I'm streaming StarCraft II on Linux using ffmpeg (Intel corei7 920 CPU). I'm trying to find the appropriate knobs to turn for the x264 encoder to get decent quality with only 500 kbps upload to spare for the purpose.
I'm currently using these options:
-strict experimental -vcodec libx264 -threads 4 -profile:v main -preset:v fast -tune:v zerolatency -x264opts crf=25:bitrate=500:fps=15
-acodec aac -ar 22050 -ab 32k -vol 1365
-f flv "rtmp://live.justin.tv/app/$STREAMING_KEY"
The `-tune:v zerolatency` is a last resort measure, as I understand it, as it basically kills any opportunity to properly compress the stream. I get really low quality on the twitch.tv stream. [This also overrides some of the options I specify later, as I understand it.]
The settings  I've tried playing with have either (a) looked just as bad as -tune:v zerolatency or (b) caused noticeable lag in the game. Can someone give me some help getting this figured out?