2 * Copyright (c) 2010 Bobby Bingham
4 * This file is part of FFmpeg.
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.
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.
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
23 * aspect ratio modification video filters
26 #include "libavutil/mathematics.h"
33 static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
35 AspectContext *aspect = ctx->priv;
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);
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);
51 gcd = av_gcd(FFABS(aspect->aspect.num), FFABS(aspect->aspect.den));
53 aspect->aspect.num /= gcd;
54 aspect->aspect.den /= gcd;
58 if (aspect->aspect.den == 0)
59 aspect->aspect = (AVRational) {0, 1};
61 av_log(ctx, AV_LOG_INFO, "a:%d/%d\n", aspect->aspect.num, aspect->aspect.den);
65 static void start_frame(AVFilterLink *link, AVFilterBufferRef *picref)
67 AspectContext *aspect = link->dst->priv;
69 picref->video->sample_aspect_ratio = aspect->aspect;
70 avfilter_start_frame(link->dst->outputs[0], picref);
73 #if CONFIG_SETDAR_FILTER
74 /* for setdar filter, convert from frame aspect ratio to pixel aspect ratio */
75 static int setdar_config_props(AVFilterLink *inlink)
77 AspectContext *aspect = inlink->dst->priv;
78 AVRational dar = aspect->aspect;
80 av_reduce(&aspect->aspect.num, &aspect->aspect.den,
81 aspect->aspect.num * inlink->h,
82 aspect->aspect.den * inlink->w, 100);
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);
87 inlink->sample_aspect_ratio = aspect->aspect;
92 AVFilter avfilter_vf_setdar = {
94 .description = NULL_IF_CONFIG_SMALL("Set the frame display aspect ratio."),
98 .priv_size = sizeof(AspectContext),
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 },
108 .outputs = (AVFilterPad[]) {{ .name = "default",
109 .type = AVMEDIA_TYPE_VIDEO, },
112 #endif /* CONFIG_SETDAR_FILTER */
114 #if CONFIG_SETSAR_FILTER
115 /* for setdar filter, convert from frame aspect ratio to pixel aspect ratio */
116 static int setsar_config_props(AVFilterLink *inlink)
118 AspectContext *aspect = inlink->dst->priv;
120 inlink->sample_aspect_ratio = aspect->aspect;
125 AVFilter avfilter_vf_setsar = {
127 .description = NULL_IF_CONFIG_SMALL("Set the pixel sample aspect ratio."),
131 .priv_size = sizeof(AspectContext),
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 },
141 .outputs = (AVFilterPad[]) {{ .name = "default",
142 .type = AVMEDIA_TYPE_VIDEO, },
145 #endif /* CONFIG_SETSAR_FILTER */