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WMV stutters and skips

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Miguel Ortiz
WMV stutters and skips
on Oct 15, 2008 at 3:53:10 pm

Whenever I encode to a WMV the playback stutters and seems to skip frames.

I have tried Squeeze 5 and Compressor 3 with the same results.
The version of Flip4Mac that I am using is 2.21.11

The general settings I am using are,

Source is uncompressed QuickTime.

Video
WM Video V9
3500-5500Kbps 2-pass VBR
864x480
1280x720
30fps

Audio
WM V9 Audio
192 Kbps
44100 Sample rate
Stereo

The specs of my Mac are,

Dual 3GHz Quad core
9GB of RAM
OS X 10.4.11
QT 7.5.0

Playing back on a Windows machine pretty much has the same results.
Has anyone experienced this or have any ideas?

Thank you.





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Daniel Low
Re: WMV stutters and skips
on Oct 15, 2008 at 6:18:08 pm

I'd say that your data rate was WAY too high for the 864x480 frame size and even too high for the 1280x720.

What keyframe setting are you using?

What kind of content is it?

Try 832x468 at 1.2Mb/s keyframe every 10 seconds or 300 frames

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Miguel Ortiz
Re: WMV stutters and skips
on Oct 15, 2008 at 6:37:26 pm

Key frame at ever 10 sec.
The content is all 3D animation.

I will give that a try.

Thanks!




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Miguel Ortiz
Re: WMV stutters and skips
on Oct 15, 2008 at 10:35:06 pm

I tried that, but still have the same issues.


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Daniel Low
Re: WMV stutters and skips
on Oct 15, 2008 at 10:52:28 pm

Exactly the same problems or similar?

Have you tried to play these back using the latest version of VLC?

If you are viewing in Quicktime player can you step through frame by frame and see every single frame through the problem areas?

Just for the sake if it can you try and encode at 320x180 @ 300Kb/s

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Please post back saying what solved your problem. It could help others, and saying 'thanks' is free!


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Miguel Ortiz
Re: WMV stutters and skips
on Oct 16, 2008 at 4:58:12 pm

Similar, every few sec. it looks like it drops/skips a frame.

Same results with the VLC player.

It seemed to look better at 320x180 @ 300Kb/s, but because of the size and compression it's hard to tell.









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Daniel Low
Re: WMV stutters and skips
on Oct 16, 2008 at 6:57:39 pm

Did you do like I suggested and step through the video frame by frame?

Is it possible for you to post this video somewhere?

Does this happen when you play it back on other computers?

Does it drop/skip a frame in the same place each time and with each different encode?

Have you double checked that it isn't a problem with the source file?

__________________________________________________________________
Please post back saying what solved your problem. It could help others, and saying 'thanks' is free!


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Miguel Ortiz
Re: WMV stutters and skips
on Oct 16, 2008 at 10:37:44 pm

Did you do like I suggested and step through the video frame by frame? Yes, did not see anything.

Is it possible for you to post this video somewhere? I will check w/ our IT guy.

Does this happen when you play it back on other computers? On a Windows box, using the settings you suggested (1.2Mbs) it looks ok, but not on the Mac

Does it drop/skip a frame in the same place each time and with each different encode? No, different place, different with each encode.

Have you double checked that it isn't a problem with the source file? The source playsback fine.








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Daniel Low
Re: WMV stutters and skips
on Oct 16, 2008 at 11:10:14 pm

On a Windows box, using the settings you suggested (1.2Mbs) it looks ok, but not on the Mac

It shouldn't be the case but you've nailed it here. WMV on the Mac is not an ideal combination. Never has been. Silverllight may go some way to improve matters (I've yet to see it) but is there a specific reason you are using WMV rather than the superior H.264?

These days I only advise people to use WMV when they are forced to have the specific DRM requirements that Microsoft offers, it's a pain to encode, as it's so slow and can't use multiple cores, and it only plays back well under Windows.

__________________________________________________________________
Please post back saying what solved your problem. It could help others, and saying 'thanks' is free!


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Miguel Ortiz
Re: WMV stutters and skips
on Oct 16, 2008 at 11:53:47 pm

We use WMV because the custom application we use only plays back WMV.

I have tried to get the programmers to re-write the code to allow h.264 to be played, but its not happening. Also some of our clients can not play QT.

On the subject of h.264...
I have tried the color fix from http://www.videocopilot.net/blog/?s=h.264

but it did not seem to do anything.
Is there anything else?

Thanks for your time and help with the WMV issue.




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Daniel Low
Re: WMV stutters and skips
on Oct 17, 2008 at 7:03:24 am

Don't get Quicktime and H.264 confused, although the Quicktime file format was used as the basis for the MPEG-4 file format and H.264 is the choice of encoding format for Apple and Apple, quite rightly pushes it heavily, that's all.

You don't need to have Quicktime installed to play back H.264 and there are plenty of other ways to encode H.264 without using Quicktime.

Suggest to your programmers that they should recode to use Flash or Silverlight as both of those formats can playback H.264 and Flash has the greatest player penetration of anything.

Ditch WMV, I think it's days are over.

__________________________________________________________________
Please post back saying what solved your problem. It could help others, and saying 'thanks' is free!


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Miguel Ortiz
Re: WMV stutters and skips
on Oct 20, 2008 at 5:53:28 pm

I will push our programmers.
Thanks Daniel for your help.



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