From caca1b2e3c56cad4a9107e6dc7ac2a3483a39e35 Mon Sep 17 00:00:00 2001
From: Iain Skett <iain.skett@gmail.com>
Date: Tue, 8 Oct 2019 00:17:21 +0100
Subject: [PATCH] Generalise fps to support fractional arguments (rational or
 float) as well as integer.

---
 src/animation.jl | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/src/animation.jl b/src/animation.jl
index 7d55b567..aa8fe78e 100644
--- a/src/animation.jl
+++ b/src/animation.jl
@@ -64,10 +64,12 @@ gif(anim::Animation, fn = giffn(); kw...) = buildanimation(anim, fn; kw...)
 mov(anim::Animation, fn = movfn(); kw...) = buildanimation(anim, fn, false; kw...)
 mp4(anim::Animation, fn = mp4fn(); kw...) = buildanimation(anim, fn, false; kw...)
 
+ffmpeg_framerate(fps) = "$fps"
+ffmpeg_framerate(fps::Rational) = "$(fps.num)/$(fps.den)"
 
 function buildanimation(anim::Animation, fn::AbstractString,
                         is_animated_gif::Bool=true;
-                        fps::Integer = 20, loop::Integer = 0,
+                        fps::Real = 20, loop::Integer = 0,
                         variable_palette::Bool=false,
                         show_msg::Bool=true)
     if length(anim.frames) == 0
@@ -76,20 +78,21 @@ function buildanimation(anim::Animation, fn::AbstractString,
 
     fn = abspath(expanduser(fn))
     animdir = anim.dir
+    framerate = ffmpeg_framerate(fps)
 
     if is_animated_gif
         if variable_palette
             # generate a colorpalette for each frame for highest quality, but larger filesize
             palette="palettegen=stats_mode=single[pal],[0:v][pal]paletteuse=new=1"
-            ffmpeg_exe(`-v 0 -framerate $fps -loop $loop -i $(animdir)/%06d.png -lavfi "$palette" -y $fn`)
+            ffmpeg_exe(`-v 0 -framerate $framerate -loop $loop -i $(animdir)/%06d.png -lavfi "$palette" -y $fn`)
         else
             # generate a colorpalette first so ffmpeg does not have to guess it
             ffmpeg_exe(`-v 0 -i $(animdir)/%06d.png -vf "palettegen=stats_mode=diff" -y "$(animdir)/palette.bmp"`)
             # then apply the palette to get better results
-            ffmpeg_exe(` -v 0 -framerate $fps -loop $loop -i $(animdir)/%06d.png -i "$(animdir)/palette.bmp" -lavfi "paletteuse=dither=sierra2_4a" -y $fn`)
+            ffmpeg_exe(` -v 0 -framerate $framerate -loop $loop -i $(animdir)/%06d.png -i "$(animdir)/palette.bmp" -lavfi "paletteuse=dither=sierra2_4a" -y $fn`)
         end
     else
-        ffmpeg_exe(`-v 0 -framerate $fps -loop $loop -i $(animdir)/%06d.png -pix_fmt yuv420p -y $fn`)
+        ffmpeg_exe(`-v 0 -framerate $framerate -loop $loop -i $(animdir)/%06d.png -pix_fmt yuv420p -y $fn`)
     end
 
     show_msg && @info("Saved animation to ", fn)