Chroma Key with DVCProHD?

[Gary Adcock]

[stokestack] ” And regardless of what you’re doing, there’s still no reason not to ingest the footage in its native form over FireWire. You can then manipulate it and save the result uncompressed.”

Sorry G, that is not how it works, IF you put the content on scopes you will definitely see the difference, Content handled this way will be rejected by every network I know. One cable Major network will reject files uprezed via any thing but Teranex.

There is a VERY real difference in the look and feel of the footage in compressed vs uncompressed – and lets be realistic about the data flow –DVCProHD 720p24 @ 8bit is 44 megs a second data steam, and you can handle that type of content uncompressed without loss of quality or breaking the bank.

Oh and how do you monitor the footage, output to a different source etc without some kind out 3rd party card.

I’ve been working in DVCProHD for awhile, I cut regularly in FW only capture also, but I never do color correction or finish in anything but the UC space. ( and tape is only 8bit )

From IBC

Gary Adcock
Studio37
HD and Film Consultation
Chicago, IL

[Gavin Stokes]

Hey Gary,

I’m not sure you’re interpreting my posts correctly. If you have DVCPro material on tape and you bring it into the computer, it doesn’t matter how it gets in there as long as it stays digital and you don’t recompress. Decompressing it before it gets into the computer is pointless because it can’t possibly increase the quality. At best, it will be an exact duplicate of the already compressed images on the tape. Which is exactly what you get when you bring in the data over FireWire, at greatly reduced storage cost.

When you open the native DVCPro files in your compositing or editing app, they are decompressed at that instant and promoted to whatever the native, uncompressed workspace is for that app. From then on, they’re uncompressed, unless the software is crap.

Consider this scenario: You open a DVCPro HD QuickTime file in Shake, do a bunch of effects on it, and then write it out to an uncompressed QuickTime file. Alternatively, you play out your DVCPro HD tape over SDI and capture it to uncompressed QuickTime, process it with Shake, and then write it out to uncompressed QuickTime. The results are the same. All you’ve done with the SDI step is unnecessarily bloat the ingested data.

You mentioned uprezing, but I didn’t. I’m not talking about changing resolution. I’m just talking about getting the data into the machine. Doing it over FireWire and decompressing in software at the beginning of your pipeline is just as good decompressing outside the computer and sending the data over SDI. Why decompress the data before you’re using the images? Save yourself the time and storage space by decompressing only the necessary footage and doing it IN SOFTWARE.

Regards,
Gavin