OfflineAudioContext destination channelCount and channelCountMode changes?

[rtoy]

The channelCount and channelCountMode are normally writable. But what about the AudioDestinationNode for an OfflineAudioContext?

I don't know how to make sense to create an offline context of, say, 7 channels, and then change the channelCount to 3. We've already created a 7-channel buffer to hold the result, so what does it mean to have a channelCount of 3?

Also, the default channelCountMode is "explicit" for the destination. What if I change to "max"? Using the above example, if I now feed in a 10-channel source, the "max" setting kind of implies that output will have 10 channels. But the buffer has already been created.

For simplicity, I propose that channelCount and channelCountMode cannot be changed for an offline context. I think it's fine to allow the user to change the channelnterpretation to get the desired mixing effects (or not).

[hoch]

Just to be clear, channelCount and channelCountMode are members of AudioDestinationNode. I think it would be slightly easier to create a OfflineAudioDestinationNode to apply these constraints.

[padenot]

I agree.

[rtoy]

I think the conclusion is that we no longer want to add an OfflineAudioDestinationNode, based on comments in #856 and from the blink-dev intent to implement.

The constraints on the channel count and mode for the offline destination is handled in #968, fixed by #999.

[rtoy]

Closing this. I think #968 and #999 cover this issue and we don't need to do anything here.