Results of my first XDR Timelapse

[Lance Librandi]

Hi Mark,
I just checked my setup and all my testing has been on Sandisk Extreme IV 16 GB CF card I am going for another try a 5am tomorrow and I will use the Sandisk Extreme III 32 GB cards.

Well this time I will take a shot gun to get rid of all the large pacific seagulls that keep doing flybys and destroying my vision. (Just Kidding it's easier not to pack near over full rubbish bin)

[Dan Keaton]

Dear Mark,

I do not know why you are getting 3 second files in timelapse mode.

We will run some tests in our lab.

[Mark Job]

Hi Dan:
Same results this time too. No speed jump. Nothing but a series of tiny 3 second clips :-( These are no good for file import purposes for us. I suppose I could just hit playback and see if the XDR will playout the entire clip as one continual sequence. I will go test this now and see on my HD-SDI portable monitor.

.....Someone else reading this thread who has a Flash XDR and has the latest 1.1.63 firmware upgrade please try a timelapse sequence and tell us what your file structure looks like. Do you get a whole bunch of tiny 3 second clips on your CF card ?

[Tommy Schell]

Mark,
What's your record trigger? (System->Record Trigger)
Tommy

[Dan Keaton]

Dear Mark,

What is your time interval?

Is it 1 second or, for example 5 seconds?

How long are you recording your timelapse sequence?



If you are recording with a time interval of 5 seconds, and you record for 9 minutes, you will get a 3 second timelapse sequence.

3 seconds at 30 frames per second (actually usually 29.97) = 90 frames.

90 frames times 5 seconds for each frame = 450 seconds = 9 minutes.


If you are recording with a time interval of 1 seconds, and you record for 90 seconds, minutes, you will get a 3 second timelapse sequence.

3 seconds at 30 frames per second (actually usually 29.97) = 90 frames.

90 frames times 1 second for each frame = 90 seconds = 1.5 minutes.


If you record for much longer times, you will get corespondingly longer files.

[Mark Job]

Originally Posted by Tommy Schell

Mark,
What's your record trigger? (System->Record Trigger)
Tommy

...Hi Tommy:
I'm on System>Record Trigger>Record Button.

Mark

[Mark Job]

Originally Posted by Dan Keaton

Dear Mark,

What is your time interval?

Is it 1 second or, for example 5 seconds?

How long are you recording your timelapse sequence?



If you are recording with a time interval of 5 seconds, and you record for 9 minutes, you will get a 3 second timelapse sequence.

3 seconds at 30 frames per second (actually usually 29.97) = 90 frames.

90 frames times 5 seconds for each frame = 450 seconds = 9 minutes.


If you are recording with a time interval of 1 seconds, and you record for 90 seconds, minutes, you will get a 3 second timelapse sequence.

3 seconds at 30 frames per second (actually usually 29.97) = 90 frames.

90 frames times 1 second for each frame = 90 seconds = 1.5 minutes.


If you record for much longer times, you will get corespondingly longer files.

,,, Hi Dan:
I have just completed my third timelapse sequence, which has run all night at 1 frame every 15 seconds. I don't think it is the issue of my time interval-Whatever I set my time interval to be should be surperfluous as to what the actual size of the data chunk I wind up with at the end of the day on my CF card. (??) EDIT: Obviously, if I only shoot for an hour than my corresponding file will be small indeed. However, this is not the case with my tests. The shortesttest I have run so far is four and one half hours. Test 2 was about five hours and test three was nine hours. EDIT 2: Whatever you record, why should it not be put into one data chunk ?

The good news is that if I play back the entire sequence out of the XDR via HD-SDI, then I get the whole sequence playing out fluidly and completely with no speed jump I can see.

** However, Playback pause, then play, then pause is *unstable* If I hit pause for longer than 5 seconds, then the XDR locks up and then the picture disappears from my monitor ! Then sometimes it begins to play back two different clips at the same time alternately ! What the hell ?! DMA Read error ?

[Aaron Newsome]

I forgot to post back my results. The timelapse worked perfectly. All the clips were 5 seconds each. I laid them on the timeline in FCP and the played back as fluid as can be. I wanted to punch them up a little bit so I sent the timeline to color, then back to FCP (as ProRes422).

Everything worked as expected, no weirdness, no speedups.

[Aaron Newsome]

Originally Posted by Dan Keaton

Dear Aaron,

Please try to stop the timelapse before the battery shuts down. We do require power the whole time, otherwise we will lose some of the file, probably a lot of the timelapse sequence.

Dan, my camera and XDR are powered off the same battery. My camera always shuts down first, XDR loses signal and closes the file properly. I've never lost a file on the XDR because the camera always shuts down first on low battery.

[Mark Job]

Hi Aaron:
OK. Your results seem to confirm mine. Congratulations-this is a malfunction. THe XDR is not supposed be giving you little file chunks. I spoke with Dan Keaton of Convergent Design today and he confirmed you are not supposed to get a whole bunch of little files. If you set your recorded file size to 100 %, then you should be getting much larger or large single file on your CF card.

[Aaron Newsome]

My file size is set to 75%. I did this on day one of owning the XDR (as a protection against losing a large file on power off). As it turns out, I can probably set my file size to 100% and just leave it there forever.

[Mark Job]

Hi Aaron:
I suspect that even if you do set your file size @ 100 % you will still experience having these tiny MPEG files of only a few seconds.

[Mike Schell]

Hi Mark, Aaron-
Here's the story on time-lapse and file size. Our time-lapse feature records I-Frames into a 15-frame GOP (12-frames in 720p mode). So depending on the time interval, it takes 15 or more seconds to fill up a GOP, which is then transferred to the CF card. If the time interval is 1 frame per hour, then it will take 15 hours to capture just one GOP of data. Naturally after writing a certain of GOPS, we have to close the file to make it usable to the NLE.

Our big concern in developing time-lapse was the potential lose of power to the nanoFlash. Given the potentially long interval before data is written to the CF cards (and file closure), we worried about the lose of power and the potential lose of all the footage. So, to minimize this potential lose, we reduced the file size based on the time interval. So, at 1 frame per second, the file size was reduced to 20%, but by 1 frame every 15 seconds the size dropped to 2%.

We now realize that this strategy needs to be revamped. So, look for appropriate corrections to this issue in the next firmware release, scheduled for the end of this month.

Best-

[Aaron Newsome]

This confuses me since I-frame only codec has no GOP. It's intraframe, meaning each frame stands alone, not as part of a group of pictures like long GOP.

Maybe it would make more sense if you just wrote each image to a single frame Quicktime / MXF.

[Mark Job]

Originally Posted by Mike Schell

Hi Mark, Aaron-
Here's the story on time-lapse and file size. Our time-lapse feature records I-Frames into a 15-frame GOP (12-frames in 720p mode). So depending on the time interval, it takes 15 or more seconds to fill up a GOP, which is then transferred to the CF card. If the time interval is 1 frame per hour, then it will take 15 hours to capture just one GOP of data. Naturally after writing a certain of GOPS, we have to close the file to make it usable to the NLE.

.....Mike:
Yes, I follow how you have engineered your SSDR's to handle your I - Frame MPEG Time Lapse, but what I don't quite follow is why you have designed to register I-Frame MPEG using *Long GOP methods to do it ???* Mike, is there an important technological reason why it is being handled in this manner ? Like Aaron, I also understand I- Frame to be the opposite of Long GOP, because Long GOP is not a good way to do animation or time lapse on digital video. - Or so I understood.

Originally Posted by Mike Schell

Our big concern in developing time-lapse was the potential lose of power to the nanoFlash. Given the potentially long interval before data is written to the CF cards (and file closure), we worried about the lose of power and the potential lose of all the footage. So, to minimize this potential lose, we reduced the file size based on the time interval. So, at 1 frame per second, the file size was reduced to 20%, but by 1 frame every 15 seconds the size dropped to 2%.

......Yes, I understand. Please feel free to extend this ratio back up to as large a file size as possible to obtain with your methods. The loss of power and our work is strictly our problem - not yours. *OR* How about this possibility ? - Could the engineers at CD write an adjustment software switch that would give the end user the ability to set this ratio just like you have done with regular motion video capture ? You would add this adjustment parameter to the Time Lapse Mode Program menu.

Originally Posted by Mike Schell

We now realize that this strategy needs to be revamped. So, look for appropriate corrections to this issue in the next firmware release, scheduled for the end of this month.

....Thank you Mike. I know I appreciate CD's flexibility on working with our end user feedback.

Originally Posted by Mike Schell

Best-

...Thank you Mike.