Frame Recompression with Canopus DV files

plasmavideo wrote on 10/13/2006, 8:25 PM
Here's a question that's been bugging me for a while.

I have a number of DV files with the Canopus DV CODEC, as I split time betwen Vegas OHCI and Edius with a Storm card. When playing back Canopus DV files on the Vegas timeline (with no effects or trnasitions), frame recompression happens when playing back to an external monitor through firewire, and the frame rate drops to around 23fps. As Canopus files work in the same colorspace as Vegas DV files, I would have thought that frame recompression would not be necessary. I have found no way to modify this behaviour - checking Ignore third party DV CODECS in preferences does not do it, and turning off frame recompression in the external monitor options merely allows no video to go to the external monitor.

I will add that this is only if I have BEST preview quality selected. With GOOD I do get full motion, full framerate playback.

Anyone know a way to change this?

TIA

Tom

Comments

John_Cline wrote on 10/13/2006, 8:37 PM
Tom,

Canopus DV files have a "FourCC" code of "CDVC" in their headers. The "FourCC" code tells Windows (and Vegas) what codec to use to decompress the files. The Canopus DV file is indeed just a DV file, except for the header. A standard DV .AVI file has a FourCC code of "dvsd"

I use the HEX Editor in VirtualDub to manually change the FourCC code in the header from "CDVC" to "dvsd"

It appears twice in the header, it will be obvious when you get the AVI file in the hex editor. Just change both of them and all is good.

For more info on FourCC: http://en.wikipedia.org/wiki/FourCC

John
rs170a wrote on 10/14/2006, 5:34 AM
Tom, I'm not sure if this will help but check out MarcoB's solution to my problem in the
Help Needed - Canopus AVIs & Vegas thread.

Mike
plasmavideo wrote on 10/14/2006, 8:57 AM
Interesting coments. John, thanks for the VirtualDub tip. I have never used that feature.

Mike, although I have not typically had any problems with Canopus files rendered to mpg in Vegas for DVDA, that's an interesting discussion. It may be that that situation was corrected in Vegas or DVDA by the time I purchased and started using DVDA. I'm going to read that thread carefully and take a look at the ini file, but at first glance this appears to be related to PAL. not NTSC.

Interesting that the same field order issue had been reported in Ulead's DVD Workshop with Canopus files, both for NTSC and PAL. I happened to see that thread on the Canopus boards a year or so ago.

I'm really using Vegas a lot more these days since I got an ADS Pyro A/V link running on my editing workstations and can really see the results an a decent NTSC monitor. The realtime Edius and Storm combo is hard to beat, but there are so many nice things in Vegas that cannot be done in Edius yet, including true alpha channel support with effects and advanced compositing. Plus, the audio features in Vegas are lightyears ahead.

Tom
rs170a wrote on 10/15/2006, 6:43 AM
Tom, mine was definitely an NTSC issue. I changed the ini file as suggested and my problem was solved. Come to think of it, I never bothered changing it back and I haven't had any issues. I looked through the 6.0d readme and I didn't notice any fixes for this issue (I was using 6.0c at the time of this problem).

I still have two dpsVelocity systems at work (love the realtime feature) but find that I'm doing most of my work on Vegas, especially anything audio-related :-)

Mike
plasmavideo wrote on 10/16/2006, 6:57 AM
Thanks Mike. I'll take a look this week at the thread and the ini file. I was slammed this weekend and didn't get to it.

I just acquiired a used DPS Reality card to mess around with. I know it isn't quite the same as the Velocity, but it might be fun to play with. Right now I'm integrating Xena cards into the workstations at work.

T