2024-01-17, 16:12
I posted this on LibreElec forums but not had any replies. Hoping someone here can point me to how to debug/diagnose this further.
I have a Optiplex 3050 which has both a DisplayPort 1.2 (capable of 4k) and HDMI 1.4 (capable of 1080p only).
I'm using LibreElec 11 stable (although tried 12 nightly too) and I cannot get HD audio to work on the DP using a Benfei DP->HDMI adapter (reading around, seems to be a common problem with NUC's as well). DD/DTS work fine.
I can, however, get HD audio working over the HDMI 1.4 connection.
If it is a limitation of the DP itself, I'd like to understand why.
Here's my findings:
HD Audio (TrueHD and DTS HD MA) from HDMI 1.4 works - log here:
HD Audio (TrueHD and DTS HD MA) from DP 1.2 DOES NOT work - log here:
In both cases, it first tries to create a 2 channel output stream:
Sample Rate : 44100
Sample Format : AE_FMT_S32NE
Channel Count : 2
Channel Layout: FL, FR
and then an 8 channel output stream:
Sample Rate : 192000
Sample Format : AE_FMT_S16NE
Channel Count : 8
Channel Layout: RAW, RAW, RAW, RAW, RAW, RAW, RAW, RAW
I suspected perhaps the DP 1.2 does not support 192000khz with 8 channels, but if I run a speaker-test command, it works fine:
If I turn off passthrough in Kodi settings, LPCM 7.1 is sent fine via the DP for all 8 channel HD audio streams.
Any guidance on what I can check next?
I have a Optiplex 3050 which has both a DisplayPort 1.2 (capable of 4k) and HDMI 1.4 (capable of 1080p only).
I'm using LibreElec 11 stable (although tried 12 nightly too) and I cannot get HD audio to work on the DP using a Benfei DP->HDMI adapter (reading around, seems to be a common problem with NUC's as well). DD/DTS work fine.
I can, however, get HD audio working over the HDMI 1.4 connection.
If it is a limitation of the DP itself, I'd like to understand why.
Here's my findings:
HD Audio (TrueHD and DTS HD MA) from HDMI 1.4 works - log here:
Quote:https://paste.kodi.tv/tevameminu
HD Audio (TrueHD and DTS HD MA) from DP 1.2 DOES NOT work - log here:
Quote:https://paste.kodi.tv/ijiziposic
In both cases, it first tries to create a 2 channel output stream:
Sample Rate : 44100
Sample Format : AE_FMT_S32NE
Channel Count : 2
Channel Layout: FL, FR
and then an 8 channel output stream:
Sample Rate : 192000
Sample Format : AE_FMT_S16NE
Channel Count : 8
Channel Layout: RAW, RAW, RAW, RAW, RAW, RAW, RAW, RAW
I suspected perhaps the DP 1.2 does not support 192000khz with 8 channels, but if I run a speaker-test command, it works fine:
Quote:LibreELEC:~ # speaker-test -D hdmi:CARD=PCH,DEV=0 -c 8 -r 192000 -b 9600 -p 2400 -F S32_LE
speaker-test 1.2.8
Playback device is hdmi:CARD=PCH,DEV=0
Stream parameters are 192000Hz, S32_LE, 8 channels
Using 16 octaves of pink noise
Rate set to 192000Hz (requested 192000Hz)
Buffer size range from 8 to 131072
Period size range from 4 to 65536
Requested period time 2400 us
Requested buffer time 9600 us
was set period_size = 461
was set buffer_size = 1844
0 - Front Left
4 - Front Center
1 - Front Right
7 - Rear Right
3 - Rear Right Center
2 - Rear Left Center
6 - Rear Left
5 - LFE
Time per period = 23.984268
If I turn off passthrough in Kodi settings, LPCM 7.1 is sent fine via the DP for all 8 channel HD audio streams.
Any guidance on what I can check next?