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FFmpeg/libavfilter/vf_ccrepack.c
Andreas Rheinhardt 2f62a433f2 avfilter: Deduplicate default video inputs/outputs
Lots of video filters use a very simple input or output:
An array with a single AVFilterPad whose name is "default"
and whose type is AVMEDIA_TYPE_VIDEO; everything else is unset.

Given that we never use pointer equality for inputs or outputs*,
we can simply use a single AVFilterPad instead of dozens; this
even saves .data.rel.ro (8312B here) as well as relocations.

*: In fact, several filters (like the filters in vf_lut.c)
already use the same outputs; furthermore, ff_filter_alloc()
duplicates the input and output pads so that we do not even
work with the pads directly.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2023-08-07 09:21:13 +02:00

98 lines
2.7 KiB
C

/*
* CEA-708 Closed Caption Repacker
* Copyright (c) 2023 LTN Global Communications
*
* Author: Devin Heitmueller <dheitmueller@ltnglobal.com>
*
* 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
*/
/*
* Repackage CEA-708 arrays, which deals with incorrect cc_count for a given
* output framerate, and incorrect 708 padding.
*
* See CEA CEA-10-A "EIA-708-B Implementation Guidance", Section 26.5
* "Grouping DTVCC Data Within user_data() Structure"
*/
#include "avfilter.h"
#include "internal.h"
#include "ccfifo.h"
#include "video.h"
#include "libavutil/opt.h"
typedef struct CCRepackContext
{
const AVClass *class;
CCFifo cc_fifo;
} CCRepackContext;
static const AVOption ccrepack_options[] = {
{ NULL }
};
AVFILTER_DEFINE_CLASS(ccrepack);
static int config_input(AVFilterLink *link)
{
CCRepackContext *ctx = link->dst->priv;
int ret = ff_ccfifo_init(&ctx->cc_fifo, link->frame_rate, ctx);
if (ret < 0) {
av_log(ctx, AV_LOG_ERROR, "Failure to setup CC FIFO queue\n");
return ret;
}
return 0;
}
static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
{
CCRepackContext *ctx = inlink->dst->priv;
AVFilterLink *outlink = inlink->dst->outputs[0];
ff_ccfifo_extract(&ctx->cc_fifo, frame);
ff_ccfifo_inject(&ctx->cc_fifo, frame);
return ff_filter_frame(outlink, frame);
}
static av_cold void uninit(AVFilterContext *ctx)
{
CCRepackContext *s = ctx->priv;
ff_ccfifo_uninit(&s->cc_fifo);
}
static const AVFilterPad avfilter_vf_ccrepack_inputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.filter_frame = filter_frame,
.config_props = config_input,
},
};
const AVFilter ff_vf_ccrepack = {
.name = "ccrepack",
.description = NULL_IF_CONFIG_SMALL("Repack CEA-708 closed caption metadata"),
.uninit = uninit,
.priv_size = sizeof(CCRepackContext),
.priv_class = &ccrepack_class,
FILTER_INPUTS(avfilter_vf_ccrepack_inputs),
FILTER_OUTPUTS(ff_video_default_filterpad),
};