View Full Version : Question regarding file structure on NanoFlash CF Cards


Perrone Ford
December 27th, 2009, 01:25 PM
I have a question regarding the file structure on the NanoFlash CF Cards.

I understand that the chipset for the codec comes from Sony, and is essentially XDCam. My question is does the Nano simply write raw MXF/MOV files to the directory, or are those recording placed in the familiar (to XDCam users) BDAV folder structure.

This isn't a show stopper, BUT would have a huge bearing on my workflow should I switch to this recorder.

Olof Ekbergh
December 27th, 2009, 01:28 PM
The Nano just puts .mov files in a folder (if you set it for QT). No need to use XDcam transfer and no BPAV BS.

I love it.

Perrone Ford
December 27th, 2009, 01:43 PM
The Nano just puts .mov files in a folder (if you set it for QT). No need to use XDcam transfer and no BPAV BS.

I love it.

The "BPAV BS" is *VERY* helpful to those on AVID systems. I wonder if this is something that could be fit into a firmware choice.

Olof Ekbergh
December 27th, 2009, 02:00 PM
You can set NanoFlash to save as MXF files instead of QT.

From manual available at the CD website:
Avid Media Composer (3.1.1 or better)
I-Frame only formats are supported (MXF files).
Long-GOP formats up to 50 Mbit are supported.
Long-GOP 100 Mbit and above is not yet supported.
Standard Def is supported.

Perrone Ford
December 27th, 2009, 02:21 PM
You can set NanoFlash to save as MXF files instead of QT.

From manual available at the CD website:
Avid Media Composer (3.1.1 or better)
I-Frame only formats are supported (MXF files).
Long-GOP formats up to 50 Mbit are supported.
Long-GOP 100 Mbit and above is not yet supported.
Standard Def is supported.

Thanks Olaf, but it's not quite the same :)

Dave Chalmers
December 27th, 2009, 06:12 PM
I agree Perrone, I think now that the NanoFlash media is directly compatible with XDCAM optical disc, there is a STRONG case for an option to mimic the XDCAM disc folder tree on the NanoFlash.

This would, in theory, make a whole bunch of NLE tools treat the NanoFlash media like an XDCAM disc and handle it natively.

Of course there may be some flaws in this theoretical approach, as there are lots of other files on an XDCAM disc that may be hard to re-create but prove vital to pulling off the trick.

I've already suggested this to CD as something to consider in future.

Regards

Dave C

Dan Keaton
December 27th, 2009, 06:26 PM
Dear Dave and Perrone,

We will look into this, we will have to study the ramifications.

Perrone Ford
December 27th, 2009, 07:00 PM
Thanks Dan,

I will make an important distinction here.

The XDCamHD disks are not the same as the XDCamEX cards. There is no proxy written to the cards. In Avid's AMA, when you load a disk, you can very quickly bring the proxies in for an offline edit. Someone in the field could even upload the proxies, the editor can start cutting, and when the disks come in from the field, you can link to the HD sources for the online.

The cards work differently. When Avid scans the cards, it only brings in the metadata. It is directly accessing the cards for the cut. My 16GB disks are ready to cut in about 4 seconds. If I am doing a quick assemble edit, like a long form conference where I am dropping in lower thirds, an opener and a closer, and exporting, this workflow is incredibly fast. I can be exporting on the AVID, where I would still be ingesting in Sony Vegas.

Since I assume the Nano is not writing proxies during recording, it might make more sense to emulate the structure of the cards. Provided of course that the NLE will recognize the underlying codec as XDCam even though the bitrate is vastly different.

The benefit of doing this, is that any NLE updates that get made to make XDCam workflow faster or easier, will directly benefit the Nanoflash. If the Nano could directly stand in for XDCam cards or disks, I would imagine broadcasters would be MOST interested. Maybe not in the workflow where the XDCamHD opticals get archived, but in a place that transfers all footage to SAN, or where the cards are the primary acquisition format.

Just me brainstorming, but it seems like a win for CD, and a major coup for clients.

Dan Keaton
December 27th, 2009, 08:42 PM
Dear Perrone,

Thank you for the added information and insight.

Piotr Wozniacki
December 28th, 2009, 10:26 AM
Perrone,

I'm not using XDCAM HD optical, just XDCAM EX - and I can tell you it would be nice to have the nanoFlash write the same directory structure as the EX cameras do. However, this structure contains no proxies; to have the nano mimic all possible directory structures (including the XDCAM optical structure with proxies), CD would have to considerably expand the current capability of this wonderful device. Dan please correct me if I'm wrong, but this would require quite a lot of effort (as all the options would need to be configurable through the nanoFlash menu).

But, why not ask? Perhaps in some future firmware upgrade (along with the extended metadata support)...

Perrone Ford
December 28th, 2009, 10:33 AM
Piotr, I was nnly asking if they could do what the XDCam cards do, not the opticals.

Piotr Wozniacki
December 28th, 2009, 11:00 AM
Ah, OK Perrone.

So we're in the same boat, and we would like to have the option of nanoFlash creating the whole BPAV structure...

Suppose it's easy for CD to implement ANY directory structure instead of the single {clp} folder; the questions remain though:

- why favor the EX cam users?
- they would need to come up with mp4 wrapper, in addition to mov and mxf

So, I guess we'd be asking too much.

Piotr

Dan Keaton
December 28th, 2009, 11:20 AM
Dear Friends,

We may be able to set up the BPAV directory structure.

We will not be able to create the MP4 proxies.

Piotr Wozniacki
December 28th, 2009, 11:30 AM
Thanks Dan. So I thought; writing to any directory structure is easy while providing yet another container (mp4) is not.

Personally, I don't see any advantage of having the BPAV structure when the CLP folder's content is MXF rather then MP4; it wouldn't be compatible with NLEs capable of reading SxS native - thus negating the purpose of the additional effort...

Having MXFs ready is absolutely fine with me (I'm using Vegas).

Oh, while we're on that, Dan: could you please comment in this thread of mine:

http://www.dvinfo.net/forum/convergent-design-nanoflash/469373-nano-clips-vegas-9-0c.html

Thanks in advance!

Piotr

Perrone Ford
December 28th, 2009, 11:39 AM
Piotr,

He said they would not be able to do mp4 proxies (So they can't replicate the disks). He said nothing of a re-wrap to MP4. That should be trivial.

Piotr Wozniacki
December 28th, 2009, 11:48 AM
Indeed, I failed to make distinction between mp4 and mp4 proxies.

Perhaps due to the fact that - while having many times dreamed of having proxies to the nanoFlash full HD clips - I sort of rejected it as not being viable with the current hardware, and bitrates available.

Perrone Ford
December 28th, 2009, 12:08 PM
The idea of having proxies written in addition to full-res images is a VERY interesting one. Particularly for NLEs that do not access the media directly, but must copy it over first. I am not sure if systems like CompactFlash would support parallel write operations.

It would certainly be a boon to have DV sized proxy files at say 8-10 Mbps, encoded with the same encoder.

Bob Griffiths
December 28th, 2009, 06:15 PM
Perrone,

Check out ProxyMill. http://www.imagineproducts.com/index.php?main_page=product_info&cPath=1&products_id=1

It is not quite the same as recording simultaneous .mp4 proxies but it's darn close. You have to back-up the CF cards somehow so doing it through a Mac with ProxyMill might do the trick for you.

Perrone Ford
December 28th, 2009, 06:25 PM
Thank you Bob,

However, I have two problems with that.

1. I don't use a Mac.
2. I can do the same for free on the PC. :)

That looks like a nice option for Mac users though.

Chris Hurd
December 29th, 2009, 08:18 AM
Thread title changed from "Basic NanoFlash question" to "Question regarding file structure on NanoFlash CF Cards."

Please avoid ambiguous thread titles on DV Info Net. Thanks in advance,

Dave Chalmers
December 30th, 2009, 04:46 AM
This is an interesting point raised here - is it easier for a NanoFlash to emulate an EX card or an XDCAM disc, and which gives more benefit?

The Nano is producing 50Mbit files as MXFs with no proxy.
The EX produces 35Mbit files as MP4s with no proxy.
The XDCAM HD produces 50Mbit files as MXFs with a proxy.
In addition the card itself has to be named the right thing.

Clearly the Nano isn't about to start producing proxies, so the question is whether, if you create a clone of an XDCAM HD disc BUT without the proxies, is this recognised by NLE apps as a valid disc?
(It might be possible to test this by deleting the proxy files on an existing XDCAM disc)

Regarding editing off the card - that is effectively what Avid AMA gives you, and I don't know if that needs to see proxies to work or not.

CD have already stated that they are working on AMA support for Nano cards in Avid.

The FCP import tools from Sony already work with Nano cards, as they are less fussy about file structure etc.

I guess maybe it's only the PDZ-1 software on a PC that would benefit from this arrangement, but again it usually works off proxies which wouldn't be there.

So, I'm questioning my own assertion that this would be useful.
To be selfish I'd settle for Avid AMA support, but clearly there's other scenarios out there.

Dave C.