Capturing frame rate

[rorschach]

Hi, I'm a capturing newbie on a Win 2000 box with Maxtor Marvel Analog to Digital converter and using PC-VCR as the software to navigate and control the capturing.

In capturing, it's sometimes frustrating that the resulting file isn't always, precisely, the frame rate that I need for best results. Of course, that's 29.97fps. And only that is what must be for a good video.

Often I'll get a file that's 29.963fps or even lower, something in that area. I often wonder "Is that good enough?" Sometimes a video editing app like Premiere won't accept it. I have to, sometimes, attempt a capture many times just to hit that frame rate.

But I wonder: Is there any reason why I can't take the file, and using Quicktime Pro, EXPORT AS a file with the proper frame rate. When I see the file with the proper 29.97, I don't see any defects and use it. Supposedly this is bad because it promotes off-synched video. But if the source video is "so close" to the real rate of 29.97, the difference is not noticeable? Can I do this? Thanks.

[SLK001]

You should capture your video at 29.97 and dynamically resample your audio to match.

You don't say what format you are capping to. There are applications that allow you to rewrite the headers to the proper frame rate.

[rorschach]

By default (and I wish there were more options) the capture format is AVI and playable under Windows Media Player on the PC but as soon as I complete a file, I transfer it to the Mac and use Quicktime Pro to play it back and edit/process the file. It's in QTP where I have the idea that I can "render up" a file that may have been captured "less than but close to" the true 29.97 so that I can avoid more struggles of capturing at the rate it should be.

[FulciLives]

Same thing happens to me because the dynamic resample audio trick doesn't work for me ... at least not on my computer system.

So I can only get sync by using a MASTER STREAM set to AUDIO which in the end gives me a frame rate that is usually a bit under the target. I often get 29.967fps or sometimes 29.966fps instead of 29.970fps

To "correct" this I use AviSynth with the following line AT THE END of my script:

AssumeFPS(29.970, true)

This works with Cinema Craft Encoder and TMPGEnc although if you use CCE I would run the script through CCE just for the video and then again through TMPGEnc just for the audio using 16-bit Stereo 48k PCM WAV audio and use SSRC as your plug-in.

That's how I do it.

- John "FulciLives" Coleman

[rorschach]

A capture that I've just completed at a rate of 29.967fps was imported to MacOS and Quicktime Pro read it AS 29.97fps. I shrugged and thought, "Okay, great!"

The capturing in general is actually working quite well, it's just that "instant capturing" at best rate doesn't always happen. I'm sure it's a combo of PC speed, capture settings, tape quality, etc., I think my real question is: "Is there any way I can IMPROVE the quality of the capture rate at each attempt, so that I don't have to attempt so many times in getting the true 29.97fps."

I'm also very annoyed that PC-VCR/capturing splits my AVI file into chunks once the running time exceeds 15 minutes. What if I have, say, a 45 min program, I have to later join all these chunks and joining isn't always seamless because of the chunking process. I'm still looking at, investigating, tech that can give me this on the Mac.

I know VirtualDub which I have also captures video (the capture rate of this is LESS RELIABLE than PC-VCR), but is there any other software I can get that captures analog video + TV tuner, WITH the hardware Maxtor Marvel Analog to Digital converter? Thanks.

[SLK001]

Try using VirtualVCR. If your card has DirectShow drivers, it should work.