Strong banding in "high quality" encode -- is this

DaveF · Post by **DaveF** » Wed Jul 25, 2007 3:13 am

Initial experiments with Handbrake are giving me mixed results -- and maybe I need my expectations for MP4 encoding recalibrated.

What I expect to be high-quality conversions have strong banding (Moire patterns, suggesting aliasing), and I'm wondering if this if normal? I can't find it discussed in the forums.

I ripped X-Men 3 with MacTheRipper and encoded in HandBrake with AppleTV preset, plus 2x encode and 2500 average bitrate. The banding is most prominent on hard edges.

Here's a screen shot showing the banding. I see this in both QT and VLC.
http://www.screencast.com/t/mCR7yxYlgMp

Here's a reference shot of the same scene from the DVD rip
http://www.screencast.com/t/6Fj1tHY_BVR

Perhaps incorrectly, I thought MP2 re-encoded into MP4 could produce same quality video at a smaller size. My initial results, working around the AppleTV preset, are that the results are noticeably inferior to straight DVD playback. Is this normal?

Thanks.

jbrjake · Post by **jbrjake** » Wed Jul 25, 2007 2:10 pm

That doesn't look like banding to me. Honestly, it looks like you deinterlaced or are using a really bad scaler.

Also, if you are changing setting from a preset in the current released beta (0.8.5b1) then you have to re-enter all the x264 options after changing the bitrate or turning on two-pass or whatever. Otherwise you lose the part that makes it "high quality." This is fixed for the next beta.

And the AppleTV preset is in no way, shape, or form intended to be a transparent copy of a DVD.

For that matter, there's no way you can lossily encode a lossy source at the same resolution and maintain all the detail. It's impossible.

Cavalicious · Post by **Cavalicious** » Wed Jul 25, 2007 2:24 pm

Video Banding will show up as 1inch stripes across the whole display. Usually, a problem with poor LCD displays.

DaveF · Post by **DaveF** » Wed Jul 25, 2007 9:44 pm

Thanks for the tips.

Unmodified AppleTV settings give the same results. Is this typical for H.264 encoding?

General images (regular scenes with people, soft edges) looks good. But any high-contrast portion is strongly aliased: FOX logo, car grills, Tweed jackets, roofs, etc.

[EDIT] Indeed, it was a deinterlacing problem! Handbrake's deinterlacer was enabled. Disabling it dramatically improved the image quality. It was set to default on in Preferences; I don't know if I did that or if it's HB's default.

Thanks again for the tip. Getting the right terminology lead to the solution.