Twitching output quality Big Sur Imac

[viitah]

Hi,

my video output quality is poor, with a delay / twitching phenomena. I am using H264 video material, frame rate 25 and Full HD. My computer is a 2021 Imac with Big Sur.

What to do?

[ProjectileObjects]

I’d first recommend exporting one or more of your clips into the HAP codec and seeing if the playback issue goes away.

If you want to use H.264 you’ll have to make sure that all of your clips have a key frame for every frame. If not, then your computer has to interpret the data and make a frame on the fly.

More on that here:

HELP - HAP workflow with M1 and Intel in Premiere and VDMX

Yes, 100%. H.264 can be a nasty format for older machines, but many newer machines have the ability for some sort of hardware H.264 decoding. With that said, when an H.264 video is created, to squeeze out a smaller file size, some frames are full images (key frames (or i Frames)), and others are B frames or P frames (predictive frames, compressed data, not a full image). P frames and B frames are resource heavy when decoding. And when you jump to random parts of your video clip, if you jump…

As for the output quality, what is your output composition resolution set to?

If you use a built in ISF shader is the quality better?

Please share photos or videos if you can.

[viitah]

Thanks for your reply.

I did convert my files to HAP and that makes the output somewhat smoother. The files are quite large (some of them 11 min long) so I’ m not sure whether that causes some of the problems.

I am not using an ISF shader (not familiar with one).

The resolution of the output is se to HD 16:9 images, ie 1920 x 1080 frames.

[viitah]

I am unable to send screen recorded video material at the very moment, if the problem remains, I will try and get that done for further help / query