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vf_vflip.c
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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/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; ///< vertical chroma subsampling
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 
47  int w, int h)
48 {
49  FlipContext *flip = link->dst->priv;
50  AVFilterBufferRef *picref;
51  int i;
52 
53  if (!(perms & AV_PERM_NEG_LINESIZES))
54  return ff_default_get_video_buffer(link, perms, w, h);
55 
56  picref = ff_get_video_buffer(link->dst->outputs[0], perms, w, h);
57  if (!picref)
58  return NULL;
59 
60  for (i = 0; i < 4; i ++) {
61  int vsub = i == 1 || i == 2 ? flip->vsub : 0;
62 
63  if (picref->data[i]) {
64  picref->data[i] += (((h + (1<<vsub)-1) >> vsub)-1) * picref->linesize[i];
65  picref->linesize[i] = -picref->linesize[i];
66  }
67  }
68 
69  return picref;
70 }
71 
73 {
74  FlipContext *flip = link->dst->priv;
75  int i;
76 
77  for (i = 0; i < 4; i ++) {
78  int vsub = i == 1 || i == 2 ? flip->vsub : 0;
79 
80  if (frame->data[i]) {
81  frame->data[i] += (((link->h + (1<<vsub)-1)>> vsub)-1) * frame->linesize[i];
82  frame->linesize[i] = -frame->linesize[i];
83  }
84  }
85 
86  return ff_filter_frame(link->dst->outputs[0], frame);
87 }
89  {
90  .name = "default",
91  .type = AVMEDIA_TYPE_VIDEO,
92  .get_video_buffer = get_video_buffer,
93  .filter_frame = filter_frame,
94  .config_props = config_input,
95  },
96  { NULL }
97 };
98 
100  {
101  .name = "default",
102  .type = AVMEDIA_TYPE_VIDEO,
103  },
104  { NULL }
105 };
106 
108  .name = "vflip",
109  .description = NULL_IF_CONFIG_SMALL("Flip the input video vertically."),
110 
111  .priv_size = sizeof(FlipContext),
112 
113  .inputs = avfilter_vf_vflip_inputs,
114  .outputs = avfilter_vf_vflip_outputs,
115 };