5.1 Source but sees 8 streams

[rtX]

v1.78.7

I have a ProRes 4444 file from which I am going to master a DCP for delivery to a UK distributor (first one to be so delivered!).

The source file is a ProRes4444 file within which there are 8 sound channels. I don't want to use any of these as I have 6 wav files (a 5.1 mix) I want to use as the sound source. On the DCP tab, I've selected 6 audio channels. On the Audio tab of the Content tab "stream" is showing as 8 channels (not adjustable). I don't want to use any of these for the DCP. I'm aware of how to add sound files and disable the sources (by clicking them 'off'), but I only want 6 channels on the DCP. I've previously had a similar configuration for a test version of the same film. When I took it to a screening room they said the file name suggested that the content was a 7.1 mix. I want to avoid this happening again as it caused some consternation. The DCP, however, seemed to play okay.

How do I make sure that only 6 channels of sound are used and implied by the file name?

[carl]

With the setup you describe, DCP-o-matic should set the name up to suggest it's 5.1. It didn't always do it right, but I believe it was fixed in 1.78.0.

A DCP name is something like this:

MyGreatMovie_FTR-1_F_51_2K_20150424_SMPTE

where the "51" indicates 5.1 audio. If that is "71" it would indicate 7.1. If you look at the DCP name in the "DCP" tab you can check whether that part of the name is right. If it's not, let us know. If all else fails you can fix it yourself by clicking "Copy as name" and then editing the name directly.

[rtX]

I had to use the "Copy as name" workaround. The file name had "71" rather than "51". Thanks for the advice re the workaround.

[carl]

Would you mind sending me the "metadata.xml" file from your project so I can see what is going wrong?

[rtX]

Would you mind sending me the "metadata.xml" file

Before I make the DCP proper (after setting it all up) or after the DCP has been made?

[carl]

If you set the film up and save it, then send me the metadata.xml, that would be great.

[rtX]

It's running now and has been for a few hours. I'll send as soon as it's finished.

[Carsten]

I have been playing around with this a bit - it seems the ISDCF naming doesn't work properly for the audio part. E.g. when I have 5.1 audio assigned in track selector, then change the number of audio channels in DCP tab from 6 to 4, the ISDCF name doesn't follow. It seems it reacts to 'actions' (e.g. deselecting a track in the audio tab), but doesn't always follow the 'state' of the complete track assignment. Maybe this function needs some more tweaking. I know it's new, and I understand the whole system of assigning tracks, channel counts and creating the ISDCF name from it is a bit wonky due to the weakness in the ISDCF audio channel description system itself.

I never thought about it before, but I guess it is possible to have two audio streams active at the same time, with different channel mappings, and DCP-o-matic would mix them into assigned tracks - e.g. when having an audio stream from a composite audio/video file, plus an audio-only file starting at the same time. This is not a mistake, it should be possible to do it, although the use is 'exotic' to say the least. But that basic ability is needed to have e.g. 6 individual mono audio tracks assigned to the DCP audio channels. So, the ISDCF audio labeling should follow all these channel counts and settings to give the best possible indication.

- Carsten

[carl]

When I have 5.1 audio assigned in track selector, then change the number of audio channels in DCP tab from 6 to 4, the ISDCF name doesn't follow.

Well spotted, it didn't take into account the fact that channels might be mapped but then be left out of the DCP if its channel count is too low. FIxed locally.

I never thought about it before, but I guess it is possible to have two audio streams active at the same time, with different channel mappings, and DCP-o-matic would mix them into assigned tracks - e.g. when having an audio stream from a composite audio/video file, plus an audio-only file starting at the same time. This is not a mistake, it should be possible to do it, although the use is 'exotic' to say the least. But that basic ability is needed to have e.g. 6 individual mono audio tracks assigned to the DCP audio channels. So, the ISDCF audio labeling should follow all these channel counts and settings to give the best possible indication.

This should already work.