alsa-devel.alsa-project.org archive mirror
 help / color / mirror / Atom feed
* NVIDIA HDMI: Channel remapping does not work for stereo?
@ 2013-10-24 23:31 Anssi Hannula
  2013-10-29 23:12 ` Aaron Plattner
  0 siblings, 1 reply; 6+ messages in thread
From: Anssi Hannula @ 2013-10-24 23:31 UTC (permalink / raw)
  To: Aaron Plattner; +Cc: alsa-devel@alsa-project.org

Hi!

I just noticed while testing the ALSA HDMI channel remapping code that
my NVIDIA codec 0x10de0015 does not seem to follow the Audio Sample
Packet (ASP) channel mapping (set by verb F34h as per HDA spec 7.3.3.41)
when playing back stereo audio.

This can be reproduced by e.g.:
$ speaker-test -c2 -Dhdmi:CARD=NVidia,DEV=0 -m FR,FL
The channels are reversed compared to what the printout is (i.e. the
codec plays the streams straight-through instead of swapping channels as
instructed).

E.g. this works expectedly, however:
$ speaker-test -c4 -Dhdmi:CARD=NVidia,DEV=1 -m FR,FL,RR,RL

(note that recent sound git master or for-next is needed for these kind
of remappings to work properly at all)

On Intel HDMI codec 0x80862806 both work.

While stereo right-left swapping is admittedly a rather corner-case
situation, I guess we should probably refuse such chmaps when they are
not supported.

Aaron, do you have any information on whether this affects all NVIDIA
HDMI codecs?

-- 
Anssi Hannula

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2013-11-04  9:12 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2013-10-24 23:31 NVIDIA HDMI: Channel remapping does not work for stereo? Anssi Hannula
2013-10-29 23:12 ` Aaron Plattner
2013-10-29 23:39   ` Anssi Hannula
2013-10-30  6:34     ` Takashi Iwai
2013-11-03 15:15       ` [PATCH] ALSA: hda - hdmi: Disallow unsupported 2ch remapping on NVIDIA codecs Anssi Hannula
2013-11-04  9:12         ` Takashi Iwai

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).