Memory leak with open_video_out

[yakir12]

When encoding a video with large frames, Julia crashes because the system runs out of memory.
I made the following MWE to illustrate this (I stole @yiyuezhuo get_memory_usage function from this gist, thank you yiyuezhuo!)

using VideoIO, ColorTypes, FixedPointNumbers
function get_memory_usage()
    open("/proc/$(getpid())/statm") do io
      parse(Int, split(read(io, String))[1])
    end            
end
n = 20
y = zeros(Int, n)
sz = (3840, 2*2160)
frame = rand(RGB{N0f8}, sz)
encoder_options = (crf=23, preset="medium")
framerate = 300
open_video_out("video.mp4", frame, framerate=framerate, encoder_options=encoder_options) do writer
  for i in 1:n
    frame = rand(RGB{N0f8}, sz)
    write(writer, frame)
    y[i] = get_memory_usage()
  end
end
using UnicodePlots
lineplot(y)

which looks like this:

          ┌────────────────────────────────────────┐ 
  2100000 │⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢀⠔⠊⠉│ 
          │⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢀⠤⠤⠃⠀⠀⠀│ 
          │⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣀⡔⠁⠀⠀⠀⠀⠀⠀│ 
          │⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢀⠔⠉⠀⠀⠀⠀⠀⠀⠀⠀⠀│ 
          │⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⡠⠔⠒⠃⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀│ 
          │⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣀⣀⠎⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀│ 
          │⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⡠⠊⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀│ 
          │⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⡠⠒⠊⠁⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀│ 
          │⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣀⠤⠎⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀│ 
          │⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⡠⠊⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀│ 
          │⠀⠀⠀⠀⠀⠀⠀⠀⢀⠔⠊⠉⠁⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀│ 
          │⠀⠀⠀⠀⠀⢀⠤⠔⠃⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀│ 
          │⠀⠀⠀⠀⡔⠁⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀│ 
          │⠀⠀⠔⠉⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀│ 
  1700000 │⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀│ 
          └────────────────────────────────────────┘ 
          ⠀0⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀20⠀ 

[IanButterworth]

What if you put a gc safepoint in the loop?

[yakir12]

Sorry, I forgot to mention I already tried that. I added

Base.GC.gc()

to the loop but it didn't have any affect. Maybe "gc safepoint" refers to something else?

[IanButterworth]

I mean GC.safepoint() but what you did is the more explicit option to test the same thing.

Is the memory still retained after close and a sleep?

[yakir12]

Not sure what exactly you mean by close and sleep, but if I have more than 20 frames in the example above then Julia crashes and the memory is released. If I am careful and use only 20 frames, then the memory isn't released before I exit that Julia session.

[yakir12]

Not sure what exactly you mean by close and sleep, but if I have more than 20 frames in the example above then Julia crashes and the memory is released. If I am careful and use only 20 frames, then the memory isn't released before I exit that Julia session.

[IanButterworth]

I see the same and it's freed after close and GC

julia> begin
           n = 20
           y = zeros(Int, n)
           sz = (3840, 2*2160)
           frame = rand(RGB{N0f8}, sz)
           encoder_options = (crf=23, preset="medium")
           framerate = 300
           open_video_out("video.mp4", frame, framerate=framerate, encoder_options=encoder_options) do writer
               for i in 1:n
                   write(writer, frame)
                   @show Base.format_bytes(get_memory_usage())
               end
           end
           @show Base.format_bytes(get_memory_usage())
           GC.gc()
           @show Base.format_bytes(get_memory_usage())
           nothing
       end
Base.format_bytes(get_memory_usage()) = "4.256 MiB"
Base.format_bytes(get_memory_usage()) = "4.286 MiB"
Base.format_bytes(get_memory_usage()) = "4.293 MiB"
Base.format_bytes(get_memory_usage()) = "4.322 MiB"
Base.format_bytes(get_memory_usage()) = "4.352 MiB"
Base.format_bytes(get_memory_usage()) = "4.347 MiB"
Base.format_bytes(get_memory_usage()) = "4.377 MiB"
Base.format_bytes(get_memory_usage()) = "4.407 MiB"
Base.format_bytes(get_memory_usage()) = "4.402 MiB"
Base.format_bytes(get_memory_usage()) = "4.431 MiB"
Base.format_bytes(get_memory_usage()) = "4.461 MiB"
Base.format_bytes(get_memory_usage()) = "4.456 MiB"
Base.format_bytes(get_memory_usage()) = "4.486 MiB"
Base.format_bytes(get_memory_usage()) = "4.516 MiB"
Base.format_bytes(get_memory_usage()) = "4.511 MiB"
Base.format_bytes(get_memory_usage()) = "4.540 MiB"
Base.format_bytes(get_memory_usage()) = "4.570 MiB"
Base.format_bytes(get_memory_usage()) = "4.565 MiB"
Base.format_bytes(get_memory_usage()) = "4.595 MiB"
Base.format_bytes(get_memory_usage()) = "4.624 MiB"
Base.format_bytes(get_memory_usage()) = "4.630 MiB"
Base.format_bytes(get_memory_usage()) = "1.005 MiB"

[yakir12]

So is this expected?

[galenlynch]

I can take a look at this

…

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