Labeling surround tracks

Hi. Is there a way to label tracks with their surround channel? L, R, C, Lfe, Ls, Rs for example.
ProTools has a way of putting this info in the header (I think), and then other apps know exactly where those tracks go in a multi-channel surround environment. If I run 5.1 audio files that originally came from ProTools thru Audacity, I loose this metadata. For example, I might take a 5.1 mix and edit out the 2-pop in Audacity and then re-export. These exports are not automatically recognized as surround channels even when the naming does not change. The one exception is that the left and right channels are usually proper recognized. Thanks!

Audacity has a very simple method. By default, Audacity puts the first track as “channel 1”, second track as “channel 2”, and so on.

Custom mapping of tracks to channels is available via the “advanced mixing options” (Advanced Mixing Options - Audacity Manual)

I don’t think it does. As far as I’m aware, both software and hardware players decide which speaker to send audio to, based on the channel number. Some systems also use psychoacoustic encoding algorithms to generate more or less speaker channels from the provided channel streams, but the channel streams are still just numbered channels.

There are several “standard” channel maps: Surround sound - Wikipedia
Unfortunately, not everyone uses the same standards, so sometimes you will find surround sound files with the “wrong” mapping (they were using a different “standard”).

It would perhaps be useful if the “Advanced Mixing Options” showed the most common channel mapping for the selected export format.

Thanks Steve for your detailed response. I think you were referring to multi-track audio files regarding the channel order. I’m actually talking about where each surround channel is a different file. When I get audio from a mix session, I typically get 6 files, one for L, one for R, (etc C, Lfe, Ls, Rs).
When I bring these into DCP authoring tools, it automatically knows where these files need to be assigned. I originally thought this was based on the file name, but it’s not. It’s somewhere in the metadata or header… I assume.

Also, I think the native channel mapping of ProTools and Adobe Premiere (for example) are different, but files end up with the correct assignment when imported, so I feel like there is more than just assumptions being made with channel order. I don’t know. Maybe Premiere sees that the source is ProTools and knows how to translate channel mapping. :slight_smile:

For separating individual files (per track), maybe it would be good to assign a channel number even it is just a mono file. For example, the Rs file is mono but still has channel 6 in the metadata. This if over my pay grade so feel free to tell me this ain’t the way it works…

I appreciate your time and let me know if you ever have a chance to look deeper into this.


Ahhh. Scratch that… I just did some testing and it seems, at least with my DCP authoring tools, that it is based on the file names. I can change the “_L”, “_Ls”, etc at the end of the file name and trick the software when importing the media. I may be barking up to wrong tree.