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/*
* Copyright (c) 2011 Stefano Sabatini
*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* buffer sink
*/
#include "libavutil/fifo.h"
#include "avfilter.h"
#include "buffersink.h"
typedef struct {
AVFifoBuffer *fifo; ///< FIFO buffer of video frame references
} BufferSinkContext;
#define FIFO_INIT_SIZE 8
static av_cold void uninit(AVFilterContext *ctx)
{
BufferSinkContext *sink = ctx->priv;
while (sink->fifo && av_fifo_size(sink->fifo)) {
AVFilterBufferRef *buf;
av_fifo_generic_read(sink->fifo, &buf, sizeof(buf), NULL);
avfilter_unref_buffer(buf);
}
av_fifo_free(sink->fifo);
}
static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
{
BufferSinkContext *sink = ctx->priv;
if (!(sink->fifo = av_fifo_alloc(FIFO_INIT_SIZE*sizeof(AVFilterBufferRef*)))) {
av_log(ctx, AV_LOG_ERROR, "Failed to allocate fifo\n");
return AVERROR(ENOMEM);
}
return 0;
}
static void end_frame(AVFilterLink *link)
{
AVFilterContext *ctx = link->dst;
BufferSinkContext *sink = ctx->priv;
if (av_fifo_space(sink->fifo) < sizeof(AVFilterBufferRef *) &&
(av_fifo_realloc2(sink->fifo, av_fifo_size(sink->fifo) * 2) < 0)) {
av_log(ctx, AV_LOG_ERROR, "Error reallocating the FIFO.\n");
return;
}
av_fifo_generic_write(sink->fifo, &link->cur_buf, sizeof(link->cur_buf), NULL);
link->cur_buf = NULL;
}
int av_buffersink_read(AVFilterContext *ctx, AVFilterBufferRef **buf)
{
BufferSinkContext *sink = ctx->priv;
AVFilterLink *link = ctx->inputs[0];
int ret;
if (!buf) {
if (av_fifo_size(sink->fifo))
return av_fifo_size(sink->fifo)/sizeof(*buf);
else
return avfilter_poll_frame(ctx->inputs[0]);
}
if (!av_fifo_size(sink->fifo) &&
(ret = avfilter_request_frame(link)) < 0)
return ret;
if (!av_fifo_size(sink->fifo))
return AVERROR(EINVAL);
av_fifo_generic_read(sink->fifo, buf, sizeof(*buf), NULL);
return 0;
}
AVFilter avfilter_vsink_buffer = {
.name = "buffersink",
.description = NULL_IF_CONFIG_SMALL("Buffer video frames, and make them available to the end of the filter graph."),
.priv_size = sizeof(BufferSinkContext),
.init = init,
.uninit = uninit,
.inputs = (AVFilterPad[]) {{ .name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.end_frame = end_frame,
.min_perms = AV_PERM_READ, },
{ .name = NULL }},
.outputs = (AVFilterPad[]) {{ .name = NULL }},
};
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