VapourSynth ProRes crashing

[r3dfx]

Hi!
For some reason VapourSynth's viewer and subsequent encoding crashes with ProRes source from AJA's ControlRoom (Hybrid 2025.05.18.2)

   

[Selur]

AFK atm. did you try another source filter? I.e. BestSource?

[r3dfx]

This actually fixes the problem, but I don't quite understand why..

[Selur]

BestSource uses a newer libav library as source and that propably fixed some problem related to the format or container.

Cu Selur

[r3dfx]

Sorry for being kinda off-topic, but how to properly convert 10bit->8bit footage?10 bits in ProRes are excessive for my use case (VHS) since SNR is pretty low
fmtconv inserted before QTGMC looks like a potential solution

[Selur]

Hybrid by default tries to only apply color changes when necessary.
Hybrid offers multiple ways to change the color space:

• 'Filtering->Vapoursynth->Misc->Source->Convert to target color space after source' will convert to the output color format directly after loading the source.
  
• For most filters under "Filtering->Vapoursynth" with "Filtering->Vapoursynth->Misc->UI->Show 'Gimmick'-controls" enabled, you can:
  • Convert to a specific color, or
    
  • Restrict the bit depth
    
  
  
• You can always add custom code in a 'Custom'-section before some Filter. (note that the filter does not have to be used, this is about the filter position in the filter order)
  In case of wanting a specific color space, you could even let Hybrid do it by entering:
  
  # requires colorformat YUV422P8
  Hybrid would then add something like:
  
  # defining beforeDeCross-function - START
def beforeDeCross(clip):
  # requires colorformat YUV422P8
  return [clip]
# defining beforeDeCross-function - END
...
# adjusting color format to YUV422P8 for custom section
clip = core.resize.Bicubic(clip=clip, format=vs.YUV422P8, range_in_s="limited")
[clip] = beforeDeCross(clip)
  to the script and thus you could force a specific color space even before the deinterlacing.
  You could also use fmtc in such a 'Custom'-section. If you change the color format make sure to let Hybrid know you did so.
  

  Insert before:
  Select the position the custom script addition should be inserted before.
  
  
  In custom sections you can use:
  - '# scantype <tff|bff|telecine|progressive>' to let Hybrid know that the scan type changed.
  - '# colorformat <YUV420P8|...YUV444P16|RGB24|..|RGBS>' to let Hybrid know the color format changed.
  -'# width <48-16384>' to let Hybrid know the width changed.
  -'# height <48-16384>' to let Hybrid know the height changed.
  -'# framerate <0.01-1000>' to let Hybrid know the frame rate changed.
  -'# colormatrix <Rec.709|FCC|Rec.601/470bg/470m|..|Chroma cl>' to let Hybrid know the color matrix changed.
  -'# requires mod <1-..>' to let Hybrid know the custom addition requires modX.
  -'# requires colorformat <YUV420P8|...YUV444P16|RGB24|..|RGBS>' to let Hybrid know the custom addition requires a specific color format.
  -'# requires colormatrix <Rec.709|FCC|Rec.601/470bg/470m|..|Chroma cl>' to let Hybrid know the custom addition requires a specific color matrix.
  
  - '# additional output <variablename> [, colorformat: <Vapoursynth>][, width: <48-16384>][, height: <48-16384>][, fps: <0.01-1000>][, colormatrix: <Rec.709|FCC|Rec.601/470bg/470m|..|Chroma cl>][, yuvluminancescale: <limited|full>][, scanorder: <progressive|tff|bff|telecine>]' add an additional output with characteristics, all not specified characteristics will be copied from the current variable
  Hybrid will also replace:
  - %FILTERPATH% with the current filter base path
  - %SCRIPTPATH% with the current script base path

  (tool-tip of 'Insert before')
  

Cu Selur

[r3dfx]

Thank you so much for the detailed explanation!