Help me, I've been looking in all the Internet and I seem to be the only person in the world with this problem.
I'm doing a project in cs5.5 in 600x340 and I noticed that the playback after rendering (with the green line) is all wrong. The quality of the video gets worse, the image is a bit flattened and a BLACK BAR appears on the bottom half of the playback monitor. When I export, the black bar is not there, but the quality is still bad. This happens in both my computers but it doesn't happen when working with native resolution (1080p, 720p...)
I have tried changing all settings in sequence and rendering and the only thing that kinda fixes it is using custom settings and changing "I-Frame only mpeg" to any other. But if I render with P2, my computer is extremely low.
Here is proof:
good (unrendered, red line)
bad (green line, in this computer there are black bars on the side too for some reason)
I know it's a weird problem, but I need to do this project in those dimensions and I simply want to know why the hell is it happening.
Edit your Project using a setting that matches your source footage.
Nest it in a project that suits your dimensions and make a scale change that works ( fits).