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mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-12-07 11:13:41 +02:00
FFmpeg/libavfilter/fifo.c
Anton Khirnov b9c928a486 avfilter: add AVFILTER_FLAG_METADATA_ONLY
This flag allows distinguishing between filters that actually modify the
data and those that only modify metadata or gather some stream
information.
2021-12-04 14:07:19 +01:00

166 lines
4.1 KiB
C

/*
* Copyright (c) 2007 Bobby Bingham
*
* 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
* FIFO buffering filter
*/
#include "libavutil/common.h"
#include "libavutil/mathematics.h"
#include "audio.h"
#include "avfilter.h"
#include "internal.h"
typedef struct Buf {
AVFrame *frame;
struct Buf *next;
} Buf;
typedef struct FifoContext {
Buf root;
Buf *last; ///< last buffered frame
/**
* When a specific number of output samples is requested, the partial
* buffer is stored here
*/
AVFrame *out;
int allocated_samples; ///< number of samples out was allocated for
} FifoContext;
static av_cold int init(AVFilterContext *ctx)
{
FifoContext *s = ctx->priv;
s->last = &s->root;
return 0;
}
static av_cold void uninit(AVFilterContext *ctx)
{
FifoContext *s = ctx->priv;
Buf *buf, *tmp;
for (buf = s->root.next; buf; buf = tmp) {
tmp = buf->next;
av_frame_free(&buf->frame);
av_free(buf);
}
av_frame_free(&s->out);
}
static int add_to_queue(AVFilterLink *inlink, AVFrame *frame)
{
FifoContext *s = inlink->dst->priv;
s->last->next = av_mallocz(sizeof(Buf));
if (!s->last->next) {
av_frame_free(&frame);
return AVERROR(ENOMEM);
}
s->last = s->last->next;
s->last->frame = frame;
return 0;
}
static void queue_pop(FifoContext *s)
{
Buf *tmp = s->root.next->next;
if (s->last == s->root.next)
s->last = &s->root;
av_freep(&s->root.next);
s->root.next = tmp;
}
static int request_frame(AVFilterLink *outlink)
{
FifoContext *s = outlink->src->priv;
int ret = 0;
if (!s->root.next) {
if ((ret = ff_request_frame(outlink->src->inputs[0])) < 0)
return ret;
if (!s->root.next)
return 0;
}
ret = ff_filter_frame(outlink, s->root.next->frame);
queue_pop(s);
return ret;
}
static const AVFilterPad avfilter_vf_fifo_inputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.filter_frame = add_to_queue,
},
};
static const AVFilterPad avfilter_vf_fifo_outputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.request_frame = request_frame,
},
};
const AVFilter ff_vf_fifo = {
.name = "fifo",
.description = NULL_IF_CONFIG_SMALL("Buffer input images and send them when they are requested."),
.init = init,
.uninit = uninit,
.priv_size = sizeof(FifoContext),
.flags = AVFILTER_FLAG_METADATA_ONLY,
FILTER_INPUTS(avfilter_vf_fifo_inputs),
FILTER_OUTPUTS(avfilter_vf_fifo_outputs),
};
static const AVFilterPad avfilter_af_afifo_inputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_AUDIO,
.filter_frame = add_to_queue,
},
};
static const AVFilterPad avfilter_af_afifo_outputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_AUDIO,
.request_frame = request_frame,
},
};
const AVFilter ff_af_afifo = {
.name = "afifo",
.description = NULL_IF_CONFIG_SMALL("Buffer input frames and send them when they are requested."),
.init = init,
.uninit = uninit,
.priv_size = sizeof(FifoContext),
.flags = AVFILTER_FLAG_METADATA_ONLY,
FILTER_INPUTS(avfilter_af_afifo_inputs),
FILTER_OUTPUTS(avfilter_af_afifo_outputs),
};