DV Info Net

DV Info Net (https://www.dvinfo.net/forum/)
-   Canon XL H Series HDV Camcorders (https://www.dvinfo.net/forum/canon-xl-h-series-hdv-camcorders/)
-   -   Tapeless future for the H1? (https://www.dvinfo.net/forum/canon-xl-h-series-hdv-camcorders/56834-tapeless-future-h1.html)

Steve Rosen December 26th, 2005 10:53 AM

Tapeless future for the H1?
 
I asked this queston in another forum and was jumped on by the Panasonic fans who recommended that I get an HVX 200...

Does it seem possible that when P2 cards become an affordable option that a device could be developed that would take advantage of the uncompressed HD available from the Canon?

I realize it would involve audio and timecode cable and sync issues, but wouldn't that be a bright future to look forward to? Is there some technical reason that this can't happen? Steve Rosen

Shannon Rawls December 26th, 2005 12:44 PM

Steve,

One company is already one step ahead but more then likely won't do it. I asked them about capturing a raw file, and they said there's no way they could do it via portable hard drive or flash memory. Just too much data.

Instead...

The portable device will be able to capture your HD-SDI signal to a choice of other codecs. (CINEFORM, SONY YUV, AVID HD, HDCAM, DVCPRO-HD, etc...) They said this can be easily done to flash memory or a tiny 2.5mm hard drive.

Only problem he told me...

The damn HD-SDI output on the Canon XL-H1 doesn't give any timecode or audio. Video signal only. And because of that, the device would have to generate its own timecode, and now we have another pile of issues to address....which in fact....may not inspire them to ever release the device because it might not sell well.

- ShannonRawls.com

Steve Rosen December 26th, 2005 02:18 PM

I wonder why they couldn't use TC and audio out from the camera. It would mean lot's of cables, admittedly, but better than nada... or, and this is really off the wall and I don't know if it's even technically possible (remember I'm not a techno person)... output the raw file from one port and a reference file w/ audio and TC from firewire...

Sounds complicated, but I remember more than a few years ago a friend of mine wrote an article for a mag in which he suggested that in the forseeable future we would be capturing video to something "like a floppy disk", he got a lot of "you're an idiot" mail.. but guess what, the future is here...

My personal opinion is that HDV is a transitional acquisition format, mainly because the audio is poor and everyone's running into the woods screaming "compression artifacts!!" and "drop-out, drop-out!!" (by the way, I've shot 5 Sony ME DVM63 HD tapes this last week and haven't had a drop-out yet) ...Steve Rosen

Bob Grant December 26th, 2005 03:15 PM

Grass Valley have an affordable recorder coming out (afforable is relative I know) that'll take the HD-SDI stream and record that to Zip disks. Note that Zip disks are absurdly cheap compared to P2 cards and can be bought in most large computer stores. A Zip drive so you can ingest the footage is only a few hundred dollars and again can be bought in most computer stores.

A. J. deLange December 27th, 2005 02:11 PM

SMPTE 292M (HDSDI) has plenty of room for audio and time code but we aren't looking for a device that records HDSDI. Everyone recognizes that such a device isn't going to be seen on the back of an XL-H1 until the technology matures quite a bit. What we are looking for is a device that compresses the video conveyed by HDSDI and multiplexes it with TC and audio into a format that can be written to a small disk and that can be read from that disk, preferrably directly, by the NLE's we are likely to use. If anyone decides to manufacture such a device it's probably nearly as easy to aquire (and digitize) T/C and audio signals from their respective connectors than it would be to demultiplex them from a 292M stream.

Bob Grant December 27th, 2005 05:25 PM

Isn't the camera already providing the required data stream via 1394 using HDV compression. Several recorders seem to exist that'll do what you're after.
However I don't to see how the Grass Valley solution would fail to fill your needs?

A. J. deLange December 27th, 2005 09:24 PM

Yes but I think what most of us are looking for is less compression than either HDV or MPEG-1 require. I think there is especial interest in a higher level of chroma sampling.

Pete Tomov December 28th, 2005 12:12 AM

Much higher level of chroma sampling.

Bob Grant December 28th, 2005 06:12 AM

Well sure, we'd all like 10bit 4:4:4 but we also know how much data that means having to handle unless you compress every last breath out of it.
Which is why I keep coming back to the Grass Valleys recorder, you get a choice of just about every codec known to man and one that's hardly known at all, JPEG 2000!
Why not take a look at the list here:
http://www.thomsongrassvalley.com/pr...nity/recorder/

and someone tell me what's not to get excited about because we're planning on buying one (or two), yes to go with a XL H1, as soon as we can get our hands on one. Someone tell me if we're nuts or not.

Now what mightn't be apparent is that this thing records into a SMPTE certified MXF wrapper, you can mix and match codecs within that wrapper and the essence markers tell your NLE which codec it needs for that clip. As far as I know FCP handles this just fine and as Grass Valley just bought Canopus it's good odds that the Edius lineup will too if it doesn't already.
Also you get mpeg4 proxies written to the disks as well, very handy for time critical edits in ENG or just to save space on you local drives, from the proxies choose the clips you want to download or even flag them in the recorder in the field.

A. J. deLange December 28th, 2005 10:49 AM

This device may very well turn out to be quite adequate for your needs. You'll just have to try it out and see. It is apparently (the slicks adroitly avoid disclosing any pertinent technical detail, as is usually the case) a 25 Mbps device and in that sense not much better than the HDV tape transport on the camera. This represents approximately 40:1 compression which is a lot. What may be a big plus is the JPEG 2000. If it can handle 40:1 compression with the same picture quality as some of the older 20:1 or 10:1 compressor that's equivalent to, respectively, 50 or 100 Mbps i.e. a better signal than usually associated with 25Mbos. The device promises 4:2:2 in HD which should be appealing to many. I think the paradox here is that a lot of the ability to compress derives from the fact that human color vision is bandwidth limited. Does 4:4:4 look that much better than 4:2:2 or even 4:1:1 to the average viewer? Can't say but I can say that it is going to be much easier to develop a good mask by color keying from a 4:4:4 signal than a 4:1:1.

Bob Grant December 28th, 2005 02:22 PM

Digging a bit further into the specs reveals a write speed of upto 110Mb/s but the details do start to get a little vague other than saying 45 minutes of HD per 35GB disk.
I agree with your comments re chroma sub sampling, my vote is to ditch YUV altogether and stick with RGB, not just because of the difficulties with masking but also the errors in the conversion process.


All times are GMT -6. The time now is 06:15 AM.

DV Info Net -- Real Names, Real People, Real Info!
1998-2024 The Digital Video Information Network