h.264 HD bitrates

[cicero]

I've been trying to get clean h.264 encodes of my HD recordings off my EyeTV 500 ever since Tiger came out. I have done tons of great SD encodes, but for some reason I just cant get smooth HD encodes.

I usually start with the traditional bit rate calc:

frame size * frame rate * codec factor

I use 0.15 for h.264 class encoders. So something like 1920*1080*29.97*0.15 = ~9Mbit/s.

I usually do the mpeg4 export option in EyeTV and pick h.264 and the above bit rate in the settings. I've had good luck with SD encodes using the streaming multi-pass setting, great looking small files. I've tried that with HD but there is a slight chop (jerky motion) in the playback, even though QT claims it's keep up with 30fps and activity monitor says I'm only using 60% of 2x 2.7GHz G5. I also noticed the final bit rate was around ~6Mbit/s. So I tried the other multi-pass settings and single pass at varying bit rates, and I always seem to have that slight chop on playback. Also, I normally do automatic key frame rate, but I've also tried 1 every 30 frames too and it doesn't seem to help.

Now that there's a version of ffmpegX out that can handle a proper h.264 mp4 file, I plan to give that a try.

Note that the original program stream plays smoothly and the 1080 files from the HD gallery on the QT site play perfectly as well.

Any recommendations out there?

Thanks!

[live4ever]

Definately try x264 codec in ffmpegX, QuickTime's implementation doesn't seem to work as well (I've only used it a couple times in an export from iMovie but found it to be slow and gave results that were subpar).

[cicero]

I'd just like to add that the latest update to QT (7.0.2) apparently has improvements to the h264 encoder. Using the same settings the chop is significantly less and barely noticable in the encodes I've done so far. I'm still working out some other settings and still looking into ffmpegX.