What are the absolute best video parameters for PT

[drguitar]

We are running an HD 1 system here on a dual processor G4. Panther running PT TDM 6.4. We seem to have figured out that the movie needs to be encoded in DV or dv/dvcpro to run well (or maybe that's just to be able to run out of the canopus). But we have only tried that with nothing but basically the video in the session and are worried about it possibly getting bogged down once the session gets thick.

I believe the old method of thinking in OS 9 was to limit the video file to 2 GB. I think that shouldn't probably apply anymore with how well panther takes advantage of processors, RIGHT?, especially dual processors and that the graphics card does most of the work in panther....am I correct about that thinking?

Also, does it matter what the resolution is or the what the movie data RATE is? We obviously would love to hear that file size, resolution, and data rate are not issues at all and that the only thing that is important is to have our video in the dv/dvcpro codec. so that it will look as good as possible both when using the canopus for output and when NOT using the canopus.

[drguitar]

bump..help!

[Frank Kruse]

the 2 GB limitation was because of HFS (non extended) or OS8.6 I think. This limit has nothing to do with the actual quality. It´s just unconvenient.

I have a DC30+ running 1meg/sec half pal size (384x288). Good picture and low PCI load. Don´t know about DV converters...

frank.

[Chief Technician]

It's DV or bust when using PT. Any other codec and PT chokes on it and slows to a crawl.

[jimlongo]

I wouldn't say that to all the people using motion-jpeg based pci card systems all these years. They can be quite efficient, low bitrate, small file size.

No matter what you use you are going to use resuources that PTs might want. PCI bus errors in the case of pci based systems, and Firewire bus traffic in the case of DV convertors.

That said if you are asking about DV the bitrate is fixed at 2.5 Mbps. Very large file sizes and very high quality on a monitor . . . i don't know about projection of that picture.

It works well and you can use iMovie to capture. iMovie will split video into 2GB clips. THere are various ways to stitch these together. I copy and paste together in QTPro and Save As . . . normally allowing dependencies, that creates a small reference movie that you can import into PTs.

hth

[matt connolly]

The advantage of DV - like old fashioned hardware based motion JPEG cards (a la miro & aurora) is that the video decoding is done by hardware. All Pro Tools / Quicktime has to do is stream the data to the driver, and it happens. Same with streaming DV video out the firewire port. Displaying the video on the Mac monitor is a different issue - this does require CPU power (with the exception of OS9 Aurora drivers that were very clever and wrote directly to the computer/VGA display).

Off loading the video decompression is desirable because it makes the CPU more response to the user interface, and allows more RTAS plugins.

For reference, DV Video data rate is 3.4MB/s. It is a fixed datarate codec. And it's about the same in PAL & NTSC.

[Tiago Silva]

The best thing about a DC30+ is the lack of it. Of latency, I mean.

Beware, though. The OS X driver for them LOATHES original Sawtooths... (PowerMac G4/AGP first series), but we have one running in a MDD (a G4/1.25 single processor) like butter. We use quarter-resolution PAL video files (captured with BTV) and limited to 1MB/s, so that helps. If we standardize on MDDs on all rooms, and now that we have storage space to spare, we'll probably go to half or full resolution in 2.5MB/s bandwidth and see how they handle it.

[jimlongo]

the miro card has latency just like any other system . . . less than your typical DV box, but not insignificant.

[jimlongo]

DV datarate expressed one of two ways

3.4 MB/sec megabytes per second
25 Mb/sec magabits per second

either way it equals about 1GB for 4m45s of picture with 48k stereo soundtrack.