HVX to Powerbook Capture Results
 

Since many others are obviously considering this same setup for shooting instead of P2, I decided to start this thread is to compliment the one about optimizing setups for using a Powerbook for direct capture from the HVX.

I've been in testing mode for about 5 days on this combination and will report findings after I've had time to become more familiar with the performance characteristics and any unseen pit-falls I've run into.

Look for updates later this week.

Great, thanks!

Results, as Promised...
 

After 5 days of testing direct capture to the PB here's what I've learned - and the results were a bit surprising.

The capture method was done in 3 "modes" to test all configurations:

Mode 1 - Capture directly to the internal drive only - no external drive connected.

Mode 2 - Capture to an external drive using both on-board FW ports; HVX into FW400 port, External drive out from the FW800 port.

Mode 3 - Capture to an external drive on it's own FW bus using the LaCie PCMCIA FW800 card; HVX into FW400 port, External drive on the LaCie FW800 card port.

Since my project is going to be shot in 720p/30 that's the only camera mode we tested. We used a 10ft FW cable between camera and PB and both camera and PB were powered by their a/c connectors, not battery.

Of all the configurations, Mode 1 and 2 gave the most unexpected results.

In Mode 1 we had a 90% good capture with dropouts occurring mostly at the beginning of a clip. Once the internal drive stabilized the clip seemed to smooth out. It's certainly not a stable capture but it would work as a last resort if nothing else were available - but only for a short run and certainly nothing I'd attempt for a pro production. However, attempting to playback a clip from the timeline caused FCP to become unstable and it always stopped playback reporting dropped frames or worse, caused FCP to crash completely forcing a system reboot. Even with all the preferences set to "low" we could never get a stable playback - from the timeline. If we viewed the clip in the viewer instead it would play but often cause the system to lock-up.

Mode 2 was better - and worse. The capture had a few, really nasty dropouts where the viewer screen was full of bad data blocks, sound clicks and frame stutter. However the clip would play from the timeline, dropouts, clicks and all.

Mode 3 was perfect. No dropouts, no stutter and no sound clicks. Like tape, both the internal and external drives needed to stabilize during the first few seconds of capture, but after that it was smooth sailing.

NOTE: If you playback an HD clip from the timeline in a PB and hear sound clicks from the internal speakers even in "Mode 3" these clicks are not in the actual capture, it's a limitation of Core Audio's capability to handle HD content playback from the timeline in a PB. This is a known issue and Apple is working on a fix.

Is the capture directed towards a capture folder in the scratch disk?

And do the clips come as .mov files?

Rob
this is great News, thanks,

Hopefully the Final Cut Pro that is available next month will fix at least most of the issues.

Those aren't issues related to Final Cut Pro, they are issues related to the single firewire bus on a PB.

You'll note that once capture occurred in Bob's third configuration using the internal PB bus and a second firewire bus represented by the cardbus FW device, the issues disappear.

FCP 5 has a lot of overhead, and single firewire bus captures usually present a problem.

I have been trying to get this down myself... similar results. IMHO, it is still not stable enough for prime time.



ash =o)

David,

When using an external drive the capture was being directed to that external drive. All the other files, project, render, auto-save, etc were kept on the internal. However, "auto-render" and "auto-save" were turned off since we didn't want that to accidentally run in the background during a capture.

And you're absolutely right; the issues in Mode 2 are relative to forcing the same, single FW bus to do double work - both ingest and export HD footage simultaneously. Imagine trying to inhale and exhale at the same time - a human would simply pass out, a PB just gets a bad case of the hiccups! (laughs)

Ash,

We feel Mode 3 is absolutely ready for "prime time". In fact, it's a faster workflow than using P2 because the files have already been captured into FCP and don't require the MXF files being translated by FCP during import. You also get the added benefits of having shot, scene and clip naming conventions used for editing. This is a true DTE solution, just obviously not as portable as P2.

Great! Thanks Robert!

If you get a chance can you try 1 more thing? Just for the record...? Mode 3B, with the HVX on the Firewire PC card, and the drive on the built-in firewire? I know in the old days long ago there were some issues that indicated FCP preferred the camera to be on the built-in FW bus... but the built in bus provides bus-power for drives, while PC cards don't. So in some cases Mode 3B would be preferable...

Thanks again for very useful results!

Also, can you confirm whether FCP removes pulldown during capture?

-Barry

Real-Life Test
 

I just completed a day of interviews with Robert's setup ... mode 3, as it may have been called. I have a 17" PowerBook with 1 gig of RAM, a Lacie Firewire 800 PC card, a 500 GB OWC Firewire 800 RAID and, obviously, the HVX. I set up my system exactly how Robert suggested ...

I did three 30-45 minute interviews yesterday morning recording at 720/30 P ...

... and it worked PERFECTLY!

No dropped frames, no strange shutodwns, no errors.

I would stop and save from time to time but I had some captures that went for 20 minutes straight (not what I wanted to do but I simply forgot as I was also the interviewer.)

The footage just looked awesome and I haven't detected any drops or glitches.

Good news! Anybody want 3 4 GB P2 cards?! Just kidding :o)

Is anyonw willing to speculate on whether or not the new Duo with its 7200 rpm drive and the new version of Final Cut will be able to perform without the external drive? This would be a far simpler setup and make Steadicam shots, of which I do many, a feasable option with a well ventilated backpack.

Jerry,
Since day one I have been thinking along these lines.
Yet to try it though with the HVX - I have an older 17"PB (that has a 7200 drive)
a few thoughts:
- It's a bit big lugging it around in a shoulder pack and being careful with balance
- Fan noise from time to time
- and some folks have told me their concerns about moving a spinning hard drive (esp with Apple's new motion sensors)

But I still am trying to do this.
I am even thinking about tryingg it with an older 12" PB - just putting in a 7200 drive in it -
and strapping it to the Vest of my rig - That way I could use it as a monitor as well/

Lets see what Apple is going to release in the near future -- smaller/faster

Perhaps someone could investigate a way to replace the optical drive with a second HDD for capture...

Perhaps the FS-100 will be the best of both worlds. Large capasity and small to strap it on.