Settings - Metadata Tab

You can configure certain aspects of how iHomeServerâ„¢ processes metadata and artwork using the 'Metadata' tab within the iHomeServer Settings window.  The Settings window is accessed from the 'Settings' button on the main Watch Folder tab:
Settings - Metadata Tab

Preferred language

1. Preferred language
This field dictates which language will be used to send results to metadata providers and which is the preferred language that metadata results and artwork should be provided back in.  It is provided only as a hint to the metadata providers, and therefore may or may not be used.  Additionally, metadata providers may use this field in different ways or may ignore the field completey.

Rating standard

2. Rating standard
The rating standard determines the preferred rating standards that will be used for selecting a 'Content Rating' during an AutoTag operation.  The Content Rating is used to set ratings against video media, eg PG13.

TV artwork handling

3. TV artwork handling
This field defines how TV artwork will be handled by the TV Series Auto-Tag Feature.  There are three different options:
Always use season artwork
This is the default setting.  iHomeServer will tag each episode of a TV season with the same season artwork.  This is the best setting on current versions of iTunes / iOS.
Always use episode artwork
iHomeServer will tag each episode of a TV season with its own episode artwork.  The primary metadata provider for TV series is which provides screen captures of each episode.
iTunes / iOS devices theoretically should show individual artwork for each episode, however, in testing no combination of iTunes or iOS versions yielded this result.  This appears to be a bug within iTunes.
Use season for ep 1, episode for the rest
In theory, iTunes and IOS devices are supposed to take the artwork from the first episode of a season and use this as the overall artwork for the season (eg the artwork displayed on the Season's folder within Apple TV).
This setting would provide the best of both worlds - the season artwork should be used for the season's folder, as the first episode of the season will be tagged with season artwork.  Subsequent episodes would be tagged with episode artwork.
However, as above, there are bugs in the current (at the time of writing) versions of iTunes and iOS that mean that episode #1 is not the episode that is used for cover art.  Instead it appears to be the first episode ever indexed for a season that is used for season cover art.  This cannot be reliably determined.
As per the descriptions above, it is recommended that the 'Always use season artwork' option is chosen.  The other two options are provided in case iTunes / iOS are updated to better support "per episode" artwork, however, in the meantime, they do not provide consistent or expected results due to probably bugs within iTunes / iOS.

Automatically downscale cover

art if greater than check

4. Automatically downscale cover 
art if greater than check
If artwork that is embedded into a media file is very large, it can take a long time for the image to be downloaded to other devices, such as iOS devices or Apple TVs - this means that when opening your media collection via the Video app or Apple Remote all, your device may appear to hang whilst it downloads artwork.
A prime example of this is if you have no artwork assigned.  If no artwork is set on a video file, iTunes will create a frame grab dynamically and will use it as the artwork.  This framegrab tends to be huge (multi-Mb) and that is why browsing video files with no artwork is sluggish from within iTunes or other iOS devices via Home Sharing.
iHomeServer can workaround this issue by automatically downscaling any cover art if it is greater than a threshold bytesize that you can define.  If the embedded cover art bytesize is greater than the threshold, iHomeServer will generate a downscaled image with a maximum width or height of 1024 pixels (maintaining aspect ratio).  This can improve performance on Home Sharing devices.
The default is 'unchecked'

Only update iTunes metadata

(not content) on media changes check

5. Only update iTunes metadata 
(not content) on media changes check
If iHomeServer detects a file has changed (due to file size or file dates), it can employ one of two tactics to update iTunes; it can either tell iTunes to fully refresh the file, or it can tell iTunes to update metadata only.  The latter is faster than the former.  Therefore, by default, iHomeServer will only update the metadata of a file (including artwork) if it detects media changes.  There should be no reason to change this default.

Clear iTunes Content IDs

if forcing media types check

6. Clear iTunes Content IDs 
if forcing media types check
iHomeServer has an option, that can be configured per Watch Folder, that allows media within a Watch Folder to be set to a specific media type (eg Movie, or TV show) when it is indexed.  This option will only work if the content is not protected or purchased; otherwise iTunes blocks the ability to modify the media type.
iHomeServer can work around this by clearing the 'Content ID' metadata field within the file prior to attempting to switch the media type.  This field is an internal metadata field that links the media file with an iTunes store reference.

Force Home Video to Movie media type

7. Force Home Video to Movie media type
Video files contain a metadata tag which determines whether the file is a movie or television episode.  Before iTunes 11 was released, by default all media that did not have this flag set was assumed, by iTunes, to be a movie file so most user's media ended up in the Movies tab in iTunes and on your Apple TV.
iTunes 11 onwards introduced a new media type called 'Home Video' which became the new default if this tag was not set.  Therefore many users have found that their movies now appear in the Home Videos tab instead of Movies inappropriately.
Unfortunately, once iTunes has imported a file, it never re-reads the tag from the file contents so it's not that easy to recategorise media into the Movies tab by editing the file data.  Furthermore, Apple has not extended the iTunes API to support the 'Home Videos' video type so we cannot update media files by calling into iTunes.
Our solution is to switch the media type of a file temporarily to another media type and then switch it back to Movie.  This forces iTunes to both categorise the media as a Movie (not a Home Video) and write the updated tag to the file itself.  However, this has a performance impact if majority of your files are working ok as it requires two writes to each media file in a watch folder so this behavior is disabled by default but can be enabled by checking this option.

Set Album Artist field to  Producers for TV episodes

8. Set Album Artist field to  Producers for TV episodes
This option sets the Album Artist metadata field to equal the 'Producers' field for TV episodes.  Some users find this preferable, however, it is not enabled by default.

Set Episode ID on AutoTag

9. Set Episode ID on AutoTag
Episode ID technically means the internal episode reference provided by the studio.  In early versions of iHomeServer, we set this field when AutoTagging metadata if it was provided by the internet metadata source or created one based on the series / episode number if it was not set.  Users have reported that some versions of the iPad use the Episode ID to sort TV episodes in preference to the Series / Episode number, therefore we have disabled this option by default.  It can be re-enabled by checking this option.

Do not tag if media contains errors

10. Do not tag if media contains errors
Video metadata editing involves modifying the underlying media file.  We use a trusted third party library for these calls, however, we have occasionally had reports from users that metadata editing may have corrupted a file.
We always recommend that users make a backup of their media before using iHomeServer, however, in order to minimise the risk of corruption, iHomeServer runs a check of the original media file before making any changes to it.  If this check throws up warnings, then by default iHomeServer will not make any subsequent metadata changes to the file.  A warning message will be logged in the messages window.
This is quite overzealous in terms of safety however is a safety mechanism to protect your files by default.  Many media files to contain errors and iHomeServer can update the metadata in these filese just fine, however, it is difficult to determine which files will work and which files will fail.
If you are finding lots of your files fail because of this safety check, we suggest temporarily disabling it and then testing the metadata updates on some media files for which you have taken a backup

Metadata Providers button

11. Metadata Providers button
This button will display the list of metadata providers that is currently available to iHomeServer.  Note that this list may change without notice.