In aspect filter, fix display for input resolution
[ffmpeg.git] / libavfilter / vf_aspect.c
1 /*
2  * Copyright (c) 2010 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  * aspect ratio modification video filters
24  */
25
26 #include "avfilter.h"
27
28 typedef struct {
29     AVRational aspect;
30 } AspectContext;
31
32 static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
33 {
34     AspectContext *aspect = ctx->priv;
35     double  ratio;
36     int64_t gcd;
37     char c = 0;
38
39     if (args) {
40         if (sscanf(args, "%d:%d%c", &aspect->aspect.num, &aspect->aspect.den, &c) != 2)
41             if (sscanf(args, "%lf%c", &ratio, &c) == 1)
42                 aspect->aspect = av_d2q(ratio, 100);
43
44         if (c || aspect->aspect.num <= 0 || aspect->aspect.den <= 0) {
45             av_log(ctx, AV_LOG_ERROR,
46                    "Invalid string '%s' for aspect ratio.\n", args);
47             return AVERROR(EINVAL);
48         }
49
50         gcd = av_gcd(FFABS(aspect->aspect.num), FFABS(aspect->aspect.den));
51         if (gcd) {
52             aspect->aspect.num /= gcd;
53             aspect->aspect.den /= gcd;
54         }
55     }
56
57     if (aspect->aspect.den == 0)
58         aspect->aspect = (AVRational) {0, 1};
59
60     av_log(ctx, AV_LOG_INFO, "a:%d/%d\n", aspect->aspect.num, aspect->aspect.den);
61     return 0;
62 }
63
64 static void start_frame(AVFilterLink *link, AVFilterBufferRef *picref)
65 {
66     AspectContext *aspect = link->dst->priv;
67
68     picref->video->pixel_aspect = aspect->aspect;
69     avfilter_start_frame(link->dst->outputs[0], picref);
70 }
71
72 #if CONFIG_SETDAR_FILTER
73 /* for setdar filter, convert from frame aspect ratio to pixel aspect ratio */
74 static int setdar_config_props(AVFilterLink *inlink)
75 {
76     AspectContext *aspect = inlink->dst->priv;
77     AVRational dar = aspect->aspect;
78
79     av_reduce(&aspect->aspect.num, &aspect->aspect.den,
80                aspect->aspect.num * inlink->h,
81                aspect->aspect.den * inlink->w, 100);
82
83     av_log(inlink->dst, AV_LOG_INFO, "w:%d h:%d -> dar:%d/%d par:%d/%d\n",
84            inlink->w, inlink->h, dar.num, dar.den, aspect->aspect.num, aspect->aspect.den);
85     return 0;
86 }
87
88 AVFilter avfilter_vf_setdar = {
89     .name      = "setdar",
90     .description = NULL_IF_CONFIG_SMALL("Set the frame display aspect ratio."),
91
92     .init      = init,
93
94     .priv_size = sizeof(AspectContext),
95
96     .inputs    = (AVFilterPad[]) {{ .name             = "default",
97                                     .type             = AVMEDIA_TYPE_VIDEO,
98                                     .config_props     = setdar_config_props,
99                                     .get_video_buffer = avfilter_null_get_video_buffer,
100                                     .start_frame      = start_frame,
101                                     .end_frame        = avfilter_null_end_frame },
102                                   { .name = NULL}},
103
104     .outputs   = (AVFilterPad[]) {{ .name             = "default",
105                                     .type             = AVMEDIA_TYPE_VIDEO, },
106                                   { .name = NULL}},
107 };
108 #endif /* CONFIG_SETDAR_FILTER */
109
110 #if CONFIG_SETSAR_FILTER
111 AVFilter avfilter_vf_setsar = {
112     .name      = "setsar",
113     .description = NULL_IF_CONFIG_SMALL("Set the pixel sample aspect ratio."),
114
115     .init      = init,
116
117     .priv_size = sizeof(AspectContext),
118
119     .inputs    = (AVFilterPad[]) {{ .name             = "default",
120                                     .type             = AVMEDIA_TYPE_VIDEO,
121                                     .get_video_buffer = avfilter_null_get_video_buffer,
122                                     .start_frame      = start_frame,
123                                     .end_frame        = avfilter_null_end_frame },
124                                   { .name = NULL}},
125
126     .outputs   = (AVFilterPad[]) {{ .name             = "default",
127                                     .type             = AVMEDIA_TYPE_VIDEO, },
128                                   { .name = NULL}},
129 };
130 #endif /* CONFIG_SETSAR_FILTER */
131