Converting MXF to Mp4 vs ProRes

[psion99]

Hi there,

I'm working with a bunch of 4k MXF files that are giving me trouble when attempting to import to Premiere various ways.  Converting to ProRes increases the file size so dramatically and excessively that it's filling up my drives.  I'm told that H265 is not recommended as an editing codec and will slow my machine down. Is converting to H264 a viable option?  Does anyone know what the quality loss is when converting MXF to H264 -if I select a very high bitrate?  

[Steve Griffiths]

Remember there are multiple versions of Prores ... so you could perhaps use (say) Prores 422 and get a file size saving of approx one third over ProresHQ. All depends on which version of Prores you are currently converting too.

You are correct in that H.265 is not an ideal editing format. 

Any conversion to H.264 is going to result in some quality loss. That said maintaining a high datarate (say 40Mbit+) might be enough to avoid any 'visible' issues. Depends too on if your edit is staying at 4k or your final product is HD? If you don't need to stay at 4K - consider converting the 4KMXFs to HD Prores as this will result in significantly smaller files

What problem are you having with the original MXF? And do you know which codec the MXF's currently are, as they can be a whole bunch of different codecs i.e. AVC-Intra, DNx, XAVC, XDCam etc.

If it's just that these clips are importing but playback is lagging within Premiere Pro - have you tried creating 'proxies' for these clips inside of Premiere Pro?

To play 4K native clips inside Premiere Pro you need to have fairly fast drives and relatively modern and powerful hardware.

Good Luck.

[psion99]

Hey there,

Thanks for chiming in.  

The mxf files are wrapped around an HEVC 422 Base codec (which I believe is H265?) generated by a Canon XF705.  Which could be the issue right there, since H265 is not an edit friendly codec. 

I'm working in Adobe Premere 15.4.1.  

Even with HD prores proxies created and attached, premiere lags and stutters and runs up my CPU trying to play it back. Event Status says "Frame substitution recursion attempt aborting after multiple attempts"

Converting to HD before cutting is not an option since I'll need to punch in where necessary.   ProRes vs ProResHQ doesn't save enough storage space at this point.  

My assistant ended up converting to ProRes first and then converting to H264 which was probably overkill, but he felt it went faster than going straight to H264.