At Tue, 3 Aug 2010 23:32:45 +0300, Anssi Hannula wrote:
pl bossart kirjoitti tiistai, 3. elokuuta 2010 23:15:28:
Well, this is one of my looong-standing TODOs. Originally I wanted to implement a new API to get/set the channel-mapping, mainly for HDMI. But, I've been recently too busy for other tasks (I can spend little time for ALSA), thus it's pending forever.
You would only need an API to get the channel mapping. The HDMI sink will report its speaker configuration through a CEA code (section 7.4 of the spec), and if we parsed the EDID info we could present the relevant channel order to user-space apps.
I'm not sure I see how that will help with the problem of this thread, though, i.e. NVIDIA MCP7A hdmi codec apparently assuming audio being fed in windows channel order instead of alsa channel order.
If we get the channel order, the channels could be remapped either by the app itself or an alsa-lib plugin. The channel-map API itself is just a bridge for that...
Takashi