I’ve just switched to a Raspberry Pi 4 4GB after years running OSMC on a Pi3B. Playing video files that use Dolby Digital Plus / E-AC3 results in no sound and after approx 5 seconds the playback stutters and stops. The picture remains still, it hasn’t crashed, and I can press Stop, or skip through the video which then plays another 5 seconds before stopping.
Through various posts here, this seems to be due to problems resampling the audio. The Pi is connected using official Raspberry Pi HDMI to a Sony amp that supports DD/DDP/DTS (STR-DA3500ES). I have audio in Kodi set to 7.1 and allow passthrough (sync to display is disabled, stereo upmix is disabled). So for AC3 streams this works perfectly.
The difference I find with the Pi4 is the option to enable passthrough for E-AC3 is missing from the GUI. This is available on the Pi3 and enabled (OSMC with Kodi v18).
I saw on this thread that “HD audio” support was pulled from the Pi until Bullseye. I’m not sure if “HD audio” there includes E-AC3, This is a new OSMC install on a Pi4, running the latest May 23 release from the installer, with no updates available.
I’ve uploaded logs which show playing a file with AC3 that uses passthrough at 2023-05-26 09:12:08.462. I then tried a file using E-AC3 and you can see the errors at 2023-05-26 09:12:30.145
I can mitigate the issue by changing the speaker config option to 2.0 with passthrough still enabled for AC3 and DTS only, but I would like to be able to use the receiver’s support for E-AC3 rather than downgrading these streams to 2.0.
@candm In the GUI->settings->system->audio menu, you’ve to change the audio output device (on top of the menu) from ‘MAI PCM i2s-hifi’ to last item of the displayed list ‘SNY SONY AVAMP on HDMI’ … and you need to restart the system.
Believing the STR-DA3500ES manual, the AVR supports ALL passthrough options of the mediacenter.
Important addition: I’ve now fallen into the same trap even with the right output device set. After restart of the RPi4, I’m only presented with a few passthrough options.
Workaound here:
Shut down the RPi4
turn off the AVR (!!!)
reboot the RPi4 (power off and on again)
… and then wait 2-3 minutes before turning the AVR back on.
This worked, with the addition of rebooting again with the TV/AVR on, as there was no signal otherwise. Thank you so much! Sorry that it took a while to reply - been away last week so only just been able to try this.
My steps:
Changed audio device (first option under Settings > System > Audio) to the last option vc4hdmi0 SONY AVAMP. No change in behaviour at this point.
Turn off TV and AVR. Use SSH to reboot Pi.
Turn on TV and AVR. No HDMI signal to AVR.
Turn off TV and AVR. Use SSH to reboot Pi.
Turn on TV and AVR. No HDMI signal to AVR.
Use SSH to reboot Pi while TV and AVR on.
Audio settings now show the extra option for E-AC3. Enabling this and now Dolby Digital+ streams are passed through to the AVR, and there’a no video playback issues.
(The lack of signal on reboot I assume is due to boot config options; haven’t tested it yet. On the old Pi3 I had the option set to force HDMI, but haven’t altered any options on Pi4 (yet!), trying to keep it near-stock.)