Audio Passthrough is not working.

  • Hello Everyone...

    I'm not sure whether I encountered a bug or if it's a problem of my setup. I'm using LibreELEC (Krypton) v7.90.010 ALPHA and Audio Passthrough (AC3, E-AC3, TrueHD, DTS, DTS-HD, etc.) won't work. To me, it would seem that it is setup correctly, as my AVR is shown in the available HDMI connectors.

    What could be going wrong?

    Thanks for any help!

    Greetings,

    OnbekendHH
    log-2016-12-30-23.00.00.zip

  • Do you have "Sync playback to display" enabled? If so, turn it off and passthrough should then work (the help text for the Sync option explains that passthrough will be disabled).

  • Yes, I do have it on.

    But why does this happen now? Is this a temporary bug? This option used to be necessary in order to achieve "perfect" 23/24 FPS playback.

    Thanks for a response.

    Edited once, last by OnbekendHH (December 31, 2016 at 8:40 AM).

  • Sync Playback to Display tells Kodi to use the display clock for sync purposes, but passthrough audio requires VideoPlayer to use media for clock sync (else you are modifying the source, which is not true passthrough) so if you enable SP2D passthrough is automatically disabled. This is different from Jarvis where SP2D is effectively broken but a collection of hacky things kind-of works. Krypton fixes things, so in summary: Krypton != Jarvis.

  • on my system passthrough works with videos/films but not with live TV (although with an audio delay problem of ca 200ms). Live TV transcodes to PCM :( (without audio delay problem)
    Any clue?

    Edited once, last by kszabo (February 17, 2017 at 8:19 AM).


  • on my system passthrough works with videos/films but not with live TV (although with an audio delay problem of ca 200ms). Live TV transcodes to PCM :( (without audio delay problem)
    Any clue?

    Krypton for live stream sets SP2D to always on. In Amlogic builds I fixed this by following patch. It can be applied commonly in Libreelec.

  • thank you! unfortunately I am quite new to LibreELEC and need some clues how to apply this patch to my libreelec setup. (ssh with putty and file access over winSCP would be no problem)


  • I was afraid too... :( hoped that it could be a simple config file and reboot...

    Grab yourself a cheapo Amlogic s905/s905X box. Kszaq has this patch enabled on his 8.0 builds.

    So far it's working just fine. I get passthrough from all sources and haven't had one single problem with livetv going out of sync.

  • I would prefer to get it sorted out with the existing hardware as it is otherwise quite fine and is there ;) should be possible an a "standard" x86/64 PC.

    edit: solved
    after adding his advancedsettings.xml to user config folder I have quite sync play of 23.98 and 24 fps

    Edited once, last by kszabo (February 19, 2017 at 7:50 PM).

  • I always prefer to just have 'Adjust display refresh rate' to 'On Start/Stop' only, never to sync the audio to the display. This does seem way more effective on RPi3 and Amlogic devices compared to x64 Intel setups though, where I've had noticeable audio sync issues before.

  • I just installed 7.95.3 on my Intel NUC. Passthrough works fine in Kodi for Windows, but not in LibreELEC.

    Strangely, I heard rumors before I acquired the NUC last week that only Linux variants had successfully implemented support for passthrough, and that there was a bug with the official Intel audio driver for Windows.

  • I replaced my old HTPC on AMD basis with an Intel Kaby Lake build. I can confirm that HDMI-Passthrough works fine on LibreELEC 8.0 (but not on Live TV, which is not a bug as this is deactivated on purpose in LibreELEC Kodi Video Player).

    Edited once, last by kszabo (March 4, 2017 at 12:54 PM).

  • ^^ it is not deactivated on purpose in LE, it is not part of the VideoPlayer design in Kodi. We are not to blame for anything. We simply consume upstream code.

    Thank you for correcting! I edited my post accordingly. It was not any kind of blaming, just wanted to make people aware that they have to test passthrough on Video files, not live TV. I find this deactivation not disturbing at all as live TV AC3s are mainly of low bitrate and not about best possible Quality. If this increases the playback stability, I am in.