Matrox MXO Mini- L&T through FW or HDMI???

[Jonathan Levin]

Greetings everyone.

This has been an expensive week- new mac pro, HDD's, monitors, and a new Ipod classic.

I am ordering a Matrox MXO Mini today.

With my tape based Canon HV30, I would normally capture my video from the camera tape (1080, 30p) using a firewire cable to my old mac desktop. The new mac pro I ordered only has FW 800, no problem so I can order a FW 6 pin to FW800 adapter for a few bucks.

However, it occurred to me that the camera has an HDMI out. I was chatting with Matrox tech support (really nice people by the way) and I was told to capture the video from the camera using HDMI out on camera to the HDMI in on the Mini. Doing this would be an improvement in picture quality according to the folks at Matrox.

Does this workflow seem like sound advice? I guess my question would be, what difference it would make sine the video is already digitized and compressed as it is written to the tape in the camera, and whether or not FW or HDMI, it's just a pipeline to get video to hard drive.

Your input always appreciated.

Jonathan

[Geoffrey Cox]

I have a similar set up to you and use FW to capture. Not sure why HDMI via the Matrox would be better but like you I've always found the Matrox people very helpful. Try looking on the Matrox forum? Though I've never bothered surely the way to test this is to capture the same clip using each method and compare how they look?

[Andy Mees]

The HDMI to MXO2 Mini route gives you the option to capture in real time to a you choice of codec (including up, down or cross convert) any number of which would likely be preferable to HDV, so there are advantages for sure ... but as you note yourself, there's no inherent qualitative advantage to the HDMI route vs native capture, w/ or w/o transcode.

Hope it helps
Andy

[William Hohauser]

Using HDMI means two things:

1) You are capturing a higher quality output from the camera than is possible via an mpeg transport stream thru FireWire. The caveat is that it's a higher quality output of the same mpeg transport stream meaning that the quality is limited to the whatever the stream recorded. These days with real-time ProRes capture possible thru FireWire or just transcoding the files with Compressor after HDV capture, the quality gains you get might be limited. Maybe not, I haven't seen any qualitative tests comparing the HDV capture options since before ProRes was introduced. Perhaps someone has a link to a good comparison article. The captured files thru HDMI are larger as well, about 3 times larger.

2) HDMI capture means that you lose time code information. Each capture defaults to zero, however Apple's realtime ProRes capture does the same thing.

[Jonathan Levin]

Hi Geoffrey in UK,

Thanks for being the first to add to this. Hopefully someone may have tried this, but if not when I get my entire new rig set up, I'll be in a position to try this out.

If there is some quality bump from FW to HDMI, I'd sure like to have that extra advantage. Andy Mees who is one of a bunch of people I follow on this and other forums seems to be real knowledgeable about the Matrox system. So maybe he has some insight.

Cheers.

Jonathan

[Jonathan Levin]

Hi William,

I was just posting about Geoffrey's comment when I saw yours. Interesting indeed. For now, I have not needed the time-code for much of the work I'm doing, however I do see the importance of that in certain situations.

If in fact there is no little or no difference in the capture, than I might stick with FW, since I know that works, albeit, a little poodle-ish..

My thoughts are once video is captured to tape, it's compressed, re-conoitered, whatever. As far as I know, whether or not the signal from the camera/deck goes by FW or HDMI, it is just a pipeline. Maybe ones a bit faster than the other, but no difference in image quality plus or minus.

But I just don't know. So until I or someone else can confirm this, I won't sleep at night....

Thanks.

Jonathan