What is the maximum bitrate to use for Xbox 360 VC1 encodes?

[Furiousflea]

Hi there, I'm abit stuck here. I'm backing up my HD DVDs for playback on my Xbox 360 and am abit confused about how to encode...

I understand the Xbox 360 supports video encoded with the VC1 codec up to maximum bitrate of 15Mbits per second, I also understand that I should use "peak bitrate" based encoding...

So I've been encoding with a peak bitrate of 15Mbits in Windows Media Encoder 9 then using a bitrate calculator to get the output to fit a dual layer disc.

No probs?

Well the problem is that even when I set this "maximum", I often see in the statistics monitor that Windows Media Encoder is in face allowing a much higher bitrate, sometimes as high as 20Mbits, not for long periods of time normall not more than a couple of seconds....

Will this be a problem?

If so, how should I set it, if Windows Media Encoder isn't going to pay strict attention to this "Maximum"...

I thought a "Peak" meant just that, the peak, not "It doesn't matter if its goes a few Mbits over!!!"....

I've also noticed that the video FAQ on the Xbox website says there is no specific maximum, just that 15mbits at 30fps 1080p is the most that is recommended without dropping frames\stuttering...

Bearing in mind that my encodes are all 720p and 23.976fps would that make this all ok etc?

Thanks for any information\enlightenment with this, Rob :)

[Acilles]

I think the video FAQ may be outdated. Based on what I've seen, the current VC-1 decoder can handles spikes of up to about 30 Mbits/s (or even a little higher for the actual stream bitrate, as opposed to the input bitrate which is what you're specifying with peak VBR encoding I believe) without a problem.

[FoxRacR17]

the 360 CANNOT handle 30mbit/s. One time i ripped batman begins and instead of encoding it i just stripped the .vc1 and muxed it into a .wmv file with encoded audio. It was the pure video from the hddvd but when i streamed it to my 360 it would stutter like a mofo. So then i re-encoded it at 720p and at around 8mb/s CBR and it played fine. I remember reading that the 360 can not handle anything over 12mb/s i believe.

[Acilles]

One time i ripped batman begins and instead of encoding it i just stripped the .vc1 and muxed it into a .wmv file with encoded audio. It was the pure video from the hddvd but when i streamed it to my 360 it would stutter like a mofo.

How long ago was this? I know at some point Microsoft updated the VC-1 encoder to allow for higher bitrates. At any rate, I have encoded movies in VC-1 using peak VBR and setting the peak to 30 Mbits/s and didn't see any lapses in framerate during playback.

[FoxRacR17]

How long ago was this? I know at some point Microsoft updated the VC-1 encoder to allow for higher bitrates. At any rate, I have encoded movies in VC-1 using peak VBR and setting the peak to 30 Mbits/s and didn't see any lapses in framerate during playback.

Are you sure that they updated the VC1 decoder for the 360? It was probably about 3-4 months ago that i did this. And at the time i was reading a thread and everyone was saying that microsoft was supposed to update the decoder but when the dashboard update finally came out it turns out that they never did update the decoder at all.

[bluesk1d]

the 360 CANNOT handle 30mbit/s. One time i ripped batman begins and instead of encoding it i just stripped the .vc1 and muxed it into a .wmv file with encoded audio. It was the pure video from the hddvd but when i streamed it to my 360 it would stutter like a mofo. So then i re-encoded it at 720p and at around 8mb/s CBR and it played fine. I remember reading that the 360 can not handle anything over 12mb/s i believe.

The streaming part was likely the problem. I encode videos at 20+Mbps and they are all flawless. Play the file off of a removable device to eliminate bandwidth issues.

[Furiousflea]

Thanks for the input, in that case its all good then. I thought going by the "Video FAQ" (The FAQ isn't out of date mind you, its based on the "Spring 2007 Update"), I was in the doodoo...

Sounds like its not quite as strict as it was.

FoxRacR17 From reading what you say I'm sure you must be referring to plauing video before the Spring update this year (Came out around May). Back then it was neccasary to use CBR encoding at at around 6-8mbits. Its much much better now, To be honest CBR at that bit rate would be pointless for HD DVD backups, terrible macroblocking etc.

Anyway thanks to everyone :)

[FoxRacR17]

I know that i tried to do the encodes after the spring 07 update. However they actually never did update the decoder in the spring update
Here is some good info for you to read:
http://forum.doom9.org/showthread.php?p=1002364#post1002364
http://forum.doom9.org/showthread.php?p=1038639#post1038639
http://forum.doom9.org/showthread.php?p=1001196#post1001196

[ACrowley]

I know that i tried to do the encodes after the spring 07 update. However they actually never did update the decoder in the spring update
Here is some good info for you to read:
http://forum.doom9.org/showthread.php?p=1002364#post1002364
http://forum.doom9.org/showthread.php?p=1038639#post1038639
http://forum.doom9.org/showthread.php?p=1001196#post1001196

yep..true

Dont know why people was talking about a Decoder Update fo the Spring Update
There where no Informations about from MSr

And no Update, no higher Bitrate support etc etc

For WVC1 encodes the max Bitrate is :

-2pass VBR PEAK = ~13Mbps Peak bitrate

-1pass CBR = ~16-20Mbps

For Remuxed VC1/HDDVD :
-Cant say 100% sure

[Furiousflea]

yep..true

Dont know why people was talking about a Decoder Update fo the Spring Update
There where no Informations about from MSr

And no Update, no higher Bitrate support etc etc

For WVC1 encodes the max Bitrate is :

-2pass VBR PEAK = ~13Mbps Peak bitrate

-1pass CBR = ~16-20Mbps

For Remuxed VC1/HDDVD :
-Cant say 100% sure

Hmmm...guess I'll have to try out a couple of backups I've done and hope for the best ;) Thanks for posting tho with all the info to everyone :)

Rob

[zambelli]

The VC-1 decoder in the Xbox dash update should have similar capabilities to the one included in the HD-DVD unit. In other words, any content that came from an HD-DVD disc should play just as well in the dashboard.

[ACrowley]

In Fact the high Bitrate from HDDVD VC1 will not run in the Dashboard Player :)


4. What exactly does the Xbox 360 support for WMV (VC-1)?

Xbox 360 supports the following for WMV:

· File Extensions: .wmv

· Container: asf

· Video Profiles: WMV7 (WMV1), WMV8 (WMV2), WMV9 (WMV3), VC-1 (WVC1 or WMVA) in simple, main, and advanced up to Level 3

· Video Bitrate: 15 Mbps with resolutions of 1920 x 1080 at 30fps. See question number 11 for more information.

· Audio Profiles: WMA7/8, WMA 9 Pro (stereo and 5.1), WMA lossless

· Audio Max Bitrate: No restrictions. See question number 11 for more information.

I made dozens on WVC1 reencodes from HDDVD/Bluray. These Values are proven. 2pass VBR Peak above ~13Mbps will not running smooth, especially for 1080p
When you want high Bitrate for 1080p encodes better use CBR Mode where you easily can go up to ~18Mbps

I pers use 2pass VBR Peak (12Mbps) for 720p encodes and 1pass CBR (+12Mbps) for 1080p

[scarbrtj]

It will be interesting to see if the new v2 media center extenders will handle these high bitrate encodes. I have high hopes for the Niveus extender.