File size: 5,460 Bytes
8ead80b |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 |
/*
* Copyright 2010 S.N. Hemanth Meenakshisundaram <smeenaks ucsd edu>
* Copyright 2010 Stefano Sabatini <stefano.sabatini-lala poste it>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* null audio source
*/
#include <inttypes.h>
#include <stdio.h>
#include "libavutil/channel_layout.h"
#include "libavutil/internal.h"
#include "libavutil/opt.h"
#include "audio.h"
#include "avfilter.h"
#include "filters.h"
#include "formats.h"
#include "internal.h"
typedef struct ANullContext {
const AVClass *class;
char *channel_layout_str;
AVChannelLayout ch_layout;
char *sample_rate_str;
int sample_rate;
int64_t duration;
int nb_samples; ///< number of samples per requested frame
int64_t pts;
} ANullContext;
#define OFFSET(x) offsetof(ANullContext, x)
#define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
static const AVOption anullsrc_options[]= {
{ "channel_layout", "set channel_layout", OFFSET(channel_layout_str), AV_OPT_TYPE_STRING, {.str = "stereo"}, 0, 0, FLAGS },
{ "cl", "set channel_layout", OFFSET(channel_layout_str), AV_OPT_TYPE_STRING, {.str = "stereo"}, 0, 0, FLAGS },
{ "sample_rate", "set sample rate", OFFSET(sample_rate_str) , AV_OPT_TYPE_STRING, {.str = "44100"}, 0, 0, FLAGS },
{ "r", "set sample rate", OFFSET(sample_rate_str) , AV_OPT_TYPE_STRING, {.str = "44100"}, 0, 0, FLAGS },
{ "nb_samples", "set the number of samples per requested frame", OFFSET(nb_samples), AV_OPT_TYPE_INT, {.i64 = 1024}, 1, UINT16_MAX, FLAGS },
{ "n", "set the number of samples per requested frame", OFFSET(nb_samples), AV_OPT_TYPE_INT, {.i64 = 1024}, 1, UINT16_MAX, FLAGS },
{ "duration", "set the audio duration", OFFSET(duration), AV_OPT_TYPE_DURATION, {.i64 = -1}, -1, INT64_MAX, FLAGS },
{ "d", "set the audio duration", OFFSET(duration), AV_OPT_TYPE_DURATION, {.i64 = -1}, -1, INT64_MAX, FLAGS },
{ NULL }
};
AVFILTER_DEFINE_CLASS(anullsrc);
static av_cold int init(AVFilterContext *ctx)
{
ANullContext *null = ctx->priv;
int ret;
if ((ret = ff_parse_sample_rate(&null->sample_rate,
null->sample_rate_str, ctx)) < 0)
return ret;
if ((ret = ff_parse_channel_layout(&null->ch_layout, NULL,
null->channel_layout_str, ctx)) < 0)
return ret;
return 0;
}
static int query_formats(AVFilterContext *ctx)
{
ANullContext *null = ctx->priv;
const AVChannelLayout chlayouts[] = { null->ch_layout, { 0 } };
int sample_rates[] = { null->sample_rate, -1 };
int ret;
if ((ret = ff_set_common_formats (ctx, ff_all_formats (AVMEDIA_TYPE_AUDIO))) < 0 ||
(ret = ff_set_common_samplerates_from_list(ctx, sample_rates)) < 0)
return ret;
return ff_set_common_channel_layouts_from_list(ctx, chlayouts);
}
static av_cold int config_props(AVFilterLink *outlink)
{
ANullContext *null = outlink->src->priv;
if (null->duration >= 0)
null->duration = av_rescale(null->duration, null->sample_rate, AV_TIME_BASE);
return 0;
}
static int activate(AVFilterContext *ctx)
{
ANullContext *null = ctx->priv;
AVFilterLink *outlink = ctx->outputs[0];
if (null->duration >= 0 && null->pts >= null->duration) {
ff_outlink_set_status(outlink, AVERROR_EOF, null->pts);
return 0;
}
if (ff_outlink_frame_wanted(outlink)) {
AVFrame *samplesref = ff_get_audio_buffer(outlink, null->duration >= 0 ? FFMIN(null->nb_samples, null->duration - null->pts) : null->nb_samples);
if (!samplesref)
return AVERROR(ENOMEM);
samplesref->pts = null->pts;
null->pts += samplesref->nb_samples;
return ff_filter_frame(outlink, samplesref);
}
return FFERROR_NOT_READY;
}
static av_cold void uninit(AVFilterContext *ctx)
{
ANullContext *s = ctx->priv;
av_channel_layout_uninit(&s->ch_layout);
}
static const AVFilterPad avfilter_asrc_anullsrc_outputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_AUDIO,
.config_props = config_props,
},
};
const AVFilter ff_asrc_anullsrc = {
.name = "anullsrc",
.description = NULL_IF_CONFIG_SMALL("Null audio source, return empty audio frames."),
.init = init,
.uninit = uninit,
.priv_size = sizeof(ANullContext),
.inputs = NULL,
FILTER_OUTPUTS(avfilter_asrc_anullsrc_outputs),
FILTER_QUERY_FUNC(query_formats),
.activate = activate,
.priv_class = &anullsrc_class,
};
|