Live record from JVC HD250U into Final Cut ProRes

[Jeremy Garchow]

Use a capture device such as an AJA Kona, ioHD, or the new KiPro.

Does your camera have HDSDI out?

[Brian Corbin]

We don’t have those kinds of capture devices. I know they can be kind of expensive. We are a non profit group so we have to be careful how we spend. I just don’t see a need for those things when I can digitize from the tape in the camera in real time to ProRes, but I can’t do a live to ProRes. Or why is it the HDV codec in Final Cut allows for a live record from the camera, and no the HDV to ProRes codec? It just doesn’t make sense.

The camera does have HDSDI.

[Mark Petereit]

Don’t have access to my camera or my Mac at the moment, but it sounds like the problem may lie in the transport control. Have you tried setting it to “non controllable device” (or something along those lines)?

[Jeremy Garchow]

[Brian Corbin] “I just don’t see a need for those things when I can digitize from the tape in the camera in real time to ProRes”

But it’s not real time, it’s delayed. [Brian Corbin] “Or why is it the HDV codec in Final Cut allows for a live record from the camera, and no the HDV to ProRes codec?”

Because essentially when coming in via firewire, it’s a data transfer, when trying to come in ProRes, it’s a transcode, you are taking the HDV signal and making it something else, namely ProRes. proRes is a pretty computationally intense codec, so it’s no wonder it’s not working in real time.

What kind of computer(s) do you have?

Jeremy

[Brian Corbin]

I thought the exact same thing. It has to be something with the transport. So we tried Non Controllable, HDV Firewire, HDV Firewire Basic, Sony HDV Firewire, and non of them like it. They all do the same thing. We get two frames of live video, then it stops and Final Cut says End of Tape. Now this is when we have the capture preset set to HDV-Apple ProRes 422. But it has no issue if we put a tape in the deck and record footage in using the HDV-Apple ProRes 422. I mean a stream is a stream whether live or from tape it’s still having to make a conversion on the fly from HDV to ProRes. It just make no sense.

But here is where is gets more interesting. If we set the Control Preset to just HDV, it will record live from the camera no problem no matter what device control I use. So I’m thinking there is something that Apple needs to write into their own HDV-Apple ProRes 422 capture preset that doesn’t make it care about the end of tape issue. Because the HDV capture preset doesn’t care and it works fine. That is just my take on what I’m noticing in all of this.

[Brian Corbin]

But see that just doesn’t make sense. Why is it I can play and HDV tape in the camera, and record it into the computer in real time and use the HDV-Apple ProRes 422 capture preset, and it works. It records in real time from HDV directly into ProRes no problem. It’s just a stream. Except I’m asking it not to use tape but the live picture instead. It’s still just a stream and so it shouldn’t care. It should still do the same job of recording HDV to ProRes on the fly just like the tape. I think it’s something in how the control preset is written by Apple as compared to the HDV control preset. That’s just my take on it.

[Jeremy Garchow]

[Brian Corbin] “I mean a stream is a stream whether live or from tape it’s still having to make a conversion on the fly from HDV to ProRes.”

Actually, it’s not. With a firewire protocol, you aren’t sending uncompressed video, you are sending an encoded stream of HDV data. In the case of ProRes, you then have to decode and then transcode that stream to another file format (ProRes) and then write that now transcoded file to disk. This is not an easy process and it’s why when you use a firewire deck to transcode to ProRes, you will notice it lags a few seconds behind and the process is automatic, (meaning you don’t have much control over it).

With a live capture, there’s nothing governing that process, so if you start a capture and then end it, it would take a few seconds for FCP to finish transcoding the current file. If in that time you hit record again, it wouldn’t have enough bandwidth to finish transcoding the cached data, and being a new cache of the current incoming video.

With HDV, it is simply handing off the already encoded data and writing ti disk. Once you hit stop, it’s an easy process to close the file and get ready for a new one.

Hope that makes more sense. With a capture card you can do this in real time from the base band HD SDI video.

Jeremy

[Mark Petereit]

I’m seeing the same issue. When I capture from tape over Firewire to ProRes, there is no delay at all. It captures live (even says real-time in the capture window.) But nothing I try will capture live from the camera over Firewire to ProRes.

Bummer.