143 lines
		
	
	
		
			4.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			143 lines
		
	
	
		
			4.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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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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| #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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| 
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| typedef struct AudioDynamicSmoothContext {
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|     const AVClass *class;
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| 
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|     double sensitivity;
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|     double basefreq;
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| 
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|     AVFrame *coeffs;
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| } AudioDynamicSmoothContext;
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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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|     AudioDynamicSmoothContext *s = ctx->priv;
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| 
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|     s->coeffs = ff_get_audio_buffer(inlink, 3);
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|     if (!s->coeffs)
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|         return AVERROR(ENOMEM);
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| 
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|     return 0;
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| }
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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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|     AudioDynamicSmoothContext *s = ctx->priv;
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|     const double sensitivity = s->sensitivity;
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|     const double wc = s->basefreq / in->sample_rate;
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|     AVFrame *out;
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| 
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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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| 
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|     for (int ch = 0; ch < out->channels; ch++) {
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|         const double *src = (const double *)in->extended_data[ch];
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|         double *dst = (double *)out->extended_data[ch];
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|         double *coeffs = (double *)s->coeffs->extended_data[ch];
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|         double low1 = coeffs[0];
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|         double low2 = coeffs[1];
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|         double inz  = coeffs[2];
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| 
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|         for (int n = 0; n < out->nb_samples; n++) {
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|             double low1z = low1;
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|             double low2z = low2;
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|             double bandz = low2z - low1z;
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|             double wd = wc + sensitivity * fabs(bandz);
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|             double g = fmin(1., wd * (5.9948827 + wd * (-11.969296 + wd * 15.959062)));
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| 
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|             low1 = low1z + g * (0.5 * (src[n] + inz)   - low1z);
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|             low2 = low2z + g * (0.5 * (low1   + low1z) - low2z);
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|             inz = src[n];
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|             dst[n] = ctx->is_disabled ? src[n] : low2;
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|         }
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| 
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|         coeffs[0] = low1;
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|         coeffs[1] = low2;
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|         coeffs[2] = inz;
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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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| 
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| static av_cold void uninit(AVFilterContext *ctx)
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| {
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|     AudioDynamicSmoothContext *s = ctx->priv;
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| 
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|     av_frame_free(&s->coeffs);
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| }
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| 
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| #define OFFSET(x) offsetof(AudioDynamicSmoothContext, 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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| 
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| static const AVOption adynamicsmooth_options[] = {
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|     { "sensitivity",  "set smooth sensitivity",  OFFSET(sensitivity),  AV_OPT_TYPE_DOUBLE, {.dbl=2},     0, 1000000, FLAGS },
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|     { "basefreq",     "set base frequency",      OFFSET(basefreq),     AV_OPT_TYPE_DOUBLE, {.dbl=22050}, 2, 1000000, FLAGS },
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|     { NULL }
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| };
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| 
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| AVFILTER_DEFINE_CLASS(adynamicsmooth);
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| 
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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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| };
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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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| };
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| 
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| const AVFilter ff_af_adynamicsmooth = {
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|     .name            = "adynamicsmooth",
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|     .description     = NULL_IF_CONFIG_SMALL("Apply Dynamic Smoothing of input audio."),
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|     .priv_size       = sizeof(AudioDynamicSmoothContext),
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|     .priv_class      = &adynamicsmooth_class,
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|     .uninit          = uninit,
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|     FILTER_INPUTS(inputs),
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|     FILTER_OUTPUTS(outputs),
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|     FILTER_SINGLE_SAMPLEFMT(AV_SAMPLE_FMT_DBLP),
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|     .flags           = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL,
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|     .process_command = ff_filter_process_command,
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| };
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