Adobe Media Encoder h.264 at low bit rates.

[x2x3x2]

I was wondering if anyone knew why AME does a relatively bad job when encoding h.264 at low bitrates.

For this particular example I'm encoding a source edited in Premiere to 480x272/29.97fps, target 320kbps, max 2mbps.
The issue in question is that there's very noticeable artifacting on keyframes. Tried longer intervals up to 300 between keyframes with similarly noticeable artifacting.

Contrast that to Xvid4PSP where encoding with h.264 at 480x272/29.97, 320kbps doesn't produce any noticeable artifacting at keyframes.

Any suggestions? Or is AME just plain bad at lower bitrates?
Of course I could just encode edited footage at high bitrates and then re-encode using Xvid4PSP but it'd be double work.

[lordsmurf]

AME is tweaked for professional use, and those bitrates are below normal use.

[x2x3x2]

I see, so what do you suggest the best option is for low bit rates? The 2-step encode with AME first then use Xvid4PSP/Handbrake/etc?
FYI the reason for this is because I'll be distributing the videos free online, as such size is a consideration.

[fitch.j]

If you want to do a 2 step encode don't export compressed from premiere. Use something like PNG in a MOV container so that you have an uncompressed file to work with for the second encode step, otherwise you'll just simply be doubling up on artifacts.

Those bitrates do seem low though even for web use.

[x2x3x2]

OK cool, thanks man I guess have to work with other encoders for low bit rates then.

Btw, on a somewhat related topic. I was checkin out some of the default settings for AME's h.264 settings.
The following seems abit odd to me, why is the target bitrates between 720p and 1080p so different?

HDTV 720p, 23.976fps, High Quality. Target bitrate 6Mbps, Maximum bitrate 10Mbps.
HDTV 1080p, 24fps, High Quality, Target bitrate 32Mbps, Maximum bitrate 40Mbps.

Obviously there's no way 1080p frames have over 5x the info compared to 720p frames.
Yet they are both labeled as "High Quality" level by AME. Wonder how Adobe related their so-called quality settings to these kinda bitrates?

[lordsmurf]

Industry standard settings in broadcasting.