2 * Aspect ratio modification video filter
3 * Copyright (c) 2010 Bobby Bingham
5 * This file is part of FFmpeg.
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.
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.
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
24 * aspect ratio modification video filter
33 static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
35 AspectContext *aspect = ctx->priv;
40 if(sscanf(args, "%d:%d", &aspect->aspect.num, &aspect->aspect.den) < 2) {
41 if(sscanf(args, "%lf", &ratio) < 1)
43 aspect->aspect = av_d2q(ratio, 100);
45 gcd = av_gcd(FFABS(aspect->aspect.num), FFABS(aspect->aspect.den));
47 aspect->aspect.num /= gcd;
48 aspect->aspect.den /= gcd;
53 if(aspect->aspect.den == 0)
54 aspect->aspect = (AVRational) {0, 1};
59 static void start_frame(AVFilterLink *link, AVFilterBufferRef *picref)
61 AspectContext *aspect = link->dst->priv;
63 picref->video->pixel_aspect = aspect->aspect;
64 avfilter_start_frame(link->dst->outputs[0], picref);
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)
71 AspectContext *aspect = inlink->dst->priv;
73 av_reduce(&aspect->aspect.num, &aspect->aspect.den,
74 aspect->aspect.num * inlink->h,
75 aspect->aspect.den * inlink->w, 100);
80 AVFilter avfilter_vf_aspect = {
82 .description = NULL_IF_CONFIG_SMALL("Set the frame aspect ratio."),
86 .priv_size = sizeof(AspectContext),
88 .inputs = (AVFilterPad[]) {{ .name = "default",
89 .type = AVMEDIA_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 },
96 .outputs = (AVFilterPad[]) {{ .name = "default",
97 .type = AVMEDIA_TYPE_VIDEO, },
100 #endif /* CONFIG_ASPECT_FILTER */
102 #if CONFIG_PIXELASPECT_FILTER
103 AVFilter avfilter_vf_pixelaspect = {
104 .name = "pixelaspect",
105 .description = NULL_IF_CONFIG_SMALL("Set the pixel aspect ratio."),
109 .priv_size = sizeof(AspectContext),
111 .inputs = (AVFilterPad[]) {{ .name = "default",
112 .type = AVMEDIA_TYPE_VIDEO,
113 .get_video_buffer = avfilter_null_get_video_buffer,
114 .start_frame = start_frame,
115 .end_frame = avfilter_null_end_frame },
118 .outputs = (AVFilterPad[]) {{ .name = "default",
119 .type = AVMEDIA_TYPE_VIDEO, },
122 #endif /* CONFIG_PIXELASPECT_FILTER */