Since 5.3, BlackmagicMediaSource causes a memory leak. This didn't happen on 5.2.
You can see the leak on PIE.

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If "Just-In-Time Rendering" option in the MediaBundle is turned off, this memory leak seems to stop.

I checked this leak with MemPro and it shows the following callstuck causes the memory leak. 

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Steps to Reproduce
  1. Download the attached project
  2. Open it with UE5.3 or ue5-main.
  3. You need to set Blackmagic capture card to output a video.
  4. check that the MediaBundle in the scene correctly track the video from BlackMagicCaptureCard.
  5. display Stat PlatformMemory and run PIE.
  6. You can see that  Used Phsyicla/Virtual graduaaly increase.
  7. Turn off "Just-In-Time Rendering" option in the MediaBundle.
  8. You can see that the memory leak stops.

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ComponentUE - Virtual Production - IO - Media
Affects Versions5.3
Target Fix5.4
Fix Commit30136400
Main Commit30136415
CreatedOct 31, 2023
ResolvedDec 5, 2023
UpdatedFeb 23, 2024
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