Dear Piotr,

When we fill up one file, we start another, and then while we are writing the video and audio to the new file, we go back to write the large index to the old file.

If the card is not fast enough to keep up with this double writing, then the level of the FIFO will increase.

If the FIFO buffer level then goes down before before the second file is finished, then you are ok.


Please understand that you need to perform a recording, to your card under test, until the card is full.

But has this issue always been there or is it something new with this build?

Peter,

You misunderstood one of my previous posts on this - the audio drift used to be even longer with previous firmware releases (I don't know about the 1.6.29, though - as I skipped that).

So if I mention the 4 milliseconds now is because I appreciate it's improving, but still not quite there yet:)

Piotr

Piotr,

You are obviously very technically adept and clearly you strive for excellence in your productions - as we all should. I come from a telecommunications and telemetry background and from all the training I have done, the 4 ms delay you are worried about would be absolutely imperceptible to the average punter.

You know its there because you have the means to test it. The viewer, on the other hand, probably hasn't a clue. I have copied and pasted a paragraph (below) from a paper about the subject (which as you will know is commonly just referred to as lip-synch problems).

Quote:

From time to time, standards committees in various countries have addressed the problem
of audio to video timing errors, and have set standards or guidelines for the maximum
allowable amounts of these errors. For the most part, these standards or guidelines are in
agreement that lip sync errors start to become noticeable if the audio leads the video by 25
ms to 35 ms, or if the audio lags the video by 80 ms to 90 ms."

End quote

The paper was authored by:

J. Carl Cooper
Mirko Vojnovic
Chris Smith

and can be viewed here:

http://www.pixelinstruments.com/pdf/...c%20Errors.pdf

Honestly, whilst I think it is admirable that you are striving for perfection in everything that you do, I think Dan probably has a lot more to worry about than trying to correct things that simply don't matter to the end-user of the recordings.

Cheers

Russ

Thanks Russ for your comments, and the link to some interesting reading.

I'm not ranting - to the contrary; the delay used to be almost half a second when I first got my nanoFlash, and now it has been greatly reduced. But still - and I'm sure Dan understands me well - the matter is two-fold:

1. From purely technical viewpoint, I don't see a reason for any discrepancies between nano and native recordings. Of course, there is some latency to any type of connection, including SDI - so I have no problem with the fact that the nano clips start a couple of frames later than the native ones. But, inside the SDI stream, the picture is spot-on with the TC - why not the audio?

2. As to what is noticeable and what's not - I can assure you that if a guitarist's fingernail, pulling a string, is more than 5 ms off in relation to the sound, it will be noticeable (especially on 50+ inch screen's closeups). So, 4 ms is just barely tolerable (I agree that for the lip-synch, even 25 ms may be OK; also some other instruments might pose much lesser demands in this regard than the guitar does).

Cheers

Piotr

PS. I've just noticed you're located in Australia - if you are in touch with Bob Grant, you might ask him about the amount of effort I put into editing that particular guitar recital; he also is in possession of the DVD I produced....

G'day Piotr,

sorry if you got the impression that I thought that you were ranting, because I certainly didn't intend for you to interpret it that way. I think that the point about the audio/video being out of synch is being laboured a bit, not ranted about.

Anyway, hopefully the team at CD have got their teeth into the problem by now, although there will be a limit to how much they will be able to achieve. As you pointed out yourself, there are latency issues, and many other issues that are not even the nano's fault, so I don't think that perfection will be achieved. Time will tell.

I do correspond with Bob, and although we live on opposite sides of the country, I hope to catch up with him next year when I go to Sydney, even if it's just for a coffee (or beer.)

Cheers

Russ

Just curious, at what stage of the beta firmware does CD recommend downloading the new firmware?

Thanks

Dear Anthony,

1.6.226 is a Public Beta. Thus, we encourage our users to download and load this version on their nanoFlashes so that they can test it.

After they have finished their testing, then we recommend re-installing 1.6.29 for production work.

And, of course, if you have any quetions or problems with the firmware, please contact us.

We have had very few reported problems with 1.6.226, thus I would expect that we will issue Production Level firmware fairly soon.

Looking good then Dan.

Thanks.

I can confirm that the newest Beta is the best nanoFlash firmware ever - no doubts about it. A real milestone, and very stable, too.

Piotr

Thank you Piotr, I think I will download it and try it.

Thanks.

I personally would never do a job with Beta FW.

Try it, help debug it. But if you have an important job go with the latest official version.

I think that is what CD wants you to do. You don't want to find a bug while on a job. Just my opinion.

Thanks Olof.

MPG recording audio sync seems fixed
 

Hi all,

We've been testing the audio sync when recording lower bitrate MPG recordings (as viewing copies).
used to be 4 frames out, but now seems to be dead on and a lot more stable.

Still testing, but looking good for that improvement.

Thanks guys.

Regards

Dave

Dear Olof,

Exactly, thank you for making that clear.

Our Public Betas are to allow others to test the upcoming release.

While our testing is very exhaustive, we may miss something, and we do not have every camera in our lab.

And others may use the nanoFlash or Flash XDR differently than we do.

After testing the nanoFlash, for production we recommend going back to the Production Level releases.

Our next step is to release Production Level releases.

Dear Dave,

Thank you for the good news.

We greatly appreciate the feedback.

Only thing I have noticed with the beta version is when I press the camera record button (TC) the light on the remote control cable stayed red for about 90sec then started flashing then another time it could take maybe 15mins (or more) before it flashed.

Why the variation in time?

Thanks.

Dear Anthony,

When the Tally Lights flash, your media is nearly full.

It starts to flash when you have less than 5 minutes left.

Then it flashes faster when you have less than 2 minutes left.

Hi Dan,

I have 106 mins of SDHC card left and 48 mins of CF card remaining and its still flashing.
Perhaps its a setting on the NF, thinking I'm almost out of media.

I don't mind the flashing, I'm glad to see it, I know the NF is recording, its just, why the difference in time before it begins to flash.

With the 1.6.29 firmware the remote cable button stayed red all the time while I was recording, now with the beta firmware it flashes, thats fine, no problem with that, it was when it stayed on full red then decided to flash, its that I was curious about, thats all.

Dear Anthony,

If you are using1.6.29 (Production Level) or 1.6.226 (Public Beta) firmware, both should stay on full, until the card get low.

Much earlier firmware flashed all of the time.

The nanoFlash can not determine the level of your in-camera media, such as SDHC cards.

Have you formatted the CompactFlash cards in the nanoFlash?

Maybe we have a problem with the Public Beta, we can check.

Is anyone else seeing the Remote Tally light or the Status Light on the side of the nanoFlash flash while there is still over 5 minutes of recording time left?

Hi Dan, I will try SxS cards and see what happens.

Yes, I formated the CF in the NF.

Thanks.

Dear Anthony,

The nanoFlash records separately from the camera.

And the nanoFlash does not know the level of the media in the camera, they are completely separate.

I hope this helps.

Hi Dan I thought you meant it applied to SDHC cards only,... thats why I said I would try SxS,

NF set at TC and also set for Remote record and the tally light on the remote cable is flashing at both settings :) (status light on the side of the NF flashing too btw)

So are you saying it shouldn't flash at all, even with this beta version that is, until the cards get low.

Dear Anthony,

If you have more than 5 minutes of Record Time left,
and you are using 1.6.29 or later,
the Tally Light on the wired remote control should not flash.

At the bottom right of the screen is a number. This is the number of minutes of recording time left.

What does your nanoFlash display for the number of minutes left?

If you format your cards in the nanoFlash, does this number change?

While you are recording, does this number decrement for each minute you record?

What do the Card Space Used indicators, at the top of the screen show?

What firmware are you using, this is in System|About?

Hi Dan,

69 mins left
Formated Card it now says 116 mins
Yes, decending and after recording it now says 112 mins
Card space plenty, just the start of a line going from L to R
Firmware 1.6.226
MP2 Codec: 01.02.06

Thanks.

UPDATE. Flashing with 78min remaining on CF card.

Dear Anthony,

Thanks.

By Flashing I am assuming you mean the Tally Light at the end of the wired remote control, in other words, the LED in the remote control switch is flashing.

And I am assuming that you do not mean the LED on the side of the nanoFlash that flashes Red when the nanoFlash is recording.

Are my assumptions correct?

In any case, we will attempt to duplicate this in our lab.

Hi Dan,

Yes, the LED tally light on the remote control cable is flashing.


I do not mean the LED on the side of the nanoFlash. (although this does flash when recording too btw)

Thanks again.

Dear Anthony,

Thank you for the confirmation.

We will duplicate the problem in our labs and then fix it.

Hi Dan thanks.

It would be me :)

I have no problem with the tally light on the remote cable flashing, I was just curious why it took anything from 90 sec to 15mins, or more, before it started to flash, thats the only reason.

I don't have a lot of experience with the NF having only just bought it but what I really like about this beta firmware is the ability to hotswap the CF cards and the power saving option. All very useful when recording weddings.

So thanks CD and to you Dan. I would highly recommend a NF to anyone thinking of buying.