Userscripts.org

When both "FLV High Quality" and "MPEG H.264" options are available, the script will select the "FLV High Quality" option even though the "MPEG H.264" format is better. The setting is set to "Best Quality".

FLV High Quality IS better than MPEG H.264. Try comparing both with the same vid.

I actually have the exact opposite issue. It keeps picking MP4 SD and I have to select FLV HQ manually every time.

I've already addressed the issue in the 1080p thread
http://userscripts.org/topics/38520
18< 34< 35 they are all H.264 and AAC-LC audio now

18 Baseline @L2.1 480x270 270p mp4 low (i think)
34 Main @L3.0 640x360 360p new flv standard if you set play higher quality
35 Main @L3.1 854x480 480p HQ FLV

profiles in terms of quality
Baseline < Main < High < Auto/guess/unconstrained
baseline profile means it leaves out certain functions in the encoding and decoding so 18 is the worst quality

2.0-3.0-3.1
hints at the maximum amount of bit rate per a second
levels go from 1-5.1 to unconstrained which will be really hard on the cpu

As you go up from baseline to high profile and from 1 to 5.1 it becomes harder on the cpu but better quality and variance in bit rate fun fact :)

I forget how he originally named it in the script but i changed that first thing as it confused me