1/*
2 * Copyright (c) 2010 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
21/**
22 * @file
23 * aspect ratio modification video filters
24 */
25
26#include "libavutil/mathematics.h"
27#include "avfilter.h"
28
29typedef struct {
30    AVRational aspect;
31} AspectContext;
32
33static 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    char c = 0;
39
40    if (args) {
41        if (sscanf(args, "%d:%d%c", &aspect->aspect.num, &aspect->aspect.den, &c) != 2)
42            if (sscanf(args, "%lf%c", &ratio, &c) == 1)
43                aspect->aspect = av_d2q(ratio, 100);
44
45        if (c || aspect->aspect.num <= 0 || aspect->aspect.den <= 0) {
46            av_log(ctx, AV_LOG_ERROR,
47                   "Invalid string '%s' for aspect ratio.\n", args);
48            return AVERROR(EINVAL);
49        }
50
51        gcd = av_gcd(FFABS(aspect->aspect.num), FFABS(aspect->aspect.den));
52        if (gcd) {
53            aspect->aspect.num /= gcd;
54            aspect->aspect.den /= gcd;
55        }
56    }
57
58    if (aspect->aspect.den == 0)
59        aspect->aspect = (AVRational) {0, 1};
60
61    av_log(ctx, AV_LOG_INFO, "a:%d/%d\n", aspect->aspect.num, aspect->aspect.den);
62    return 0;
63}
64
65static void start_frame(AVFilterLink *link, AVFilterBufferRef *picref)
66{
67    AspectContext *aspect = link->dst->priv;
68
69    picref->video->pixel_aspect = aspect->aspect;
70    avfilter_start_frame(link->dst->outputs[0], picref);
71}
72
73#if CONFIG_SETDAR_FILTER
74/* for setdar filter, convert from frame aspect ratio to pixel aspect ratio */
75static int setdar_config_props(AVFilterLink *inlink)
76{
77    AspectContext *aspect = inlink->dst->priv;
78    AVRational dar = aspect->aspect;
79
80    av_reduce(&aspect->aspect.num, &aspect->aspect.den,
81               aspect->aspect.num * inlink->h,
82               aspect->aspect.den * inlink->w, 100);
83
84    av_log(inlink->dst, AV_LOG_INFO, "w:%d h:%d -> dar:%d/%d sar:%d/%d\n",
85           inlink->w, inlink->h, dar.num, dar.den, aspect->aspect.num, aspect->aspect.den);
86
87    inlink->sample_aspect_ratio = aspect->aspect;
88
89    return 0;
90}
91
92AVFilter avfilter_vf_setdar = {
93    .name      = "setdar",
94    .description = NULL_IF_CONFIG_SMALL("Set the frame display aspect ratio."),
95
96    .init      = init,
97
98    .priv_size = sizeof(AspectContext),
99
100    .inputs    = (AVFilterPad[]) {{ .name             = "default",
101                                    .type             = AVMEDIA_TYPE_VIDEO,
102                                    .config_props     = setdar_config_props,
103                                    .get_video_buffer = avfilter_null_get_video_buffer,
104                                    .start_frame      = start_frame,
105                                    .end_frame        = avfilter_null_end_frame },
106                                  { .name = NULL}},
107
108    .outputs   = (AVFilterPad[]) {{ .name             = "default",
109                                    .type             = AVMEDIA_TYPE_VIDEO, },
110                                  { .name = NULL}},
111};
112#endif /* CONFIG_SETDAR_FILTER */
113
114#if CONFIG_SETSAR_FILTER
115/* for setdar filter, convert from frame aspect ratio to pixel aspect ratio */
116static int setsar_config_props(AVFilterLink *inlink)
117{
118    AspectContext *aspect = inlink->dst->priv;
119
120    inlink->sample_aspect_ratio = aspect->aspect;
121
122    return 0;
123}
124
125AVFilter avfilter_vf_setsar = {
126    .name      = "setsar",
127    .description = NULL_IF_CONFIG_SMALL("Set the pixel sample aspect ratio."),
128
129    .init      = init,
130
131    .priv_size = sizeof(AspectContext),
132
133    .inputs    = (AVFilterPad[]) {{ .name             = "default",
134                                    .type             = AVMEDIA_TYPE_VIDEO,
135                                    .config_props     = setsar_config_props,
136                                    .get_video_buffer = avfilter_null_get_video_buffer,
137                                    .start_frame      = start_frame,
138                                    .end_frame        = avfilter_null_end_frame },
139                                  { .name = NULL}},
140
141    .outputs   = (AVFilterPad[]) {{ .name             = "default",
142                                    .type             = AVMEDIA_TYPE_VIDEO, },
143                                  { .name = NULL}},
144};
145#endif /* CONFIG_SETSAR_FILTER */
146
147