Statistics
| Branch: | Revision:

ffmpeg / libavfilter / vf_aspect.c @ 3922deb5

History | View | Annotate | Download (4.32 KB)

1
/*
2
 * Aspect ratio modification video filter
3
 * Copyright (c) 2010 Bobby Bingham
4

5
 * This file is part of FFmpeg.
6
 *
7
 * FFmpeg is free software; you can redistribute it and/or
8
 * modify it under the terms of the GNU Lesser General Public
9
 * License as published by the Free Software Foundation; either
10
 * version 2.1 of the License, or (at your option) any later version.
11
 *
12
 * FFmpeg is distributed in the hope that it will be useful,
13
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15
 * Lesser General Public License for more details.
16
 *
17
 * You should have received a copy of the GNU Lesser General Public
18
 * License along with FFmpeg; if not, write to the Free Software
19
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20
 */
21

    
22
/**
23
 * @file libavfilter/vf_aspect.c
24
 * aspect ratio modification video filter
25
 */
26

    
27
#include "avfilter.h"
28

    
29
typedef struct {
30
    AVRational aspect;
31
} AspectContext;
32

    
33
static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
34
{
35
    AspectContext *aspect = ctx->priv;
36
    double  ratio;
37
    int64_t gcd;
38

    
39
    if(args) {
40
        if(sscanf(args, "%d:%d", &aspect->aspect.num, &aspect->aspect.den) < 2) {
41
            if(sscanf(args, "%lf", &ratio) < 1)
42
                return -1;
43
            aspect->aspect = av_d2q(ratio, 100);
44
        } else {
45
            gcd = av_gcd(FFABS(aspect->aspect.num), FFABS(aspect->aspect.den));
46
            if(gcd) {
47
                aspect->aspect.num /= gcd;
48
                aspect->aspect.den /= gcd;
49
            }
50
        }
51
    }
52

    
53
    if(aspect->aspect.den == 0)
54
        aspect->aspect = (AVRational) {0, 1};
55

    
56
    return 0;
57
}
58

    
59

    
60
static AVFilterPicRef *get_video_buffer(AVFilterLink *link, int perms,
61
                                        int w, int h)
62
{
63
    return avfilter_get_video_buffer(link->dst->outputs[0], perms, w, h);
64
}
65

    
66
static void start_frame(AVFilterLink *link, AVFilterPicRef *picref)
67
{
68
    AspectContext *aspect = link->dst->priv;
69

    
70
    picref->pixel_aspect = aspect->aspect;
71
    avfilter_start_frame(link->dst->outputs[0], picref);
72
}
73

    
74
static void end_frame(AVFilterLink *link)
75
{
76
    avfilter_end_frame(link->dst->outputs[0]);
77
}
78

    
79
#if CONFIG_ASPECT_FILTER
80
/* for aspect filter, convert from frame aspect ratio to pixel aspect ratio */
81
static int frameaspect_config_props(AVFilterLink *inlink)
82
{
83
    AspectContext *aspect = inlink->dst->priv;
84

    
85
    av_reduce(&aspect->aspect.num, &aspect->aspect.den,
86
               aspect->aspect.num * inlink->h,
87
               aspect->aspect.den * inlink->w, 100);
88

    
89
    return 0;
90
}
91

    
92
AVFilter avfilter_vf_aspect = {
93
    .name      = "aspect",
94
    .description = NULL_IF_CONFIG_SMALL("Set the frame aspect ratio."),
95

    
96
    .init      = init,
97

    
98
    .priv_size = sizeof(AspectContext),
99

    
100
    .inputs    = (AVFilterPad[]) {{ .name             = "default",
101
                                    .type             = CODEC_TYPE_VIDEO,
102
                                    .config_props     = frameaspect_config_props,
103
                                    .get_video_buffer = get_video_buffer,
104
                                    .start_frame      = start_frame,
105
                                    .end_frame        = end_frame },
106
                                  { .name = NULL}},
107

    
108
    .outputs   = (AVFilterPad[]) {{ .name             = "default",
109
                                    .type             = CODEC_TYPE_VIDEO, },
110
                                  { .name = NULL}},
111
};
112
#endif /* CONFIG_ASPECT_FILTER */
113

    
114
#if CONFIG_PIXELASPECT_FILTER
115
AVFilter avfilter_vf_pixelaspect = {
116
    .name      = "pixelaspect",
117
    .description = NULL_IF_CONFIG_SMALL("Set the pixel aspect ratio."),
118

    
119
    .init      = init,
120

    
121
    .priv_size = sizeof(AspectContext),
122

    
123
    .inputs    = (AVFilterPad[]) {{ .name             = "default",
124
                                    .type             = CODEC_TYPE_VIDEO,
125
                                    .get_video_buffer = get_video_buffer,
126
                                    .start_frame      = start_frame,
127
                                    .end_frame        = end_frame },
128
                                  { .name = NULL}},
129

    
130
    .outputs   = (AVFilterPad[]) {{ .name             = "default",
131
                                    .type             = CODEC_TYPE_VIDEO, },
132
                                  { .name = NULL}},
133
};
134
#endif /* CONFIG_PIXELASPECT_FILTER */
135