Strange behavior with sound channels while importing from PC to MAC CS5

[Bart Walczak]

Hi,

I have experienced a very strange behavior with sound channels.

We had one editor edit a project on a PC Premiere CS5. All footage was Cineform avi 720p25, source channel mapping was set to mono, since we had 2 separate lavalier channels recorded.

Then we moved the project to the Mac, Premiere CS5 for finishing. Everything imported fine, as is usually the case, with one exception. For some reason the audio channels were mapped back to stereo, resulting in two identical mono tracks with the first audio channel only, where we had the first one on one track, and the second one on another. Now it is not possible to change the audio channel mapping back (understandable, this is how PPro works), but due to this error in importing we are stuck with a nasty problem on our hands.

We know that everything was fine on the PC project, because we exported DVD and the sound was OK.

I would welcome suggestion for a workaround or a fix which do not involve me replacing 1000+ audio edits or using PC. We need to use Mac, because this is where we have Production Premium installed with AE and other tools.

Thanks.

[Battle Vaughan]

If I understand your problem, you have two stereo tracks where you had two mono tracks and want to delete the redundant parts of each track?

Off the top of my head, as I am presently unable to test this thesis, but I think this would work: Nest the clips into one big clip in a new sequence window, select the nested clip in the project window, select clip > audio options (maybe it's called modify>audio in cs5?), select breakout to mono....results in copy clips, one with left track and one with right. Delete the tracks you don't want. Or am I missing something?

Here's the Adobe help info quoted from on-line help:

Change the source audio channel mapping for one or more clips
1.Select one or more clips containing audio in the Project panel and choose Clip > Modify > Audio Channels.
Note: If you select more than one audio clip, make sure that the track format is the same for all the selected clips.
2.In the Audio Channels pane of the Modify Clip dialog box, do any of the following:
■Select a format from the Track Format list.

■To enable or disable an audio channel, select or deselect the Enable option for a source channel. When you add a clip to a sequence, Premiere Pro adds only the enabled channels to a Timeline panel.

■To map a source channel to a different output track or channel, drag a track or channel icon to another source channel row. This step swaps the output channels or tracks for the two source channels.

Note: When you view a clip with remapped source channels in a Timeline panel, the tracks appear in ascending order. However, the mapping determines their associated source channels.
■To map less than six source channels to the output channels in 5.1 surround audio, drag the channel icon to another source channel row. Alternatively, click the 5.1 Channel icon until the source channel is mapped to the desired output channel.

3.To preview the audio in a channel, select the source channel and click the Playback button or use the slider.
4.Click OK.
In Premiere Pro CS5.5, you cannot modify audio channels of a merged clip. They must be mono by default. However, you can still reorder and enable/disable all of the available audio channels from the component clips.

[Bart Walczak]

No, unfortunately this is not the case. I could easily cope with two stereo tracks with Fill Left/Right filter or use audio channels if the project was not almost done.

The problem is that I have two mono tracks with the same channel, instead of two mono tracks with first/second channel, and there seems to be no way to get the second one back except for replacing them one by one.

It looks like an importing bug from PC to Mac. All clips that were flagged as "mono" in channel mapping on PC are now flagged as stereo on Mac, and behave accordingly - they need a stereo track to place the audio on the timeline.

Thanks for trying to help though.

[David Beisner]

Strange indeed... my workaround (depending how much audio editing was still required) would be to simply render out an AIFF from PrPro on your PC of your audio channels... one for each channel, and then bring that back into PrPro on your Mac and sync it up with your video. However, if you've still got some editing and cutting required and need access to the handles of your audio from your PC edit, then that wouldn't work.

If that's the case, then I would export an EDL from PrPro on your PC, create a new project with it on your Mac, import your media and your EDL and rebuild it that way. Shouldn't take long, and would give you everything you need as it was on the PC.

Perhaps someone who does this on a regular basis would have an idea re: why it's doing that. I don't have any clue, unless it may have something to do with your original audio being in stereo, and you used channel mapping to break it to mono and when it gets opened on the Mac, it ignores that original channel mapping you used, but also doesn't properly recognize which channel had which audio in your original stereo file.

[Bart Walczak]

Thanks David, some good ideas here, I might actually consider using EDL just for importing these invalid sound tracks. We've done a few edits to the main project before we found out the problem, but it won't be that much of a hassle to sync them.

I think it's a bug during import, and it might have something to do with using Cineform files. It's the first time Premiere did something like this, even though we've used this workflow (PC to Mac) for past 3 years. But it's the first time we used Cineform here.

[David Beisner]

Ah, yes. Cineform, while excellent, can introduce some "odd" behaviors at times. I used Neo for a year back in '08, but ran into more issues (paired with CS3) than benefits so I stopped using it. I've found PrPro's handling of native formats to be so good as not to need an intermediary codec. The reason I used it then was because it supported scene capture from HDV while PrPro didn't, and I couldn't get HDVSplit to work on my system for some still-unknown reason.

[Bart Walczak]

The only reason we used Cineform was because our JVC VTR had its firewire port and HDV processor smoked for the third time (don't get me started on this, though, I'm not buying JVC products anymore), so we had to capture via HDMI, and we decided that Cineform would be the best intermediate of all possibilities space- and quality-wise, and we happened to have one installed as well.

No problem with it whatsoever, except for what I mentioned. Cineform is pretty robust these days. CS3 was a pain in the neck though.