(AVFilterContext *ctx)
      47             : {
      48           1 :     DCShiftContext *s = ctx->priv;
      49             : 
      50           1 :     s->limiterthreshhold = INT32_MAX * (1.0 - (fabs(s->dcshift) - s->limitergain));
      51             : 
      52           1 :     return 0;
      53             : }
      54             : 
      55           1 : static int query_formats(AVFilterContext *ctx)
      56             : {
      57             :     AVFilterChannelLayouts *layouts;
      58             :     AVFilterFormats *formats;
      59             :     static const enum AVSampleFormat sample_fmts[] = {
      60             :         AV_SAMPLE_FMT_S32P, AV_SAMPLE_FMT_NONE
      61             :     };
      62             :     int ret;
      63             : 
      64           1 :     layouts = ff_all_channel_counts();
      65           1 :     if (!layouts)
      66           0 :         return AVERROR(ENOMEM);
      67           1 :     ret = ff_set_common_channel_layouts(ctx, layouts);
      68           1 :     if (ret < 0)
      69           0 :         return ret;
      70             : 
      71           1 :     formats = ff_make_format_list(sample_fmts);
      72           1 :     if (!formats)
      73           0 :         return AVERROR(ENOMEM);
      74           1 :     ret = ff_set_common_formats(ctx, formats);
      75           1 :     if (ret < 0)
      76           0 :         return ret;
      77             : 
      78           1 :     formats = ff_all_samplerates();
      79           1 :     if (!formats)
      80           0 :         return AVERROR(ENOMEM);
      81           1 :     return ff_set_common_samplerates(ctx, formats);
      82             : }
      83             : 
      84          20 : static int filter_frame(AVFilterLink *inlink, AVFrame *in)
      85             : {
      86          20 :     AVFilterContext *ctx = inlink->dst;
      87          20 :     AVFilterLink *outlink = ctx->outputs[0];
      88             :     AVFrame *out;
      89          20 :     DCShiftContext *s = ctx->priv;
      90             :     int i, j;
      91          20 :     double dcshift = s->dcshift;
      92             : 
      93          20 :     if (av_frame_is_writable(in)) {
      94          20 :         out = in;
      95             :     } else {
      96           0 :         out = ff_get_audio_buffer(outlink, in->nb_samples);
      97           0 :         if (!out) {
      98           0 :             av_frame_free(&in);
      99           0 :             return AVERROR(ENOMEM);
     100             :         }
     101           0 :         av_frame_copy_props(out, in);
     102             :     }
     103             : 
     104          20 :     if (s->limitergain > 0) {
     105          60 :         for (i = 0; i < inlink->channels; i++) {
     106          40 :             const int32_t *src = (int32_t *)in->extended_data[i];
     107          40 :             int32_t *dst = (int32_t *)out->extended_data[i];
     108             : 
     109       41000 :             for (j = 0; j < in->nb_samples; j++) {
     110             :                 double d;
     111             : 
     112       40960 :                 d = src[j];
     113             : 
     114       40960 :                 if (d > s->limiterthreshhold && dcshift > 0) {
     115           0 :                     d = (d - s->limiterthreshhold) * s->limitergain /
     116           0 :                              (INT32_MAX - s->limiterthreshhold) +
     117           0 :                              s->limiterthreshhold + dcshift;
     118       40960 :                 } else if (d < -s->limiterthreshhold && dcshift < 0) {
     119           0 :                     d = (d + s->limiterthreshhold) * s->limitergain /
     120           0 :                              (INT32_MAX - s->limiterthreshhold) -
     121           0 :                              s->limiterthreshhold + dcshift;
     122             :                 } else {
     123       40960 :                     d = dcshift * INT32_MAX + d;
     124             :                 }
     125             : 
     126       40960 :                 dst[j] = av_clipl_int32(d);
     127             :             }
     128             :         }
     129             :     } else {
     130           0 :         for (i = 0; i < inlink->channels; i++) {
     131           0 :             const int32_t *src = (int32_t *)in->extended_data[i];
     132           0 :             int32_t *dst = (int32_t *)out->extended_data[i];
     133             : 
     134           0 :             for (j = 0; j < in->nb_samples; j++) {
     135           0 :                 double d = dcshift * (INT32_MAX + 1.) + src[j];
     136             : 
     137           0 :                 dst[j] = av_clipl_int32(d);
     138             :             }
     139             :         }
     140             :     }
     141             : 
     142          20 :     if (out != in)
     143           0 :         av_frame_free(&in);
     144          20 :     return ff_filter_frame(outlink, out);
     145             : }
     146             : static const AVFilterPad dcshift_inputs[] = {
     147             :     {
     148             :         .name         = "default",
     149             :         .type         = AVMEDIA_TYPE_AUDIO,
     150             :         .filter_frame = filter_frame,
     151             :     },
     152             :     { NULL }
     153             : };
     154             : 
     155             : static const AVFilterPad dcshift_outputs[] = {
     156             :     {
     157             :         .name = "default",
     158             :         .type = AVMEDIA_TYPE_AUDIO,
     159             :     },
     160             :     { NULL }
     161             : };
     162             : 
     163             : AVFilter ff_af_dcshift = {
     164             :     .name           = "dcshift",
     165             :     .description    = NULL_IF_CONFIG_SMALL("Apply a DC shift to the audio."),
     166             :     .query_formats  = query_formats,
     167             :     .priv_size      = sizeof(DCShiftContext),
     168             :     .priv_class     = &dcshift_class,
     169             :     .init           = init,
     170             :     .inputs         = dcshift_inputs,
     171             :     .outputs        = dcshift_outputs,
     172             :     .flags          = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,
     173             : };

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