[alsa-devel] Channel map API patches: to be 3.7 or not to be?

[Raymond Yau]

2012-9-11 上午1:43 於 "Takashi Iwai" <tiwai at suse.de> 寫道：
>
> Hi,
>
> does anyone have concern if I push the current channel map API patches
> (in sound-unstable git tree topic/tlv-chmap branch) for linux-next,
> i.e. for inclusion to 3.7 kernel?
>
> I don't worry too much about the kernel API.  This can be refactored
> later.  But the kernel ABI must retain, so we won't change in an
> incompatible way any longer once after it's merged to the upstream.
>
> So, if anyone sees a flaw in the kernel ABI definition using control
> elements, let me know.
>
> (But note that the API can't be perfect for all generic purposes.
>  It's designed to be "good enough" for a big lack for multi-channel
>  streaming.  Of course, this doesn't discourage to use the API for any
>  other purposes.)
>

How about the channel map of the usb mono playback device and those sound
card which can pan mono to stereo speakers and headphone?

Pulseaudio developer has just changed the downmixing method

The mono playback is not left anymore

https://bugs.launchpad.net/ubuntu/+source/pulseaudio/+bug/416190