diskOS Disco! 2.6.0

Steadier under pressure: smoother fast skipping, a much more careful Bluetooth, up-to-date help, and a crash log.

Testing: the fast-skipping changes and the crash log were used on the maintainer's Disc with deliberately rough
skipping, without crashes. The Bluetooth changes and the updated help were checked with automatic tests and on a
computer only. The AAC fallback was confirmed on the maintainer's Disc; LDAC hasn't been tried (no such headphones at hand). Reports are welcome on
issue #13.

Smoother fast skipping

• Skips are paced. Pressing Next or Previous quickly sends them to the player one every 0.3 s, so it never gets
  flooded; you still land on the same song. Up to 8 presses can wait; Play/Pause stops any still waiting. (The Disc's
  own buttons go straight to the player, as before.)
• Covers settle first. A song's cover is decoded once the song has been current for about 0.3 s, so the songs
  you fly past cost nothing. Title, artist and times still change at once.
• Play history counts a song after it has played for a second, not the moment it flashes by.

Bluetooth

• No more pauses a few seconds into a song. Disco no longer sends play/pause on its own to "fix" playback after
  a Bluetooth change: that single command could pause music that was in fact playing. If music really stopped, it
  shows "Playback paused - press Play to resume" instead.
• Switching to AAC/LDAC no longer stops a playing song. Changing codec rebuilds the Bluetooth link, which pauses
  FiiO's player. Disco now only switches with nothing playing, or pauses first, switches, waits until BlueALSA
  confirms the new codec, and then plays again: a short silence instead of a stuck pause. If the link is already on
  the chosen codec, nothing is switched at all.
• Codec fallback: LDAC, then AAC, then SBC. With any LDAC setting, headphones without LDAC get AAC when they offer
  it; SBC only when they offer neither. An LDAC request that can't get through also tries AAC first.
• More reliable routing: the same headphones reconnecting get the full set-up again; changing source (USB DAC,
  Bluetooth receiving...) and coming back routes afresh; a route started while a song is still starting waits a moment;
  a step that fails is reported instead of being taken for success.
• Connecting and disconnecting: device search is stopped before pairing and never runs twice at once; Disconnect
  cancels a connection still in progress; turning Bluetooth off and on quickly ends with it on; Forget only says so
  when the device is really gone.
• Old commands can't act late: commands waiting for a busy player are dropped if the player restarted meanwhile,
  and a cancelled codec switch is withdrawn.
• The connected device is found in long device lists too.

Help

• First-use hints and Help > How to match what Disco does today: Immersive with circular control, the time
  preview when holding the progress line, Quick Settings EQ (tap: on/off, hold: Equalizer), "hold an item" for
  artists and folders too. Two new How-to pages: Queue / picking and Start-up / battery (Volume Up at power-on
  for the other interface; holding the battery line to reset its totals).

A crash log

Disco now keeps a small log at /usr/data/diskos_crash.log: when it started, when the player restarted, crashes
(with where in the code), low memory and moments the interface was held up. If Disco ever drops back to FiiO's own
interface, that file tells us why: please attach its last lines to an issue.

Installing and updating

• Already on diskOS Disco! 1.4.1 or newer? Update from the SD card: download mq_ui, sign it with your own
  keys and copy the diskos-update folder to the card (how). Your settings, music and stats stay.
• New install? Start from FiiO's stock V2.57 firmware (recommended). Installing over upstream diskOS or
  another diskOS build is not supported and can be buggy; restore stock first. See Install.
• Windows: Unsupported, but working as intended: confirmed several times by users, installs and SD updates included.

After updating

• Settings > System > About shows 2.6.0.
• The new version starts as a trial: play some music or tap Keep to keep it. If it doesn't start properly,
  the Disc goes back to the previous version by itself, or choose Go back.