Are 4 Audios Channels in InterOp DCPs an Error?

[4lm]

We have some customers DCPs of old movies, which are mono and therefore only have audio on the center channel but because of the needs of the InterOp audio channel mapping have 4 channels:

1: Left - silent 2: Right - silent 3: Center - audio 4: LFE - silent

dcp_inspect reports this as an error, but the DCPs seem to work in the cinemas.

Is this way of doing the channel mapping an error?

Please compare with note 1 on page 1 in this document: http://isdcf.com/papers/ISDCF-Doc4-Interop-audio-channel-recommendations.pdf

• "Not all channels need to be present in a given DCP."
• "In all cases, an even number of channels shall be used."

[wolfgangw]

Will have to investigate. Thanks for the feedback.

[wolfgangw]

For future reference: [ISDCF] Channel count in Interop compositions