[tlacct]

I've got a lot of home videos that need to be backed up before they degrade any further. While I can use a USB capture card, it's not really an elegant solution because it creates weird artifacts and tends to lag.

Ideally I'd like to use my O2 because I have the A/V card. From what I've read, the A/V card should be perfect for capturing analog video from something like a VCR. I'm just not sure what software to use (the built-in recorder maybe?) and I don't want to fill up the hard drive. Has anyone ever used an O2 to convert tapes?

[Raion]

You'd also need to consider a TBC and other equipment.

[weblacky]

It's been awhile but I know there are command-line video capture routines and normally you don't do all the capture at once. You record each video segment at a time, then re-encode it. Normally I think the O2 can capture MJPEG, so you'll need to recompress anyway. Last capture I did was on Indy so I might be wrong, but it thought O2 was hardware optimized MJPEG.

I'd advise you to use a modern PC to run FFMPEG to encode to something like 480i MPEG-2 DVD. You'll need to fool with interlacing but you might get better. If you an find an S-VHS VCR you can do S-Video output (slightly better).

I don't know about performance, so I'm unsure if an O2 optional 10/100 ethernet card can actually keep up with an capture, so you may not be able to capture to network share, you may need to record locally and then upload the raws. But that's what I'd advise.

But that's how I'd do it, capture locally on O2, use 10/100 ethernet card to upload raws to a PC/MacOS/Linux whatever system. Fiddle with FFMPEG to do correct transcoding to final video version on PC. Use a standard set top playable format like Video-CD/DVD/Blu-Ray so you don't need a PC video player in the future. Once you get a work flow going, you can capture and then transfer, then batch re-encode while capturing again.

There is a reason the O2 was never given a Gigabit card (cannot handle the interrupt swamping)...so don't be tempted to send RAW captured video while capturing new video...you won't be able to do it well.

I used to use my O2 for Capturing DVDs as SGIs (O2 and Indy) are MACROVISION immune, so DRM didn't work on them. Works great.

[indigofan]

I did a bunch of captures back in the day on some work that I did for SGI. I captured and encoded to MPEG-1. You can also use Premiere to stitch together any videos. Works fine for old school VHS tapes.

[Raion]

Gigabit ethernet was also INCREDIBLY expensive at the time the O2 launched, not to get too off-topic.

Personally, if you have a high end VCR and TBC, an O2 should be great for this - especially if it can output S-Video. Modern PCs don't have as much support for old capture cards anymore, especially Windows 8 and 10.

[weblacky]

Gigabit ethernet was also INCREDIBLY expensive at the time the O2 launched, not to get too off-topic.

Let me fix that for you : "All SGI hardware was INCREDIBLY expensive at the time the O2 launched, not to get too off-topic."

I understand the real reason was that the CPU simply cannot handle Gigabit networking. The interrupts cannot be serviced that fast while actually using the station as a workstation. It's like trying to placing gigabit ethernet in a 1995 Pentium Pro or perhaps a 1998 pentium II. 

But what's cost?  Even if Gigabit ethernet was $3,000 USD an adapter in 1998, the stations are all much more expensive than that.  So it's not a cost thing, it was a limitation + end user experience issue.

[Raion]

Let me fix that for you : "All SGI hardware was INCREDIBLY expensive at the time the O2 launched, not to get too off-topic."

I understand the real reason was that the CPU simply cannot handle Gigabit networking. The interrupts cannot be serviced that fast while actually using the station as a workstation. It's like trying to placing gigabit ethernet in a 1995 Pentium Pro or perhaps a 1998 pentium II. 

But what's cost?  Even if Gigabit ethernet was $3,000 USD an adapter in 1998, the stations are all much more expensive than that.  So it's not a cost thing, it was a limitation + end user experience issue.

PCI bus is also limited in the O2, AFAIK, to 33MHz. That's not a lot of bandwidth, no matter how you slice it.

[weblacky]

I cannot confirm either way. Technically the O2 PCI Slot is PCI-X 64bit which may run at 66Mhz with a supported PCI-X HBA. However even if it was 33Mhz due to running a 32-bit HBA in the PCI slot that’s just over 100MB/s. Which is faster than the disk subsystem. So unless it’s too limited due to bus sharing the DMA speeds can keep up.

But again, TCP/IP in this case is CPU bound (cycles plus IRQ handling), not a simple DMA transfer.

https://forums.sgi.sh/index.php?threads/...rence.124/

Which is the real reason for lack of faster ethernet.