MAJOR PROBLEM

bruceo wrote on 9/12/2007, 10:08 AM

We have rendered 3 different projects on 4 different machines (p4, Pd, Q6600, Dual Dual) Vista & XP and all HDV projects rendered with smart render have occasional gitches similar to footage that is captured with bad firewire cable. If you put a filter on the track and force render then all of the footage is pristine.

So it looks like enable no recompression on long GOP needs to be unchecked in preferences until this much needed/desired feature is FIXED.

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Comments

Wolfgang S. wrote on 9/14/2007, 4:45 AM

I can only say, that I have found the error - the blocking shown in the link above - in a part of a HDV2 clip, that has no transistions at the place where the error occures. You do not find the error in the original footage. I do not know, if that is on an I-frame or not.

I do not think that this is a general issue with the approach - there are also Pinnacle Studio and Edius 4.51c, that allow you to smartrender HDV2 material. But I have not heard anything about complains from this 2 products, regarding HDV-smartrendering.

I have forewarded both the original footage, the small test project file and the picture to the development team, and received the feedback that they can repro. That are good news, so I am optimistic here.

Hammer65 wrote on 9/14/2007, 8:18 PM

I'm seeing the same problem. Sometimes near a cut, sometimes not. Definitely a bug. Any word on a fix?

farss wrote on 9/14/2007, 8:42 PM

I've been having a problem with understanding how this can work at all.
The HDV spec says a 15 frame GOP and a bandwidth constraint of 25Mb/sec. Assuming one was to cutout all but the I frames of a length of video wouldn't one easily exceed the 25Mb/sec limitation. This mightn't matter rendering to a file but would surely throw the VCR into a tail spin doing a PTT.
Personally I think SCS were being very wise resisting this feature for so long. That other products have gotten it to work is interesting, maybe the mpeg-2 decoders are loose enough so that non compliant GOPs aren't a problem but breaking a spec always seems a formula for something to go wrong somewhere down the road.
Interestingly enough DVDA 4 does show you where the I frames are, very handy feature when placing chapter markers.

Bob.

Wolfgang S. wrote on 9/15/2007, 1:24 AM

I am not the right person, to explain you really how that works out. But you are right, smartrendering must be able to handle the issue that you can edit your video not only at I-frames, but at every frame of the GOP. Means, that there must be a solution how to handle the frames before and after a cut. Maybe they make a shorter GOP, maybe they substitute the frames befor and after the cut by some I-frames.

The smartrendering function in some NLEs (Vegas8, Pinnacle 11+) is significantly slower, compared to other tools - for example like womble. On my old 3.2 Ghz P4 it works in realtime only, womble is faster. So, I assume that some kind of analysis is done for such a smartrender process. But that is another, more theoretical discusion. Generally, the smartrendering works, I am sure.

> Any word on a fix?

Yes, it will be fixed, but I do not know more details.

mbryant wrote on 9/19/2007, 5:10 AM

I know for many upgrading to V8 is a no-brainer; but I'm non-pro and I need to see features of clear value to me before I upgrade. As I mainly work with HDV, this smart render feature was the one thing which I wanted to upgrade for. What worries me is statements that other software has similar problems; maybe it's a problem with third party MainConcept.... this doesn't fill me with any confidence that this will be fixed (at least not before the 10/31 offer ends). I may have to skip V8.

(I know there is the 32 bit thing, but I still can't really understand how important that is).

Mark

Wolfgang S. wrote on 9/19/2007, 6:04 AM

As said, it will be fixed - and I assume that this will work fine in the next update. However, when Sony will publish a Vegas 8a, is unknown.

So, for sure you can wait, but you take the risk that you pay more, if you upgrade afer the 10/31. Your decision, your risk.