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 AVFilterBufferRef *get_video_buffer(AVFilterLink *link, int perms,
int w, int h)
{
FlipContext *flip = link->dst->priv;
AVFilterBufferRef *picref;
int i;
if (!(perms & AV_PERM_NEG_LINESIZES))
return ff_default_get_video_buffer(link, perms, w, h);
picref = ff_get_video_buffer(link->dst->outputs[0], perms, w, h);
if (!picref)
return NULL;
for (i = 0; i < 4; i ++) {
int vsub = i == 1 || i == 2 ? flip->vsub : 0;
if (picref->data[i]) {
picref->data[i] += ((h >> vsub)-1) * picref->linesize[i];
picref->linesize[i] = -picref->linesize[i];
}
}
return picref;
}
static int start_frame(AVFilterLink *link, AVFilterBufferRef *inpicref)
{
FlipContext *flip = link->dst->priv;
AVFilterBufferRef *outpicref = avfilter_ref_buffer(inpicref, ~0);
int i;
if (!outpicref)
return AVERROR(ENOMEM);
for (i = 0; i < 4; i ++) {
int vsub = i == 1 || i == 2 ? flip->vsub : 0;
if (outpicref->data[i]) {
outpicref->data[i] += ((link->h >> vsub)-1) * outpicref->linesize[i];
outpicref->linesize[i] = -outpicref->linesize[i];
}
}
return ff_start_frame(link->dst->outputs[0], outpicref);
}
static int draw_slice(AVFilterLink *link, int y, int h, int slice_dir)
{
AVFilterContext *ctx = link->dst;
return ff_draw_slice(ctx->outputs[0], link->h - (y+h), h, -1 * slice_dir);
}
static const AVFilterPad avfilter_vf_vflip_inputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.get_video_buffer = get_video_buffer,
.start_frame = start_frame,
.draw_slice = draw_slice,
.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,
};