DVCPRO HD compatibility

[Job Ter burg]

I haven’t heard of that. Pretty sure that I worked on a project last year that was started on 2.8 and continued on 3.0.

[Rob Alexander]

It’s going backwards from 3 to 2.8

[Job Ter burg]

AFAIK you should be fine when the media has been brought into the system, should you not?

[Dino]

Rob, if you’re asking an actual question or expect some assistance you’re going to have to supply more information. It’s starting to look more like your presenting a riddle than requesting that others give you free help and advise.

I’ve had DVCProHD media from P2 cards work in Media Composer 2.6. There are absolutely tools and processes in 3.X that are not available in 2.8 but the Avid MXF media, once tucked into the proper media folder structure, should be valid.

[Rob Alexander]

Well Dino it is a riddle as to why media which plays perfectly in MC 3.1 won’t play without transcoding to DNX in 2.8.

Why are we doing this? Because we’re effectively ‘offlining’ on the 3.1 version and taking it to a facility for mastering to HDCAM, and it’s not just one facility. We’ve had the same problem taking project and media to the BBC.

The reason I’m being vague is that media should be media regardless of which version you’re running, hence I’m trying to find out whether there is a known problem between the versions of media composer.

[Dino]

Look at that, you give us some information and we can solve your riddle.

DVCProHD sub samples the full raster (Avid calls it thin raster) as part of making HD fit in such a tiny package. That is:
-1280 is re-sampled to only 960
-1920 is re-sampled to only 1280

On systems using Adrenaline hardware it is not possible to play this material out at full resolution. This is also true on a Symphony using the old Nitris hardware. These hardware sets require media at the full raster to deliver full resolution video. Thus the need to transcode to either DNxHD or uncompressed. Systems making use of the new DX hardware do not have this problem. As much as this makes it look like a hardware issue, I believe most of the improvement comes from improvements in the software.

So you see, what you were calling a compatibility issue or problem is actually just a functional limitation. The result may not be the wanted outcome but MC 2.8 is performing exactly as designed.

[Rob Alexander]

Thanks Dino,

If as you say this is mainly to do with software then am I to understand that an Adrenaline system running 3.x would play the media correctly?

How did the older systems work with DVCPRO HD P2 media?

Cheers

[Dino]

Cant recall when specifically it was added (2.5 or later) till 2.8, Media Composer could capture and output DVCProHD over Firewire as well as use media from P2 cards. Realtime playback through hardware would only work at best at the yellow/green timeline quality setting. I imagine the CPU has something to do with what level of playback is possible. As mentioned before, full quality output requires a transcode to a full raster resolution. I believe this is still the case with MC 3.X on non DX hardware.

Using MC 3.X with the newer DX hardware will handle the material properly. There are specific options available in regards to timeline settings. I suggest you research what Avid calls “thin raster support”. Your particular situation will drive how you choose to handle this.

[Job Ter burg]

I’ve occasionally used P2 DVCPROHD media on a classic Nitris (just a short test), and as long as you have a really fast CPU, it seems to work.
Thing is, as said, DVCPROHD is thin raster, and this means that upon output, the footage needs to be scaled to full raster. The DX boxes have hardware to handle this, all other boxes do not.
Ever since MC/SN v.3, the architecture of the software has changed, so that various tasks can be distributed over GPU, CPU and hardware boxes. This has caused increased performance overall.