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-   -   Recording capabilities (https://www.dvinfo.net/forum/convergent-design-odyssey/139007-recording-capabilities.html)

Per Johan Naesje December 5th, 2008 05:17 AM

Recording capabilities
 
As a wildlife filmmaker I'm very much interested in the Flash XDR unit. My current setup is Canon XLH1 and different kind of 35mm lenses.

My question before I take the step to make an order for the unit will be:
In the Flash XDR brochure at your website (http://convergent-design.com/downloa...20Brochure.pdf)
you're advertising the ability to do pre-recording and time lapse (in I-frame mode).

I'm aware that this function is not present at the current firmware? When will this be accessible?

For wildlife shooters I believe these two function is very important.

Steve Phillipps December 5th, 2008 06:50 AM

I agree Per, very useful. The pre-recording (cache recording/loop mode) is very useful (essential?) for catching the moment a bird takes flight from a perch etc. The other thing that it does apart from allowing you to capture the moment is it cuts down on shooting ratios, as without it you will know that if you have a bird on a perch you have to keep running on it as when it takes flight you'll be too late pressing the trigger, so you might have 3 minutes or who knows how much of the bird just sitting there and the useful 10 seconds of shot as it takes flight! With cache record you just wait 'til it flies then hit the button and you've got 5 seconds or so (upto 30 seconds on the PDW700!) of the bird sitting there before flying.
Steve

Per Johan Naesje December 5th, 2008 08:10 AM

Hi Steve, yes that's what I gonna use it for! The Flash XDR will be a major upgrade for those of us using e.g. Canon H1. Hopefully this function will be available soon....?

Dan Keaton December 5th, 2008 10:32 AM

Dear Per Johan and Steve.

Our developers plan on providing 8 seconds of pre-record buffer in 100 Mbps mode, and 16 seconds in 50 Mbps mode.

We are attempting to finish MXF and a few other things before we can implement the pre-record buffer.

Time-lapse will appear about the same time frame as the pre-record buffer.

Per Johan Naesje December 5th, 2008 11:32 AM

Quote:

Originally Posted by Dan Keaton (Post 973418)
Our developers plan on providing 8 seconds of pre-record buffer in 100 Mbps mode, and 16 seconds in 50 Mbps mode.

Wow, fantastic news! That gonna be a very nice feature. Not gonna miss any of those hard to capture moments!

Quote:

Originally Posted by Dan Keaton (Post 973418)
Time-lapse will appear about the same time frame as the pre-record buffer.

Dan, will you describe the details for this function? Which intervals and time frame are you planning?

Thanks a lot!

Dan Keaton December 5th, 2008 03:04 PM

Dear Per Johan,

By time frame, I meant that around the time that we will have the pre-record buffer ready, we will also have the Time-Lapse recording ready for delivery.

The time-lapse recording feature will work with I-Frame only. We will be receiving HD-SDI, convert each frame to MPEG2 I-Frame Only, then record only certain frames to the CompactFlash card, bypassing the others.

I know that we will have a menu item that will allow you to specify the time interval before we record the next frame. We may need to also allow you to specify the number of frames to record after each interval. We will determine this during our testing.

If you are going to record overy a long time period, for example days or weeks, you will need a good power system to power the Flash XDR. If for example, one needs to record, in time-lapse mode, a major construction project, over months or years, then an AC power supply would be appropriate.

We intend to be very flexible in allowing you to specify a very wide range of recording intervals, from just one frame to minutes, hours, days, weeks or months (which would be extreme).

Paul Cronin December 6th, 2008 03:34 PM

Dan are you saying the XDR will be accepting all the frames from the camera then only recording the ones selected for the time lapse in I-Frame mode?

So with camera's like the EX series where we have time lapse options we would not use that and only record normal?

Steve Phillipps December 6th, 2008 03:39 PM

Dan, I think 8 seconds is good for cache recording, don't really need more than that, in fact I usually have my PDW700 set to about 5 seconds. Looking good, keep it up guys!
Steve

Dan Keaton December 6th, 2008 03:50 PM

Dear Paul,

Our future time-lapse mode, to be released in a future firmware release, is not dependent on the camera. This allows us to do time-lapse recording with a wide variety of cameras.

I think it would be best, if you want to use our time-lapse feature, to use normal modes on the camera.

I do not know, during EX1/EX3 time-lapse modes, what comes over the HD-SDI.

Without any special feature in the Flash XDR, we should be able to record whatever the EX1/EX3 puts out, but I would assume that they are putting out normal video and not time-lapse video.

Dan Keaton December 6th, 2008 03:52 PM

Quote:

Originally Posted by Paul Cronin (Post 973950)
Dan are you saying the XDR will be accepting all the frames from the camera then only recording the ones selected for the time lapse in I-Frame mode?


Dear Paul,

Yes.

Paul Cronin December 7th, 2008 08:44 AM

Thanks Dan sounds like a great way to go.

Per Johan Naesje December 7th, 2008 03:51 PM

Quote:

Originally Posted by Steve Phillipps (Post 973954)
Dan, I think 8 seconds is good for cache recording, don't really need more than that, in fact I usually have my PDW700 set to about 5 seconds. Looking good, keep it up guys!
Steve

Well as stated by Dan in a previous post (http://www.dvinfo.net/conf/convergen...r-owner.html):
Quote:

Just like your XL H1, these is a slight delay from when the timecode starts incrementing before the first frame is recorded. On the XL H1, this is about 3 seconds, it is faster on the Flash XDR.

In a future release we will probabaly reduce the delay to the smallest value possible. I understand the current delay is around 1 second or less.
I think it will be better to have at least 15 seconds of pre-record cache if we use record triggering with time code detection!

Dan Keaton December 7th, 2008 05:21 PM

Dear Per Johan,

We are limited by the amount of memory that we can devote to the pre-record buffer, and the amount of processing that has to take place when we start to record.

Just think of it this way, we can only get so far behind. But, we will work out all of those details and provide as much pre-record buffer as possible.

50 Mbps bit-rate produces very good video. Of course, 100 Mbps is better, for demanding applications.

So, if you choose 50 Mbps, you get a longer pre-record buffer. Then one has to determine if the video is good enough for their application. If it is not, then 100 Mbps is for you.

(I tried to see which of my previous posts that you were referring to, but the link does not work, sorry.)

Per Johan Naesje December 8th, 2008 12:18 AM

Dan, I was refering to your thread: http://www.dvinfo.net/conf/973764-post28.html in the topic: new flash xdr owner by Paul Cronin, where you stated that there is a slight delay from the XL-H1, when you use time-code triggering for recording to the XDR. Sorry for my bad link!

Dan Keaton December 8th, 2008 04:16 AM

Dear Per Johan,

We will be attempting to reduce the delay down to a minimum. In any case, it is currently much less than tape at this time.

I will report back when I have a better answer as to how long the delay will be. I am hoping for a few frames or less.


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