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  • only in /asuswrt-rt-n18u-9.0.0.4.380.2695/release/src-rt-6.x.4708/router/ffmpeg/libavfilter/
1/*
2 * copyright (c) 2007 Bobby Bingham
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21/**
22 * @file
23 * video vertical flip filter
24 */
25
26#include "libavutil/pixdesc.h"
27#include "avfilter.h"
28
29typedef struct {
30    int vsub;   ///< vertical chroma subsampling
31} FlipContext;
32
33static int config_input(AVFilterLink *link)
34{
35    FlipContext *flip = link->dst->priv;
36
37    flip->vsub = av_pix_fmt_descriptors[link->format].log2_chroma_h;
38
39    return 0;
40}
41
42static AVFilterPicRef *get_video_buffer(AVFilterLink *link, int perms,
43                                        int w, int h)
44{
45    FlipContext *flip = link->dst->priv;
46    int i;
47
48    AVFilterPicRef *picref = avfilter_get_video_buffer(link->dst->outputs[0],
49                                                       perms, w, h);
50
51    for (i = 0; i < 4; i ++) {
52        int vsub = i == 1 || i == 2 ? flip->vsub : 0;
53
54        if (picref->data[i]) {
55            picref->data[i] += ((h >> vsub)-1) * picref->linesize[i];
56            picref->linesize[i] = -picref->linesize[i];
57        }
58    }
59
60    return picref;
61}
62
63static void start_frame(AVFilterLink *link, AVFilterPicRef *picref)
64{
65    FlipContext *flip = link->dst->priv;
66    int i;
67
68    for (i = 0; i < 4; i ++) {
69        int vsub = i == 1 || i == 2 ? flip->vsub : 0;
70
71        if (picref->data[i]) {
72            picref->data[i] += ((link->h >> vsub)-1) * picref->linesize[i];
73            picref->linesize[i] = -picref->linesize[i];
74        }
75    }
76
77    avfilter_start_frame(link->dst->outputs[0], picref);
78}
79
80static void draw_slice(AVFilterLink *link, int y, int h, int slice_dir)
81{
82    AVFilterContext *ctx = link->dst;
83
84    avfilter_draw_slice(ctx->outputs[0], link->h - (y+h), h, -1 * slice_dir);
85}
86
87AVFilter avfilter_vf_vflip = {
88    .name      = "vflip",
89    .description = NULL_IF_CONFIG_SMALL("Flip the input video vertically."),
90
91    .priv_size = sizeof(FlipContext),
92
93    .inputs    = (AVFilterPad[]) {{ .name             = "default",
94                                    .type             = AVMEDIA_TYPE_VIDEO,
95                                    .get_video_buffer = get_video_buffer,
96                                    .start_frame      = start_frame,
97                                    .draw_slice       = draw_slice,
98                                    .end_frame        = avfilter_null_end_frame,
99                                    .config_props     = config_input, },
100                                  { .name = NULL}},
101    .outputs   = (AVFilterPad[]) {{ .name             = "default",
102                                    .type             = AVMEDIA_TYPE_VIDEO, },
103                                  { .name = NULL}},
104};
105