View Full Version : clarify MXF


Ed Kukla
March 22nd, 2009, 12:00 PM
Is the MXF wrapper created in the camera or by the clip browser during transfer?

Craig Seeman
March 22nd, 2009, 02:46 PM
EX camera is .mp4. MXF can be done in ClipBrowser. MOV done in XDCAM Transfer on Mac.
Other XDCAM cameras record MXF

Ed Kukla
March 22nd, 2009, 04:48 PM
I knew the camera records in mpeg4. What I'm unclear on is where the mxf file comes from? Is it also recorded by the camera or is it added by the clip browser? Sounds like it is added. Confusing.

Craig Seeman
March 22nd, 2009, 05:07 PM
ClipBrowser does not "add" anything. It rewraps the file.

David Heath
March 22nd, 2009, 05:15 PM
I knew the camera records in mpeg4.
No, the recording - the codec - is MPEG2. The .mp4 refers to the "wrapper" - see MPEG-4 Part 14 - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/MPEG-4_Part_14)
........is a multimedia container format standard specified as a part of MPEG-4. It is most commonly used to store digital audio and digital video streams, especially those defined by MPEG......
Conversion to .mxf defines a rewrapping - the underlying data remains MPEG2.

Leonard Levy
March 23rd, 2009, 12:49 AM
I think Ed is asking if the files that the camera records onto the SxS card are wrapped as MFX by the Ex-1 in the first place.


When clip browser copies them, does it just copy the mfx wrapper with everything inside it, or does it go back to the original data and re-wrap it in a new MFX wrapper ( which is probably identical to the original one.?)

Paul Kellett
March 23rd, 2009, 02:05 AM
When you rewrap the bapv file into mxf you end with just the clip.

Ed, an analogy would be, i don't recognise you with a blue coat on, but i do recognise you with a red coat on, it's still you inside, nothing has changed, you just look different on the outside, this is what clip browser does, it just changes the wrapper on the clips so that different editing systems can see it.

Some editing systems can use the native files, i use vegas which can't so i have to rewrap the clips into mxf.

Hope this makes sense.

Paul.

Ed Kukla
March 23rd, 2009, 06:23 AM
Paul
Where did you get the red coat? Am I wearing the coat all the time under the blue coat or did you give it to me? That's what I'm curious about...where does the wrapper come from?

Are the mpeg2 files CONVERTED or are they added on by the wrapper provided by the software? Or is the wrapper already there in the original recording, it's just 'activated' by the software?

Paul Kellett
March 23rd, 2009, 06:42 AM
The original footage is mpeg2 long gop (group of pictures) in an mp4 wrapper, clip browser rewraps it with different wrappers for different editing programs, for example i need the footage in an mxf wrapper for vegas.
Some editing programs don't need the footage rewrapping though, (come on sony, catch up, it's your camera and editing program after all) so i suspect there won't be much rewrapping going on in the future.

Paul.

Ed Kukla
March 23rd, 2009, 10:55 AM
What edit programs don't require rewrapping?
What problem is there with rewrapping other than time to process the rewrap?
Does the rewrapping take a long time?

I'm planning a system now. Considering Vegas first but also Premiere and Edius. I haven't read anywhere that the rewrapping is a big deal. Should I be considering this?

Ilya Spektor
March 23rd, 2009, 12:16 PM
What edit programs don't require rewrapping?


NewTek SpeedEDIT (current version 1.55) does not need rewrapping - you can put .mp4 files encoded with MPEG2 on the timeline directly...

There is an opposite thing with SpeedEDIT though - it cannot play (at least, now...) .mxf files encoded with MPEG2 and also, it cannot play .mp4 files encoded with H.264 (AVCHD...) Hopefully, it will be fixed with the next version of this NLE...

Alister Chapman
March 23rd, 2009, 03:07 PM
Edius, Avid Media Composer and Premier Pro can all work with native MP4 files. FCP requires a re-wrap to .MOV and Vegas and Liquid needs MXF.

Most of the metadata (stored in XML files in the BPAV flder) is also added in to the MXF wrapper when making MXF's.