[alsa-devel] [PATCH v5] drm/i915: pass ELD to HDMI/DP audio driver

Wu Fengguang fengguang.wu at intel.com
Mon Sep 5 03:19:51 CEST 2011

On Sun, Sep 04, 2011 at 06:57:23PM +0800, James Cloos wrote:
> >>>>> "WF" == Wu Fengguang <fengguang.wu at intel.com> writes:
> WF> ... If only the stereo playback capability is reported, the user
> WF> won't be able to start 8-channel playback; if the 8-channel ELD is
> WF> reported, then user space applications may send 8-channel samples
> WF> down, however the user may actually be listening to the 2-channel
> WF> monitor and not connecting speakers to the 8-channel monitor.
> WF>  Overall, it's more safe to report maximum profiles to the user
> WF> space, so that the user can at least be able to do 8-channel
> WF> playback if he want to.
> Be aware that many TVs will either refuse the display anything or pop-up
> an OSD warning whenever they receive hdmi audio which they cannot handle.

OK, good to know that.

> Sending 8-channel in your example may render the stereo-only monitor useless.


> That said, one step at a time is reasonable.  But eventually you will 
> require configurability and/or per-monitor audio control even when the
> video is cloned.

Fair enough.


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