[roach-commuter]

I've got an EVO board on one Octane and it's cable-connected to an SI video card. The board itself has a few BNC input/output ports and one S-Video (or S-VHS) port. I connected my VCR's scart with an adapter (which converts from SCART to composite and S-Video) and from there to the Octane via the S-Video cable. In the Video panel I chose Y/C and one of the 625  formats, can't remember which (I believe that's for PAL) and what I see on screen is a B/W picture of what the VCR is actually playing. What am I doing wrong? Why is the output only B/W on my octane? See pics.

[Raion]

It's possible your unit isn't tuned properly for PAL - that's my guess with a static B/W image as NTSC, SECAM and PAL all encode colors differently. Also, I'm sure you checked this, but watch out for French-built/marketed VCR. So yeah, this looks to be a config issue.

[robespierre]

625 line video can encode color in either the PAL, SECAM, or NTSC-I systems, which have the same monochrome format but incompatible color formats.

See this very enjoyable read:
http://g3ynh.info/photography/articles/analog_tv.html

In particular, the section "VHS Video Recording methods" describes some issues that can crop up with VHS players.
Is it a 525-format tape playing back on a 625-format deck? This can cause the output to be in a "hybrid color signal" that may be confusing to converter hardware.

Another thought:
The two pins of S-Video are a complete monochrome video signal, and the chroma subcarrier.
So if you disconnected just the chroma pin, you would see monochrome video (which you are seeing).
What's the story with your SCART adapter? Does it have any signal at all on the chroma pin? Does your VCR output chroma on the designated SCART pin (15), or does it use the older SCART pinout with no chroma at all?

See this page for the two different SCARTs:
https://www.rigacci.org/docs/biblio/onli...inout.html

[roach-commuter]

625 line video can encode color in either the PAL, SECAM, or NTSC-I systems, which have the same monochrome format but incompatible color formats.

See this very enjoyable read:
http://g3ynh.info/photography/articles/analog_tv.html

In particular, the section "VHS Video Recording methods" describes some issues that can crop up with VHS players.
Is it a 525-format tape playing back on a 625-format deck? This can cause the output to be in a "hybrid color signal" that may be confusing to converter hardware.

Another thought:
The two pins of S-Video are a complete monochrome video signal, and the chroma subcarrier.
So if you disconnected just the chroma pin, you would see monochrome video (which you are seeing).
What's the story with your SCART adapter? Does it have any signal at all on the chroma pin? Does your VCR output chroma on the designated SCART pin (15), or does it use the older SCART pinout with no chroma at all?

See this page for the two different SCARTs:
https://www.rigacci.org/docs/biblio/onli...inout.html

I am gonna do some testing with A) Different tape B) Different adapter and C) Different cable (Composite vs S-VHS) and I'll report back. Thanks for the precious suggestions!

[roach-commuter]

So basically, changing the cable from S-VHS to Composite fixed the issue and I can now see the videos in color. I have another problem now. My Octane has a 400Mhz CPU and 1GiB of RAM. I am using the 'media recorder' tool that is provided by Irix and I have set the stream to Quicktime Uncompressed PAL size. Very Often the recording stops because of dropped frames. Also when I manage to record some videos I can't hear any audio, is the audio supposed to be recorded together with it or separately?  Also which other software for Irix could I use to do acquisition from a VCR ? Thanks ! Please See attached pics

[jpstewart]

I have another problem now. My Octane has a 400Mhz CPU and 1GiB of RAM. I am using the 'media recorder' tool that is provided by Irix and I have set the stream to Quicktime Uncompressed PAL size. Very Often the recording stops because of dropped frames.

This I'm not so sure about, but it might be related to the quality of the incoming video signal.  In the Nekochan days somebody wrote a lot about video capturing on the O2 and how
a stable input signal was needed.  I seem to recall something was said about using a pro-grade VCR with a built-in Time Base Corrector (TBC) to ensure a clean input signal.  I wouldn't be surprised if the same holds true for the EVO.

But that's all a vague recollection to be taken with a grain of salt, until you either dig up the discussion in the Nekonomicon or somebody with more direct knowledge posts here.

Also when I manage to record some videos I can't hear any audio, is the audio supposed to be recorded together with it or separately?

The EVO is strictly video only.  You'll need to connect your VCR's audio outputs to the Octane's audio inputs.  But you've only mentioned the composite video cable which doesn't carry an audio signal at all.  Once you've made the connections, I'd expect 'media recorder' to be able to capture both simultaneously but it may require additional configuration to do so.

[roach-commuter]

Ok I figured out how to record Video + Audio from the VCR. Obviously you need to have the video composite cable plug into the BNC connector on the EVO board but you also need to have audio RCA cables from the VCR connected into the RCA ports on your Octane's system board. At that point it's just a matter of runnig the Media Recorder tool and choose the proper settings. Note: my audio panel settings were defaulting to the 'Microphone' input instead of the 'Line IN' and that's why when I did the initial testing no audio was recorded. You obviously need to change that. One thing I noticed is that on the current Octane (512Mb RAM and 300Mhz R12K cpu) I need to acquire video at HALF the PAL resolution and uncompressed if I want to get anything decent at all. Anything above that and capture fails. Maybe if I had a double 600Mhz with 4G of RAM things would be different. In this way the end result is a clip of approximately 1Gb x minute in Quicktime fomat, with .mov extension. I'll try to import that into my Mac G5 and see if I can further process it.

[robespierre]

Uncompressed video is pretty demanding for disk throughput.
Have you tried making a XLV stripe (software RAID0) across the internal and external SCSI busses and capturing to it?
That would be the best performance on the built-in hardware, I expect.

[roach-commuter]

Uncompressed video is pretty demanding for disk throughput.
Have you tried making a XLV stripe (software RAID0) across the internal and external SCSI busses and capturing to it?
That would be the best performance on the built-in hardware, I expect.

That's an interesting idea. Any special hw requirements? I bet U320 disks should do both internally and externally. For the external part do you recommend any specific storage solution ? Thanks in advance

[weblacky]

roach-commuter:

I think you may misunderstand how SCSI works. While it's all called SCSI, due to the command set, each adaptation has distinctions and many are DOWNWARD compatible (with help), except SAS and Fibre Loop (that's the SCSI command set in a brand new medium that isn't downwards compliant). ULTRA160/320/640 LVD SCSI is very different from the previous incarnations (SCSI-I/II/Ultra fast, Wide). You could get an U320 DISK that CAN be forced into Single-Ended (SE) mode to work on an Octane. But that won't make the SCSI Bus move any faster.

It doesn't magically become an U320 SCSI Bus. Theoretically, an Octane SCSI Bus is NOT FASTER than an O2 HDD SCSI bus, in practice...it will be slightly faster as it can handle the upper transfer rate/standard better. Now of course the Octane has two SCSI busses and Internal and external. So of course the entire Octane does not share a single Bus. You can expect MAX bus performance from an internal drive and an external drive at the same time.

But more drives on a single SCSI bus won't necessarily give you more speed.

Now comes the BUT moment. BUT, various vintages of mechanical drives have expected, achievable, max speeds. Modern consumer drives can reach 150MiB/s or slightly more due to VERY high plater sector density and newer ICs running the show.

An Octane UW SCSI bus should max at around 80MiB/s. Many of the drives from the 90's cannot actually MOVE that fast internally so having multiple, older, drives will actually show improvement due to parallel operation (assuming you setup parallel operation through LVM or the like). But a single (more moden) scsi drive at say 300GB, can absolutely MAX OUT a 80MiB/s SCSI bus (as long as the seek time doesn't drop that rate).

Remember, you're NOT dealing with HD video here (not really), the best you can get is basically progressive NTSC/PAL video (like a DVD) from the 90's. A nice SCSI drive of that time period or better vintage should be able to keep up with a single capture stream just fine.

Now, nothing is stopping you from ADDING more SCSI/Fibre/HBA buses (using shorehorn or PCI card cage) to attach MORE drives to more Buses (not shared).

If you're doing multiple streams, the ONLY accepted method was really using QLogic Fibre FC-AL HBA to a drive array. You can get 2Gb/s redundant HBAs for the Octane to give you MANY TIMES what a SCSI controller could do in the day.

And that's what video houses did. Fibre drives are very cheap on eBay (because only few people can run them now...but MANY business/data centers used them for 15+ years). Fibre FC-AL is still used as an interface for SATA/SAS cabinets for broad compatibility. In fact you could even use software like Linux SCST or another SCSI target mode setup to share normal SATA drives OVER FC-AL to your SGIs (I've done this). Because it's software the speed is a little lower than all hardware...but with correct drives will be fast enough for what you want using moden hardware (less the REQUIRED compatible Octane Fibre HBA and fibre channel cabling cost).

Even today (outside of like 10GB+ Ethernet iSCSI stuff) Fibre is STILL the go to way to connect storage area networks and this was well known back in the 90's.

So if you want the best speed you can get for video work, fibre channel - period. It's cheap because most places are off-loading it for favor of network-based storage solutions.

But you could pick up a couple Host Adapters (HBAs), two runs of Fibre, and either emulate or pickup a old drive array with actual FC drives in them for under $600 (less shipping). Most people consider FC drives trash because they cannot be adapted to parallel or serial SCSI. They are their own media standard. So they are sold like paving bricks!


I have 20-30 of these drives for older setups. Was always planning on using FC-AL for ALL SGIs I could (not all can do it) and then be able to attach storage remotely and share among my collection as needed. Since it's still in use today, you have A LOT more to choose from on the used market.