iMac Firewire to camera issues.

Hello all, I have an interesting problem involving an iMac and connecting it to cameras through firewire.

I would like to note that using just one camera connected to the firewire port works with no issues.

The problem is that I need to (if its possible) connect two cameras to one iMac. These cameras need to be able to work together in Ustream Producer to facilitate live broadcasts.

This is a problem that I inherited upon taking this job, so here is what is currently in place.

An iMac 20" with a core 2 duo processor, running an up to date installation of Leopard, and it is less than 1 year old. The iMac has one 800 Mbs firewire bus, and just one firewire port on the back.

The person before me bought a powered firewire hub to connect the two cameras and then connect the hub to the pc.

When Ustream is launched, a notification is displayed that states the firewire bandwidth has been exceeeded.

If I go to the system profiler, it shows the firewire bus with these two cameras attached, and that neither of them can exceed 100 Mbs bandwidth use.

I have, on occasion, managed to get both cameras to work in Ustream Producer but it never works for more than 15 minutes before completely conking out.

So my question is, why are these cameras exceeding the available bandwidth, when the iMac indicates it can handle far more than what can be used?

I don't believe the camera models are particularly important (happens irregardless of camera used) but I will get the models if anyone is interested.

If anyone has suggestions on how to fix this issue it would be appreciated.

Thanks.

I'm assuming that each camera can use the full bandwidth when attached separately without utilizing the hub? Have you run tests to see if that's true?

Two things to check: The hub itself may be eating bandwidth or the iMac 800 MBS FW port or circuitry may not be functioning correctly. Running the Apple Hardware Test on the machine should be able to spot a malfunctioning circuit.

Another thing to think about - is that while FW devices can be daisy chained (similar to SCSI) a hub is probably going to add overhead.

Regards.

Sorry for the delay in getting back to you on this.

Bandwidth issues do not occur if just one camera is in use at a time. Its when the hub is involved that it becomes a problem. I do not have the OS disc for this Mac, so I can't run the hardware test.

Right now I have both cameras hooked up through the hub to the Mac. This is what is displayed in the system profiler:


FireWire Bus:

Maximum Speed: Up to 800 Mb/sec

VIXIA HV40:

Manufacturer: Canon
Model: 0x10
GUID: 0x850001EE40B4
Maximum Speed: Up to 100 Mb/sec
Connection Speed: Up to 100 Mb/sec
Sub-units:
VIXIA HV40 Unit:
Unit Software Version: 0x10001
Unit Spec ID: 0xA02D

Unknown Device:

Manufacturer: Unknown
Model: Unknown
Maximum Speed: Up to 800 Mb/sec
Connection Speed: Unknown

Unknown Device:

Manufacturer: Unknown
Model: Unknown
Maximum Speed: Up to 800 Mb/sec
Connection Speed: Unknown

Unknown Device:

Manufacturer: Unknown
Model: Unknown
Maximum Speed: Up to 800 Mb/sec
Connection Speed: Unknown

DCR-HC52:

Manufacturer: Sony
Model: 0x380164
GUID: 0x800460103DC76CE
Maximum Speed: Up to 100 Mb/sec
Connection Speed: Up to 100 Mb/sec
Sub-units:
DV-VCR Unit:
Unit Software Version: 0x10001
Unit Spec ID: 0xA02D



I'm beginning to think the iMac is having difficulty correctly recognizing the hub.

I hope it's okay to post another question on this thread. I am trying to transfer video from my Canon Vixia HV40 to my new iMac via firewire cable and the computer is not recognizing the camcorder. I have rebooted; unplugged everything and no luck. If anyone can help me I would really appreciate it. I am beyond frustrated!

I'm beginning to think the iMac is having difficulty correctly recognizing the hub.

Click to expand...

It looks that way from what you posted from the System Profiler. If possible, you might try using another hub although I'm not sure that's going to help with the bandwidth. Make sure if you do buy another hub (they're not cheap) that you can return it for a refund.

And, you really need to get hold of a set of install disks for your machine. They're necessary for trouble shooting.

Regards.

@sskeen

I hope it's okay to post another question on this thread.

Click to expand...

It's neither OK or polite to jump in on someone's else's thread. If you have something to add or assist by posting, that's fine.

To answer your question.... Make sure you're using the correct firewire cable and your Canon is turned on when connecting. If your Canon has a USB output, try that instead. You might also open Disk Utility to see if the Canon is showing up there.

Regards.

chscag said:

It looks that way from what you posted from the System Profiler. If possible, you might try using another hub although I'm not sure that's going to help with the bandwidth. Make sure if you do buy another hub (they're not cheap) that you can return it for a refund.

And, you really need to get hold of a set of install disks for your machine. They're necessary for trouble shooting.

Regards.

Click to expand...

Yeah my next step is going to be trying a different hub. This one is generic as generic gets. No brand, model, nothing to identify the manufacturer.

I do not have the install discs because the university keeps OS discs deemed necessary in a central location...I could go borrow one but if the hardware is at fault, it probably wouldn't be working flawlessly with one camera.

Regarding sskeen's issue, I have not tried pulling recorded video off this Canon camera yet, but I have noticed that I have to set the camera to playback mode to initialize the connection to the Mac. If you're trying to pull stuff off in camera mode, its worth seeing if setting it to play mode works better. I know that doesn't make sense, but thats what I got to do to get this camera to be picked up by Ustream.

I have trouble having my Canon camcorder and my external firewire 800 drive connected at the same time. When I have one or the other, they work fine. When I connect both for capturing into FCP, the camera will not operate. I'm not sure, but I heard that this might be an issue with Canon video cameras. It sucks because I have to capture my footage onto my HD then transfer them over to my external drive.

I know that this post is old, but I wanted to let you guys know that I have tried a different mac that has 2 firewire ports.

The unavailable bandwidth issue still exists, even though system info shows this:

FireWire Bus:

Maximum Speed: Up to 800 Mb/sec

VIXIA HV40:

Manufacturer: Canon
Model: 0x10
GUID: 0x850001EE40B4
Maximum Speed: Up to 100 Mb/sec
Connection Speed: Up to 100 Mb/sec
Sub-units:
VIXIA HV40 Unit:
Unit Software Version: 0x10001
Unit Spec ID: 0xA02D

DCR-HC52:

Manufacturer: Sony
Model: 0x380164
GUID: 0x800460103DC76CE
Maximum Speed: Up to 100 Mb/sec
Connection Speed: Up to 100 Mb/sec
Sub-units:
DV-VCR Unit:
Unit Software Version: 0x10001
Unit Spec ID: 0xA02D


This mac can detect both devices no problem. Both cameras in use would be 200 Mb/sec use max. No other firewire devices or hubs are in use. The bus is supposed to handle 800.

Something just doesn't add up here. If anyone has any further input that would be great. I am also going to get into contact with Ustream directly to see what they have to say about this.

Here is how I understand firewire...

As you noticed, your miniDV firewire cameras operate at 100Mbit/s. In all the cases you mentioned, they are sharing a common bus. As I understand it, the bus will only operate as fast as the closest attached device and does not allow for simultaneous communication with more than one device at a time. So, two cameras connected to an external hub (or two built in ports on a Mac) is not going to get you 200 Mbit/s of bandwidth to share. The serial interface communicates with one device at a time and switches very quickly.

"When Ustream is launched, a notification is displayed that states the firewire bandwidth has been exceeeded."

It would be interesting to know if the problem might be with the UStream software specifically. I'd try testing that. Hook up both cameras and use two other applications such as iMovie and Final Cut to preview the input from the cameras. If you don't get problems with that, then I would suspect the Ustream software is the bottle neck.