Statistics
| Branch: | Revision:

ffmpeg / libavfilter / vf_aspect.c @ d313e17a

History | View | Annotate | Download (4.08 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
static void start_frame(AVFilterLink *link, AVFilterPicRef *picref)
60
{
61
    AspectContext *aspect = link->dst->priv;
62

    
63
    picref->pixel_aspect = aspect->aspect;
64
    avfilter_start_frame(link->dst->outputs[0], picref);
65
}
66

    
67
#if CONFIG_ASPECT_FILTER
68
/* for aspect filter, convert from frame aspect ratio to pixel aspect ratio */
69
static int frameaspect_config_props(AVFilterLink *inlink)
70
{
71
    AspectContext *aspect = inlink->dst->priv;
72

    
73
    av_reduce(&aspect->aspect.num, &aspect->aspect.den,
74
               aspect->aspect.num * inlink->h,
75
               aspect->aspect.den * inlink->w, 100);
76

    
77
    return 0;
78
}
79

    
80
AVFilter avfilter_vf_aspect = {
81
    .name      = "aspect",
82
    .description = NULL_IF_CONFIG_SMALL("Set the frame aspect ratio."),
83

    
84
    .init      = init,
85

    
86
    .priv_size = sizeof(AspectContext),
87

    
88
    .inputs    = (AVFilterPad[]) {{ .name             = "default",
89
                                    .type             = CODEC_TYPE_VIDEO,
90
                                    .config_props     = frameaspect_config_props,
91
                                    .get_video_buffer = avfilter_null_get_video_buffer,
92
                                    .start_frame      = start_frame,
93
                                    .end_frame        = avfilter_null_end_frame },
94
                                  { .name = NULL}},
95

    
96
    .outputs   = (AVFilterPad[]) {{ .name             = "default",
97
                                    .type             = CODEC_TYPE_VIDEO, },
98
                                  { .name = NULL}},
99
};
100
#endif /* CONFIG_ASPECT_FILTER */
101

    
102
#if CONFIG_PIXELASPECT_FILTER
103
AVFilter avfilter_vf_pixelaspect = {
104
    .name      = "pixelaspect",
105
    .description = NULL_IF_CONFIG_SMALL("Set the pixel aspect ratio."),
106

    
107
    .init      = init,
108

    
109
    .priv_size = sizeof(AspectContext),
110

    
111
    .inputs    = (AVFilterPad[]) {{ .name             = "default",
112
                                    .type             = CODEC_TYPE_VIDEO,
113
                                    .get_video_buffer = avfilter_null_get_video_buffer,
114
                                    .start_frame      = start_frame,
115
                                    .end_frame        = avfilter_null_end_frame },
116
                                  { .name = NULL}},
117

    
118
    .outputs   = (AVFilterPad[]) {{ .name             = "default",
119
                                    .type             = CODEC_TYPE_VIDEO, },
120
                                  { .name = NULL}},
121
};
122
#endif /* CONFIG_PIXELASPECT_FILTER */
123