ffmpeg/libavfilter/vsink_buffer.c

140 lines
4.2 KiB
C

/*
* Copyright (c) 2011 Stefano Sabatini
*
* 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
* buffer video sink
*/
#include "libavutil/fifo.h"
#include "avfilter.h"
#include "vsink_buffer.h"
typedef struct {
AVFifoBuffer *fifo; ///< FIFO buffer of video frame references
enum PixelFormat *pix_fmts; ///< accepted pixel formats, must be terminated with -1
} BufferSinkContext;
#define FIFO_INIT_SIZE 8
static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
{
BufferSinkContext *buf = ctx->priv;
if (!opaque) {
av_log(ctx, AV_LOG_ERROR, "No opaque field provided, which is required.\n");
return AVERROR(EINVAL);
}
buf->fifo = av_fifo_alloc(FIFO_INIT_SIZE*sizeof(AVFilterBufferRef *));
if (!buf->fifo) {
av_log(ctx, AV_LOG_ERROR, "Failed to allocate fifo\n");
return AVERROR(ENOMEM);
}
buf->pix_fmts = opaque;
return 0;
}
static av_cold void uninit(AVFilterContext *ctx)
{
BufferSinkContext *buf = ctx->priv;
AVFilterBufferRef *picref;
if (buf->fifo) {
while (av_fifo_size(buf->fifo) >= sizeof(AVFilterBufferRef *)) {
av_fifo_generic_read(buf->fifo, &picref, sizeof(picref), NULL);
avfilter_unref_buffer(picref);
}
av_fifo_free(buf->fifo);
buf->fifo = NULL;
}
}
static void end_frame(AVFilterLink *inlink)
{
AVFilterContext *ctx = inlink->dst;
BufferSinkContext *buf = inlink->dst->priv;
if (av_fifo_space(buf->fifo) < sizeof(AVFilterBufferRef *)) {
/* realloc fifo size */
if (av_fifo_realloc2(buf->fifo, av_fifo_size(buf->fifo) * 2) < 0) {
av_log(ctx, AV_LOG_ERROR,
"Cannot buffer more frames. Consume some available frames "
"before adding new ones.\n");
return;
}
}
/* cache frame */
av_fifo_generic_write(buf->fifo,
&inlink->cur_buf, sizeof(AVFilterBufferRef *), NULL);
}
static int query_formats(AVFilterContext *ctx)
{
BufferSinkContext *buf = ctx->priv;
avfilter_set_common_pixel_formats(ctx, avfilter_make_format_list(buf->pix_fmts));
return 0;
}
int av_vsink_buffer_get_video_buffer_ref(AVFilterContext *ctx,
AVFilterBufferRef **picref, int flags)
{
BufferSinkContext *buf = ctx->priv;
AVFilterLink *inlink = ctx->inputs[0];
int ret;
*picref = NULL;
/* no picref available, fetch it from the filterchain */
if (!av_fifo_size(buf->fifo)) {
if ((ret = avfilter_request_frame(inlink)) < 0)
return ret;
}
if (!av_fifo_size(buf->fifo))
return AVERROR(EINVAL);
if (flags & AV_VSINK_BUF_FLAG_PEEK)
*picref = *((AVFilterBufferRef **)av_fifo_peek2(buf->fifo, 0));
else
av_fifo_generic_read(buf->fifo, picref, sizeof(*picref), NULL);
return 0;
}
AVFilter avfilter_vsink_buffersink = {
.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,
.query_formats = query_formats,
.inputs = (AVFilterPad[]) {{ .name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.end_frame = end_frame,
.min_perms = AV_PERM_READ, },
{ .name = NULL }},
.outputs = (AVFilterPad[]) {{ .name = NULL }},
};