ffmpeg/libavfilter/vf_aspect.c

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/*
* 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 filters
*/
#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;
char c = 0;
if (args) {
if (sscanf(args, "%d:%d%c", &aspect->aspect.num, &aspect->aspect.den, &c) != 2)
if (sscanf(args, "%lf%c", &ratio, &c) == 1)
aspect->aspect = av_d2q(ratio, 100);
if (c || aspect->aspect.num <= 0 || aspect->aspect.den <= 0) {
av_log(ctx, AV_LOG_ERROR,
"Invalid string '%s' for aspect ratio.\n", args);
return AVERROR(EINVAL);
}
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};
av_log(ctx, AV_LOG_INFO, "a:%d/%d\n", aspect->aspect.num, aspect->aspect.den);
return 0;
}
static void start_frame(AVFilterLink *link, AVFilterBufferRef *picref)
{
AspectContext *aspect = link->dst->priv;
picref->video->sample_aspect_ratio = aspect->aspect;
avfilter_start_frame(link->dst->outputs[0], picref);
}
#if CONFIG_SETDAR_FILTER
/* for setdar filter, convert from frame aspect ratio to pixel aspect ratio */
static int setdar_config_props(AVFilterLink *inlink)
{
AspectContext *aspect = inlink->dst->priv;
AVRational dar = aspect->aspect;
av_reduce(&aspect->aspect.num, &aspect->aspect.den,
aspect->aspect.num * inlink->h,
aspect->aspect.den * inlink->w, 100);
av_log(inlink->dst, AV_LOG_INFO, "w:%d h:%d -> dar:%d/%d sar:%d/%d\n",
inlink->w, inlink->h, dar.num, dar.den, aspect->aspect.num, aspect->aspect.den);
inlink->sample_aspect_ratio = aspect->aspect;
return 0;
}
AVFilter avfilter_vf_setdar = {
.name = "setdar",
.description = NULL_IF_CONFIG_SMALL("Set the frame display aspect ratio."),
.init = init,
.priv_size = sizeof(AspectContext),
.inputs = (AVFilterPad[]) {{ .name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.config_props = setdar_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_SETDAR_FILTER */
#if CONFIG_SETSAR_FILTER
/* for setdar filter, convert from frame aspect ratio to pixel aspect ratio */
static int setsar_config_props(AVFilterLink *inlink)
{
AspectContext *aspect = inlink->dst->priv;
inlink->sample_aspect_ratio = aspect->aspect;
return 0;
}
AVFilter avfilter_vf_setsar = {
.name = "setsar",
.description = NULL_IF_CONFIG_SMALL("Set the pixel sample aspect ratio."),
.init = init,
.priv_size = sizeof(AspectContext),
.inputs = (AVFilterPad[]) {{ .name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.config_props = setsar_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_SETSAR_FILTER */