h264 files causing blocking?

[JaredSMark]

I rendered some lower 3rds out of After Effects (Pro Res) and the master files are fine, but when I compress to an h264 file something weird happens. The lower 3rd is a circular object that's a solid color with text on the top of it, and while it's fine in a Pro Res format, at certain points in time I'm seeing these weird thick lines or blocking going on with an h264. I should probably get some screenshots but I'm not at my work computer at the moment.

I tried rendering out of multiple programs (Premiere and Handbrake) but both give me the exact same thing. h264 files don't seem to want to handle big portions of solid colors, or something. Does anyone know what may be causing this?

 

[Andrius Simutis]

h264 is a lossy codec. The space savings has to come from somewhere and you're seeing it in your graphics. Try compressing with a higher bit rate.