[Dreambox One] No HD Audio passthrough

    I’m running LibreELEC 12 and I have no sound with any TrueHD or DTS-HD track. I've tried it with three movies, without success.

    To explain further, this is what I expected to see on my receiver:

    3MBblAer_o.png

    0ceINxA0_o.png

    Does anyone know what I might be doing wrong?

    Have you enabled Advanced or Expert mode in Kodi settings?. IIRC the pass-through settings for individual formats aren't exposed in the standard settings level, and if they're not enabled and there's no DTS core audio to fall back to in media, there'll be silence.

    Quote from chewitt

    Have you enabled Advanced or Expert mode in Kodi settings?. IIRC the pass-through settings for individual formats aren't exposed in the standard settings level, and if they're not enabled and there's no DTS core audio to fall back to in media, there'll be silence.

    Thanks, passthrough is enabled now but when I play True-HD 7.1 material sound is there but it's Dolby Digital Plus 5.1.

    Maybe it's because I'm running emanuel’s LibreELEC. Is there any difference between that image and the one that can be downloaded here? I assumed it would be the same.

    I've no idea what patches and changes _emanuel_ adds to his images (he is not pushlishing the sources to his GitHub account) but I doubt he deviates far from AMGLX.

    It sounds like it falls back to the 5.1 'core' audio. Have you checked cables? - it requires high bandwidth and if the HDMI connection can't handle that it will cause fallback. Please also enable debug logging in Kodi, demonstrate the issue by playing something, and then run "pastekodi" over SSH and share the URL generated.

    I do only repack the normal *box.img after building, add extra scripts (autoexec.img, ..) and a chain u-boot.ext to FAT partition and rename it to DREAMBOOT.

    All changes are only necessary for the original tpm protected dreambox bootloader in order to boot or shutdown the 6.X kernel.

    There are no src changes/patches, all is original LE git.

    I've got only a packing script nothing more.

    it can all be done from Nightly builds or *.tar from Nigthly can be used for update.

    Quote from chewitt

    I've no idea what patches and changes _emanuel_ adds to his images (he is not pushlishing the sources to his GitHub account) but I doubt he deviates far from AMGLX.

    It sounds like it falls back to the 5.1 'core' audio. Have you checked cables? - it requires high bandwidth and if the HDMI connection can't handle that it will cause fallback. Please also enable debug logging in Kodi, demonstrate the issue by playing something, and then run "pastekodi" over SSH and share the URL generated.

    I’ll do 3 things. Buy a new HDMI cable, a new SDXC card and new tests with an official LibreELEC version.

    I assume there will be no difference in performance if I choose aarch64 or arm11. I’ll download one of these two for the Dreambox One, although I can try both:

    LibreELEC-AMLGX.aarch64-12.0.2-box.img.gz

    LibreELEC-AMLGX.arm-11.0.6-box.img.gz

    Quote from _emanuel_

    I do only repack the normal *box.img after building, add extra scripts (autoexec.img, ..) and a chain u-boot.ext to FAT partition and rename it to DREAMBOOT.

    All changes are only necessary for the original tpm protected dreambox bootloader in order to boot or shutdown the 6.X kernel.

    There are no src changes/patches, all is original LE git.

    I've got only a packing script nothing more.

    it can all be done from Nightly builds or *.tar from Nigthly can be used for update.

    Thank you. I see you’ve also done something similar with CoreELEC for Dreambox:

    Index of ./DREAMONE/old/

    In another thread I’ve created here I have been recommended to use CE for the HDR to SDR issue. It seems that you start from a 2020 version, I can't find another one, this: CoreELEC-Amlogic.arm-9.2.3-Generic.img.gz

    Release CoreELEC 9.2.3 · CoreELEC/CoreELEC
    CoreELEC 9.2.3 is now available. While there are no big individual changes, CoreELEC 9.2.3 does bring many updates, a number of bug fixes identified thanks to…
    github.com

    I have downloaded this version: CoreELEC-Amlogic-ng.arm-21.2-Omega-Generic.img.gz

    Releases · CoreELEC/CoreELEC
    A lightweight OS for KODI. Contribute to CoreELEC/CoreELEC development by creating an account on GitHub.
    github.com

    But I don't know which device_tree file I should choose for Dreambox One or what changes I should do to use the latest CE version.

    At first glance the differences I see are that in emanuel's CoreELEC the files "autoexec.img" and "autoexec.src" appear (as in emanuel's LibreELEC) and "aml_autoscript", "cfgload" and "config.ini" disappear. We see also inside device_tree a single file, "g12b_a311d_dreamone.dtb" that would correspond to "g12b_a311d_khadas_vim3.dtb" of Khadas Vim3, its SOC, however, is A311D, instead of S922X in the Dreambox One.

    emanuel’s CoreELEC:

    Original CoreELEC:

    A priori, version 9.2.3 (emanuel's CoreELEC) is enough to test the HDR to SDR issue on one of my non-HDR compatible displays but I think that version does not fix the artifacts and banding with S922X devices that I guess will have been solved in 21.2, after 5 years. Hence my interest in trying the latest CoreELEC version, although on the rest of my displays I’ll use LibreELEC only.

    GitHub - emanuel4you/pack-libreelec-for-dreambox: Scripts to build Dreambox LibreElec Images
    Scripts to build Dreambox LibreElec Images. Contribute to emanuel4you/pack-libreelec-for-dreambox development by creating an account on GitHub.
    github.com

    It is absolutely necessary to provide the LibreElec image with a chain boot loader. Otherwise the manufacturer's boot loader of the Dreamboxes cannot boot the image. A script for repacking is available here on github, or the pre-packed images are available from me on ihad.

    Edited once, last by _emanuel_ (January 26, 2025 at 12:02 AM).

    Quote from _emanuel_

    https://github.com/emanuel4you/pack-libreelec-for-dreambox

    It is absolutely necessary to provide the LibreElec image with a chain boot loader. Otherwise the manufacturer's boot loader of the Dreamboxes cannot boot the image. A script for repacking is available here on github, or the pre-packed images are available from me on ihad.

    According to this:

    https://wiki.libreelec.tv/hardware/amlogic

    To run LibreELEC on a Dreambox One you only need to edit the file “uEnv.ini” and then just insert the SD card in the box and power on. Some box devices detect the presence of the SD card automatically

    At this point I don't understand why you choose to use scripts and a Nightly build instead of directly downloading the latest stable version and doing the above.

    I will try all with the new SDXC card in a few days when it arrives. But to run the scripts I will have to install Linux first.

    BTW, I see that you don't mention anything I ask about CoreELEC, I imagine that the Dreambox version is something you have completely abandoned. Unless you have to run some script and use a Nigthly build also with CE.

    Regarding CoreElec: Yes, I've given up on that completely because the source is no longer compatible with the Dreambox. The Dreambox uses an ancient manufacturer kernel (4.9) and the associated bootloader, which prevents a lot of things, e.g. new CoreElec with video (in my old one, even DVB-S2 works).

    The huge difference between an Amlogic Dreambox and a conventional Amlogic Android box is that the Dreambox has a security chip (tpm) built in. This means that if I swap the bootloader for one not built by the manufacturer, the box is broken. This is also the reason why there is no separate Dreambox image in the Nightly. The board-specific images here all have a bootloader for the kernel 6.X flashed at the beginning of the SD. So you can only use the box image of the Nightly for the Dreambox, which is intended for manual configuration. LibreElec uses a brand new kernel 6.X. the Dreambox's conventional boot loader can no longer handle such a kernel and the box simply freezes.


    To boot a kernel 6.X on the Dreambox anyway, you can only do this:
    1.) Dreambox boot loader decrypts and opens the box
    2.) finds the autoexec.img script and executes it.
    3.) The script overwrites the boot loader with a new bootloader that is for kernel 6.X and is located on the first partition.
    4.) the new bootloader starts the kernel and LE
    5.) LE switches off and wants to shutdown the kernel. But the Dreambox now reboots into the manufacturer image because the bootloader for kernel 6.X cannot operate the security chip. So a script has to help out again so that the box does not boot again and shuts down when it boots in the manufacturer's bootloader again.

    I know, it's all complicated. I've been doing this for years now. To make it short, the images in Ihad are built 1 to 1 like those in Nightly, I even grabbed the last ones directly from the download feed. You just have to flash them.

    I hope I don't get into trouble because of the link (everything I did there is published).

    packed images are ready here for all 3 bootloader variants:

    a) for original bootloader, *.img.gz
    b) GPT multiboot loader (manufacturer Multiboot) *gpt-multiboot.img.gz
    c) gboot multiboot *multiboot.img.gz


    Believe me, I would prefer it without this stupid tpm chip. The new Dreambox doesn't have one anymore. Because they only sell boxes anyway and no longer have any developers who can even build something like that. The new one is like any conventional Android box.

    What irony, developers protect their work with a tpm chip, but have no work anymore...

    Quote from _emanuel_

    the Dreambox's conventional boot loader can no longer handle such a kernel and the box simply freezes

    The root cause is probably missing memory-region mappings in the device-tree file, combined with changes in kernel memory use which now allow or result in an in-use region being overwritten. If older Linux kernels <6 worked and newer ones >=6 don't, the trigger is probably a change in kernel memory features and usage, i.e. changes to defaults in kernel defconfig.

    I forget who, but someone told me that Dreambox One/Two used signed boot firmware. That's the normal Amlogic approach for protecting boot (along with ARM OP-TEE for apps and firmware) and is widely used by e.g. Amazon, Freebox, and similar streaming services. It's not impossible, but it would be the first time I heard of a TPM chip used with Amlogic hardware. TPM chips add to the manufacturing cost (an expense the normal Amlogic signing approach avoids) and will be a physical/visible chip on the board. The net result is the same though; the Amlogic BL1 bootrom (in silicon) will only boot vendor signed (in software) code.