thumbnail extractors

extract (or generate) thumbnails for custom file formats or override default thumbnail extraction for standard media files

usage

• load plugins with --th-extract baz=~/dev/copyparty/bin/thumbs/randomcolor.py
  • baz is the file extension (may be comma-separated list of extensions)
  • add multiple different extractor plugins by repeating the --th-extract argument

api

in

each plugin must define a function main(abspath, **kwargs):

• abspath is the path to a file to extract thumbnail for
• kwargs currently receives these keyword arguments:
  • vn is the VFS which contains the requested file
  • th_srv is an instance of copyparty/th_srv

out

the main() function must

• return None or raise an Exception in case it is unable to extract thumbnail
• return tuple fmt, stream, offset, whence, size otherwise:
  • fmt: str – format (filename extension) of the thumbnail; should be one of the image formats supported by copyparty (see --th-r-* options)
  • stream: IO[bytes] – binary file-like object supporting seek(), read(), close() methods; should contain extracted thumbnail image
  • offset: int, whence: int – arguments to stream.seek(); copyparty will call stream.seek(offset, whence) once before starting reading the stream contents
  • size: int | None – number of bytes to read from the stream; if size is negative or None, copyparty will read until the end of the stream

notes

it is possible to extract or generate custom thumbnails for standard media files too, e.g. run copyparty with --th-extract mp3,m4a,aac,flac,opus=~/dev/copyparty/bin/thumbs/my_custom_mp3_th_extractor.py and do your magic with audio file thumbnails

in case copyparty doesn't like the fmt option, it will close() the stream without ever calling seek() or read()

if your scenario involves heavy computation or i/o, it is better to defer the heavy parts until the first seek() or read() to avoid redundant work in case the result gets rejected based on fmt value

if you provide custom stream object: copyparty performs buffered reading, so expect multiple read() calls, respect size argument in read(size) calls, and maintain correct seek position

examples

• randomcolor generates a random .gif image

some other known plugins seen on the internets

• fpkg_thumb extracts cover images from playstation4 software installation packages ("pkg" and "fpkg" files)