Any ideas on channel spill for Field Recorder "Functionality"?

[Frank Kruse]

Originally Posted by mfranken

The only problem I'm seeing is the issue where a location recorder doesn't start it's recordings on a frame edge and when the WAVs are loaded into a picture editing system, the WAVs will be moved to start on a frame edge. Then when you expand tracks (using an AAF or EDL as the location reference) the location WAVs are up to a frame out-of-sync because PT understands samples. Actually in this case case I feel the audio in MC is out-of-sync and the audio in PT is correct!

I know this occurs with deva recorders, not an issue with SD recorders. Avid said it was addressed in MC7.04 and MC8 with a pref that reads: 'Subframe Alignment to Broadcast Wav Start Time'

More here:

http://www.pro-tools-expert.com/home...t-of-sync.html

Which has a link to Frank's DUC post (not sure if you've seen this):

http://duc.avid.com/showthread.php?t=345993&page=6


The film on at the moment was recored in Germany and Australia. The Australian recordings all phase nicely, but the German recordings are up to a frame out-of-sync when I expand from AAF or EDL (via EdiLoad conform ref tracks). The German sound sheets don't say what the recorder is (guess I could look at the metadata for clues) and the picture assistant says this audio was loaded into MC before he came on so he isn't sure what the pref was set to during load.

So not sure if this MC pref actually resolves this issue.

Hence for this job I'm using a combination of clips from the AAF (which has incorrect channel names) and conformed tracks.

BTW, regarding the EdiLoad conform, there were 3 events that didn't find any location audio, but not bad for a 2 hour film.


Regards,

Mark

Funny, a blog post about a blog post about a DUC-thread :) Hadn't seen that before.

Back then when I posted this over at jwsound after analyzing the issue I pretty much got laughed at and the recordist's consensus was: 'Shut up and just re-sync everything manually like you've done for the last ten years. We've got bigger fish to fry' Fortunately some were concerned and AVID came up with a solution.

Companies like SD and Aaton have been very clever starting and stopping files on the 00-frame at all times. This not only avoids the mentioned issue but also enables us to cross-jam between different TC-rates even after the recording is long over as they are are all the same on the full second. And it also avoids sync discrepancies when using EDLs that are obviously only frame accurate as well.
This is impossible when your files are stamped in between frames or on in between full seconds.

F.

[Ray JB]

OK so agreed about the tc offset issues which I regard as being reasonably "fixed" in some respects thanks to you guys getting some major stuff sorted out.

The major issue I currently have which is the real root cause of this thread, is to try and work out why AVID MC loses the channel information? Those original poly files have all the track information presented in the iXML info. Is it because is AVID MC can't deal with the idea of having the sibling channels of audio imported with non-sequential track numbers? Because what I'm seeing is a situation with a location sound BWAV recording a poly track with say 3 tracks, being boom on track 3, and 2 radio mics on track 5 and track 7, and then after importing to AVID, that channel info is lost in the MXF file. Those files will show in ProTools as having channel suffixes of .A1, .A2 and .A3 and with no track name or original track number. So then the link to the original track name and number is lost.

I seem to recall some issues like this in the deep distant past, relating to the early days of polyphonic file recording say an 8 track poly file and then halfway through a setup, disarming say channel 5, and now recording a 7 track file, and then problems with Media Composer shifting those channels down the pile.
The solution was back then to keep recording the same number of channels i.e.: keeping all the tracks armed but the inactive channels muted (recording silence), and this would keep the channel order the same, but was wasteful for storage.

So what I wanted to see in my AVID test was if it was possible to keep the original track name and number metadata carrying thru to the MXF files.

Cheers, r

[trevora]

If you've got some sample files I'm happy to put them through Avid MC and export an AAF for you. I can also put them through PPro as I'm using that much more these days... and the PPro AAF is still very much work in progress.

[octagondd]

I am hoping this helps, or at least points us in the right direction.

Metadata on mxf media for Channel Name, Sound Roll, etc. - From speaking to our digital dailies guys, I have learned that one of two things may solve this issue. I have not tried it out yet, but it is something we are looking into this summer. The dailies house or the assistant Picture editor need to consolidate the mxf media. This will take the channel name, sound roll, and other metadata and embed it into the mxf file. This is not the consolidate that we think of in ProTools where you define handles and you only get a portion of the file. They can do a consolidate with a whole file. I hope to have test results of this process this month.

If this solves the problem, then using the mxf media can indeed be the real and working Field Recorder Workflow that has been teased for so many years. No more Titan syncing.

[Ray JB]

Originally Posted by octagondd

I am hoping this helps, or at least points us in the right direction.

Metadata on mxf media for Channel Name, Sound Roll, etc. - From speaking to our digital dailies guys, I have learned that one of two things may solve this issue. I have not tried it out yet, but it is something we are looking into this summer. The dailies house or the assistant Picture editor need to consolidate the mxf media. This will take the channel name, sound roll, and other metadata and embed it into the mxf file. This is not the consolidate that we think of in ProTools where you define handles and you only get a portion of the file. They can do a consolidate with a whole file. I hope to have test results of this process this month.

If this solves the problem, then using the mxf media can indeed be the real and working Field Recorder Workflow that has been teased for so many years. No more Titan syncing.

Yes that sounds promising! I'm interested to see what happens with this approach and if it would be possible to do this retrospectively after the dailies process so that we could "fix" a show to work properly for Dialogue Editing after realising not much metadata is coming thru with the MXF files.