- ffmpeg writes JPEG XL with -update 1, so a % in a file name is never an
image-sequence pattern, and reads videos as file:<path>. The clear and a
startup sweep remove temp files that interrupted writes left behind.
- Convert outdated converts each group of same-stem files once, from the
first source in the R2 order. An old preview that is already gone counts
as removed, and each file's bytes count once. A current preview is only
kept if it decodes.
- An encoder that fails makes the write detect encoders again once. Another
encoder is used if one is found; with none, the file is written as WebP
and the availability Appearance shows is refreshed.
- Changing the thumbnail format, quality or size while Convert outdated runs
returns 409 busy. If the format still changes underneath, the job stops
without removing anything.
- Legacy preview spellings are matched case-insensitively, so X_thumb.JPG
counts as outdated.
- History's cover uses the same lookup as Images. It serves .jxl only when
Accept lists image/jxl, and otherwise the original or the placeholder.
- A video whose thumbnail the browser cannot show keeps its own element
(Images) or its label (Library).
Thumbnail format (webp default, jxl, jpeg), quality (1-100, default 80)
and size limit (128-2048 px, default 512) are server settings in the
config.json thumbnails section, saved with the settings revision. The
never-read gallery thumbnail_size is gone: older saves wrote its unused
default 256 into config.json.
One module names previews (<stem>_thumb.webp/.jxl/.jpg) and finds the
preview a source owns, preferring the configured format; legacy names
are still found. The encoder module writes every preview atomically and
verifies it decodes. JPEG XL needs no new dependency: Pillow (natively
or with pillow_jxl), ffmpeg with libjxl, or cjxl; without one the
settings refuse jxl (400 jxl-unavailable) and GET says why. Encoder
processes are tracked, bounded and killed at shutdown.
Vito Sansevero