View Full Version : MVC Splitter


David M. Cole
April 6th, 2012, 09:49 AM
Does anyone happen to know if you pay a transcode penalty when demuxing MCV into dual AVCHD files using either Sony's Content Management Utility or Panasonic's HD Writer XE?

There is the possibility that these utilities separate the MVC file without transcoding - but - I'd sure like to know for sure.

Thanks!

Bruce Schultz
April 12th, 2012, 02:56 PM
David, if you look at the thread I started a few months ago
http://www.dvinfo.net/forum/3d-stereoscopic-production-delivery/505405-panasonic-3da1-vs-sony-nx3d1-resolution-tests.html
wherein I posted some pictures of resolution tests, you will find a picture of a resolution chart for the Sony NX3D1 camera left & right data. These L/R streams were decoded with Sony Content Management Utility and seem to display no resolution loss between the full resolution Left and the processed Delta Right frames. The frames come out of the MVC format as separate L/R MTS files when using Sony CMU to process.

David M. Cole
April 13th, 2012, 07:43 AM
Thanks, Bruce. Unfortunately, a transcode generational loss may or may not be apparent on a resolution chart test (could be i-frame we're looking at).

Here's the thing... the reference codec for MVC (JMVC) can only decode MVC back to a raw image sequence. There is no reference provided for splitting a muxed MVC stream into 2 representative AVCHD streams without transcoding. It's easy to get one stream out without transcoding (because one stream is simply an AVCHD stream). Our engineers say it IS possible (and non-trivial) to extract the dependent stream without transcoding too, if you deeply parse the reference frame structure and build the dual stream GOP structure accordingly.

So... inquiring minds want to know... are we losing a generation w/ these utilities or not. If so, it argues to use GoPro Studio to transcode into Cineform or Peter Wimmer's utility to split into an uncompressed format for critical footage.

Bruce Schultz
April 13th, 2012, 07:26 PM
I use Go Pro Studio Premium to mux and edit Panasonic 3DA1 footage. Their new version doesn't yet fully support MVC files but I'm told that it's coming Real Soon Now. In the meantime I'm splitting out L/R with Sony CMU and muxing into Cineform with GPSP manually.

David M. Cole
April 14th, 2012, 06:32 AM
The PC version of GoPro Studio Premium and Pro support MVC now.

Bruce Schultz
April 14th, 2012, 07:59 PM
Yes, their PC versions always are ahead of the OS X versions.

Neil Richards
April 15th, 2012, 07:51 AM
At least they have OS X versions, unlike *cough* Edius :)