Hi Takashi, list,
I am implementing multichannel support for HDMI on Texas Instruments' OMAP4. I would like to know if ALSA mandates a specific channel order or has a preferred one.
I tried to find some guidance in alsa-lib or in the alsa driver. All I could find is the order described in speaker-test: FL/FR/RL/RR/C/LFE/SL/SR. This order seems to be in use due to historical reasons [1]. It was also mentioned that an API to set/get the channel mapping was going to be implemented [2]; I tried to find it without success. As [1] and [2] are very old posts, I was wondering if the situation has changed.
My question arises from the fact that HDMI audio uses the channel ordering defined in CEA-861 section 6.6.2, which is different from what speaker-test expects. This also different from the order that SMPTE 320M specifies. OMAP4 is able to alter the channel mapping, so I could match what ALSA expects if such required/preferred order exists.
Thanks in advance for your comments.
Ricardo
[1].http://www.spinics.net/lists/alsa-devel/msg24444.html [2].http://www.spinics.net/lists/alsa-devel/msg24495.html