- From: Karl Tomlinson <karlt+public-audio@karlt.net>
- Date: Fri, 23 Aug 2013 13:25:04 +1200
- To: public-audio@w3.org
Some AudioNodes have limitations on the number of input channels, but the computedNumberOfChannels calculation in [1] currently doesn't necessarily consider these limitations. The input channel limitation is clearly spelled out for PannerNode, for example: "The audio stream from the input will be either mono or stereo, depending on the connection(s) to the input." Would it make sense to spec that an exception is thrown if a PannerNode's channelCount is set > 2? This is similar to how AudioDestinationNode is currently spec'd to handle maxChannelCount. There may be a good reason to allow channelCount to be set to 1, as the panning effects on stereo inputs are different from mono inputs. I propose NOT_SUPPORTED_ERR, as when setting channelCount to zero. For channelCount to be effective in limiting the number of input channels, channelCountMode cannot be "max". Would it make sense to spec that an exception is thrown if a PannerNode's channelCountMode is set to "max"? There may be a good reason to allow channelCountMode to be set to "explicit" to force up-mixing to 2 channels, as the effects of the equalpower panner on 2 duplicate channels are different from a mono input. This approach feels more transparent to me than silently adjusting the computedNumberOfChannels calculation. [2] implies that a similar situation applies to ConvolverNode, and, looking at [3], I wonder whether a similar situation applies in ScriptProcessorNode? See also [4]. It may make sense to limit channelCountMode for AudioDestinationNode, but [5] is advocating a different approach. [1] https://dvcs.w3.org/hg/audio/raw-file/tip/webaudio/specification.html#UpMix [2] https://dvcs.w3.org/hg/audio/raw-file/tip/webaudio/specification.html#Convolution-reverb-effect [3] https://www.w3.org/Bugs/Public/show_bug.cgi?id=17534 [4] http://lists.w3.org/Archives/Public/public-audio/2013JanMar/0136.html [5] http://lists.w3.org/Archives/Public/public-audio/2013AprJun/0439.html
Received on Sunday, 25 August 2013 18:01:05 UTC