Any news on DNxHD and will it be MXF?

[Christopher Young]

Hi Dan ~

Any updates as to progress on DNxHD development?

Looking forward to hearing the state of play. I see Blackmagic have already taken the step with their latest v2.3 firmware upgrades as of last Friday Nov 18 by going MXF with their DNxHD support. For us Windows users this is a very welcome step in getting away from the now unsupported QuickTime dependence.

Chris Young
CYV Productions
Sydney

[Jack Zhang]

Is that OP1a though? (referring to the Blackmagic update)

If it's not, and it's OP-Atom, don't bother with Blackmagic's implementation. The risk of file corruption is way too high with OP-Atom. EVEN MORE SO ON SD CARDS.

[Christopher Young]

Was wondering the same Jack. Just updated a Video Assist and checked it. Sadly it is OP Atom, one video file and two audio files. There were we hoping for OP1a :(

Chris Young
CYV Productions
Sydney

[Gary Huff]

Originally Posted by Jack Zhang

Is that OP1a though? If it's not, and it's OP-Atom, don't bother with Blackmagic's implementation. The risk of file corruption is way too high with OP-Atom. EVEN MORE SO ON SD CARDS.

Why is the OP-Atom specification more at risk of file corruption?

[Jack Zhang]

You're transferring a video stream file and, in the case of stereo, 2 audio channel files. If you're transferring 3 files simultaneously, they can corrupt.

OP1a is a single file stream. It's more metadata friendly too.

[Gary Huff]

Originally Posted by Jack Zhang

You're transferring a video stream file and, in the case of stereo, 2 audio channel files. If you're transferring 3 files simultaneously, they can corrupt.

So it's just in your opinion then?

[Christopher Young]

Not just his opinion. Worked for years with Panasonic P2 Atom based MXF and saw and experienced quite a few problems. Once we moved to Sony OP1a MXF with its single file structure our problems dropped by about 90%.

The main issue was not in the acquisition stage it was in the subsequent handling, transferring and copying of the files between work stations, servers, editors, drives etc. Seven items per folder per clip. If you lost or corrupted that LASTCLIP.TXT belonging to a clip then you were really battling to try and reconstruct that particular clip. A short clip you may get away with losing it but if it was a half or quarter of a football game... oops!

It became a big enough issue with enough broadcast P2 users that Panasonic eventually issued a document called: "Important Notes at P2 content Copy" I still have it! See attached. The last bold underlined text warning at the bottom of page two was a warning to people not used to working with Atom based MXF.

I for one was hoping to see OP1a. Just hope CD decide to go OP1a as it's becoming an industry standard as I previously pointed out in another post..

Sony's OP1a XDCAM MXF is supported by Adobe After Effects, Adobe Premiere Pro, Apple Final Cut Pro X, Autodesk Smoke, Avid, Capella systems, Dalet, EVS, Imagine Communications Corp., Omneon, Quantel, Rhozet, Sony Vegas Pro, Sorenson Squeeze, Telestream FlipFactory, GrassValley EDIUS, Grass Valley K2, and Merging Technologies VCube just to name a few.

Chris Young
CYV Productions
Sydney

[Gary Huff]

Originally Posted by Christopher Young

Not just his opinion.

So far, yes it is. What you describe is operator error. I used an HPX170 for years without issue because I copied the entirety of the card contents. What Jack is describing is a fundamental hardware issue in the writing of three separate files to an SDXC card, completely ignoring the fact that the CinemaDNG functionality of the Pocket Camera is the same issue (one file PER FRAME and then a stereo WAV file) which requires far more bandwidth.

[Jack Zhang]

Ouch. Yup, that DNG writing is going to be much worse than OP-Atom.

[Jack Zhang]

Originally Posted by Christopher Young

Was wondering the same Jack. Just updated a Video Assist and checked it. Sadly it is OP Atom, one video file and two audio files. There were we hoping for OP1a :(

Chris Young
CYV Productions
Sydney

Guess what? OP-Atom corrupting files has now cost me my job. Take that as a stern warning to NEVER use the Blackmagic DNxHD MXF implementation cause it will cost you your job.

[Noa Put]

Where the files corrupt because you didn't copy the entire contents or did the corruption occur during recording?

[Christopher Young]

Noa I guess what it comes down to in my experience is that in the P2 Atom structure there are just so many files per folder as opposed to OP1a's single file. Sure I have seen corrupted OP1a and when the file is badly corrupted it is almost impossible to recover.

I've see operators take great care in transferring P2 folders and end up with more failures than expected. I think it's down to the fact that with seven files per clip you have more chances of one of one of those seven items having an issue than with the one file structure of OP1a. Just my theory.

What I do know is if that LAST CLIP.TXT file is corrupted well then you have lost the entire information structure of that folder contents and have to rebuild the LAST CLIP.TXT file. Plenty of info out there on how to do the rebuild. Totally possible but it means you have check out the video files to get the clip info plus the number of video files in that folder plus there are issues if the clips have spanned two cards. Just one hell of a lot of mucking around while chewing up time.

Chris Young
CYV Productions
Sydney

[Jack Zhang]

The HyperDeck doesn't record OP-Atom to specific folders. It just throws 3 MXF files in the root directory per clip.

It's compatibility is so bad that footage recorded on different firmware revisions might not be readable by the same hardware. It also only plays back on the hardware itself in MONO.

The audio stream errors for sure showed up in the recording upon playback at a regular interval. That rules out the SSD it was recorded on as a root cause of the issue.

[Jack Zhang]

New products, still no word on DNxHD.

[Dan Keaton]

Dear Friends,

Our next firmware, which will include modes supporting DNxHD, is in the final testing stages at this time.

We have completed on internal testing program, and it is being testing with a small group of beta testers.

Once we get approval from our beta testers, using it in a variety of ways, we should release the firmware.

Respectfully,