127 lines
		
	
	
		
			4.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			127 lines
		
	
	
		
			4.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Copyright (c) 2012 Andrey Utkin
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|  * Copyright (c) 2012 Stefano Sabatini
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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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| /**
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|  * @file
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|  * Filter that changes number of samples on single output operation
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|  */
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| 
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| #include "libavutil/channel_layout.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 "filters.h"
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| #include "internal.h"
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| #include "formats.h"
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| 
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| typedef struct ASNSContext {
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|     const AVClass *class;
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|     int nb_out_samples;  ///< how many samples to output
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|     int pad;
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| } ASNSContext;
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| 
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| #define OFFSET(x) offsetof(ASNSContext, x)
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| #define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
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| 
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| static const AVOption asetnsamples_options[] = {
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|     { "nb_out_samples", "set the number of per-frame output samples", OFFSET(nb_out_samples), AV_OPT_TYPE_INT, {.i64=1024}, 1, INT_MAX, FLAGS },
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|     { "n",              "set the number of per-frame output samples", OFFSET(nb_out_samples), AV_OPT_TYPE_INT, {.i64=1024}, 1, INT_MAX, FLAGS },
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|     { "pad", "pad last frame with zeros", OFFSET(pad), AV_OPT_TYPE_BOOL, {.i64=1}, 0, 1, FLAGS },
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|     { "p",   "pad last frame with zeros", OFFSET(pad), AV_OPT_TYPE_BOOL, {.i64=1}, 0, 1, FLAGS },
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|     { NULL }
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| };
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| 
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| AVFILTER_DEFINE_CLASS(asetnsamples);
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| 
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| static int activate(AVFilterContext *ctx)
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| {
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|     AVFilterLink *inlink = ctx->inputs[0];
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|     AVFilterLink *outlink = ctx->outputs[0];
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|     ASNSContext *s = ctx->priv;
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|     AVFrame *frame = NULL, *pad_frame;
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|     int ret;
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| 
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|     FF_FILTER_FORWARD_STATUS_BACK(outlink, inlink);
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| 
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|     ret = ff_inlink_consume_samples(inlink, s->nb_out_samples, s->nb_out_samples, &frame);
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|     if (ret < 0)
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|         return ret;
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| 
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|     if (ret > 0) {
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|         if (!s->pad || frame->nb_samples == s->nb_out_samples) {
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|             ret = ff_filter_frame(outlink, frame);
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|             if (ff_inlink_queued_samples(inlink) >= s->nb_out_samples)
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|                 ff_filter_set_ready(ctx, 100);
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|             return ret;
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|         }
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| 
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|         pad_frame = ff_get_audio_buffer(outlink, s->nb_out_samples);
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|         if (!pad_frame) {
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|             av_frame_free(&frame);
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|             return AVERROR(ENOMEM);
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|         }
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| 
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|         ret = av_frame_copy_props(pad_frame, frame);
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|         if (ret < 0) {
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|             av_frame_free(&pad_frame);
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|             av_frame_free(&frame);
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|             return ret;
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|         }
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| 
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|         av_samples_copy(pad_frame->extended_data, frame->extended_data,
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|                         0, 0, frame->nb_samples, frame->ch_layout.nb_channels, frame->format);
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|         av_samples_set_silence(pad_frame->extended_data, frame->nb_samples,
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|                                s->nb_out_samples - frame->nb_samples, frame->ch_layout.nb_channels,
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|                                frame->format);
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|         av_frame_free(&frame);
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|         return ff_filter_frame(outlink, pad_frame);
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|     }
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| 
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|     FF_FILTER_FORWARD_STATUS(inlink, outlink);
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|     FF_FILTER_FORWARD_WANTED(outlink, inlink);
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| 
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|     return FFERROR_NOT_READY;
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| }
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| 
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| static const AVFilterPad asetnsamples_inputs[] = {
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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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| static const AVFilterPad asetnsamples_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_asetnsamples = {
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|     .name        = "asetnsamples",
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|     .description = NULL_IF_CONFIG_SMALL("Set the number of samples for each output audio frames."),
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|     .priv_size   = sizeof(ASNSContext),
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|     .priv_class  = &asetnsamples_class,
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|     FILTER_INPUTS(asetnsamples_inputs),
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|     FILTER_OUTPUTS(asetnsamples_outputs),
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|     .activate    = activate,
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| };
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