DV Transcoding

[StevieB]

During Capture Mode, I get a "DV transcoding" message. Can someone explain what that is and why -- when I hit "escape" (as the dialog box invites me to) during capture, the capturing is immediately cut-off?

Should I be escaping from this or should I let it run . . . it doesn't appear every time by the way . . . not clear why that's the case . . .

Thanks

Steve

[GeorgeW]

What's happening is the video is going into your computer via firewire, but it is being buffered, and your computer is transcoding it to mpeg on-the-fly. The problem is when that buffer fills up, it stops capturing to "flush" the buffer (finish transcoding the dv video that's already in the buffer). When it's done flushing the buffer, it starts up again with the dv capture.

This works fine when you are dealing with a digital camcorder, because when the capture stops, the digital camcorder also pauses -- so you don't get any "gaps" in your finished video.

But this does not work when you are using an analog-to-dv converter because when the capture stops, there's no way to pause the analog video source -- so the video source keeps on playing even though the dv capture process has momentarily stopped while the flushing of the buffer occurs.

[Ken Berry]

This is also one of the reasons there is a widespread preference NOT to capture 'direct' to MPEG-2 since it is not really direct at all: first capture is the 'native' format of your mini DV tape in the vidcam (i.e. AVI/DV), then transcoding on the fly to MPEG-2. This seems only to work well if your computer has plenty of resources, including a fast CPU, good graphics card (with a good sized built-in cache??) and plenty of RAM. If you think you have these resources, then go right ahead and capture to MPEG-2. But if not, it is much safer to capture first to DV format, do your editing, then 'Share' i.e. convert the edited file to the final MPEG-2 format, presumably for eventual burning to DVD.

[thecoalman]

This is also one of the reasons there is a widespread preference NOT to capture 'direct' to MPEG-2 since it is not really direct at all: first capture is the 'native' format of your mini DV tape in the vidcam (i.e. AVI/DV), then transcoding on the fly to MPEG-2. This seems only to work well if your computer has plenty of resources, including a fast CPU,

Yes to capture and convert on the fly you need a very powerful machine, converting in this method is very CPU intensive. Unless your using a capture device that has a hardware encoder use AVI. I think many of the issues that I see posted here resolve to the fact that people are capturing in mpeg as opposed AVI. For the highest quality video my rcommendations are to capture in AVI>encode MPEG (once and only once)>author and burn. You would have to apply that whatever software your using. MPEG is meant for final output and not for editing, it takes longer but the results will be better.

good graphics card (with a good sized built-in cache??)

Unless it has an onboard encoder the Graphics Card doesn't do anything except for specific apps that need it to create 3-D objects or gaming. Otherwise any card will do.

[StevieB]

George and Ken:

Thanks for your clear explanations. The transcoding issue I describe occurs as I am capturing analog footage via an ACVC 100 converter . . . so, George, your explanation resonated . . . what's interesting is that, with no change in settings, sometimes it happens and sometimes it does not . . .

Steve

[GeorgeW]

the reason why sometimes it works, while other times it needs to stop might be due to other tasks running in the background. Maybe you have a VirusScanner running during capture? This could steal away cpu cycles from the transcoding process, so your computer can't keep up.

Try to stop all non-essential background tasks while capturing -- that might help the situation...

[thecoalman]

Try to stop all non-essential background tasks while capturing -- that might help the situation...

On that note check out this site.... www.blackviper.com

Edit: forgot this one.... http://home.ptd.net/~don5408/toolbox/enditall/