You may have found an old Avid drive containing MXF or OMF files compressed with Meridien codecs. Sometimes these are known by their compression ratio, e.g. “2:1” or “14:1”.
Because of the combination of the MXF/OMF container and the Meridien codec, rarely found in modern software apart from Avid, these files can be difficult to play, even if your QuickTime installation contains the Avid-distributed codecs.
So how can you view these files for free?
Easy. Avid Meridien compression is actually MJPEG – Motion JPEG compression. The free and open-source utility FFmpeg has a sister player: FFplay. Even though it doesn’t know how to find an MJPEG codec inside an MXF OP1A wrapper, or an Avid OMF wrapper, you can tell it what to do with a simple command line. Then, you can view any Meridien-compressed MXF or OMF files on your drive.
As a guide, MXF video files are named in the following way:
CLIPnameVnn.<ID>_<ID>.mxf
“ID” is a hexadecimal string that Avid uses to track the media. The pattern for OMF files is similar.
When the letter ‘V’ follows a clip name, and is succeeded by a pair of digits, you’ve found a video file. Then, the command to play it is:
ffplay -f mjpeg CLIPV01.<ID>_<ID>.MXF
The trick is the “-f mjpeg” in the command line. This forces FFplay to interpret the file as containing data encoded as Motion JPEG.
And now you can see your pictures. They’ll play with the VBI data included, and the colour range may appear washed out because you’re displaying broadcast-level pictures on a computer-level display.
Just want to say thanks for all your notes here – been very useful. I am looking to ENCODE to Meridian compressed using FFMPEG – which it does not do one could argue, except it does given..
“…Easy. Avid Meridien compression is actually MJPEG – Motion JPEG compression…”
If I wanted to make a Avid Meridien file compressed to 15:1 – what would the bitrate / resolution be?
Hello James,
That’s an interesting one. I’ve never tried this encoding to the Meridien MJPEG codecs using FFmpeg myself, mostly because I stopped using them a long time ago. If ever I need an off-line codec, I now use DV in SD (pictures running at 25MBit/s) or DNxHD at something like 36MBit/s in HD. In Avid, you can go even lower: there’s an H.264 intra-frame codec for off-lining in any resolution at 800kbit/s.
So, regrettably, my answer for bitrate is “don’t know” but certainly lower than 25MBit/s. To answer your question about resolution, in Avid Meridien it would be 720×576 or 720×486, non-square pixels. The ‘486’ is because that’s the NTSC resolution of Digital Betacam (among other formats); the analogue NTSC standard for active lines is 483 lines, though the majority of digital productions rendered to SD have only 480 active lines because of the design of certain codecs e.g. MPEG2 video for DVD, and the DV codec.