video capture with o2 - general questions

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GIJoe
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video capture with o2 - general questions

Unread postby GIJoe » Sat Mar 12, 2005 7:53 am

for years i've been looking at the sgi o2 as an underpowered, overpriced doorstop, fitted into an attractive case and that being it's biggest and nearly only selling point nowadays.
i've worked with such boxes back in 97 - 99 and never had to do anything video-related on them so i do not know much about it's capabilities in that area.
now i'm looking to replace my pc based video-capturing device which is aging and not playing well with newer pc hard- and software.

for the first time i'm considering an o2 here to replace that capture card.

what i want is something that:
- supports mjpeg in hardware (ICE does this afaik)
- can play back movies directly onto a tv, preferably through the sgi movie player (there is the control->output video to... option in sgi's media player - does that do the trick or is there other software, bundled with o2?)
- can be used to hook up another device (camera, videorecorder, dvd, etc) to it's video-in ports, display the signal in a movie window and grab it without frame-loss
- can do PAL in broadcasting quality
- does not take hours over hours to generate a mjpeg movie file
- can generate mjpeg in reasonable (read: short) time from uncompressed video - or convert into such frame sequences
- is not a wussy when it comes to being powered on and off on a daily basis

does the o2 meet these requirements? and if so, what kind of cpu/memory would i need for these tasks?
also anything else important to look out for - mobo-rev's, etc?
i'd most likely be using 6.5.12, would that be too old for capturing tasks?

i'm not looking to do anything else than video in/output on the box. no video-editing, whatsoever.

looking forward to helpful insights :) and hopefully to revise my opinion of the o2 in a positive way in the near future.

GIJoe
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Unread postby GIJoe » Sun Mar 13, 2005 2:16 pm

well, seems like i have to answer this myself.
have spent some time researching this weekend and found at least some answers:

    - seems like o2 is one hell of a picky machine when it comes to grabbing from consumer level (s)vhs equipment. my capture card does this without moaning and with hardly any frame drops as well
    - seems like certain irix versions are better suited for the tasks than others. media tools are apparently somewhat buggy/unreliable. now that's nasty... however i'd try with 6.5.12 in any case first
    + command line tools like dmplay/dmrecord would probably enable me to hook the o2 up via LAN and remote control capture/output from PC or octane. yummy, would like to put the box near the TV and video equipment instead of having to bring that stuff to the computer-corner anyway
    + seems like it's possible to output the graphics display via videoout. even more flexibility, that'S what i'm seriously missing from my PC-based capture board's software
    + seems like i could kiss the stupid windows filesize limit goodbye


now i guess a config like R12k-300+, 256 MB RAM or more and a decent 36- or 72 GB R10k harddrive would be sufficient for capturing in a reliable fashion.
i figure it should be possible to strip my spare octane cpu and put it into an R12k o2?
is it possible to have the o2 take the source from the video input, capture it AND put it out at the same time?
also, is there a codec that can be installed on the PC to compress movies into a format, that o2 can play through it's video out?

TeeTylerToe
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Unread postby TeeTylerToe » Sun Mar 13, 2005 3:44 pm

I don't know that of what I speak, but running package manager, I noticed a lot of 32 bit, and 64 bit stuff, I assume making sure the applicable packages installed were 64 bit would be a prerequisite for bypassing that file size limit.

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zafunk
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Unread postby zafunk » Sun Mar 13, 2005 4:12 pm

GIJoe wrote:now i guess a config like R12k-300+, 256 MB RAM or more and a decent 36- or 72 GB R10k harddrive would be sufficient for capturing in a reliable fashion.


If all you're doing is capture, an R5K 180 would be fine. Move the captured footage over to a PC/Mac for all editing and encoding.

Someone else could confirm this, but a TBC is needed if you're capturing from less than perfect source. I don't have experience grabbing from tape, I did all my tests using LaserDisc as source material. I captured in 30 to 60 minute blocks without any frame loss. No TBC.

Fast and big HD's are a plus. I captured to two 7200 RPM 18 GIG external disks (In sun 611 enclosures). The disks were striped together.

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GeneratriX
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RAM-Hungry

Unread postby GeneratriX » Sun Mar 13, 2005 7:57 pm

zafunk wrote:If all you're doing is capture, an R5K 180 would be fine. Move the captured footage over to a PC/Mac for all editing and encoding.


Hi ;)

Yes, I can say it for sure: an O2 R5K/180MHz can make full resolution, full rate, captures perfectly. Video playback is smooth too.

zafunk wrote:Someone else could confirm this, but a TBC is needed if you're capturing from less than perfect source.


Yes; a TBC unit is good to get more polited sync bursts, thing that helps a lot to the pretty picky O2 analog capture module.

But it turns a little bit less necessary if you use S-Video connections, that are in fact a lot cleaner kind of signal transmission that those composite video sources. Add to this the fact that many S-Video sources are ProSumer quality devices, with more spatial analog resolution, better Signal-To-Noise relation, and better dynamic range. Chroma and Luma is improved a lot. Not to mention that many S-Video devices are with built-in TBC(s).

zafunk wrote:Fast and big HD's are a plus. I captured to two 7200 RPM 18 GIG external disks (In sun 611 enclosures). The disks were striped together.


Three 7200 RPM SCSI disks are probed as close to better, considering performance/price/capacity relation; and you can stripe it easily on IRIX by software, with great performance. Enough to capture/play uncompressed video if your disks are decent units.

Three 10000 RPM SCSI disk units are of course even better, and I could suggest four disks if you think to do tons of uncompressed video I/O with audio.

If you plan to use IRIX versions greater than 6.5, RAM of >256 MBytes helps a lot on R5K/180MHz; if you target to only IRIX 6.3, you can use the O2 as a cute and sophisticated external capture board (or DDR), using just 64 MBytes.

Of course, if you are a serious IRIX 6.5.XX user, I could suggest RAM of at least 512 MBytes, whatever processor could you have. O2 is a RAM-hungry box! ;)

Good luck!
Cheers! ;)

TeeTylerToe
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Unread postby TeeTylerToe » Sun Mar 13, 2005 11:17 pm

isn't the 611 only 8 bits wide internally...
/me pats his 611 with a sun cd 32x sitting next to him
do you just use the powersupply, and bypass the scsi electronics?

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zafunk
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Unread postby zafunk » Mon Mar 14, 2005 5:16 am

TeeTylerToe wrote:isn't the 611 only 8 bits wide internally...
/me pats his 611 with a sun cd 32x sitting next to him
do you just use the powersupply, and bypass the scsi electronics?


I just used a stock 611. No modifications. My point being that capture is possible even with fairly low end hardware. You could (in North America at least) put together such a system for around $150- with parts found on ebay. Makes me want to cry when I think of how much I've spent!

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Dr. Dave
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Unread postby Dr. Dave » Mon Mar 14, 2005 6:29 am

Interestingly the 'pickyness' of the O2 regarding video timing in 6.5 is there by design... I was messing around here one day with a video source that was a bit 'off' in frequency, and on the exact same hardware where in 6.5 it would just not sync, synced up fine in Irix 6.3. I believe I read a reference somewhere about this.

jdboyd
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Unread postby jdboyd » Mon Mar 14, 2005 9:57 am

GIJoe wrote:[list]- seems like o2 is one hell of a picky machine when it comes to grabbing from consumer level (s)vhs equipment. my capture card does this without moaning and with hardly any frame drops as well


Or you can by a piece of equipment to fix the signal before feeding it to the O2. Such an item should not be hard to find. Reportedly a time base corrector is enough. I am using a set of SDI adapters to accomplish cleaning up the signal.

GIJoe wrote:- seems like certain irix versions are better suited for the tasks than others. media tools are apparently somewhat buggy/unreliable. now that's nasty... however i'd try with 6.5.12 in any case first


Some versions (I think .16 in particular) are known to be buggy. However, .15 is widely regarded as the best. I haven't had any trouble with .20, and others have had good results with other relatively new versions as well.

GIJoe wrote:+ seems like it's possible to output the graphics display via videoout. even more flexibility, that'S what i'm seriously missing from my PC-based capture board's software


That works pretty darn nicely to.

GIJoe wrote:now i guess a config like R12k-300+, 256 MB RAM or more and a decent 36- or 72 GB R10k harddrive would be sufficient for capturing in a reliable fashion.


Or a R5.2k. However, I'm getting reliable results from a r5k-180. In fact, I'm making apoint of not upgrading this machine specifically to add evidence that it is a just fine machine for certain things.

GIJoe wrote:is it possible to have the o2 take the source from the video input, capture it AND put it out at the same time?


Well, you can set the output to mirror the input, but I suspect that's not what you mean. But, I don't really know what it is you want to do here.

GIJoe wrote:also, is there a codec that can be installed on the PC to compress movies into a format, that o2 can play through it's video out?


Good question. That is on my todo list, although by codec on PC I mean conversion on linux.

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GeneratriX
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M-JPEG A

Unread postby GeneratriX » Mon Mar 14, 2005 4:28 pm

jdboyd wrote:Good question. That is on my todo list, although by codec on PC I mean conversion on linux.


You can just capture with MediaRecorder, choosing "Tasks>Movie>Video Production (Cross-Platform JPEG)"

This will generate a clip with the following parameters:

Video

File Format: QuickTime
Compression: QuickTime JPEG A
Quality / Bit Rate: As Desired
Frame Size: NTSC / PAL / Or Custom
Interlacing: Two Fields
Packing: YCrCb422

Audio

File Format: QuickTime
Channels: Stereo / Mono
Sample Rate: 44.1 (CD) KHz
Sample Width: 16-bits

With any other program supporting DigitalMedia, you can choose "M-JPEG A" as compression CODEC, being safe that there'll be intrepreted correctly on any PC/Mac NLE videoediting host supporting QuickTime (M-JPEG).

Good luck!
Cheers! ;)

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Unread postby recondas » Mon Mar 14, 2005 6:16 pm

TeeTylerToe wrote:isn't the 611 only 8 bits wide internally...


Apparently it comes in at least two flavors - I've got three here with 68 pin interfaces <all with closed faces and HD's installed - internally the interface is SCA> I've got a Sun external CD box that's narrow <50 Pin>, but it's a 411.

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lewis
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Unread postby lewis » Tue Mar 15, 2005 4:57 pm

TeeTylerToe wrote:I don't know that of what I speak, but running package manager, I noticed a lot of 32 bit, and 64 bit stuff, I assume making sure the applicable packages installed were 64 bit would be a prerequisite for bypassing that file size limit.


Nope, happily XFS only needs 64 bit integer support (which O2 has), not 64 bit addressing (which O2 does not have).

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lewis
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Unread postby lewis » Tue Mar 15, 2005 5:05 pm

If you're only capturing to MJPEG, you don't really need fast disks. It's only a couple of meg a second. The O2's analog video bits are not "broadcast" quality, but they compare well to almost any current analog solution in the PC world AFAIK. The ICE can do MJPEG down to about 4:1, depending, which isn't strictly "broadcast" but looks okay.

An O2 with a big disk would make a pretty nice little pseudo-DDR, but... Windows Media Centre Edition will do all this a lot more slickly.

GIJoe
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Unread postby GIJoe » Wed Mar 16, 2005 10:37 am

does uncompressed capturing work at all? in that case i'd probably stripe over two disks to make sure that diskspeed is no bottleneck.

that would of course only be the preferred solution IF o2 (say: R12k-300 or upwards) can play back uncompressed PAL through it's video out as well given that the harddisk(s) are fast enough.

anyone tried? and in such case - will it write an uncompressed video file that i have to convert into sequences or will it write and read tga's , rgb's or whatever?

edit: what's windows media centre?

TeeTylerToe
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Unread postby TeeTylerToe » Wed Mar 16, 2005 10:59 am

there be three versions of windows XP, home, pro, and media center. media center is the one that's designed for set top boxes & stuff.


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