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Flip4Mac - first few seconds, lots of artifacting

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Raven Plenty
Flip4Mac - first few seconds, lots of artifacting
on Sep 26, 2008 at 3:42:38 pm

I haven't used it more than a few times so far, but in all cases except for one, the resulting WMV file starts out very rough before smoothing out. Like it's looking for preceding image data that's not there until you get a few seconds into the video. (I'm no compression expert, mind you.) I have no idea why this didn't happen on one of my encodes.

Anyone else having this issue?


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Daniel Low
Re: Flip4Mac - first few seconds, lots of artifacting
on Sep 26, 2008 at 4:18:07 pm

What do these first few frames consist of?

What settings are you using?

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Raven Plenty
Re: Flip4Mac - first few seconds, lots of artifacting
on Sep 26, 2008 at 4:29:08 pm

It's just a talking head the whole way through, no camera movements or zooms.



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Daniel Low
Re: Flip4Mac - first few seconds, lots of artifacting
on Sep 26, 2008 at 4:39:51 pm

Ok, so no fade up from black?

Are there a couple of black frames at the beginning or a title or something that's trowing it off course?

What data rate are you using?

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


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Raven Plenty
Re: Flip4Mac - first few seconds, lots of artifacting
on Sep 26, 2008 at 4:42:30 pm

Nope, no extra frames or fade in or anything. Every frame is the same, except for the talking and gesticulating person.



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Daniel Low
Re: Flip4Mac - first few seconds, lots of artifacting
on Sep 26, 2008 at 4:46:52 pm

Why don't you want to tell me the datarate?

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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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Raven Plenty
Re: Flip4Mac - first few seconds, lots of artifacting
on Sep 26, 2008 at 4:50:52 pm

Sorry, didn't see that question. It's 15.60 mbit/s. (This is a high quality version that will be compressed and optimized by another team.) Thanks again for your help.



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Daniel Low
Re: Flip4Mac - first few seconds, lots of artifacting
on Sep 26, 2008 at 4:59:52 pm

Wow that's very high. It maybe that your player can't play this back and is artifacting. What are you viewing it in?

Is it a full HD clip 1920x1080?

Why are you using WMV?

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


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Raven Plenty
Re: Flip4Mac - first few seconds, lots of artifacting
on Sep 26, 2008 at 5:25:08 pm

The source clip is NTSC DV footage that is destined to be a small WMV file posted on the company intranet. Since IT wanted to do their own compression, they requested a high quality WMV file as their source. I gave them this very high bitrate version just as their master, not intended to view really.

I believe I had the problem when I created a smaller version as well.



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Daniel Low
Re: Flip4Mac - first few seconds, lots of artifacting
on Sep 26, 2008 at 6:23:47 pm



It should only need a maximum of 5mb/s and even then that's too high for just talking heads.

What have you got for your keyframe setting?

Are you deinterlacing?



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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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Raven Plenty
Re: Flip4Mac - first few seconds, lots of artifacting
on Sep 26, 2008 at 9:12:17 pm

Yes my bitrate was probably overkill, but it was only a temporary go-between file anyway. Again, I'm sure I did a lower bitrate version that still had the problem.

To be honest I don't remember what the keyframe setting was. Is there a way to detect that info in a movie file?

No deinterlacing, source is 24P, encoding preserved the 24 fps.

Thanks again.



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Craig Seeman
Re: Flip4Mac - first few seconds, lots of artifacting
on Oct 1, 2008 at 2:21:17 pm

Hard to diagnose unless you post full specs. OS, Flip4Mac 2.2.1.11, Exported using what app, and yes exactly WHAT settings. HOW are you measuring that data rate? You can't measure WMV data rate in Quicktime. You'd need WMP9Mac or some other method. You can estimate data rate based on file size in Finder. One can certainly make "archival" encodes which may not play back due to high system demands but would work OK as a source for further encoding. You really need to provide a lot of details or you're just going to get random and possibly not applicable guesses.



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Raven Plenty
Re: Flip4Mac - first few seconds, lots of artifacting
on Oct 1, 2008 at 2:49:10 pm

Well, I don't remember the exact encode settings. I made a hasty post in case it was a common problem...I'll have to do some testing later when I have time. Thanks.



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