Librelec Nightly Dolby Digital transcoding bug

  • I can confirm it.

    This bug is solved in the build from today 1/15/22.

    Thanks HiassofT

    Let's hope that with the newest release of FFMPEG 5.0 this bug doesn't return.

  • I concurr.

    You can mark the bug as being resolved in the thread header.


  • I concur.

    You can mark the bug as being resolved in the thread header.


    I don't know if it's just my setup.

    But I'm noticing some weird behavior.

    When I play something that is being transcoded into DD I got audio

    But if I stopped the audio transcoded Into DD and went to a file that has native dts

    Sometimes the audio isn't working. It's getting stuck as DD in the receiver.

    I had to stop it. Then play it again and my receiver shows DTS and I got sound.

    The other way around also occurs. It seems even more present. I mean try to play something with DTS audio.

    Then stop it. And then try to play something with native AC3 5.1.

    See if your receiver is getting stuck on DD or DTS.

    Try this a couple of times and let us know

  • I did notice something odd when playing AAC 5.1 first. The audio was crackling and interrupted. If I play an E-AC3 or AC3 first and return to the AAC 5.1 file it plays fine. These files are all Dolby Digital Sample files which were converted from AC3 to AAC and E-AC3. I replicated this with the latest update today. I have H264 and H265 mkv videos.

    I've attached a shortcut to the logfile. http://ixio/3MDd


  • Definitely, something is wrong.

    I noticed also that when you finished playing audio over passthrough, that is being transcoded or not, after playing is done, the GUI sound audio is not present anymore.

    It takes a while, I cannot precise how long, but it takes a while for the GUI sounds to be brought back. Sometimes it doesn't come back at all.

    I discovered that because after I played a movie, immediately after, I went to watch some youtube and got no sound. Only after I closed Youtube and reopened it again did I get sound.

    I have also 'forced' the same situation playing an AC3 5.1 movie and playing a DTS 5.1 movie. I got no sound on DTS.

    Let's hope everything is being captured on the log.

    Here's the log:

  • HBBS,

    I have DTS capable amp so I have that box ticked. Passthrough DTS samples play fine whether transcoding is on of off. I have no problems except for that one AAC 5.1 glitch which goes away on second attempt.

    Lets see what happens when FFMPEG is upgraded.

    Good Luck.


  • I'd like to raise the issue I found with AAC 5.1 audio conversion.

    The problem I found is a file with AAC 5.1 audio is played, it sounds broken with approx intermittent 1 second bursts of audio and approx 1 second of silence.

    Strangely it does this only on the first play. On the second play and subsequent plays the sound converts OK and sounds fine. This problem goes back to the fix posted in this thread almost 2 months ago. If you read back I reported it in January. Reported first here. RE: Librelec Nightly Dolby Digital transcoding bug

    I took a video of the first and second play uninterrupted. Posted to youtube.

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    I'm using RPI4 B with a JustBoom audio digihat which passes through via SPIFD to a Marantz amp.

    Edited 2 times, last by chook55: more info ().

  • I noticed a later version 20200224 on the server. Ive upgraded to it . I tested the AAC 5.1 video file used before and it played in 2 channels only on first play. It sounded OK without the intermittent playing but rear channels were playing from the the front speakers. Also the channel indicator on the amp showed only 2 channels were active.

    If I stopped play and reselected the file to play in a few seconds it played in all 6 channels. If I leave and come back after 10 minutes it defaults into the erroneous mode.



    So after a couple more updates I'm now at running Nighlty "LibreELEC-RPi4.arm-11.0-nightly-20220228" and the first play AAC 5.1 file are still playing intermittently on first play.

    Edited once, last by chook55 ().

  • I upgraded to the latest nightly. Nightly 220306 as it has had a FFMPEG patch applied. Alas the AAC 5.1 conversion and pass through still misbehaves. Typically it plays intermittently on first play. Resolves itself on subsequent plays. See my video posted earlier. Its a bug.