H.264 How do I Control/increase Bitrate?

[Daniel Low]

Oh, I didn’t doubt that they were probably re-coding it, I was just pointing out that high quality was possible at considerably lower rates than were being discussed.

Mezzanine for me is 50Mb/s MPEG-2 but I’ll sometimes go to 30Mb/s.

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[Dixon Johnston]

Thanks guys, for all your help. Thought Id let you know where I am with this.
I tried yet again, using the specs provided, and got no improved results. Not sure I really understand how to “trick it into upping the level”. The best end result was exporting via FCP QT conversion with compressor quality set to “best”, encoding set to multi-pass and “Automatic” Data Rate yielding a 6550kbs file. So thats what Ive uploaded, and we’ll see if anyone complains.

Here is another mystery Ive come up with. This particular 30 sec spot also had a cutdown 10 second version-where literally, the last 10 seconds was the product-no edits or alterations. I exported using FCP and the same EXACT settings described above. It yielded a 7238Kbs product-higher than the 30.

Not willing to let it go, I tried again through Compressor and it kills me that I can adjust a bitrate slider in the H264 Studio Pro presets but cannot do it in any of the interlaced SD 29.97 720×486 settings. (or at least I havent discovered a way to do it). I did try the Studio Pro preset, and as expected, got a 59.94 frame rate file at 720×480, average bit rate slider set to minimum 12Mbps. The result was 11.84 Mbps file, but was the wrong frame rate and aspect for my purposes-AND it took 3 HOURS to Transcode. Pressing on-I exported that file, to correct the frame rate and aspect, which got me a 5560Kbps file (I suppose because its half the fps). This is about the same as MOST of my earlier attempts.

Im giving up for now after 15 attempts, and will use it as ammo (whether justifiable or not) to get an Intel Mac. Is it possible all the varied results is actually CPU related?

I really appreciate all of your advice, and Im sure I’ll be looking to the cow as we transition to a P2 world. I will check back on this post to see if you guys have any more theories or solutions.

Thanks again.
Dixon

Dixon Johnston
Creative services Director-WRIC

Dual 2.0 G5, 4G RAM
OSX 10.4.1, FCP 5.1, QT 7
AJA Io-Beta SX (SDI)