ae7b9b475f78b7a471e3681137591cd13b7ee252
[libav.git] / libavfilter / vf_vflip.c
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 libavfilter/vf_vflip.c
23 * video vertical flip filter
24 */
25
26 #include "avfilter.h"
27
28 typedef struct {
29 int vsub; ///< vertical chroma subsampling
30 } FlipContext;
31
32 static int config_input(AVFilterLink *link)
33 {
34 FlipContext *flip = link->dst->priv;
35 int tmp;
36
37 avcodec_get_chroma_sub_sample(link->format, &tmp, &flip->vsub);
38
39 return 0;
40 }
41
42 static 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 picref->data[0] += (h-1) * picref->linesize[0];
52 picref->linesize[0] = -picref->linesize[0];
53 for (i = 1; i < 4; i ++) {
54 if (picref->data[i]) {
55 picref->data[i] += ((h >> flip->vsub)-1) * picref->linesize[i];
56 picref->linesize[i] = -picref->linesize[i];
57 }
58 }
59
60 return picref;
61 }
62
63 static void start_frame(AVFilterLink *link, AVFilterPicRef *picref)
64 {
65 FlipContext *flip = link->dst->priv;
66 AVFilterPicRef *ref2 = avfilter_ref_pic(picref, ~0);
67 int i;
68
69 ref2->data[0] += (link->h-1) * ref2->linesize[0];
70 ref2->linesize[0] = -ref2->linesize[0];
71 for (i = 1; i < 4; i ++) {
72 if (ref2->data[i]) {
73 ref2->data[i] += ((link->h >> flip->vsub)-1) * ref2->linesize[i];
74 ref2->linesize[i] = -ref2->linesize[i];
75 }
76 }
77
78 avfilter_start_frame(link->dst->outputs[0], ref2);
79 }
80
81 static void draw_slice(AVFilterLink *link, int y, int h)
82 {
83 AVFilterContext *ctx = link->dst;
84
85 avfilter_draw_slice(ctx->outputs[0], link->h - (y+h), h);
86 }
87
88 AVFilter avfilter_vf_vflip = {
89 .name = "vflip",
90 .description = NULL_IF_CONFIG_SMALL("Flip the input video vertically."),
91
92 .priv_size = sizeof(FlipContext),
93
94 .inputs = (AVFilterPad[]) {{ .name = "default",
95 .type = CODEC_TYPE_VIDEO,
96 .get_video_buffer = get_video_buffer,
97 .start_frame = start_frame,
98 .draw_slice = draw_slice,
99 .config_props = config_input, },
100 { .name = NULL}},
101 .outputs = (AVFilterPad[]) {{ .name = "default",
102 .type = CODEC_TYPE_VIDEO, },
103 { .name = NULL}},
104 };