Summary

From NTSC 3:2 pulldown movie, bad field temporal order when encoded in H264.

Steps to reproduce

1. Quick project
2. Open a 3:2 pulldown movie, let it encode with h264-mp4
3. Trigger and stop after hundreds of frame
4. Output is h264 interlaced. When deinterlacing with any external player (mpv, vlc), stuttering is visible, field order is like 2 1 4 3 6 5...

Expected behavior

strictly monotonous field order : 1 2 3 4 5 6....

Actual behavior

reversed field order : 2 1 3 4 6 5...

Environment

• OS: Ubuntu 24.04, nix build
• Build/commit: 07ae194
• Component: orc-core

Observations

• Such issue doesn't exist with ffv1 sink format
• Issue doesn't depend on ntsc chroma decoder, mono also fails.