USB DAC with 5.1 output, no sound out of Center and LFE outputs

Quote from Da Flex

So it's not related to Windows, and happens randomly. I still think that DAC buffer size is wrong, or not initialized at all.

Linux driver issue is my bet. Here is a link for a bug report: https://www.alsa-project.org/wiki/Mailing-lists

I was hoping your AVR shows sampling rate etc., just hearing isn't enough to estimate data rate differences. However, since we know that it's not Windows-related, it doesn't matter.

If the log becomes too large, upload by pastekodi doesn't work anymore. Then you can only copy & paste from /storage/.kodi/temp.

I don't think there is any AVR that can show device output sampling rate for its analog inputs. I would think that requires some fancy audio analyzer hardware.

I concur, it seems to boil down to a driver problem, possibly combined with quirks in hardware that seem at least somewhat persistent.

There are two primary reasons for why I'm trying to do what I am doing.

1) My receiver is over a decade old and only has inputs and outputs for HDMI at 1080p, and my 4K TV can only do PCM Stereo sound over ARC (no eARC support, and I'm not even sure if the receiver can take a 5.1 input from the TV output)

2) Kodi 20.x (and I think 19.x too) running on a Google Chromecast 4k device has an insane amount of audio latency in Passthrough mode (I believe it was not constant, it varies depending on the audio format), and in non-passthrough mode I naturally get only Stereo sound with the Chromecast hooked up directly to the TV.

Reason number 1 is primarily why I need a USB DAC also for the LibreELEC player. If there were some USB-A-to-HDMI adapter with Linux support that I could connect to the receiver, to have display out directly to TV and only audio via the USB adapter to the receiver, that would also be an alternative. Last resort may be to get an audio extractor with 5.1 analog output. I tried to search in the forum, and it seems there might not be any such devices, but someone reported that having a laptop with HDMI output they could at least select that device for audio, even if they were not able to move the video output from their built-in screen.

After more general searching, I have found a device that may be doing exactly what I need to continue using Kodi in the Chromecast for now. The Chromecast is on the slower side for Kodi, but it would enable displaying also Dolby Vision sources for example.

VSP01201 HDMI 2.0 Splitter 1x2 with EDID-Management - FeinTech

Makes it possible to distribute one HDMI source to 2 displays (monitor, TV, projector) or AV receiver, automatic downscaler for Full HD displays with UHD…

feintech.eu

As for the logging, not only did the log become too large, but it stopped writing to the file. When printing the end of log with tail (both while it was the primary kodi.log, and also after a restart as kodi.old.log) it was stuck mid-line, several hours in the past. The size didn't increase, but the modified timestamp kept updating even while it was the primary log.

miniplayer:~ # ls -ltr /storage/.kodi/temp/
total 7023
drwxr-xr-x    2 root     root          1024 Oct 21 14:24 temp
-rw-r--r--    1 root     root         41768 Oct 24 14:23 kodi_crashlog_20231024142329.log
lrwxrwxrwx    1 root     root            32 Oct 24 14:23 kodi_crash.log -> kodi_crashlog_20231024142329.log
-rw-r--r--    1 root     root       7106560 Oct 29 13:59 kodi.old.log
drwxr-xr-x    2 root     root          1024 Oct 29 13:59 archive_cache
-rw-r--r--    1 root     root         38464 Oct 29 13:59 kodi.log
miniplayer:~ # tail /storage/.kodi/temp/kodi.old.log
2023-10-29 11:46:50.029 T:2835     info <CWebserver[8080]>: Skipped 3 duplicate messages..
2023-10-29 11:46:50.029 T:2835    debug <CWebserver[8080]>: request received for /jsonrpc?Player.GetActivePlayers
2023-10-29 11:46:50.039 T:2838     info <CWebserver[8080]>: Skipped 4 duplicate messages..
2023-10-29 11:46:50.039 T:2838    debug <CWebserver[8080]>: request received for /jsonrpc?Base
2023-10-29 11:46:50.049 T:2840     info <CWebserver[8080]>: Skipped 1 duplicate messages..
2023-10-29 11:46:50.049 T:2840    debug <CWebserver[8080]>: request received for /jsonrpc?Player.GetActivePlayers
2023-10-29 11:46:50.051 T:2837    debug <CWebserver[8080]>: request received for /jsonrpc?Base
2023-10-29 11:46:50.931 T:2835     info <CWebserver[8080]>: Skipped 14 duplicate messages..
2023-10-29 11:46:50.931 T:2835    debug <CWebserver[8080]>: request received for /jsonrpc?JSONRPC.Ping
2023-10-29 11:46:50.
miniplayer:~ #

Thanks for the heads-up about the storage partition size. I'm inclined to install on a proper SSD if I get this working well enough.

An update from this past week is that I seem to have had a combination of problems. The past few times when the center channel was spontaneously lost after approximately 15 minutes, and also spontaneously returned, may be related to a poorly seated speaker connection after having moved my receiver around a few times during troubleshooting of the USB DAC. What characterized these more recent and spontaneous drop-outs was that the center channel was working initially, then volume dropped gradually over a brief moment (not instantaneous but less than a minute I would say) before the channel was lost completely. I didn't verify the USB DAC outputs, and the center channel operation did return on its own, so I suspect it was not a DAC issue these more recent times.

I've reseated all the speaker connectors properly, and hopefully this will prevent problems that are not USB DAC related. The DAC so far doesn't seem to be giving me any problems, all channels keep working. Will watch a movie or two this weekend, I'll keep this thread updated.