Recording from Mini HDMI out from AVCHD consumer Canon

[Chris7]

Hello,

I have a HF100, which I would like to record into ProRes using a Matrox MXO 2 Mini (just ordered), a 2.2 GHz MBP, and FCP6.

I assumed this was done via the mini-HDMI out into the HDMI in of the Matrox. I called Canon tech support to inquire what is the output of the HF100 through mini-HDMI. He said it is AVCHD. He also said you could plug it directly into a TV via a mini-HDMI to HDMI cable and it would play fine. (Obviously one or the other is not correct, as TV's don't have AVCHD converters build in).

So what is the output? How does a workflow like this work? (I had assumed the Camera's output was fairly uncompressed, but uncompressed 1920x1080 will not even sort of fit through an ExpressCard/34, so a bit confused here.)

As an aside, another member on this forum said my MBP was 0.2 GHz short of being able to record full 1920x1080, but that 720P would work. Matrox said I could use their hardware to downscale the image to 720P before it goes into the MBP, but 24P outputs with a telecine, so I think this may not work.

I appreciate your help,

Chris

 

[KeithPratt]

So what is the output? How does a workflow like this work? (I had assumed the Camera's output was fairly uncompressed, but uncompressed 1920x1080 will not even sort of fit through an ExpressCard/34, so a bit confused here.)

There's no such thing as "fairly uncompressed". HDMI is uncompressed. Video signals going down video cables are always uncompressed, it's data cables that can transport compressed stuff.

Is your ExpressCard/34 1.5Gbps? That's technically enough for 10-bit 1080i59.94. (You'd have no way of connecting fast enough storage to record uncompressed, though.) But e-mail Matrox and ask them what the score is.

Matrox said I could use their hardware to downscale the image to 720P before it goes into the MBP, but 24P outputs with a telecine, so I think this may not work.

Then I guess it'll do 1080i59.94 to 720p59.94. Which, as-is, doesn't really work for 23.976PsF.

 

[bigbossbmb]

the HDMI port on the cam should give you a live feed from the cam's sensor and bypass the AVC compression. With the MXO2mini, you'll capture to one of the ProRes codecs. You will not record uncompressed.

 

[Chris7]

Bigboss and Keith,

Thanks for your help here. Sorry been so long to get back – I’ve been overloaded with work. I don't know what's up with Canon tech support. I had talked to two different reps. I even called back and asked about a prosumer camera to see if the support was different. No. I'm looking at the Panasonic HMC150 for the future, and am starting to wonder if their tech support is any better.

There's no such thing as "fairly uncompressed". HDMI is uncompressed. Video signals going down video cables are always uncompressed, it's data cables that can transport compressed stuff.

Do consumer and prosumer cameras ever output uncompressed signals with chroma subsampling, say 4:2:2?

Is your ExpressCard/34 1.5Gbps? That's technically enough for 10-bit 1080i59.94. (You'd have no way of connecting fast enough storage to record uncompressed, though.) But e-mail Matrox and ask them what the score is.

I’m currently using a Sonnet Tempo Sata Pro ExpressCard/34, which I gets read speeds of about 185 MB/s with my Caldigit VR, according an AJA test. I just figured this is about 1.5Gb/s. The Matrox 2 Mini includes a different card. I’ll call Matrox later today.

 

[bigbossbmb]

I’m currently using a Sonnet Tempo Sata Pro ExpressCard/34, which I gets read speeds of about 185 MB/s with my Caldigit VR, according an AJA test. I just figured this is about 1.5Gb/s. The Matrox 2 Mini includes a different card. I’ll call Matrox later today.

The problem isn't getting uncompressed into the laptop, the difficulty is writing it to a hard drive. With the video signal going into your ExpressCard, you are left with FW800 for your hard drive (which isn't fast enough for uncompressed). That's why you must transcode to ProRes.

The HDMI on the camera will output an uncompressed 4:2:2 signal. However the image is only truly uncompressed if you are doing a live recording straight off the HDMI. If you are just playing back a previously recorded video through the HDMI, then the image has already been compressed.

 

[Chris7]

Matrox to which 1920x1080 codec?

The problem isn't getting uncompressed into the laptop, the difficulty is writing it to a hard drive. With the video signal going into your ExpressCard, you are left with FW800 for your hard drive (which isn't fast enough for uncompressed). That's why you must transcode to ProRes.

I have no use for recording uncompressed, just curious of what is coming out of the camera. ProRes would be fine, but you mentioned on another post that 2.4GHz is the minimum recommended for this, and my laptop is 2.2 GHz.

I don't know much about this stuff, but I have to wonder, how much difference does 0.2 GHz make? Is that really the difference between reliable vs. unpredictable capture?

Alternatively, is there a decent 1920x1080 codec that's a little easier on the CPU? AIC looks a ton better than consumer AVCHD, and I thought it was easier for the CPU to handle. I could then take out the telecine in post.

The HDMI on the camera will output an uncompressed 4:2:2 signal.

Interesting. Is the live feed off prosumer cameras like your Panasonic also outputing the same uncompressed 4:2:2 (of course, 720x1280 in your case)?

BTW, have you found Panasonic tech support to be fairly knowledgeable? Or does one pretty much learn this stuff from working with other professionals or from forums? Seems like I'm a bit in a no man's land here, not a pro, and not using standard consumer workflows...

Thanks again for your help,
-Chris

 

[bigbossbmb]

2.4ghz is what Matrox has found to always work... that's why they set it as a requirement. It doesn't mean that 2.2 won't work, but it's totally use at your own risk.

You might be able to go to AIC. You could also go to DVCProHD, but the codec quality isn't much different than AVC.

I don't have a panasonic cam, any more... the one I did have was a DVX.

 

[Chris7]

2.4ghz is what Matrox has found to always work... that's why they set it as a requirement. It doesn't mean that 2.2 won't work, but it's totally use at your own risk.

You might be able to go to AIC. You could also go to DVCProHD, but the codec quality isn't much different than AVC...

I assume that "AVC" a typo here, meaning "AIC," but please correct me if I'm wrong. I think I remember you writing here that DVCProHD looks much better than HDCAM EX, to which I would agree.

I got the MXO 2 Mini in the mail yesterday. Looking forward to trying it out. Thanks for your help here and on other threads.

 

[puckhead193]

I got the MXO 2 Mini in the mail yesterday. Looking forward to trying it out. Thanks for your help here and on other threads.

keep us posted, i'm interested in ordering one!

 

[joaoferro37]

The problem isn't getting uncompressed into the laptop, the difficulty is writing it to a hard drive. With the video signal going into your ExpressCard, you are left with FW800 for your hard drive (which isn't fast enough for uncompressed). That's why you must transcode to ProRes.

The HDMI on the camera will output an uncompressed 4:2:2 signal. However the image is only truly uncompressed if you are doing a live recording straight off the HDMI. If you are just playing back a previously recorded video through the HDMI, then the image has already been compressed.

You can go around using

http://www.timelinedigitalinc.com/i....html?osCsid=69af1382c17a1d7ec7719ce60277f0f2

It will add up to 3 additional PCI-e slots for any laptop with xpress34 slot.
you can add a high point or areca card, a BlackMagic Design Decklink HD card.