FFmpeg/libavfilter/vf_vflip.c
2021-02-15 00:12:38 +01:00

156 lines
4.3 KiB
C

/*
* Copyright (c) 2007 Bobby Bingham
*
* 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
* video vertical flip filter
*/
#include "libavutil/internal.h"
#include "libavutil/opt.h"
#include "libavutil/pixdesc.h"
#include "avfilter.h"
#include "internal.h"
#include "video.h"
typedef struct FlipContext {
const AVClass *class;
int vsub; ///< vertical chroma subsampling
int bayer;
} FlipContext;
static const AVOption vflip_options[] = {
{ NULL }
};
AVFILTER_DEFINE_CLASS(vflip);
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;
flip->bayer = !!(desc->flags & AV_PIX_FMT_FLAG_BAYER);
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;
int height = AV_CEIL_RSHIFT(h, vsub);
if (frame->data[i]) {
frame->data[i] += (height - 1) * frame->linesize[i];
frame->linesize[i] = -frame->linesize[i];
}
}
return frame;
}
static int flip_bayer(AVFilterLink *link, AVFrame *in)
{
AVFilterContext *ctx = link->dst;
AVFilterLink *outlink = ctx->outputs[0];
AVFrame *out;
uint8_t *inrow = in->data[0], *outrow;
int i, width = outlink->w << (av_pix_fmt_desc_get(link->format)->comp[0].step > 1);
if (outlink->h & 1) {
av_log(ctx, AV_LOG_ERROR, "Bayer vertical flip needs even height\n");
return AVERROR_INVALIDDATA;
}
out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
if (!out) {
av_frame_free(&in);
return AVERROR(ENOMEM);
}
av_frame_copy_props(out, in);
outrow = out->data[0] + out->linesize[0] * (outlink->h - 2);
for (i = 0; i < outlink->h >> 1; i++) {
memcpy(outrow, inrow, width);
memcpy(outrow + out->linesize[0], inrow + in->linesize[0], width);
inrow += 2 * in->linesize[0];
outrow -= 2 * out->linesize[0];
}
av_frame_free(&in);
return ff_filter_frame(outlink, out);
}
static int filter_frame(AVFilterLink *link, AVFrame *frame)
{
FlipContext *flip = link->dst->priv;
int i;
if (flip->bayer)
return flip_bayer(link, frame);
for (i = 0; i < 4; i ++) {
int vsub = i == 1 || i == 2 ? flip->vsub : 0;
int height = AV_CEIL_RSHIFT(link->h, vsub);
if (frame->data[i]) {
frame->data[i] += (height - 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 ff_vf_vflip = {
.name = "vflip",
.description = NULL_IF_CONFIG_SMALL("Flip the input video vertically."),
.priv_size = sizeof(FlipContext),
.priv_class = &vflip_class,
.inputs = avfilter_vf_vflip_inputs,
.outputs = avfilter_vf_vflip_outputs,
.flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,
};