lomiri-thumbnailer-admin - Thumbnailer administrative tool

lomiri-thumbnailer-adminclear [cache-id]
              Clear all internal caches.

       lomiri-thumbnailer-adminstats [cache-id]
              Display cache statistics.

       lomiri-thumbnailer-adminzero-stats [cache-id]
              Zero statistics counters.

       lomiri-thumbnailer-admingetfile [dir]
              Get a thumbnail from a file.

       lomiri-thumbnailer-adminget-artistartistalbum [dir]
              Get an artist thumbnail from the image server.

       lomiri-thumbnailer-adminget-albumartistalbum [dir]
              Get an album thumbnail from the image server.

       lomiri-thumbnailer-admincompact
              Compact internal caches.

       lomiri-thumbnailer-adminshutdown
              Shut down the thumbnailer service.

lomiri-thumbnailer-admin--helplomiri-thumbnailer-admin-h
              Display a general help message for all commands.

       lomiri-thumbnailer-adminclear [cache-id]
              Options:
                     --help-h
                            Show help message.

              Clear all three internal caches. If cache-id is provided, clear only the selected cache.

       lomiri-thumbnailer-adminstats [cache-id]
              Options:
                     --help-h
                            Show help message.
                     --verbose-v
                            Show histogram of entry sizes.

              Display detailed cache statistics. If cache-id is provided, limit  the  display  to  the  selected
              cache.

       lomiri-thumbnailer-adminzero-stats [cache-id]
              Options:
                     --help-h
                            Show help message.

              Reset  the  statistics  counters  and  timestamps  to  zero.  If  cache-id  is provided, reset the
              statistics only for the selected cache.

       lomiri-thumbnailer-admingetfile [dir]
              Options:
                     --help-h
                            Show help message.
                     --sizepixels--spixels
                            Set the thumbnail size.

              Extract a thumbnail from the specified media file.

              If dir  is  specified,  place  the  thumbnail  into  the  specified  directory  (default:  current
              directory).

              The  output file name is basename_size.png. For example, for a file song.mp3, the output file name
              is song_0x0.png if no specific size was provided.

       lomiri-thumbnailer-adminget-artistartistalbum [dir]
              Options:
                     --help-h
                            Show help message.
                     --sizepixels--spixels
                            Set the thumbnail size.

              Retrieve artist artwork for the specified artist and album. The album can be an empty string  but,
              because  artist  names  alone  can  be  ambiguous,  specifying an album as well may yield a better
              result.

              If dir  is  specified,  place  the  thumbnail  into  the  specified  directory  (default:  current
              directory).

              The  output  file name is artist_album_artist_size.png. For example, for Jethro Tull's "Aqualung",
              the file name is JethroTull_Aqualung_artist_0x0.png if no specific size was provided.

       lomiri-thumbnailer-adminget-albumartistalbum [dir]
              Options:
                     --help-h
                            Show help message.
                     --sizepixels--spixels
                            Set the thumbnail size.

              Retrieve album cover artwork for the specified artist and album. The artist can be an empty string
              but, because album titles alone can be ambiguous, specifying an artist as well may yield a  better
              result.

              If  dir  is  specified,  place  the  thumbnail  into  the  specified  directory  (default: current
              directory).

              The output file name is artist_album_album_size.png. For example, for  Jethro  Tull's  "Aqualung",
              the file name is JethroTull_Aqualung_album_0x0.png if no specific size was provided.

       lomiri-thumbnailer-admincompact [cache-id]
              Options:
                     --help-h
                            Show help message.

              Compact  all  three  internal caches so the take up the smallest possible amount of disk space. If
              cache-id is provided, clear only the selected cache.

              After some time of use, the on-disk size of a cache can be 25–30% larger than  its  nominal  size.
              Compaction reclaims the wasted space, but is slow and, while in progress, other thumbnail requests
              are  delayed  until  compaction completes.  (It can take tens of seconds to compact a cache with a
              nominal size of 100 MB, depending on the speed of the hardware.)

       lomiri-thumbnailer-adminshutdown
              Options:
                     --help-h
                            Show help message.

              Shut down the thumbnailer service. This is useful mainly after changing settings (which  are  read
              only once when the service starts).

       The   lomiri-thumbnailer-admin   program   provides   a   simple   administrative   tool  to  access  the
       thumbnailer-service(1), for example, to retrieve a thumbnail, display statistics,  or  selectively  clear
       one ore more of the service's internal caches.

   Internalcaches
       The thumbnailer service maintains three internal caches:

       Image cache
              The  image  cache  stores images that are expensive to retrieve (namely images downloaded from the
              image server (dash.ubuntu.com) or extracted from video files). Images in this cache  are  kept  at
              high resolution, up to a limit of max-thumbnail-size (usually 1920) pixels in the larger dimension
              (see  thumbnailer-settings(5)). The image cache is used to create thumbnails at smaller sizes that
              are then inserted into the thumbnail cache (to  avoid  repeated  download  or  extraction  of  the
              original images).

       Thumbnail cache
              The  thumbnail  cache  stores  images that are scaled to a size that was previously requested by a
              client. If a client asks for a thumbnail that was previously generated at the  same  size,  it  is
              returned from this cache.

       Failure cache
              The  failure  cache  contains the keys for media (local or remote) for which no thumbnail could be
              generated, either because a local file does not contain artwork, or because the image  server  has
              returned  an  authoritative answer that no image is available.  If a client asks for an image that
              is in the failure cache, the service does not try to create a thumbnail for some period  of  time,
              to avoid expensive repeated attempts to retrieve artwork that does not exist.

       Commands that can selectively be applied to these caches use the following cache-id:

       i      Image cache

       t      Thumbnail cache

       f      Failure cache

   Sizesandscaling
       Thumbnails  are  never  larger  than  max-thumbnail-size  in  the  larger  dimension  (usually  1920, see
       thumbnailer-settings(5)), even if a larger size is requested.

       Commands that create thumbnails expect a size in pixels to be specified as follows:

       widthxheight
              Create a thumbnail scaled to fit a bounding box of width and height, for example, --size640x480.
              If  only a single dimension is provided, the thumbnail is scaled to fit into a square bounding box
              of the specified size, for example, -s256.

              Specifying a size with one dimension explicitly set to zero leaves that  dimension  unconstrained.
              For example, --size0x480 produces a thumbnail no taller than 480 pixels of any width, (subject to
              the max-thumbnail-size limit).

              Specifying   a   size   of  zero  (or  not  specifying  any  size)  is  equivalent  to  specifying
              max-thumbnail-size in both dimensions.

              Scaling always maintains the aspect ratio of the original image, and ensures that a thumbnail  has
              a size of at least one pixel in the smaller dimension.

              Requests  for  thumbnails that are larger than the original image are automatically reduced to the
              original image size, that is, original artwork is never scaled up.

   Mediaformatsandoutputfiles
       Most common image formats, such as PNG, JPEG, BMP, and so on, are recognized. For  streaming  media,  the
       recognized formats depend on the installed gstreamer codecs.

       Thumbnails  are  always  returned  in  PNG  format, regardless of the encoding of the original image. The
       generated thumbnail file is tagged with the requested (not actual) image size. For example,

              lomiri-thumbnailer-adminget--size=320x240screen.jpg

       creates a file named screen_320x480.png.

       lomiri-thumbnailer-admin - Thumbnailer administrative tool

thumbnailer-service(1),thumbnailer-settings(5)

Ubuntu                                           05 August 2015                      lomiri-thumbnailer-admin(1)

lomiri-thumbnailer-admincommand [options]