wmv playback issues on htpc and 360

[UberDuper]

I'm thinking about switching from an MCE htpc to an xbox360 for my movies. I've been evaluating wmv for the last few weeks and I'm running into some odd problems.

I've been using Serenity and The Illusionist for my tests. In both cases, the picture quality is fantastic on the 360. Both look horrible when played back via the MCE htpc with wmp11 installed. On the htpc there is very bad color blocking in the background and dark areas. The 360 doesn't show this. The 360 is noticeably darker and this may be hiding what I'm seeing on the htpc. Overall not that huge a deal since I'd use the 360 for playback in most cases.

Another problem I'm having is the smoothness of the playback on the 360. Serenity plays back very smooth with no issues. The Illusionist has a lot of twitchyness to it. Not just in panning scenes. The htpc plays both smoothly.

Serenity was encoded:
846x360 - I'm not really sure why I chose 846 instead of 852. I think it was based on some bad info I read at the time.
23.976 fps
WMA 10 Pro CBR 440kbps 48kHz 5.1 channel 24bit
WMV 9 Advnaced Profile quality based 90%

The Illusionist was encoded:
852x480
23.976 fps
WMA 10 Pro CBR 440kbps 48kHz 5.1 channel 24bit
WMV 9 Advnaced Profile quality based 90%

Both encoded using Windows Media Encoder.
If any of you could shed some light on this I could really use the help.

Thanks,
UD.

[veffremov]

Interesting choice for horizontal resolution. What source material did you use for the encode (not that it is relevant for the twitchy playback).

Would it be possible to cut a small piece of the file (1-2 min) that has the problem and send it to me? I'll let you know if this is a perf problem or something else.

[UberDuper]

Not that interesting of a choice. I'm maintaining proper aspect ratio without throwing away resolution. The source has a PAR of 1.185. I'm encoding to a format with a 1:1 PAR. 720 x 1.185 = 853.2. Rounded down to the nearest even number is 852.
852 with a PAR of 1 == 720 with a PAR of 1.185.

I'll see what I can do about sending a sample. Do the rules of the forum allow such a thing?
Oh. The source is a dvd vob.

UD.

[veffremov]

I only need a sample of the encoded file, not the original source. PM me to arange the best way to transfer the file.

[zambelli]

Originally Posted by UberDuper

On the htpc there is very bad color blocking in the background and dark areas. The 360 doesn't show this. The 360 is noticeably darker and this may be hiding what I'm seeing on the htpc. Overall not that huge a deal since I'd use the 360 for playback in most cases.

This is most likely due to your display(s) being differently calibrated for the Xbox and the HTPC. It sounds like your Xbox display is properly calibrated for NTSC 16-235 luma range, while your HTPC display is calibrated for PC 0-255 luma range.

[veffremov]

Originally Posted by zambelli

This is most likely due to your display(s) being differently calibrated for the Xbox and the HTPC. It sounds like your Xbox display is properly calibrated for NTSC 16-235 luma range, while your HTPC display is calibrated for PC 0-255 luma range.

Actually this will make his Xbox brighter, but it's the oposite.

[gooberlx]

Originally Posted by UberDuper

Not that interesting of a choice. I'm maintaining proper aspect ratio without throwing away resolution. The source has a PAR of 1.185. I'm encoding to a format with a 1:1 PAR. 720 x 1.185 = 853.2. Rounded down to the nearest even number is 852.
852 with a PAR of 1 == 720 with a PAR of 1.185.

I'll see what I can do about sending a sample. Do the rules of the forum allow such a thing?
Oh. The source is a dvd vob.

UD.

Not meaning to hijack the thread, but regarding aspect ratios and resolutions: is there a rule of thumb, like base everything off of 852 width and calculate height from there? I'm considering trying to convert my library for streaming to my xbox360 but want to figure out the optimal resolutions for the various aspect ratios used in movies and tv shows (1.78:1, 1.3:1, 2.4:1, etc, etc...). How do I find the source PAR? I've done a couple test converts using this guide: http://home.comcast.net/~skibit/, which have worked out well. But there's an area in the batch file where you can manipulate the resolutions and cropping.

my other problem is working bandwidth issues on my wireless network, which should be 108mbps, so that playback on the 360 isn't choppy...but that's for another thread I suppose...

[foxyshadis]

If you ever manage to sustain more than 4 or 5 mbps for SD video, you must have an insanely complicated source. For HD video, the rough maximum of 40% of that 108 (wireless really sucks) is still above the maximum of HD-DVD and Bluray.

For DVD, a common method of converting to 1:1 par with minimum loss is to start with the height of the video, and convert the width to match. If 360 supports AR, you can just encode everything as-is. On a DVD, the source DAR is always 4:3 or 16:9, PAR can be determined by determining by ratio of the video frame AR (perhaps something like 704x370) with the full DVD AR. SMT has a tool somewhere to help with that, paranoia.

[killerhex]

what program did you use