From 77a72d348519584bac1499210619ea38adead130 Mon Sep 17 00:00:00 2001
From: Nicolas George <nicolas.george@normalesup.org>
Date: Thu, 25 Oct 2012 17:58:08 +0200
Subject: [PATCH] lavfi/vf_fps: allow to set the rounding method.
By default, fps selects frames near PTS 0, 0.5, 1.5, 2.5, etc.
With round=down, it selects the frames near PTS 0, 1, 2, 3, etc.
---
doc/filters.texi | 3 +++
libavfilter/vf_fps.c | 11 +++++++++--
2 files changed, 12 insertions(+), 2 deletions(-)
diff --git a/doc/filters.texi b/doc/filters.texi
index adec96ef394..93fdcec39fc 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -2186,6 +2186,9 @@ This filter accepts the following named parameters:
@item fps
Desired output framerate.
+@item round
+Rounding method. The default is @code{near}.
+
@end table
@section framestep
diff --git a/libavfilter/vf_fps.c b/libavfilter/vf_fps.c
index 114b06241f5..d9eedc8b31b 100644
--- a/libavfilter/vf_fps.c
+++ b/libavfilter/vf_fps.c
@@ -46,6 +46,7 @@ typedef struct FPSContext {
AVRational framerate; ///< target framerate
char *fps; ///< a string describing target framerate
+ int rounding; ///< AVRounding method for timestamps
/* statistics */
int frames_in; ///< number of frames on input
@@ -59,6 +60,12 @@ typedef struct FPSContext {
#define F AV_OPT_FLAG_FILTERING_PARAM
static const AVOption fps_options[] = {
{ "fps", "A string describing desired output framerate", OFFSET(fps), AV_OPT_TYPE_STRING, { .str = "25" }, .flags = V|F },
+ { "round", "set rounding method for timestamps", OFFSET(rounding), AV_OPT_TYPE_INT, { .i64 = AV_ROUND_NEAR_INF }, 0, 5, V|F, "round" },
+ { "zero", "round towards 0", OFFSET(rounding), AV_OPT_TYPE_CONST, { .i64 = AV_ROUND_ZERO }, 0, 5, V|F, "round" },
+ { "inf", "round away from 0", OFFSET(rounding), AV_OPT_TYPE_CONST, { .i64 = AV_ROUND_INF }, 0, 5, V|F, "round" },
+ { "down", "round towards -infty", OFFSET(rounding), AV_OPT_TYPE_CONST, { .i64 = AV_ROUND_DOWN }, 0, 5, V|F, "round" },
+ { "up", "round towards +infty", OFFSET(rounding), AV_OPT_TYPE_CONST, { .i64 = AV_ROUND_UP }, 0, 5, V|F, "round" },
+ { "near", "round to nearest", OFFSET(rounding), AV_OPT_TYPE_CONST, { .i64 = AV_ROUND_NEAR_INF }, 0, 5, V|F, "round" },
{ NULL },
};
@@ -206,8 +213,8 @@ static int end_frame(AVFilterLink *inlink)
}
/* number of output frames */
- delta = av_rescale_q(buf->pts - s->pts, inlink->time_base,
- outlink->time_base);
+ delta = av_rescale_q_rnd(buf->pts - s->pts, inlink->time_base,
+ outlink->time_base, s->rounding);
if (delta < 1) {
/* drop the frame and everything buffered except the first */
--
GitLab