add a precompile workload (#384)

Project.toml

@@ -13,6 +13,7 @@ ImageCore = "a09fc81d-aa75-5fe9-8630-4744c3626534"
 Libdl = "8f399da3-3557-5675-b5ff-fb832c97cbdb"
 ProgressMeter = "92933f4c-e287-5a05-a399-4b506db050ca"
 Requires = "ae029012-a4dd-5104-9daa-d747884805df"
+SnoopPrecompile = "66db9d55-30c0-4569-8b51-7e840670fc0c"
 
 [compat]
 ColorTypes = "0.9, 0.10, 0.11"
@@ -23,4 +24,5 @@ Glob = "1.2"
 ImageCore = "0.8, 0.9"
 ProgressMeter = "1.2"
 Requires = "1.0"
+SnoopPrecompile = "1"
 julia = "1.6"

src/VideoIO.jl

@@ -5,6 +5,7 @@ using Requires, Dates, ProgressMeter
 using ImageCore: channelview, rawview
 using ColorTypes: RGB, Gray, N0f8, N6f10, YCbCr, Normed, red, green, blue
 using FileIO: File
+using SnoopPrecompile
 
 using Base: fieldindex, RefValue, cconvert
 using Base.GC: @preserve
@@ -193,6 +194,26 @@ function __init__()
     end
 end
 
+@precompile_setup begin
+    imgstack = map(_->rand(UInt8, 10, 10), 1:10)
+    @precompile_all_calls begin
+        fname = string(tempname(), ".mp4")
+        VideoIO.save(fname, imgstack)
+        VideoIO.save(fname, VideoIO.load(fname)) # the loaded video is RGB type
+        r = openvideo(fname)
+        img = read(r)
+        eof(r)
+        read!(r, img)
+        seekstart(r)
+        seek(r, 0.01)
+        skipframe(r)
+        skipframes(r, 3)
+        gettime(r)
+        counttotalframes(r)
+        close(r)
+    end
+end
+
 """
 VideoIO supports reading and writing video files.