animation fixes: show for videos, imagemagick init

src/animation.jl

@@ -53,21 +53,29 @@ immutable AnimatedGif
     filename::String
 end
 
+file_extension(fn) = Base.Filesystem.splitext(fn)[2][2:end]
+
 gif(anim::Animation, fn = giffn(); kw...) = buildanimation(anim.dir, fn; kw...)
 mov(anim::Animation, fn = movfn(); kw...) = buildanimation(anim.dir, fn; kw...)
 mp4(anim::Animation, fn = mp4fn(); kw...) = buildanimation(anim.dir, fn; kw...)
 
+const _imagemagick_initialized = Ref(false)
+
 function buildanimation(animdir::AbstractString, fn::AbstractString;
                         fps::Integer = 20, loop::Integer = 0)
     fn = abspath(fn)
     try
-    # high quality
-    speed = round(Int, 100 / fps)
+        if !_imagemagick_initialized[]
             file = joinpath(Pkg.dir("ImageMagick"), "deps","deps.jl")
             if isfile(file) && !haskey(ENV, "MAGICK_CONFIGURE_PATH")
                 include(file)
             end
+            _imagemagick_initialized[] = true
+        end
+
         # prefix = get(ENV, "MAGICK_CONFIGURE_PATH", "")
+        # high quality
+        speed = round(Int, 100 / fps)
         run(`convert -delay $speed -loop $loop $(joinpath(animdir, "*.png")) -alpha off $fn`)
 
     catch err
@@ -88,7 +96,14 @@ end
 
 # write out html to view the gif... note the rand call which is a hack so the image doesn't get cached
 function Base.show(io::IO, ::MIME"text/html", agif::AnimatedGif)
-    write(io, "<img src=\"$(relpath(agif.filename))?$(rand())>\" />")
+    ext = file_extension(agif.filename)
+    write(io, if ext == "gif"
+        "<img src=\"$(relpath(agif.filename))?$(rand())>\" />"
+    elseif ext in ("mov", "mp4")
+        "<video controls><source src=\"$(relpath(agif.filename))?$(rand())>\" type=\"video/$ext\"></video>"
+    else
+        error("Cannot show animation with extension $ext: $agif")
+    end)
 end