Dan, you are absolutely right. I am totally confused about the Project’s Video Mode and how it relates to the Export video settings.
I changed the Project’s Video Mode because my editing playback crashes, stops, loses video and garbles the audio. I blame my slow PC, not Shotcut for all this. So I thought dumbing down the Video Mode would fix the editing playback issues. This was based on my understanding that the video attributes of the Project were independent of the final export file attributes.
Looks like I was very wrong.
Time to do some reading…
Video messed up after changing video mode
After changing video mode, exported video is half length
Video mode what will happen if I change it after well into a project?
Export file doesn’t match timeline
OK, so moral of the story is NEVER use AUTOMATIC Video Mode. When you do, the entire Project’s Video Mode is based upon the attributes of the first source video you import. And if you first import an audio clip still image, you’re toast. So don’t leave it up to chance, pick a mode that matches the attributes of the video you want to export/render.
Specifically, if your project is using 30 fps and you change to 60 fps then the video playback will be twice as fast. And if your project is 4K and you change it to 1080p, then some of the effects that key off pixel location (like Text) will be shifted around.
But I still don’t understand why changing the Project’s Video Mode resolution but leaving the same FPS (which also matches the FPS of the source videos) is causing the encoding (also at 30 fps) to be so screwy. And my first video source file was the same as my project so changing it to something else and changing it back should have been OK.