⚠️ EXPERIMENTAL · UNSUPPORTED · USE AT YOUR OWN RISK

This is an unofficial, experimental CoreELEC 22 build. It is NOT an official
CoreELEC release and it is NOT a supported CE22 port. I am not a CoreELEC 22
port maintainer, and I will not be providing support, bug fixes, updates, or
ongoing maintenance for this build.

The only purpose of this build is to give Amlogic AM9 Pro-class users a more
complete Dolby Vision experience than stock CoreELEC 22, by carrying a set of
custom Kodi features I built for my own device. That is the entire scope.

READ THIS BEFORE YOU FLASH ANYTHING

• USE ENTIRELY AT YOUR OWN RISK. There is no warranty of any kind, express
  or implied. It may fail to boot, misbehave, break Dolby Vision, or do nothing
  useful on your hardware.
• BACK UP YOUR CURRENT INSTALLATION FIRST. Take a full CoreELEC backup
  (Settings → CoreELEC → Backup) and/or image your existing boot media before
  you install anything from here. Assume you may have to restore it.
• Prefer a SEPARATE SD card or USB stick you can boot from, instead of
  overwriting a working internal (eMMC) install.
• Do NOT report problems with this build to the CoreELEC team or forums.
  This is not their build; it is not their responsibility. Do not ask them to
  support it.
• I am also not offering support. If it breaks, you keep both pieces.

By downloading or using any file in this release you accept all of the above.

Install

• Clean install (recommended): flash the *.img.gz to an SD card or USB with
  balenaEtcher (or the Amlogic USB Burning Tool for eMMC), then boot from it.
• In-place update: copy the *.tar to the /storage/.update folder on an
  existing CoreELEC install and reboot. (Back up first — see above.)
• Verify your download against the SHA256 sums below before flashing.

What's changed in this update

🧪 HIGHLY EXPERIMENTAL TESTING BUILD: not for everyday viewing

This build is more experimental than my usual releases. It replaces the way
playback is timed on Amlogic boxes, so picture, sound, refresh-rate switching
and Blu-ray menus all run on new code. It is released for testing only, so
that more people can look at it. Expect rough edges. If you need a box that
just works for movie night, stay on the previous release.

• Back up first (Settings → CoreELEC → Backup), or better, run it from a spare
  SD card or USB stick.
• To go back: copy the previous release's .tar
  (v22.0-samurihl-20260928164552)
  into /storage/.update and reboot, or do a clean install of that release.
• Tested only on two boxes: one S922X (G12B) and one S905X5 (S6, AM9
  Pro class). Most of the new timing code turns itself on only on those two
  chip families. Other Amlogic chips keep the previous timing (see "What to test"
  below).

Dolby Vision still requires dovi.ko (the CE22 5.15 build) installed on your
device. It is not bundled; install it yourself as on stock CoreELEC 22. You do
not need to modify it. This build corrects it automatically at boot.

This update follows
v22.0-samurihl-20260928164552.
It is about one thing: picture and sound timed from the display's own refresh,
the way a standalone disc player does it. Starts, seeks, pauses, refresh-rate
switches and HDMI reconnects are now scheduled on the TV's refresh instead of
being corrected after the fact. Blu-ray menu programs now follow what is on
screen, not what has been read from the disc. It also brings Kodi up to the
22.0 RC1 tag with the upstream fixes since the last release.

✨ New: one clock for picture and sound (S922X and S905X5 only)

Before, the picture and the sound each started on their own and Kodi pulled them
together afterwards. Now every start is planned for a specific screen refresh,
and the first picture and the first sound land on it together.

What you should notice:

• Starts, seeks and resumes: sound comes in with the first picture. A
  seek no longer plays up to a second of picture with no sound. Resuming after a
  pause no longer creeps the sound a little further ahead each time.
• Pause: the ~0.1 s of sound that used to play on after the picture froze is
  taken back and played when you resume. This covers TrueHD, DTS-HD, DD, DD+ and PCM.
• Long films stay in sync. The box's audio clock runs very slightly fast or
  slow against the video clock. On the S922X the sound drifted ahead by
  about 10 ppm; nothing corrected it below Kodi's 50 ms threshold. The audio clock
  is now trimmed, inaudibly, to follow the picture for the whole film. (A kernel fix
  also makes the S922X audio clocks run at the rate they claim.)
• Refresh-rate switches, TV/AVR power cycles and input switches mid-film: the
  sound is paused with the picture while the TV re-syncs. Both pick up together
  from the picture on screen when the TV is back. Playback also waits for the TV to
  report it has locked, not just for your "delay after refresh change" time.
• Audio offset (the +/- audio delay): it now moves the sound, as on a
  disc player, and lands exactly at any value. Before, it moved the picture, and
  with bitstreamed audio +25 ms became a whole frame (+42 ms).
• Switching audio tracks on a Blu-ray no longer freezes the picture for ¾ of a
  second; only the sound re-cues.
• Audio-only files (FLAC, music) no longer lose their first ~0.3 s.

✨ Also new on all Amlogic boxes

• Picture timing on Amlogic: Kodi assumed a picture took four refreshes to
  reach the screen on Amlogic video; it takes two. In our measurements at the
  HDMI output that put the picture about 80 ms (at 24 fps) ahead of the sound.
  It now uses the real figure.
• Starts wait for the final TV mode. A film's start is held until the TV mode
  for it is set, so it does not begin playing while the TV is still switching.
• Format changes on disc with an AV receiver: the HDMI audio output is kept
  between segments of a disc, so a change such as TrueHD to Dolby Digital goes
  straight across instead of 2.8 s of 2-channel PCM.
• Blu-ray segment joins keep the last picture on screen instead of flashing black.
• The end of a clip always plays out. The last pictures of a segment
  (for example Halo's intro) are no longer cut off.
• TV or AVR reconnect mid-film: the film's refresh rate is restored (it used
  to stay at 60 Hz for the rest of the file), and a 4K picture no longer stays
  in a 1080p-sized box in the corner after the replug.
• Multichannel PCM on S922X: with the PCM device set to "HDMI", 5.1/7.1 PCM
  played at a third of its speed. It is now routed to the multichannel output.

🛠️ Audio fixes

Items marked (S922X/S905X5) are on only on those two chip families.

• (S922X/S905X5) TrueHD after a seek is no longer briefly taken for Dolby Digital Plus, which
  made some receivers switch formats several times.
• (S922X/S905X5) TrueHD starts are timed from the TrueHD stream itself, so a seek or track
  change no longer lands a few to tens of milliseconds off.
• (S922X/S905X5) Seamless Blu-ray joins keep audio and video together per
  stream. On a Star Trek season disc the sound no longer slides later at each
  join (up to 8.7 ms by the fourth). Steps at a join use whole audio frames only, which is
  inaudible.
• Fast-forward/rewind back to play on a disc could, about once in 70 tries,
  start the sound seconds off the picture. Fixed.
• "Seek back on start" (e.g. Plex/PM4K resume) could land the first sound
  wrong and then correct it mid-stream. On one film this made the receiver put
  the centre channel on the front left. Fixed.

🛠️ Dolby Vision / FEL

• (S922X/S905X5) Dolby Vision files (MKV/MP4) now switch the TV into Dolby Vision as part
  of the start, instead of just after playback has begun.
• VS10 tone mapping to SDR or HDR10 wins over the HDR10+ → Dolby Vision
  conversion when both are set. Before, your SDR/HDR10 choice was ignored and the
  output was Dolby Vision (reported as "dark and flat" on SDR).
• FEL decoder hang after a rewind (picture stopped, Stop hung, only a power-off
  recovered) is fixed in the video driver.
• The enhancement layer is flushed when the base layer ends, and stale
  pictures from before a seek or reset can no longer be shown after it.

🛠️ Blu-ray menus (BD-J and HDMV)

• (S922X/S905X5) Java menus follow the picture. A menu program's start, chapter marks and
  playitem events now reach it when their picture is on screen, not when the
  disc reader passes them (that could be up to a second early). Its timers stop
  while the TV is switching modes. M3GAN's menu bar now opens on time and stays
  up its full 7 seconds.
• John Wick 3: the 5-second menu freeze after the intro and the 8-second wait
  before the feature are fixed, and (S922X/S905X5) the menu background no
  longer breaks up after the logo.
• Star Trek TNG S1: the language menu no longer stays black until an HDMI
  re-sync.
• HDMV menu pages appear with their video's first picture.

🛠️ Upstream (Kodi 22.0 RC1 and later)

• Subtitles: a style is applied once, and the subtitle position is set from
  the start of playback instead of from the first line.
• Video library: many NFO import/export fixes, show-folder cleanup, Blu-ray
  playlist parsing (with an advanced setting to turn off authoring-project
  parsing), title search by original title.
• Other: 3D detection from the file name, disc image resume state, photo EXIF
  orientation, coloured media-flag icons in Estuary, a job-manager stall,
  controllers powered off on quit, several game (RetroPlayer) fixes, and a fix for
  the player spinning a CPU core when paused at the end of a file.

🔍 What to test and report

Eyes and ears are what this build needs. Please try:

• A/V sync by eye and ear: at the start of a film, after seeks, after
  pauses (short and long), after fast-forward/rewind, across a refresh-rate
  switch, and late in a long film.
• HDMI events mid-film: power the TV or AVR off and on, or switch an HDMI
  switch/AVR input away and back. Does it come back once, at the right refresh
  rate, in sync?
• Blu-ray menus, both Java (BD-J) and classic (HDMV): do they appear, time out
  correctly, and start the film promptly?
• Dolby Vision and FEL discs, from the menu and played directly.
• Multichannel PCM (5.1/7.1, e.g. decoded AAC or FLAC) and TrueHD/Atmos:
  does the receiver show the right format and channel count?
• S922X owners especially: the S922X test box has no screen, so on that chip
  the new code has only been checked with logs, never by eye.
• Other chips (S905X4, S928X, S905X2/X3 …): the new clock, audio clock trim,
  scheduled starts and pause take-back stay off there, and you get the old timing.
  The "all Amlogic boxes" changes above do apply. Please report whether playback
  is no worse than the previous release. (A311D shares the S922X's chip family, so
  it gets the new code, but it has not been tested at all.)

In a report, please include: the box model and chip, a debug log
(Settings → System → Logging → Enable debug logging, then copy kodi.log from
the Logfiles share), what was playing (title, disc or file, audio format,
frame rate), what you did, and the time it happened so it can be found in
the log.

⚠️ Known issues

• A loud pop when a film starts from the menu, as the audio output switches
  from the menu's PCM to bitstream. Seen on every start from the desktop with
  Dolby Digital to an AVR.
• Playing the next file in a playlist at a different frame rate: the new
  file's first picture can flash at the old refresh rate, and the start is not
  quite as tight as a normal start.
• TV/AVR reconnects and waking from standby can make the TV sync twice in
  quick succession. The second sync is usually too quick to notice.
• Turning Dolby Vision on live through VS10 during playback: the picture holds
  for about 0.6 s and the TV and receiver fully re-sync.
• A BD-J pop-up menu audio or subtitle change takes a few seconds to be heard
  or seen after you return to the film.
• Changing the audio offset with bitstream audio skips about 0.35 s of sound
  for each step.
• Turning "SDR → HDR" or "HDR → SDR" on or off only fully takes effect after a
  restart (or an HDMI reconnect).
• The 25 fps sync test clip measures about 1 ms early by eye. You will not
  hear it, but it is noted.
• Halo: an occasional short flash at the join from a clip back to the main menu.
• 3D frame-packed output could not be tested; no 3D TV here.

Credits

Thanks to everyone whose upstream Kodi and CoreELEC work is included:
Portisch, Malard, Dom Cobley, kel-mo / Kel Modderman, ksooo, Chris, Garrett Brown,
Christian Hewitt, olympia, jjd-uk, Markus Härer, 78andyp, KOPRajs and matthane
(HDR overlay depth fix, DRM PRIME HDR types).

Under the hood

• Kodi: a refresh-driven timekeeper is the only vblank reader; the reference
  clock counts its ticks, starts/resumes/display resets are scheduled on it, and
  ActiveAE lands passthrough and PCM at the scheduled instant (µs timestamps
  through the sink). Video and audio stream threads are split into non-blocking
  workers. Gated to S6 and G12B by CPU family; elsewhere the previous path.
• Kernel (common_drivers): 0019 exposes the sink's SCDC lock, 0020 keeps the
  G12B MPLL on the grid the hardware resolves (S922X audio −20 → +10 ppm), 0021
  adds an HDMI audio clock trim control (G12B/S6).
• media_modules: 0003 flushes whichever layer did not take end of stream; 0004
  fixes the dual-layer first-picture fast-output loop.
• libbluray: patches 15–22 (preloaded IG first display, BD-J start, marks and
  playitems at their presentation time, seek/clip-switch title position, one disc
  clock for BD-J and HDMV timers).

Source

• CoreELEC (distro): SamuriHL/CoreELEC tag v22.0-samurihl-20261014135811
• Kodi: SamuriHL/coreelec-xbmc tag v22.0-samurihl-20261014135811

Checksums (SHA256)

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24aa974782c3fb09836dabaddc21b13c07cd8d7c0974834e927c9af4351b3e00  CoreELEC-Amlogic-no.aarch64-22.0-Piers-samurihl-EXPERIMENTAL_20261014135811-Generic.img.gz