Jaggie graphics and XDCAM HD 35mbs FCP sequences

[Paul Nevison]

hey there,

with the colour space of XDCAM HD being 4:2:0 does that mean that any XDCAM HD 35mbs sequences will have issues with jaggies on graphics as per DV timelines?

thanks

[Rob Stiff]

Use Compressor2 to downcovert the HD footage to DV.
Should not have any problems. You may have to apply
a sharpening filter to your footage. As for issues you noted,
have not had a problem yet.

[Paul Nevison]

thanks for the reply Rob,

I guess what I was getting at was, if you are editing in a native XDCAM HD 35mbs sequence will you run into jaggies on your graphics because of the 4:2:0 colour space? DV shares the same colour space as XDCAM HD but the XDCAM codec is 10mbs more in information (DV is 25mbs). Can i expect an XDCAM HD sequence to behave in the same way, when it comes to graphics , as a DV sequence, which has lots of issues with jaggie graphics? or does that extra 10mbs make this a non issue?

hope that's a little clearer as to what I'm asking

thanks

[Matthias Koehler]

Originally Posted by Paul Nevison

Can i expect an XDCAM HD sequence to behave in the same way, when it comes to graphics , as a DV sequence, which has lots of issues with jaggie graphics?

I think it depends on the editing system. If You edit the material with an Avid Media Composer, there will be no problems, because all effects and all imported graphics are not in the native XDCAM HD format, but in the high quality Avid DNxHD format. This is why I am of the opinion that XDCAM HD material should only be edited with an Avid Media Composer.

But even in a 4:2:2 colourspace You need to pay attention to the used colours in graphics.

Matthias

[Andy Mees]

>I am of the opinion that XDCAM HD material should only be edited with an Avid Media Composer

odd statement ... you're saying that XDCAM HD should only be transcoded to DNxHD for editing and no other workflow is acceptable. bizarre.

not doubting the quality of the DNxHD codec here ... but neither am I doubting the quality of the Canopus HQ codec, or the DVCPRO HD codec or any other number of potential intermediate codecs, both compressed and uncompressed.

what makes you say that Avid Media Composer w/ DNxHD is the sole legitimate choice?

[Steve Connor]

Yes I'm keen to hear that answer too!

[Matthias Koehler]

Originally Posted by Andy Mees

what makes you say that Avid Media Composer w/ DNxHD is the sole legitimate choice?

I am sure that this is not the only good workflow, but the other manufacturers need to explain how they solve the problem and which codec they use. Which system uses an internal DVCPRO HD codec? When I asked the specialists on the german roadshow two weeks ago, the Avid employee gave me a much more clear answer than the Apple FCP man. And as far as I know, XDCAM HD works closer together with Avid than with Apple.

And the Canopus system is widely unknown and unused in Germany, so that there are less experiences. About 90% is Avid.

Matthias

[Nate Weaver]

Matthias,

We have to be careful in these discussions, because as we all know they can spiral out of control quickly. But as a long time FCP user, let me outline how native XDCAM HD (and all MPEG2 codecs) can work in FCP.

Apple lately has taken the tact that it's always better to allow the user to work natively with the data from the camera, despite the shortcomings a given codec may have. Why? Well for one, any recompression is undesirable, if you have a plan to overcome the shortcomings of the acquisition codec.

(for those that follow my posts, the FCP/native sermon follows. Feel free to skip)

Say you have a native XDCAM HD timeline in FCP. With the newer machines this is just as fast as DV on slightly older machines...what the system is doing to work with the difficult GOP material is completely hidden from the user. It's fast, you get full res, full framerate previews on screen, and with the appropriate Blackmagic or AJA card, full res HD-SDI or component out to an HD monitor.

So you're working in this timeline, adding graphics, doing color correction work, etc. Either the effects you add can be done in real time, or they have to be rendered. If they're rendered, it's to the same XDCAM HD codec. You have the color resolution problems you expected, but you were able to work quickly and simply.

Once you have a locked cut, and you're ready to output, here's what you do: You render out a version of your timeline to a better codec; uncompressed if you have the fast drives for it. As it renders out this Quicktime movie of your timeline, it discards the native MPEG render files. You resulting uncompressed Quicktime movie is comprised of XDCAM HD frames that have only been decompressed once, had FX/color applied to in a 4:2:2 uncompressed buffer, and then written out as uncompressed.

This is the cleanest possible path XDCAM HD footage could ever hope for. Again, it's one decompression, FX/color in an appropriate buffer space, and then output.

You can also do the same thing by copying/pasting your entire native XDCAM HD timeline once you have a locked cut into an uncompressed timeline, doing a render, and then laying off to HDCAM or D5.

Avid is a fine platform for XDCAM HD with it's oneline/offline proxy support for sure, but I had to put a little FCP FUD to rest.

[Scot Olson]

Originally Posted by Matthias Koehler

... but the other manufacturers need to explain how they solve the problem and which codec they use.

Nate made a great explanation of the process but you can also read-

Final Cut Pro and XDCAM HD White Paper

[Nate Weaver]

I should also add that I'm not an FCP teetotaler, I've been looking heavily into Media Composer lately. FCP needs multiple resolutions in a timeline, better media management, I could go on and on.

But how FCP handles difficult/subpar codecs is not one of the problems.

[Steve Connor]

Don't look too quickly Nate, I suspect there will be major changes announced at NAB, let's hope it's the changes we all want!