QTCodex in v12

I have different problems with codex .mp4, or .mov with h264 and errors like qtcodex error creating frame. After trying again it works with one clip, and other clips with same codex don't work...?

System is intel i5, nvidia quadro 600, 16 GB Ram, Win7 64bit, all videos play with vlc and media player without problems.

Also resolve is very slow, if you put a ~30 minutes clip on the edit timeline, it seems because creating the preview images...?

Quicktime is not a codec, it is a wrapper and API or as Apple calls them, framework/foundation.

mov's can house one of several codecs.

Try installing the Quicktime player for Windows and see if that helps. If not, go back to Resolve 11.

Good Fortune,
Robert