FFmpeg/libavfilter/vf_vflip.c
Stefano Sabatini b70bc02279 Add descriptions for the committed filters.
Originally committed as revision 20375 to svn://svn.ffmpeg.org/ffmpeg/trunk
2009-10-27 00:43:45 +00:00

105 lines
3.3 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 libavfilter/vf_vflip.c
* video vertical flip filter
*/
#include "avfilter.h"
typedef struct {
int vsub; ///< vertical chroma subsampling
} FlipContext;
static int config_input(AVFilterLink *link)
{
FlipContext *flip = link->dst->priv;
int tmp;
avcodec_get_chroma_sub_sample(link->format, &tmp, &flip->vsub);
return 0;
}
static AVFilterPicRef *get_video_buffer(AVFilterLink *link, int perms,
int w, int h)
{
FlipContext *flip = link->dst->priv;
int i;
AVFilterPicRef *picref = avfilter_get_video_buffer(link->dst->outputs[0],
perms, w, h);
picref->data[0] += (h-1) * picref->linesize[0];
picref->linesize[0] = -picref->linesize[0];
for (i = 1; i < 4; i ++) {
if (picref->data[i]) {
picref->data[i] += ((h >> flip->vsub)-1) * picref->linesize[i];
picref->linesize[i] = -picref->linesize[i];
}
}
return picref;
}
static void start_frame(AVFilterLink *link, AVFilterPicRef *picref)
{
FlipContext *flip = link->dst->priv;
AVFilterPicRef *ref2 = avfilter_ref_pic(picref, ~0);
int i;
ref2->data[0] += (link->h-1) * ref2->linesize[0];
ref2->linesize[0] = -ref2->linesize[0];
for (i = 1; i < 4; i ++) {
if (ref2->data[i]) {
ref2->data[i] += ((link->h >> flip->vsub)-1) * ref2->linesize[i];
ref2->linesize[i] = -ref2->linesize[i];
}
}
avfilter_start_frame(link->dst->outputs[0], ref2);
}
static void draw_slice(AVFilterLink *link, int y, int h)
{
AVFilterContext *ctx = link->dst;
avfilter_draw_slice(ctx->outputs[0], link->h - (y+h), h);
}
AVFilter avfilter_vf_vflip = {
.name = "vflip",
.description = NULL_IF_CONFIG_SMALL("Flip the input video vertically."),
.priv_size = sizeof(FlipContext),
.inputs = (AVFilterPad[]) {{ .name = "default",
.type = CODEC_TYPE_VIDEO,
.get_video_buffer = get_video_buffer,
.start_frame = start_frame,
.draw_slice = draw_slice,
.config_props = config_input, },
{ .name = NULL}},
.outputs = (AVFilterPad[]) {{ .name = "default",
.type = CODEC_TYPE_VIDEO, },
{ .name = NULL}},
};