ffmpeg/libavfilter/vf_vflip.c

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/*
* Copyright (c) 2007 Bobby Bingham
*
* 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
* video vertical flip filter
*/
#include "libavutil/internal.h"
#include "libavutil/pixdesc.h"
#include "avfilter.h"
#include "internal.h"
#include "video.h"
typedef struct {
int vsub; ///< vertical chroma subsampling
} FlipContext;
static int config_input(AVFilterLink *link)
{
FlipContext *flip = link->dst->priv;
const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(link->format);
flip->vsub = desc->log2_chroma_h;
return 0;
}
static AVFrame *get_video_buffer(AVFilterLink *link, int w, int h)
{
FlipContext *flip = link->dst->priv;
AVFrame *frame;
int i;
frame = ff_get_video_buffer(link->dst->outputs[0], w, h);
if (!frame)
return NULL;
for (i = 0; i < 4; i ++) {
int vsub = i == 1 || i == 2 ? flip->vsub : 0;
if (frame->data[i]) {
frame->data[i] += ((h >> vsub) - 1) * frame->linesize[i];
frame->linesize[i] = -frame->linesize[i];
}
}
return frame;
}
static int filter_frame(AVFilterLink *link, AVFrame *frame)
{
FlipContext *flip = link->dst->priv;
int i;
for (i = 0; i < 4; i ++) {
int vsub = i == 1 || i == 2 ? flip->vsub : 0;
if (frame->data[i]) {
frame->data[i] += ((link->h >> vsub)-1) * frame->linesize[i];
frame->linesize[i] = -frame->linesize[i];
}
}
return ff_filter_frame(link->dst->outputs[0], frame);
}
static const AVFilterPad avfilter_vf_vflip_inputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.get_video_buffer = get_video_buffer,
.filter_frame = filter_frame,
.config_props = config_input,
},
{ NULL }
};
static const AVFilterPad avfilter_vf_vflip_outputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
},
{ NULL }
};
AVFilter avfilter_vf_vflip = {
.name = "vflip",
.description = NULL_IF_CONFIG_SMALL("Flip the input video vertically."),
.priv_size = sizeof(FlipContext),
.inputs = avfilter_vf_vflip_inputs,
.outputs = avfilter_vf_vflip_outputs,
};