Bypass The Codec? at DVinfo.net

Jeffrey Baksinski · May 30th, 2003, 10:49 PM

Has anyone heard about ways to bypass the codec and go straight to a a very fast drive? I'm noticing that the automatic 5:1 compression (on the old Xl1) is making some headaches for me when trying to do high-end effects. Especially with green screens and such.

If possible, it'd be nice to go straight to a drive even if it wasn't in real time (for example, shooting minatures at a slower motion control rate) and avoid that first layer of compression. Even better would be to avoid that in real-time!

Thanks!

Jeffrey

Akos Szemenyei · May 31st, 2003, 01:22 AM

Sorry, if you shoot on DV, it's already encoded in the camera. You need to shoot DVCPRO, SD, HD or Film to have less problems. You can still use keying software to make your life easier, like the canopus keyer, Combustion, After Effects etc.

Rob Lohman · June 2nd, 2003, 10:12 AM

It might be that an uncompressed analog signal is on the XL1's
analog outputs. If you hook this up to a high quality MJPEG board
(the ones that go over 10 MB/s) you might get a better quality.
If however the camera encodes to DV and then decodes that
to analog (which could be since they could then use the same
circuitry that they use for playback) you will loose quality. If
you go down the analog route you will need very high quality
cables and other components to not loose too much quality
in that process.

But as Akos already explained, best is to go with a camera with
lesser compression.

Jeffrey Baksinski · June 3rd, 2003, 07:54 PM

Rats!

I just started thinking about the analogs out to a really fast capture card. Since I'm shooting in a controlled enviorment, I can afford to have fast hard drives and such to avoid the compression.

I should probably figure out the best way to use the Xl-1 so that the wife doesn't kill me...

Jeffrey Baksinski · June 3rd, 2003, 07:59 PM

Oh... also...

How can I find out if the analog is already getting the compression going through the camera?

That would be too bad, but I'm betting it is.

Rob Lohman · June 4th, 2003, 02:31 PM

Now that would be hard to tell indeed.... Best way probably
is to compare frames with DV and analog. The more detail
in them the better. Also sharp contrast will more easily show
macroblock compression. Then even your capture card might
introduce unwanted side effects. Best to stay uncompressed
then. As I said earlier, better stick to DV or get a higher grade
camera in my opinion...

Jeffrey Baksinski · June 5th, 2003, 02:19 PM

<<<-- As I said earlier, better stick to DV or get a higher grade
camera in my opinion... -->>>

I'll use you as a reference with the wife!

Rob Lohman · June 5th, 2003, 04:58 PM

Uh oh... glad she doesn't know were I live exactly <g>

May 30th, 2003, 10:49 PM	#1
Jeffrey Baksinski New Boot Join Date: May 2003 Location: North Hills, CA. Posts: 7	Bypass The Codec? Has anyone heard about ways to bypass the codec and go straight to a a very fast drive? I'm noticing that the automatic 5:1 compression (on the old Xl1) is making some headaches for me when trying to do high-end effects. Especially with green screens and such. If possible, it'd be nice to go straight to a drive even if it wasn't in real time (for example, shooting minatures at a slower motion control rate) and avoid that first layer of compression. Even better would be to avoid that in real-time! Thanks! Jeffrey

June 2nd, 2003, 10:12 AM	#3
Rob Lohman RED Code Chef Join Date: Oct 2001 Location: Holland Posts: 12,514	It might be that an uncompressed analog signal is on the XL1's analog outputs. If you hook this up to a high quality MJPEG board (the ones that go over 10 MB/s) you might get a better quality. If however the camera encodes to DV and then decodes that to analog (which could be since they could then use the same circuitry that they use for playback) you will loose quality. If you go down the analog route you will need very high quality cables and other components to not loose too much quality in that process. But as Akos already explained, best is to go with a camera with lesser compression. __________________ Rob Lohman, visuar@iname.com DV Info Wrangler & RED Code Chef Join the DV Challenge \| Lady X Search DVinfo.net for quick answers \| Buy from the best: DVinfo.net sponsors

June 4th, 2003, 02:31 PM	#6
Rob Lohman RED Code Chef Join Date: Oct 2001 Location: Holland Posts: 12,514	Now that would be hard to tell indeed.... Best way probably is to compare frames with DV and analog. The more detail in them the better. Also sharp contrast will more easily show macroblock compression. Then even your capture card might introduce unwanted side effects. Best to stay uncompressed then. As I said earlier, better stick to DV or get a higher grade camera in my opinion... __________________ Rob Lohman, visuar@iname.com DV Info Wrangler & RED Code Chef Join the DV Challenge \| Lady X Search DVinfo.net for quick answers \| Buy from the best: DVinfo.net sponsors

June 5th, 2003, 04:58 PM	#8
Rob Lohman RED Code Chef Join Date: Oct 2001 Location: Holland Posts: 12,514	Uh oh... glad she doesn't know were I live exactly <g> __________________ Rob Lohman, visuar@iname.com DV Info Wrangler & RED Code Chef Join the DV Challenge \| Lady X Search DVinfo.net for quick answers \| Buy from the best: DVinfo.net sponsors

May 31st, 2003, 01:22 AM	#2
Akos Szemenyei Regular Crew Join Date: May 2003 Location: Saitama, Japan Posts: 111	Sorry, if you shoot on DV, it's already encoded in the camera. You need to shoot DVCPRO, SD, HD or Film to have less problems. You can still use keying software to make your life easier, like the canopus keyer, Combustion, After Effects etc.

June 3rd, 2003, 07:54 PM	#4
Jeffrey Baksinski New Boot Join Date: May 2003 Location: North Hills, CA. Posts: 7	Rats! I just started thinking about the analogs out to a really fast capture card. Since I'm shooting in a controlled enviorment, I can afford to have fast hard drives and such to avoid the compression. I should probably figure out the best way to use the Xl-1 so that the wife doesn't kill me...

June 3rd, 2003, 07:59 PM	#5
Jeffrey Baksinski New Boot Join Date: May 2003 Location: North Hills, CA. Posts: 7	Oh... also... How can I find out if the analog is already getting the compression going through the camera? That would be too bad, but I'm betting it is.

June 5th, 2003, 02:19 PM	#7
Jeffrey Baksinski New Boot Join Date: May 2003 Location: North Hills, CA. Posts: 7	<<<-- As I said earlier, better stick to DV or get a higher grade camera in my opinion... -->>> I'll use you as a reference with the wife!