Another I Frame Only Question
 

Hi Friends,

Had a chance to shoot some really interesting footage. When this happens we break out the HDCAM. Lately we have been using the XDR as a backup on theses shoots. So it is from the camera, to the Miranda, then into the XDR as QT files.

This gig we tried the 160Mb I Frame only. On site it looked great. Played back from the XDR to the monitor looked pretty good. Back in the studio, we try to bring the files into FCP and all we get is a green screen and the occasional scrambled image.

Someone please tell me this is a codec issue in FCP with a simple setting change.

David Schmerin
Speaking for the minority one

David:

With the HDCam, why aren't you coming right out of the HD-SDI port and straight into the XDR?

I was considering the XDR strongly as a way to be able to use my HDCam with the home AVID system, without needing a deck. Is there a problem that requires the Miranda?

Hi David-

Are you using one of the Fast Compact Flash cards: 1) Transcend 300X 16GB or 2) Sandisk Extreme III 32GB? The 160 Mbps absolutely requires a fast CF card. Also are you copying the files to your hard-drive for playback or trying to play directly off the CF card? If you have a FW-800 reader, this may be OK, but I doubt a USB reader will provide sufficient bandwidth.

We can playback 160Mbps I-Frame only footage on our FCP system without any issues whatsoever.

Best-

I must just be the lucky one...
 

The cards in the XDR are Transcend 32GB 133x cards. And as I said, the files played back from the unit to the monitor with no problems. Back in the studio, we copied the files to hard drive.

Also, as a last resort, we tried to convert the files to .mxf The converter converted the files with no errors reported. When we try to open the files on a PC (also first copying the files to hard drive) the Sony utils can open the files, they just can not play them.

Thanks

David Schmerin
Speaking for the minority of one

Dear David,

What are the settings for your timeline in Final Cut Pro?

Our experience is that the Transcend 32 GB 133x is not fast enough for recording I-Frame Only at 160 Mbps.

This card works up to and including 100 Mbps, but not at 160 Mbps.

If you wish, we will be happy to examine the files on your card. We will attempt to play them on a variety of NLE's. If we find the files are good, or portions are good, we could transfer them to another card, or render them to another format that will work on a Transcend 32 GB 133x card.

What function does the Miranda box serve?

Doesn't your HDCAM have an HD-SDI port?

Hi Friends,

First, no our F-900 does not have an SDI out. Only certain models have this feature. The rest of us use a Miranda DVC-802 Full Quality Downconverter and DV Encoder for Sony HDCAM and Panasonic Varicam - Miranda Technologies in a wired configuration.

And, while the Transcend 133 cards are said not to be fast enough, it does not explain:

1) Why the video played back just fine to an on set monitor from the XDR box.

I will without prejudice assume that FCP could read the source files and the .mov to .mxf converter converted the files with no issues because the file formats were correct only the data within corrupt.

While I thank you for your offer to examine my files, these files are not mission critical as we shot to tape. Nor do I have the time or the inclination to send out customer materials. In that we also have just about every NLE to work with not much point sending materials in just we be told the files are corrupt.

Fortunately, the XDR was only used as a Backup and we have original Tape Source to work with.

David Schmerin
Speaking for a minority of one

PS: I downloaded the PDF manual to the XDR unit from the Convergent Designs web site and I personally feel (just my opinion) that it is need of serious rewriting by perhaps a professional technical writer.

Hi David-

I ran the same test this morning, using the Transcend 133X cards at 160Mbps. I did find that most of the footage would play OK on the Flash XDR, but after a minute or so, the video would jump for a second or two and then re-sync with proper playback. Playback on the PC was marginal with jumpy images and green screens.

I suspect the hardware CODEC inside the Flash XDR is simply more tolerant of errors in the bit-stream as compared to software CODECs. So while playback on the MAC/PC may choke and stop, the hardware CODEC has error resiliency and can reset and continue playing.

We are quite specific in all our documentation that the 160Mbps does require the faster CF cards. Yes, we do agree that the owner's manual needs a professional rewrite; that effort is underway now.

In a future release we may in fact be able to squeeze more performance (higher bit-rates) out of the 133X Transcend cards, but this requires more testing and evaluation.

Best-

Hi Mike,

Always a pleasure to hear from you.

Now first things first...

The first thing you have to remember about me is that I am not the brightest bulb in the box. Also, I am more then prepared to say that the issues we faced were clearly of our own doing.

With that said, there is always a however. In this case the "howevers" are:

1) Being the simple guy that I am, the first thing I did was download the PDF manual from your web site.

2) I then searched the PDF for any reference to I-Frame and found no reference to minimum requirements for the CF cards or CF cards at all. I never thought to try to search the PDF for 160. I am sure if I had I would have found Section 3.6.

And so with a basic knowledge of the workings of the unit and no reason (again my fault entirely) to think the CF cards would not be fast enough, we sallied forth on our shoot.

Now we have to go back to the very first notion that I am a simple person and as a simple person I have a few simple observations:

Even after searching your manual again (after reading your post) for 160, except for section 3.6, I did not see anything there or anywhere else (again to me the simple person) suggesting the 32G 133x would not work. I am also prepared to say if I was too stupid to find it, I should not be doing my job.

If the Transcend 32G 133x cards do not work as we can now both clearly agree on, then the superiority of your XDR units playback ability might lead other simple people like me into believing in a false sense of security. For certainly we watched playback on set from the XDR a whole lot more then 2-3 minutes had no reason to doubt the quality of the files.

Also, I am also left wondering why the XDR unit itself gave no indication during the record that we were trying to feed it too much data too fast for it to properly write to clearly inadequate storage media.

I guess really what I am saying is to me, if the cards would not work, the whole of the system should have had issues from record to playback from the XDR unit and I should have known right away and on set. Instead I found myself back in the studio going WTF to the editor and saying thank goodness we had tape rolling.

David Schmerin
Speaking for a minority of one

Hi David-

I agree with your observations. We do need to update (actually rewrite) the manual and we need to auto-detect the CF card and display a message on the LCD screen, such as "Slow Card", if the card does not meet the minimum speed requirements.

We'll get both of these issues corrected in the coming weeks.

Thanks for the feedback and recommendations.

Best-

David what setting are you using in Final Cut to edit 160Mbp/s I Frame?

Read the Release Notes
 

David:
It has been repeatedly noted on DVInfo that the 160 I-frame requires the faster 300X cards.

Beyond that, the Release Notes (very quick read) that came with the first firmware release of the 160 I-frame capability very clearly also stated the need for the faster 300X cards. The warning was the 3rd item in the Release Notes. Quote from the Release Notes is below.

********************************

"Version 0.0.245 ( 6-Feb-09 )-

o I-Frame only recording option, 100 mbit or 160 mbit (160 mbit requires faster CF cards such as Transcend 300x cards)."

********************************

And every set of firmware Release Notes thereafter also contained this same notation of the faster card requirement.

If you are going to install the firmware upgrades, you might want to read the Release Notes that come with each firmware upgrade. Important info about the new capabilities and changes made with the firmware update are contained in the Release Notes.

I sincerely hope you are not suggesting that C-D withhold releasing new capabilites and fixes until they have a technical report writer rewrite the entire manual before they release the new firmware!

The method C-D is using of supplying brief pertinent Firmware Release Notes is far superior. I think most of us would hate to wait weeks or months for a new capacity or bug fix and then spend the time parsing through a 60 page manual to learn about the changes that apply to the new firmware.

Assuming I am understanding the question....

The timeline was set to use the XDCAM HD422 1080i60 (50Mb/s)

Our thought was if this was the wrong codec to be using, the timeline would have asked to correct itself to match the video format when we tried to place the video.

David Schmerin
Speaking for a minority of one

Thanks David that is what I thought. So really there is no way to edit 160Mbp/s I Frame in Final Cut.

Hi John,

Clearly you must have me mistaken for someone who owns the product which I am not. I am a renter. And as a renter I do not upgrade units. I do not get release notes. And most importantly when I rent equipment I look to the manufacture and their documentation for support not 3rd party independent discussions boards. Clearly my mistake in thinking.

I feel independent sites as this are fine and fun but should not be the primary means of distribution for product information. I am sure on the C-D web site the Release Notes exist somewhere and I blame myself for having not seen them.

As for the manual, my comments were more general comments as to the overall level of quality of the manual on a whole and not to related to any specific issue. However, I would say that had C-D waited until the XDR unit was truly a market ready product, then the constant updates to the firmware etc would be far fewer and then the adding of an addendum or "release notes" would be a much easier task.

If nothing else, given that the only manual I ever see is a PDF downloaded from their site and not a printed manual, then yes I do think the very least a company can do is keep their electronic manual properly up to date

Speaking for the minority of one
David Schmerin

Paul,

Absolutely editing 160MB/s I Frame only should be no problem in FCP. The problem is I was unknowingly using CF cards that were actually too slow but gave every indication all was good. I have every confidence that had we used 300x 16G cards, everything would have worked out just fine.

Speaking for a minority of one
David Schmerin