| /* |
| * Aspect ratio modification video filter |
| * Copyright (c) 2010 Bobby Bingham |
| |
| * This file is part of FFmpeg. |
| * |
| * FFmpeg is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation; either |
| * version 2.1 of the License, or (at your option) any later version. |
| * |
| * FFmpeg is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with FFmpeg; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| /** |
| * @file |
| * aspect ratio modification video filter |
| */ |
| |
| #include "avfilter.h" |
| |
| typedef struct { |
| AVRational aspect; |
| } AspectContext; |
| |
| static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque) |
| { |
| AspectContext *aspect = ctx->priv; |
| double ratio; |
| int64_t gcd; |
| |
| if(args) { |
| if(sscanf(args, "%d:%d", &aspect->aspect.num, &aspect->aspect.den) < 2) { |
| if(sscanf(args, "%lf", &ratio) < 1) |
| return -1; |
| aspect->aspect = av_d2q(ratio, 100); |
| } else { |
| gcd = av_gcd(FFABS(aspect->aspect.num), FFABS(aspect->aspect.den)); |
| if(gcd) { |
| aspect->aspect.num /= gcd; |
| aspect->aspect.den /= gcd; |
| } |
| } |
| } |
| |
| if(aspect->aspect.den == 0) |
| aspect->aspect = (AVRational) {0, 1}; |
| |
| return 0; |
| } |
| |
| static void start_frame(AVFilterLink *link, AVFilterPicRef *picref) |
| { |
| AspectContext *aspect = link->dst->priv; |
| |
| picref->pixel_aspect = aspect->aspect; |
| avfilter_start_frame(link->dst->outputs[0], picref); |
| } |
| |
| #if CONFIG_ASPECT_FILTER |
| /* for aspect filter, convert from frame aspect ratio to pixel aspect ratio */ |
| static int frameaspect_config_props(AVFilterLink *inlink) |
| { |
| AspectContext *aspect = inlink->dst->priv; |
| |
| av_reduce(&aspect->aspect.num, &aspect->aspect.den, |
| aspect->aspect.num * inlink->h, |
| aspect->aspect.den * inlink->w, 100); |
| |
| return 0; |
| } |
| |
| AVFilter avfilter_vf_aspect = { |
| .name = "aspect", |
| .description = NULL_IF_CONFIG_SMALL("Set the frame aspect ratio."), |
| |
| .init = init, |
| |
| .priv_size = sizeof(AspectContext), |
| |
| .inputs = (AVFilterPad[]) {{ .name = "default", |
| .type = AVMEDIA_TYPE_VIDEO, |
| .config_props = frameaspect_config_props, |
| .get_video_buffer = avfilter_null_get_video_buffer, |
| .start_frame = start_frame, |
| .end_frame = avfilter_null_end_frame }, |
| { .name = NULL}}, |
| |
| .outputs = (AVFilterPad[]) {{ .name = "default", |
| .type = AVMEDIA_TYPE_VIDEO, }, |
| { .name = NULL}}, |
| }; |
| #endif /* CONFIG_ASPECT_FILTER */ |
| |
| #if CONFIG_PIXELASPECT_FILTER |
| AVFilter avfilter_vf_pixelaspect = { |
| .name = "pixelaspect", |
| .description = NULL_IF_CONFIG_SMALL("Set the pixel aspect ratio."), |
| |
| .init = init, |
| |
| .priv_size = sizeof(AspectContext), |
| |
| .inputs = (AVFilterPad[]) {{ .name = "default", |
| .type = AVMEDIA_TYPE_VIDEO, |
| .get_video_buffer = avfilter_null_get_video_buffer, |
| .start_frame = start_frame, |
| .end_frame = avfilter_null_end_frame }, |
| { .name = NULL}}, |
| |
| .outputs = (AVFilterPad[]) {{ .name = "default", |
| .type = AVMEDIA_TYPE_VIDEO, }, |
| { .name = NULL}}, |
| }; |
| #endif /* CONFIG_PIXELASPECT_FILTER */ |
| |