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michael
Popwire WMV Jumpy
on Jul 12, 2006 at 2:07:36 pm

I urgently need a solution.

Exporting WMV from FCP with Popwire and the
video appears jumpy/jittery.

Have tried differnt Settings for quality and Keyframes
but cant sort it out...

Please help??



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Craig Seeman
Re: Popwire WMV Jumpy
on Jul 12, 2006 at 2:26:34 pm

Please post link to file. I don't know what you mean by "jumpy."
Frame rate, interlace, droped frames, buffering, etc., can't tell without seeing the patient.


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michael
Re: Popwire WMV Jumpy
on Jul 12, 2006 at 4:48:13 pm

momentary pausing like effect.

like buffer catching up sort of thing...

hard to explain...

Thanks heaps if you have any ideas


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Craig Seeman
Re: Popwire WMV Jumpy
on Jul 12, 2006 at 5:01:26 pm

Can you post a link to file online?
Is this happening on desktop playback?

If online it could be a peak data rate issue. Try doing 2 Pass VBR Constrained or CBR encode and see if you still have the issue.
What is your data rate on the file?


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Andy Taplin
Re: Popwire WMV Jumpy
on Jul 24, 2006 at 5:17:56 pm

I've had this also and no one seems to be able to provide a solution. The Popwire guys are helpful in responding but just can't solve the problem. All the other WMV encoders on the mac are jerky too!

In fact I'm a bit dissapointed with the encoding options on the Mac generally. I now use a PC and get really smooth WMVs using Procoder express which on a 3GHZ PC is more than twice as fast as a G4 dual 1.25GHZ

I also use cinemacraft for MPEG-2 which is faster than real time and better than any other software encoder I've seen - expensive but worth every penny.


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Craig Seeman
Re: Popwire WMV Jumpy
on Jul 24, 2006 at 5:24:27 pm

Without looking at the source and the export settings it's hard to provide a solution. When I consult and bump into these issues, I have the client FTP me the source. Both Compression Master and Flip4Mac Studio Pro HD do good WMV encoding on the Mac. I haven't noted any "Jumpy" issues that weren't settings related.


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Andy Taplin
Re: Popwire WMV Jumpy
on Jul 25, 2006 at 2:34:05 pm

Thanks Craig

If you let me have your ftp details I'll send you a short sample clip and the source.

Regards

Andy Taplin

taplin@peninsulafilms.com


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Charles Simonson
Re: Popwire WMV Jumpy
on Jul 25, 2006 at 3:44:45 pm

While I'm not going to say it is a bad idea to use a PC for WMV encoding, I do find it strange to hear complaints of "jumpiness" with both Popwire and F4M's encoders. Would you call the jumpy part more like a bouncing in the actual frames or more like a strobing effect of fields?

On the PC side, the only time I have ever heard of this is if you were using an interlaced encode and viewing on a computer monitor. By default, the WMV decoder blends the fields of a VC-1 encode. But playback of interlaced WMVs is not supported on the mac (no decoder for it) and you can only really encode frame-based interlaced WMV with F4M (but still no way to view that on the mac), so that is likely not it.

When encoding and viewing WMVs on the mac, you have to remember that all encode viewing must be of progressive material (WMV3). If you have an interlaced source and do not do a proper deinterlace for the encode, then the fields will blend together and this can sometimes encode in an strange way and create what could be called a "jumpy" experience I suppose.

BTW, the mac also has some faster or close to real-time MPEG-2 SW encoders. Popwire Compression Master 4, MainConcept Encoder 1.5, and Apple Compressor 2.1 all fit this bill.


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Andy Taplin
Re: Popwire WMV Jumpy
on Jul 26, 2006 at 7:39:26 am

Hi Charles

The jerkiness is like a stuttering but it's irregular and shows up most on pans. It's mothing to do with not being deinterlaced. I always deinterlace computer based video for obvious reasons. When you say 'proper deinterlacing' what do you mean by this? In Cleaner for example I use Blend and Adaptive which produces good results for MPEG-1 and QT.

I should say that I work in PAL and it may be that encoding NTSC source material looks better with Popwire?

Andy


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Craig Seeman
Re: Popwire WMV Jumpy
on Jul 26, 2006 at 6:39:36 pm

data spikes in 2 Pass VBR encoding (fix by encoding Constrained). Field order issue? Andy do FTP the files ASAP. Maybe I can test Flash encode for you too (although I don't have VP6 codec).


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Charles Simonson
Re: Mac WMV encodes Jumpy
on Jul 27, 2006 at 3:50:57 pm

Andy, what you just mentioned sounds exactly like a blended deinterlace issue, as I described in my earlier post. This issue would be especially notable on panning sequences. This is often refered to as a "strobing" effect by some, which is usually noticed when a WVC1 interlaced encode is played back on a computer monitor with default settings. As I said, in the default playback case, the issue is because the decoder blends the fields, creating the sort of stuttering you see.

Only in your case, you are encoding progressive by first blending the fields so that you are seeing the same effect on WMV3 encodes. By default, this is the method that the PC encoder uses when encoding from an interlaced source to WMV3. Personally, I would never choose to blend the fields for an encode. I see the merits in using that method to playback an interlaced encode on a progressive monitor, but I don't see it for the actual encode method.

So... by proper deinterlace, I mean a deinterlace where a field is actually removed (adaptive is best) or a deinterlace that takes the fields and makes frames out of them (usually requires some scaling and a doubling of the frame rate). Cleaner (at least versions prior to 6.5 did; I haven't really spent too much time with 6.5 to see if there are any changes for deinterlacing) and Compression Master have good deinterlacers. If using Cleaner, Craig might be able to elaborate on how the F4M encoder handles Cleaner's deinterlace settings with F4M's own deinterlacer.

As far as Popwire, the same thing could be happening there as well if you are using just the WMV QT export component. And I doubt the issue would be that they work better with NTSC than PAL, as PAL is a better format and Popwire is a Swedish company.


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Andy Taplin
Re: Mac WMV encodes Jumpy
on Jul 27, 2006 at 5:10:49 pm

Thanks Charles

So I think you're saying dont blend the deinterlace in Cleaner but use one field or the other and use adaptive?

I've always blended the deinterlacing in Cleaner becuse it sounded like it would create a smoother image? Certainly for MPEG-1 it caused no problems and looked very good.

6.5 has the same deinterlace options as 6: use each field or blend and adaptive or not.

Thanks for your help.

Andy


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Charles Simonson
Re: Mac WMV encodes Jumpy
on Jul 27, 2006 at 6:37:36 pm

Yes, don't use blend, use the dominate field and adaptive.

Blending does create a smoother image, too smooth for my tastes, but to each their own. I greatly prefer sharpness and detail over a smooth image, but would use smooth when maybe targeting a very agressive bit rate where image quality was less important.

I understand 6.5 has the same deinterlace options as 6, I just don't know if there have been any changes to the code in this area from the previous version.


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Andy Taplin
Re: Mac WMV encodes Jumpy
on Jul 28, 2006 at 7:47:09 am

That's very helpful Charles, thanks,

Andy


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Charles Simonson
Re: Mac WMV encodes Jumpy
on Jul 31, 2006 at 6:03:22 am

If you want to see a excellent case of where blending can really hurt an encode, check out this gem on Apple's site:
http://www.apple.com/trailers/mgm/flyboys/trailer/
I could barely watch it the motion was so terrible. And certainly while I was watching it I wasn't paying attention to the actual stuff going on in the trailer.


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Andy Taplin
Re: Mac WMV encodes Jumpy
on Jul 31, 2006 at 8:35:43 am

Does look pretty bad, but not an effect I've ever seen with my own encodes using blend!


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