720/50p capture using Magma Expressbox + Aja Xena LHe + NEO HDV possible?
 

I would like to capture 720/50p from JVC HD251. I still don't know if using a Magma Expressbox - which is a PCIe 1x solution - with a AJA Xena LHe, - which is a PCIe 4x card, is a reliable solution?

My other question is that what mobile processor we need for the compression needs? I mean, in the page on Cineform's Tech notes, there is a Dell M1710 which can capture from the Sony HVR-V1U in 24p but not in 30p. They say it will be possible with the Santa Rosa platform and newer processors. It is not written on that page what resolution they captured in.

My thrid question is that is it possible to save uncompressed footage with almost no CPU usage but using a fast eSATA RAID system? I mean if we could handle 110 MB/s continous disk writes, then we wouldn't need that huge CPU power. It's entirely a theory, don't u think encoding in original YUV422 would mean almost no CPU usage?

CineForm did initial testing to verify functionality, but others that may have committed to this configuration in the field will have to comment on reliability.

Again we have not done any more performance testing beyond that done previously, so it's not possible to be definitive about what you need to capture 30p. You'll need to sustain another 20% speedup using a Santa Rosa processor which seems eminently doable given both the faster clock speed and faster FSB.

It's not a CPU issue. You can't get an uncompressed stream onto the drives on a laptop. Uncompressed 10-bit 1920x1080 30p YUV is about 155 MBytes per second.

I feel the same using today's laptop hardware, but I don't understand why. If there is no compression, then the CPU would just have to convert the SDI signal to some container, but doesn't involve any processing of the signal.

Could you tell me what is the MPEG2-TS option in NEO, and if it's available for HD-SDI signal? From the manual it's something like uncompressed data, which I was thinking about, but I don't understand how could it be possible to put HD-SDI into MPEG2-TS with no processing, because as I know HD-SDI has nothing to do with MPEG2, SDI is some type of native data on cables.

And a very important question: is it possible, or will it be possible with the next updates to aquire JVC's 25p and 50p format with NEO? On the website it's just 24p and 60p, but I think there is not programming difference between 24p <> 25p and 50p <> 60p in the case of JVC. It's all progressive, just the question of frame rate setting.

I'll repeat - uncompressed capture is not a CPU issue on a laptop, it's a drive bandwidth issue.

Neo is uni-directional. Almost any input format is converted to a CineForm file. Neo does NOT convert to anything else including MPEG2.

We support the 25p and 50p modes for capture already - it was an omission on our website that has now been corrected.

Thanks for the fast answers.

For the MPEG2 question it's about the option in NEO HDV > Capture > Prefs > Capture options > "Capture only the MPEG2-TS file (*.m2t)." What does it mean? I think it's not for HD-SDI, but what is it for?

Zsolt, CineForm's HD Link captures M2T files and converts them to CineForm files. You have a number of options when capturing. You can:

1. convert while simultaneously saving the M2T file on disk,
2. convert without saving the M2T file
3. capture the M2T files without converting. You would use this option if you want to convert later for various reasons.

Yes, I know that from the manual. I was asking that if is it possible with HD-SDI too, and what does it mean? It is a 8-bit 4:2:2 YUV data about 100MB/s for 720/50p?

You can capture HD-SDI into CineForm files using the Magma Expressbox hardware combined with a Xena card which is the discussion that started this thread. If you use Neo HD or Prospect HD the captured files are 10 bits with up to 1920x1080 spatial resolution. If you use Aspect HD or Neo HD the files are 8 bits with up to 1440 spatial resolution.

Official answer from Aja support:
"The Xena cannot run in a Magma enclosure. We have seen users attempt this before and they were not successful."

So far, the only possible way would be Intensity and HD-SDI>HDMI converter. Do you know if the Intensity card is 8-bit or 10-bit?

The Intensity card is 8 bits.

But you're only going to get 8 bits from the camera over HDMI anyway, so Intensity is not a limitation in this case. The good news is that your captured CineForm files become 10 bits which provides you the extra precision you need to carry around in post.