Hdv
 

I just went to a Canon H1 presentation here in NY and it was a lot of "Yes the Final Cut 24F plug in is About to come out" kind of stuff we already know...

But one thing I didn't know:
That when you record to HDV and THEN stream it to your computer with HD-SDI (like Barlow Elton has done)...the camera UNPACKS the compression (except for the 4:2:0 colorspace) so it is like a raw capture
--except for the color space (which is what I seriously crave)

But Still, That's Awesome !
They said "No Artifacting"

Huh? Can you expand on that process? Do you mean capture the taped footage from the camera to the computer via HD-SDI instead of Firewire?

thats not possible. once yu conpress someting, the info mation disgarded is gone. it cannot be retrived.

That sounds misleading. Almost like you can undo the compression that has already been applied. I'd like to hear more about it but it seems unlikely that it could work this way. However it could be possible that Canon implemented a proprietary algorithm that would "unpack" the frames more cleanly and efficiently than the decoders built into NLE software......but even that is stretching it a bit.

I'd like to hear more on this though.......

Yes, if we were able to unpack the footage to an uncompressed format or at least close to it, in technical terms this would be called a "frickin' miracle".

:)

I'm just sayin'

Baloney.

SDI from HDV tape is no different than firewire capture via DVHS CAP.

Okay John, the pressure is on. Tell us what you know or else.

:)

True for lossy data compression. Note that some codecs use a lossless data compression, in which case, everything can be retrieved.

Best,
Christopher

I meant to be there today, but a flight delay caused me to miss my connection to Newark last night... so I'm missing out on the last hurrah for the H1 road show.

Anyway, I heard this same pitch at the Denver event but kept my mouth shut about it because I wanted to understand exactly what the deal is before sticking my foot in my mouth. Now that John's brought it up, I'll press for a better explanation (and I know exactly who it was that John talked to today).

Thanks Chris, I'm waiting patiently for a miracle. :)

No it is not! HDV is a highly compressed format. Color space and motion are compressed too and the missing information is permanently lost. Eight bit color has a maximum of 256 colors for each of red, green, and blue. 10 bit color has 1024 colors. This color is lost forever. Motion information exceeding the capacity of the compression scheme is also lost forever.

The only way you can get 4:2:2 1.4 Gbps HD SDI is to record directly to a recorder such as the Wafian HR1 or a Sony HD SDI tape deck. However even then, the motion is compressed somewhat but 10 bit color is preserved. The motion is much better too. The real damage is caused when you record to the HDV tape or 1394 outputs. All the benefits of HD SDI are lost. The biggest problem is not color space but motion recorded to the tape. HDV compression loses some of the action, especially in fast horizontal motion.

Canon talks out of both sides of their mouth here and did so at Canon's show at Paramount's Studio 19 in Hollywood last week. To the general public they yammer about HDV, and it's benefits, but to broadcast professionals, they go get the guy that knows his stuff, and the salesman goes on to the next prospect. After questioning them at the show, this is what they told me.

If you want the highest quality the H1 can deliver you can't use HDV. You have to record directly from the HD SDI outputs live. HDV is always be HDV (good or bad, depending upon your opinion). Canon just provides the output. You can decide to use it, that's up to you. It just costs much more.

At the show, all the H1s were attached to HD SDI monitors too to show the best image. And all the demonstrations were prepared with HD SDI equipment.

This allows Canon to serve more than one market. They can appeal to prosumers and broadcast facilities at the same time with the same camera. The difference is how you choose to use it.

--Dave

Thanks Dave, that's what I figured. I'm a little confused and, frankly, surprised that Canon would be even suggesting otherwise to users. It's not in their best interest to say something can be done when it clearly cannot.

It'll be interesting to see what Chris can extract from this spokesperson/technician from Canon.

Wow...What a response!

I dont mean to be mis leading, but that is what the woman in the info room told me. I asked her if she was sure and she said yes, it takes up more disk space as well.
I was a bit awed myself...
Don't kill the messenger...I am simply reporting what I was told

(I thought it was too good to be true and asked her if she worked for Canon and she said, No, she is just a private contractor)

Sorry, I didn't mean to be misleading...Apologies...Thanks Chris for the vindication


This is kind of what she was saying......Its really a shame it's not true...I wonder then why bringing in the HD-SDI from HDV takes so much more space...I was deleriously happy for the last few hours, alas

If you use HD SDI, it takes much more space to store 1.4 Gbps information than 25 Mpbs information. However if you record HDV out of the HD SDI port, you are just recording more information, in this case uncompressed HDV data.

That doesn't make it better, only bigger. Garbage in, garbage out they always say (not that it's garbage, that's just the expression). In other words, if you uncompress HDV it looks just like uncompressed HDV and takes more space to store it... but the information is still lost, it's just bigger (uncompressed).

I hope this helps.

--Dave

OK got it - Thanks Dave

She was specifically saying that the 4:2:0 color space does Not change but that everything else compressed is reconstituted. The data rate is probably where her confusion is
She said that was the process for the Video's that were shown to us in the first part of the demo (quite stunning projected)
...It's Funny they had the watchmaker there in person on a set, and were filming him