Canopus ADVC-100 external firewire capture box at DVinfo.net

Ron Edwards · May 10th, 2007, 08:39 AM

Has anyone taken an analog video signal out of a mini dv cam, ran into the ADVC-100 box then into a PC and out to a projector? Was there a lag in what was being shown on the screen and the live action?

Richard Alvarez · May 10th, 2007, 08:55 AM

Well I've captured 'live' from an analog cam through a Canopus ADVC 100 into my computer, and there's a lag there, so I can imagine going back out to a projector would only increase it.

John Miller · May 11th, 2007, 09:48 AM

There will be a lag.

Much of it is due to the Microsoft drivers responsible for sending DV to and from the computer. They use a fixed-size (non-adjustable) buffer.

I ran a variety of experiments and have shown that there is a delay of at least four frames between an image arriving at the camera's lens and it being display on the PC via FireWire. It's even more noticeable when you have DV coming in and then being sent back out. That creates about a 0.5 second lag.

Out of curiosity, why are you using the analog output from a MiniDV camcorder and an ADVC-100? Why not use the camcorder's own DV output and by-pass the ADVC-100? (Is it fried??)

John.

Ron Edwards · May 12th, 2007, 08:07 AM

John,
Thanks for your reply. We are trying to run two Cannon GL2 cameras that are about 80 feet from the computer which is running Media Shout. Media Shout allows us to add text (lyrics) over the video and send to our projector. We can easily run the 80' with composite cables. My understanding is Firewire runs longer than 6 feet becomes a problem. We do not own the ADVC-100 yet. Just looking for a means to get the video (with lyrics) to the projector with out the 1/2 sec. delay we see.
Ron

Richard Alvarez · May 12th, 2007, 08:27 AM

Firewire boosters. Google them.

John Miller · May 12th, 2007, 04:54 PM

Ron,

How are you feeding the signal to the projector?

During development of our DV Processor software, I became quite frustrated with the lag that the MS drivers introduce, especially when using the following general arrangement:

DV Camcorder Source-->Computer-->DV Output Device-->Analog Monitor

Consequently, I added full screen video output via the graphics card:

DV Camcorder Source-->Computer-->S-Video Output-->Analog Monitor

(with the option to do both simultaneously).

This second signal path creates a much smaller lag - small enough to be acceptable for live use.

It's possible that your software (Media Shout) is also introducing a lag.

John.

May 10th, 2007, 08:39 AM	#1
Ron Edwards Regular Crew Join Date: May 2004 Location: Fairview Heights, Illinois Posts: 148	Canopus ADVC-100 external firewire capture box Has anyone taken an analog video signal out of a mini dv cam, ran into the ADVC-100 box then into a PC and out to a projector? Was there a lag in what was being shown on the screen and the live action?

May 12th, 2007, 08:07 AM	#4
Ron Edwards Regular Crew Join Date: May 2004 Location: Fairview Heights, Illinois Posts: 148	Follow Up John, Thanks for your reply. We are trying to run two Cannon GL2 cameras that are about 80 feet from the computer which is running Media Shout. Media Shout allows us to add text (lyrics) over the video and send to our projector. We can easily run the 80' with composite cables. My understanding is Firewire runs longer than 6 feet becomes a problem. We do not own the ADVC-100 yet. Just looking for a means to get the video (with lyrics) to the projector with out the 1/2 sec. delay we see. Ron Last edited by Ron Edwards; May 12th, 2007 at 08:09 AM. Reason: added info

May 10th, 2007, 08:55 AM	#2
Richard Alvarez Inner Circle Join Date: Sep 2002 Location: San Mateo, CA Posts: 3,840	Well I've captured 'live' from an analog cam through a Canopus ADVC 100 into my computer, and there's a lag there, so I can imagine going back out to a projector would only increase it.

May 11th, 2007, 09:48 AM	#3
John Miller Major Player Join Date: Oct 2005 Location: Hillsborough, NC, USA Posts: 968	There will be a lag. Much of it is due to the Microsoft drivers responsible for sending DV to and from the computer. They use a fixed-size (non-adjustable) buffer. I ran a variety of experiments and have shown that there is a delay of at least four frames between an image arriving at the camera's lens and it being display on the PC via FireWire. It's even more noticeable when you have DV coming in and then being sent back out. That creates about a 0.5 second lag. Out of curiosity, why are you using the analog output from a MiniDV camcorder and an ADVC-100? Why not use the camcorder's own DV output and by-pass the ADVC-100? (Is it fried??) John.

May 12th, 2007, 08:27 AM	#5
Richard Alvarez Inner Circle Join Date: Sep 2002 Location: San Mateo, CA Posts: 3,840	Firewire boosters. Google them.

May 12th, 2007, 04:54 PM	#6
John Miller Major Player Join Date: Oct 2005 Location: Hillsborough, NC, USA Posts: 968	Ron, How are you feeding the signal to the projector? During development of our DV Processor software, I became quite frustrated with the lag that the MS drivers introduce, especially when using the following general arrangement: DV Camcorder Source-->Computer-->DV Output Device-->Analog Monitor Consequently, I added full screen video output via the graphics card: DV Camcorder Source-->Computer-->S-Video Output-->Analog Monitor (with the option to do both simultaneously). This second signal path creates a much smaller lag - small enough to be acceptable for live use. It's possible that your software (Media Shout) is also introducing a lag. John.