6-8 channel HDMI audio on BPi A20

FPeter · June 26, 2016

Hi All!

Legacy kernel says: "Enabled audio devices: analog, 8 channel HDMI, spdif and I2S (if wired and enabled in HW configuration)"

But there is no multi channel device listed in aplay -L , like surround51, surround71, etc.

With "speaker-test -D default:sunxisndhdmi -c 6 -t wav", We got a downmixed stereo result.

Receiver device is a BEM-182 Broadcast Monitor on its HDMI input - only 2 VU-meter band appears. Other test setup is the same receiver in SDI input mode with an HDMI to SDI converter. Specs of this adapter declares that it supports 8 channel, and this time 8 VU-meter band appears on the monitor so device is ready to receive multi-channel audio, but the 6-8CH audio transmission is still downmixed to stereo...

Are there anything that should be switched manually / reconfigured on the BPi transmitter side? Or is it an incompatibility situation?

Best regards,

Peter

FPeter · July 1, 2016

Nobody using A20 as multi channel / ecasound DSP source?

We found that HDMI audio EDID information is being ignored by default due to hdmi.audio=EDID:0 in boot.cmd/scr, so we edited cmd to 1 and recompiled it to scr. Now the boot option changed, but result is still the same: there is no multi channel device in aplay -L list, and multi channel source is being downmixed and sent as stereo...

dmesg | grep "Kernel command line"

[ 0.000000] Kernel command line: console=ttyS0,115200 console=tty1 root=/dev/mmcblk0p1 rootwait rootfstype=ext4 cgroup_enable=memory swapaccount=1 sunxi_ve_mem_reserve=0 sunxi_g2d_mem_reserve=0 sunxi_no_mali_mem_reserve sunxi_fb_mem_reserve=16 hdmi.audio=EDID:1 disp.screen0_output_mode=1920x1080p60 panic=10 consoleblank=0 enforcing=0 loglevel=7

Any hints? A also tried to convert script.bin to fex, but did not find any multi channel HDMI related line in it...