Causes of framerate drop in capturing? at DVinfo.net

Ben Boer · March 10th, 2006, 05:27 PM

If it were PC spec/issues related, please explain what the main causes of a drop in frame rate, during capturing (DV) would be.

Robert M Wright · March 16th, 2006, 09:45 AM

There can be many causes. Multi-tasking your computer during capture can cause dropped frames (don't mash a spreadsheet at the same time you capture). Badly fragmented hard drives can cause dropped frames. Those are two biggies.

David Kennett · March 16th, 2006, 04:45 PM

Make sure DMA is enabled on the capture drive.

David Ellis · March 16th, 2006, 10:01 PM

how do you enable DMA on captured drive?

David Kennett · March 17th, 2006, 09:09 AM

David,

DMA is enabled in BIOS, and is probably enabled by default on newer computers. Getting into BIOS is obscure on my Toshiba laptop - usually hit delete during boot-up.

Before pursuing this further, if you send me an email, I can get your address, and attach a small program that checks drive throughput for DV capturing. I don't see a way of sending attachments through the forum. That pgm will tell you if it's drive performance or something else.

Glenn Chan · March 17th, 2006, 05:02 PM

DMA can also be enabled/disabled in Windows. Windows will try to run the drive in DMA mode, but may drop down its speed if the drive is generating errors (to the PIO interface mode). This can happen easily with CD/DVD drives, since scratched CDs will generate errors.

To make sure Windows hasn't disabled DMA (or the fastest form of it that the drive supports):

Go to control panel
system
hardware tab
device manager
IDE ATA controllers- something like that
expand that branch out
get properties on one of the channels
go into the advanced tab
Read off the transfer rate mode.

Also do that for the other IDE channel (primary/secondary).

2- DMA in the BIOS will almost certainly be on, unless the computer is very old.

3- Are you capturing to an external hard drive? That can sometimes cause problems. Capturing to an internal drive will work in that case (usually).

DMA/PIO is not a problem for external drives.

March 10th, 2006, 05:27 PM	#1
Ben Boer New Boot Join Date: Feb 2006 Posts: 6	Causes of framerate drop in capturing? If it were PC spec/issues related, please explain what the main causes of a drop in frame rate, during capturing (DV) would be.

March 16th, 2006, 04:45 PM	#3
David Kennett Major Player Join Date: Jul 2003 Location: North Ridgeville, Ohio Posts: 407	Make sure DMA is enabled on the capture drive. __________________ Dave

March 17th, 2006, 09:09 AM	#5
David Kennett Major Player Join Date: Jul 2003 Location: North Ridgeville, Ohio Posts: 407	David, DMA is enabled in BIOS, and is probably enabled by default on newer computers. Getting into BIOS is obscure on my Toshiba laptop - usually hit delete during boot-up. Before pursuing this further, if you send me an email, I can get your address, and attach a small program that checks drive throughput for DV capturing. I don't see a way of sending attachments through the forum. That pgm will tell you if it's drive performance or something else. __________________ Dave

March 16th, 2006, 09:45 AM	#2
Robert M Wright Inner Circle Join Date: Jan 2006 Location: Minnesota (USA) Posts: 2,171	There can be many causes. Multi-tasking your computer during capture can cause dropped frames (don't mash a spreadsheet at the same time you capture). Badly fragmented hard drives can cause dropped frames. Those are two biggies.

March 16th, 2006, 10:01 PM	#4
David Ellis Regular Crew Join Date: Dec 2005 Posts: 35	how do you enable DMA on captured drive?

March 17th, 2006, 05:02 PM	#6
Glenn Chan Inner Circle Join Date: Jun 2003 Location: Toronto, Canada Posts: 4,750	DMA can also be enabled/disabled in Windows. Windows will try to run the drive in DMA mode, but may drop down its speed if the drive is generating errors (to the PIO interface mode). This can happen easily with CD/DVD drives, since scratched CDs will generate errors. To make sure Windows hasn't disabled DMA (or the fastest form of it that the drive supports): Go to control panel system hardware tab device manager IDE ATA controllers- something like that expand that branch out get properties on one of the channels go into the advanced tab Read off the transfer rate mode. Also do that for the other IDE channel (primary/secondary). 2- DMA in the BIOS will almost certainly be on, unless the computer is very old. 3- Are you capturing to an external hard drive? That can sometimes cause problems. Capturing to an internal drive will work in that case (usually). DMA/PIO is not a problem for external drives.