VHS to DVD conversion: problem with firewire, nfs, whatever

Svein Halvor Halvorsen svein-freebsd-questions at theloosingend.net
Mon Jun 27 12:41:24 GMT 2005

I'm trying to convert some of my old VHS cassettes to DVDs as those are 
more practical to hadle, and since the tape is becomming worn. I don't 
have a video-in intercafe on my wideo card, but I do have a digital MiniDV 
camcorder with the ability to do analog-digital pass-through by connection 
the output from my VCR tol A/V and the firewire link to my PC. I then 
press play on the VCR and use fwcontrol -R on my PC to cature. Peace of 

However: The fwcontrol utility prints out "n blocks padded" once about 
every minute, and "fwohci0: IR DMA buffer overrun" gets printed on the 
console. I guess my computer is not fast enough to receive the data, and 
that this might have something to do with the fact that I'm saving the 
fwcontrol output over NFS. Problem is that my laptop don't have the needed 
13 GB/hour storage space, and that my only firewire-controller is on that 
said laptop. 

However, I have a hard time grasping that this should be a problem. I need 
about 3.6 MB/s tranfer rate, and when dd-ing from /dev/zero to a file on 
the NFS-mounted filesystem, I get more than twice of that. Also the 
fw-bus seems fast enough, because I don't get these buffer overruns when 
saving to local disk (at least not as often, just once or twice an hour).

Can someone please point me to where I could find some info on either 
tuning NFS or my firewire bus. Could I pipe the output through some kind 
of buffer on its way to the nfs-mount, that could help a possibly unstable 
network transfer rate? How would I go about doing this? 

Any pointers?

Svein Halvor

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