h264 Encoder Pixelating frames on output

[dm.roman]

Hi folks,

Have a weird one I haven't seen before and curious if anyone else has run into it. I'm exporting a clip, and the export is showing a few frames of pixelation/degradation that does not exist in the timeline or source media (the same exact clip was rendering out fine for about two weeks). The degradation is right at the head of the clip, lasts for 25 frames, and then the clip corrects itself. 

Tried a bunch of different fixes – rendering with and without previews, new project, new sequence, cleared the render files, cleared the media cache, triple-checked all my sequence settings to match the output, and still getting this weird degradation.

The thing is that it doesn't happen when I export ProRes. So, I rendered out a ProRes 4444 of the clip that did not pixel out and dropped it natively into Media Encoder with base-level "YouTube 1080" settings with everything set to match, and the pixelation still pops up on the output. Again, this started happening randomly after two weeks of rendering out without issue. The stills attached are about 10 frames apart on the same clip. Any thoughts?

Appreciate it!

[Justin Taylor-Hyper Brew]

Could be an issue with an effect or transition between frames during compression. If the ProRes looks fine, try transcoding that into an H.264 and see if that issue goes away.

[JOHN MONDO · Accepted solution]

Try software rendering only the ProRes clip (or the PP timeline) - for my money it's an H264 Encoder fault in media encoder. For this reason I'd revert to software encoding.

[samz14242260]

I'm having the exact same issue!

Have you found a solution for this?

Sam

[pimiento]

I HAVE THE SAME PROBLEM with my mac studio m1 max

the only thing that works is changing the encoding from HARDWARE to SOFTWARE, which makes no sense! 

is it a bug from adobe or somethign that's not working properly on my mac?

[SMWhitehead]

For anyone still finding this (like me) - i've found making sure it is set to Max Render Quality & Render At Maximum Depth along with upping the bitrate a little c. 10Mbps fixed it - it's almost a bottle neck in the H.264 encoding for me

[Harold Silva]

Aunque es algo extraño, te sugiero que exportes en VBR 2 pases y aun bitrate de 20mbps
Alguna vez me pasó algo similar y esta fue la manera en que pude corregir.
Nos avisas si se pudo solucionar.
Saludos cordiales

[catsnake]

I had the exact same problem after exporting some footage that had some color grading done along with some filters and in parts it pixelated badly with .h264. The fix was to save as .mpg. File was smaller and pixelation all gone. 

[magdalenah]

This has happened to me quite a lot recently. I found that using software encoding instead of hardware encoding does the trick for me.