mirror of
https://github.com/FFmpeg/FFmpeg.git
synced 2024-12-07 11:13:41 +02:00
44f660e7e7
It has no longer any effect.
138 lines
3.7 KiB
C
138 lines
3.7 KiB
C
/*
|
|
* Copyright (c) 2015 Paul B Mahol
|
|
*
|
|
* 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
|
|
*/
|
|
|
|
#include "libavutil/lfg.h"
|
|
#include "libavutil/opt.h"
|
|
#include "libavutil/random_seed.h"
|
|
#include "avfilter.h"
|
|
#include "formats.h"
|
|
#include "internal.h"
|
|
#include "video.h"
|
|
|
|
#define MAX_FRAMES 512
|
|
|
|
typedef struct RandomContext {
|
|
const AVClass *class;
|
|
|
|
AVLFG lfg;
|
|
int nb_frames;
|
|
int64_t random_seed;
|
|
int nb_frames_filled;
|
|
AVFrame *frames[MAX_FRAMES];
|
|
int64_t pts[MAX_FRAMES];
|
|
int flush_idx;
|
|
} RandomContext;
|
|
|
|
#define OFFSET(x) offsetof(RandomContext, x)
|
|
#define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
|
|
|
|
static const AVOption random_options[] = {
|
|
{ "frames", "set number of frames in cache", OFFSET(nb_frames), AV_OPT_TYPE_INT, {.i64=30}, 2, MAX_FRAMES, FLAGS },
|
|
{ "seed", "set the seed", OFFSET(random_seed), AV_OPT_TYPE_INT64, {.i64=-1}, -1, UINT32_MAX, FLAGS },
|
|
{ NULL }
|
|
};
|
|
|
|
AVFILTER_DEFINE_CLASS(random);
|
|
|
|
static av_cold int init(AVFilterContext *ctx)
|
|
{
|
|
RandomContext *s = ctx->priv;
|
|
uint32_t seed;
|
|
|
|
if (s->random_seed < 0)
|
|
s->random_seed = av_get_random_seed();
|
|
seed = s->random_seed;
|
|
av_lfg_init(&s->lfg, seed);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int filter_frame(AVFilterLink *inlink, AVFrame *in)
|
|
{
|
|
AVFilterContext *ctx = inlink->dst;
|
|
RandomContext *s = ctx->priv;
|
|
AVFilterLink *outlink = ctx->outputs[0];
|
|
AVFrame *out;
|
|
int idx;
|
|
|
|
if (s->nb_frames_filled < s->nb_frames) {
|
|
s->frames[s->nb_frames_filled] = in;
|
|
s->pts[s->nb_frames_filled++] = in->pts;
|
|
return 0;
|
|
}
|
|
|
|
idx = av_lfg_get(&s->lfg) % s->nb_frames;
|
|
|
|
out = s->frames[idx];
|
|
out->pts = s->pts[0];
|
|
memmove(&s->pts[0], &s->pts[1], (s->nb_frames - 1) * sizeof(s->pts[0]));
|
|
s->frames[idx] = in;
|
|
s->pts[s->nb_frames - 1] = in->pts;
|
|
|
|
return ff_filter_frame(outlink, out);
|
|
}
|
|
|
|
static int request_frame(AVFilterLink *outlink)
|
|
{
|
|
AVFilterContext *ctx = outlink->src;
|
|
RandomContext *s = ctx->priv;
|
|
int ret;
|
|
|
|
ret = ff_request_frame(ctx->inputs[0]);
|
|
|
|
if (ret == AVERROR_EOF && !ctx->is_disabled && s->nb_frames > 0) {
|
|
AVFrame *out = s->frames[s->nb_frames - 1];
|
|
out->pts = s->pts[s->flush_idx++];
|
|
ret = ff_filter_frame(outlink, out);
|
|
s->frames[s->nb_frames - 1] = NULL;
|
|
s->nb_frames--;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static const AVFilterPad random_inputs[] = {
|
|
{
|
|
.name = "default",
|
|
.type = AVMEDIA_TYPE_VIDEO,
|
|
.filter_frame = filter_frame,
|
|
},
|
|
{ NULL }
|
|
};
|
|
|
|
static const AVFilterPad random_outputs[] = {
|
|
{
|
|
.name = "default",
|
|
.type = AVMEDIA_TYPE_VIDEO,
|
|
.request_frame = request_frame,
|
|
},
|
|
{ NULL }
|
|
};
|
|
|
|
AVFilter ff_vf_random = {
|
|
.name = "random",
|
|
.description = NULL_IF_CONFIG_SMALL("Return random frames."),
|
|
.priv_size = sizeof(RandomContext),
|
|
.priv_class = &random_class,
|
|
.init = init,
|
|
.inputs = random_inputs,
|
|
.outputs = random_outputs,
|
|
};
|