Pix 240 Firmware 1.07

[Peter G. Johnson]

There's a firmware update for the Sound Devices Pix 240 (1.07) Not really greatly exciting but any improvements are always welcome.

PIX Firmware Download | Sound Devices, LLC

[Ned Soltz]

File does not unzip properly.

Emailed SD

Ned Soltz

[Matt Mayer]

Ned,

What platform are you on? I was able to download and unzip with no problems on OSX 10.7.3 using Firefox.

Are you using Safari?

[Peter G. Johnson]

It unzips properly now. The thing that caught my eye was the much improved file menu. Now, if only there were a way for it to capture 4:4:4, it would be complete. Other than that, the Pix 240 is a robust unit with both HD-SDI and HDMI. Just couldn't justify over double the price for a Gemini.

I've also recently started using a Swit S-8U62 battery to power the Pix 240 and the F3 (hirose cable to D-Tap) for the purpose of reducing weight and they both run very well for sustained periods of time. Thanks to Alister Chapman for insight.

[John Hopkins]

"We noticed that when rolling long takes, the picture lags behind the audio at an increasing rate of ~ 1 frame every 3 minutes. So an interview of 35 minutes will end up half a second out of sync."

Please check this vimeo PIX 240 audio test out:

PIX240 Sync drift on Vimeo

Has anyone experienced this problem and does anyone know how one can fix this issue in FCP or any other way? We have recorded interviews that are out of sync because of this bug and they need to be fixed. The problem of trying find sync when there is an accumulative problem of more audio frames being produced over time. Perplexing to say the least. Is there a pattern that can be precisely identified to help solve this? Could it be adapted to an Automator script or Compressor somehow to apply to these takes? Or even away to adjust each long take in FCP? It seems like an unbelievable oversight that the PIX 240 would be released without proper syncing happening for any takes over three minutes. To their credit SD has at least fixed the problem now and they are looking to see if there is a way to re-conform sync for footage impacted by this issue.

How was it that the PIX was stretching the audio to run ahead of picture over time? The fix is in 1.07 but that does not help those of us left with interviews on current productions.

We are using a F3 and recording 1080PsF 23.98 and scaling that to 1080p 23.98 in the PIX.

Thanks for any help and insights to try to resolve this.

[Peter G. Johnson]

Things do move fast these days. Since I posted almost two months ago, there's been a v1.08 and now a v1.09 update for the Pix 240. I think it might address some of these issues.

PIX Firmware Download | Sound Devices, LLC

[John Hopkins]

Has anyone had any luck with QT Sync to fix the drifting sync over time problem with the PIX 240 for interviews recorded on version below 1.07 of the recorders operating system? Apparently it works. If anyone has had this same problem and has identified the problem pattern of the PIX 240 adding more audio frames every three minutes so as to cause major gaps in sync the further the interview extends please let us know. We are looking for a method to add values to qtsync to precisely correct for this problem over time, and how does one correct for problems with this software if correcting for it is not going to work by doing a simple offset and pushing the audio ahead by x amount of frames near the beginning. Apparently, the PIX 240, before the fix, was adding one frame approximately every three minutes of interview time. One would have to use clappers to find the exact frame issue pattern. We should have done that before upgrading to 1.09. We've asked Drew for help since he's already completed this test and he may have help for the community impacted by this very frustrating issue from the PIX 240 keeping sync sound on anything beyond a three minute take.

[John Hopkins]

I've broken everything down in FCP and exported into 3 minute segments and used the formula below; Is this what you did and how you prepared each in QtSync?:

Based on 60 minutes of footage (59.57 sec). ApplePro Res HQ 1920x 1280 23.98 as recorded on my PIX240 from our Sony F3, scaling from 23.98 PsF.

Qtsync settings: offset each segment by adding 1 frame for every 3 min. segment:
from 0 to 19 segments.

This seemed to work, not sure how precisely as I was only guessing at lip sync being on with no clappers or reference sync points seen in any of the frames being a head and shoulders interview.

However joining this back together messes up the audio in Qtsync where for a few frames it seems where it is joined with the tracks of each segment being offset. Salvages only what lies within these three minute segments.

Ideally, I'd like to conform and correct sync so as not to lose any audio at the joints between the segments. Any suggestions which might work?

[Paul Ream]

If you've got an interview of 60 minutes and you want to use as one continuous long shot, why can't you just lose 1 single frame of audio every 3 minutes? I realise that will be 20 extra edits, but if you perform the cut during a pause nothing will be noticed?

Oh and make sure you're not using 1.05 any more! (They're up to v2 now)

[John Hopkins]

Had some help from Dror Lahat who suggested not to offset the audio but rather increase it over time like you suggested. *Went back and re-tried QtSync which is a free program found here:*QT Sync This seemed to do the trick and was able to get it close from the beginning to the end of the interviews affected.*

Using QtSync, set the DURATION values and "arming" the two audio channels for "17 frames," for an interview which went 59:57 minutes/frames. In a shorter interview of *27:05:12 minutes/seconds/frames it was 10.5 frames. t would be nice to get an exact formula as one has to guess and experiment until it looks and feels right on sync. Perhaps SD's engineers might help there. I was told they are looking into this, and may have an answers for those impacted soon. But for anyone struck by the same problem I suggest you try this QtSync method.

Initially, I entered the values in QtSync using the offset window at the top and could only get sync that way by breaking everything down into 3 minute segments. Not sure what the bug is, Sound Designs seemed to indicate it was something to do with the way the PIX interpreted PsF while converting to 23.98 using the PIX scaler, and recording that result to the SSD. Here's what Dror said he believes the bug is or was not that SD has corrected the bug in anything from 1.07 update up:*

"Remember that audio has no frames. Also, I eventually realized that the PIX wasn't adding frames to the video; the PIX has no capability for buffering like that, nor can it predict signal it hasn't received yet. What was the likely cause for the bug was inaccurate framerate (speed) metadata in the QT, at the Quicktime Atom level or something. I think the audio played correctly at 48,000 samples per second (or whatever audio settings were), but the video ran at 23.98fps instead of 23.976fps."

Everything we shot with the Mini KiPro was fine, but our long interviews the PIX stuff was alarming when discovered the sync problems. We chose the PIX because, using large capacity SSD's, we did not have to interrupt our interviews to change (very expensive low capacity) CF cards. Certainly it's fantastic QtSync could do this, when the paying programs I tried failed. The pic attached shows where I entered the values. You have to play with it a bit to figure out how many frames to enter when setting the "Duration" for both audio tracks. It depends on the the length of the interviews. The longer the interview the larger amount of frames you enter but you have to experiment with the number and just watch closely to see if the interviews are syncing with the lip movements.*