[HELP] Vapoursynth: core.imwri.Read on Windows 10 is extremely slow

[Selur]

What I did:

• create image sequence:
  
  ffmpeg.exe -r 1 -i "path to test file"  -r 1 e:\testing\%06d.png
  that created 159491 images.
  
• start Hybrid
  
• enable Base->Image sequence
  
• open the file open dialog
  
• press 1st frame and select the first frame
  
• press last frame and select the first frame
  
• Close 'Image sequence'-dialog by pressing 'Accept'
  
• checking the Vapoursynth Script View:
  
  # Imports
import vapoursynth as vs
# getting Vapoursynth core
core = vs.core
# Loading Plugins
core.std.LoadPlugin(path="I:/Hybrid/64bit/vsfilters/Support/libimwri.dll")
# source: 'E:/testing/000001.png'
# current color space: RGB24, bit depth: 8, resolution: 720x302, fps: 25, color matrix: 709, yuv luminance scale: full, scanorder: progressive
# Loading E:\testing\%06d.png using vsImageReader
clip = core.imwri.Read("E:/testing/%06d.png", firstnum=1)
clip = core.std.Trim(clip=clip, length=159491)
# Input color space is assumed to be RGB24
# making sure frame rate is set to 25
clip = core.std.AssumeFPS(clip=clip, fpsnum=25, fpsden=1)
# Setting color range to PC (full) range.
clip = core.std.SetFrameProp(clip=clip, prop="_ColorRange", intval=0)
# adjusting output color from: RGB24 to YUV420P10 for x265Model
clip = core.resize.Bicubic(clip=clip, format=vs.YUV420P10, matrix_s="709", range_s="full")
# set output frame rate to 25.000fps
clip = core.std.AssumeFPS(clip=clip, fpsnum=25, fpsden=1)
# Output
clip.set_output()
• Start Vapoursynth Preview
  After ~6 seconds (counted in my head), the dialog opened. (closing and opening the Vapoursynth Preview again took the same time; may be it was even a bit faster)
  

-> Can't reproduce the issue you describe here. Harddrive the images lay on, was a WD40EZRX (https://products.wdc.com/library/SpecShe...771438.pdf), which I normally use for storage.
I tested this on a Windows 11 machine, neither RAM or CPU usage were high by any means.

So my guess is that this is an issue with your system.

- core.imwri.Read is extremely slow to start processing files... once it starts processing files, then it runs normally, at expected speed.

My guess is a virus scanner or something similar is slowing down the processing.


Cu Selur