Libav
vf_vflip.c
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1 /*
2  * Copyright (c) 2007 Bobby Bingham
3  *
4  * This file is part of Libav.
5  *
6  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
26 #include "libavutil/internal.h"
27 #include "libavutil/pixdesc.h"
28 #include "avfilter.h"
29 #include "internal.h"
30 #include "video.h"
31 
32 typedef struct {
33  int vsub;
34 } FlipContext;
35 
36 static int config_input(AVFilterLink *link)
37 {
38  FlipContext *flip = link->dst->priv;
39  const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(link->format);
40 
41  flip->vsub = desc->log2_chroma_h;
42 
43  return 0;
44 }
45 
46 static AVFrame *get_video_buffer(AVFilterLink *link, int w, int h)
47 {
48  FlipContext *flip = link->dst->priv;
49  AVFrame *frame;
50  int i;
51 
52  frame = ff_get_video_buffer(link->dst->outputs[0], w, h);
53  if (!frame)
54  return NULL;
55 
56  for (i = 0; i < 4; i ++) {
57  int vsub = i == 1 || i == 2 ? flip->vsub : 0;
58 
59  if (frame->data[i]) {
60  frame->data[i] += ((h >> vsub) - 1) * frame->linesize[i];
61  frame->linesize[i] = -frame->linesize[i];
62  }
63  }
64 
65  return frame;
66 }
67 
68 static int filter_frame(AVFilterLink *link, AVFrame *frame)
69 {
70  FlipContext *flip = link->dst->priv;
71  int i;
72 
73  for (i = 0; i < 4; i ++) {
74  int vsub = i == 1 || i == 2 ? flip->vsub : 0;
75 
76  if (frame->data[i]) {
77  frame->data[i] += ((link->h >> vsub)-1) * frame->linesize[i];
78  frame->linesize[i] = -frame->linesize[i];
79  }
80  }
81 
82  return ff_filter_frame(link->dst->outputs[0], frame);
83 }
85  {
86  .name = "default",
87  .type = AVMEDIA_TYPE_VIDEO,
88  .get_video_buffer = get_video_buffer,
89  .filter_frame = filter_frame,
90  .config_props = config_input,
91  },
92  { NULL }
93 };
94 
96  {
97  .name = "default",
98  .type = AVMEDIA_TYPE_VIDEO,
99  },
100  { NULL }
101 };
102 
104  .name = "vflip",
105  .description = NULL_IF_CONFIG_SMALL("Flip the input video vertically."),
106 
107  .priv_size = sizeof(FlipContext),
108 
109  .inputs = avfilter_vf_vflip_inputs,
110  .outputs = avfilter_vf_vflip_outputs,
111 };