Blackmagic Forum

Hi Guys

I'm loading in an MP4 file via a loader. The file is a 1080p H264 MPEG-4 AVC (part10) (avc1) file. I tried directly from my NAS but also tried locally on my M2 drive.

When I play back the file, or scrub it by using the arrow keys, it appears its missing frames and not displaying frame by frame. I've set the loader's "missing frames" option to Output Color so I can better see visually where frames are missing.

My point is, why is this happening in the 1st place, why is it not loading or caching the entire file, even after scrubbing/playing through the entire file?

I need to comp CG elements over this MP4 file, but hard to work if every 5th frame the MP4 suddenly does not display a paticular frame.

My system is:
AMD Ryzen 9 5950X
128GB Ram
RTX 3090
2 X Samsung 980 Pro Drives (1 for OS and 1 for Video Cache)

You're probably better off converting your file first before working with it in Fusion.
Mp4 is meant as a delivery format and doesn't store frames for every frame.

If you go through an mp4 at random, frames have to be reconstructed sometimes from 10-15 frames earlier. This is probably what you're encountering.

Fusion works best with image sequences where every frame is indeed a seperate frame.

That is just rediculous behaviour

Any other app does this just fine. AE/Premier for example has no problem with MP4 files even 4K files.