From acf6e86c0fbb93e5c24d4f918a20dbcc6f8f4611 Mon Sep 17 00:00:00 2001
From: biggsbiggsby <33279473+biggsbiggsby@users.noreply.github.com>
Date: Tue, 14 Nov 2017 09:39:59 +0100
Subject: [PATCH 1/3] gif animation.jl

Change palette from png to gif to avoid png encoding bug in ffmpeg
---
 src/animation.jl | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/animation.jl b/src/animation.jl
index 8d3c0341..7faaa579 100644
--- a/src/animation.jl
+++ b/src/animation.jl
@@ -72,9 +72,9 @@ function buildanimation(animdir::AbstractString, fn::AbstractString,
 
     if is_animated_gif
         # generate a colorpalette first so ffmpeg does not have to guess it
-        run(`ffmpeg -v 0 -i $(animdir)/%06d.png -vf palettegen -y palette.png`)
+        run(`ffmpeg -v 0 -i $(animdir)/%06d.png -vf palettegen -y palette.gif`)
         # then apply the palette to get better results
-        run(`ffmpeg -v 0 -framerate $fps -loop $loop -i $(animdir)/%06d.png -i palette.png -lavfi paletteuse -y $fn`)
+        run(`ffmpeg -v 0 -framerate $fps -loop $loop -i $(animdir)/%06d.png -i palette.gif -lavfi paletteuse -y $fn`)
     else
         run(`ffmpeg -v 0 -framerate $fps -loop $loop -i $(animdir)/%06d.png -pix_fmt yuv420p -y $fn`)
     end

From cf58f3cbf238152d9a2b6b5199acb345588049dd Mon Sep 17 00:00:00 2001
From: biggsbiggsby <33279473+biggsbiggsby@users.noreply.github.com>
Date: Fri, 17 Nov 2017 10:30:23 +0100
Subject: [PATCH 2/3] Update animation.jl

Generates a color palette for each frame (instead of each animation) to improve quality, and avoid palette file format issues in FFMPEG 3.4
---
 src/animation.jl | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/src/animation.jl b/src/animation.jl
index 7faaa579..760a56d2 100644
--- a/src/animation.jl
+++ b/src/animation.jl
@@ -71,10 +71,9 @@ function buildanimation(animdir::AbstractString, fn::AbstractString,
     fn = abspath(fn)
 
     if is_animated_gif
-        # generate a colorpalette first so ffmpeg does not have to guess it
-        run(`ffmpeg -v 0 -i $(animdir)/%06d.png -vf palettegen -y palette.gif`)
-        # then apply the palette to get better results
-        run(`ffmpeg -v 0 -framerate $fps -loop $loop -i $(animdir)/%06d.png -i palette.gif -lavfi paletteuse -y $fn`)
+        # generate a colorpalette for each frame to improve quality
+        palette="palettegen=stats_mode=single[pal],[0:v][pal]paletteuse=new=1"
+        run(`ffmpeg -v 0 -framerate $fps -loop $loop -i $(animdir)/%06d.png -lavfi "$palette" -y $fn`)
     else
         run(`ffmpeg -v 0 -framerate $fps -loop $loop -i $(animdir)/%06d.png -pix_fmt yuv420p -y $fn`)
     end

From ee0f4e11ea1d81bbb08c1763c35d858bc105daf1 Mon Sep 17 00:00:00 2001
From: biggsbiggsby <33279473+biggsbiggsby@users.noreply.github.com>
Date: Fri, 17 Nov 2017 12:35:36 +0100
Subject: [PATCH 3/3] Update animation.jl

Changed palette for each frame to an option, made the default palette a lossless bmp file for best quality/filesize, but still compatible with FFMPEG 3.4 on Win7 x64
---
 src/animation.jl | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/src/animation.jl b/src/animation.jl
index 760a56d2..93f28427 100644
--- a/src/animation.jl
+++ b/src/animation.jl
@@ -67,13 +67,21 @@ mp4(anim::Animation, fn = mp4fn(); kw...) = buildanimation(anim.dir, fn, false;
 
 function buildanimation(animdir::AbstractString, fn::AbstractString,
                         is_animated_gif::Bool=true;
-                        fps::Integer = 20, loop::Integer = 0)
+                        fps::Integer = 20, loop::Integer = 0,
+                        variable_palette::Bool=false)
     fn = abspath(fn)
 
     if is_animated_gif
-        # generate a colorpalette for each frame to improve quality
-        palette="palettegen=stats_mode=single[pal],[0:v][pal]paletteuse=new=1"
-        run(`ffmpeg -v 0 -framerate $fps -loop $loop -i $(animdir)/%06d.png -lavfi "$palette" -y $fn`)
+        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"
+            run(`ffmpeg -v 0 -framerate $fps -loop $loop -i $(animdir)/%06d.png -lavfi "$palette" -y $fn`)
+        else
+            # generate a colorpalette first so ffmpeg does not have to guess it
+            run(`ffmpeg -v 0 -i $(animdir)/%06d.png -vf "palettegen=stats_mode=diff" -y "$(animdir)/palette.bmp"`)
+            # then apply the palette to get better results
+            run(`ffmpeg -v 0 -framerate $fps -loop $loop -i $(animdir)/%06d.png -i "$(animdir)/palette.bmp" -lavfi "paletteuse=dither=sierra2_4a" -y $fn`)
+        end
     else
         run(`ffmpeg -v 0 -framerate $fps -loop $loop -i $(animdir)/%06d.png -pix_fmt yuv420p -y $fn`)
     end