Skip to main content
R
rgr2
Inspiring
June 16, 2026

Bad reading of H265 lossless files with open-GOP.

  • June 16, 2026
  • 1 reply
  • 12 views

After Effects (and probably Premiere too) incorrectly reads frames in an H265 lossless encoded video file with open-GOP.
It skips some frames and the file sees several frames shorter than it actually is.

1 reply

Nishu Kushwaha
Community Manager
Nishu KushwahaCommunity Manager
Community Manager
June 17, 2026

Hi there,

 

Thanks for reporting this. Can you share the following details:

1. Your exact After Effects version and OS.
2. What is the source of the media?
3. The exact frame count: what the file should have vs what AE reports.
4. If possible, a short sample of the affected file so engineering can reproduce locally. Feel free to DM if you'd rather not share publicly.

The details above will help us understand the issue properly.

 

Thanks,

Nishu

R
rgr2Author
Inspiring
June 20, 2026
  1. Version 26, Windows 10.
  2. H265 lossless with open-GOP turned on.
  3. After Effects reports a few frames fewer than there actually are.
  4. The file is too large to send (60GB), but you can create it yourself using ffmpeg. Each frame will receive its own number. 
    ffmpeg -f lavfi -i testsrc2=duration=600:size=1920x1080:rate=60 -c:v libx265 -x265-params lossless=1 -pix_fmt yuv444p12 output_h265_lossless_open_gop.mp4
Firefly Community Gallery
Adobe Firefly

Remix with Firefly Community Gallery

Thousands of free creations to fall in love with and remix in Firefly.

Explore now
Terms & ConditionsAccessibility statement
Using the community Terms of use Privacy Cookie preferences Do not sell or share my personal information ad choicesAdChoices