[OpenSubtitles] Exact VS Fuzzy Subtitle Search

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rednoah
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[OpenSubtitles] Exact VS Fuzzy Subtitle Search

Post by rednoah »

The OpenSubtitles API supports 2 different ways of searching for and looking up subtitles. If you use the OpenSubtitles website manually, then you will be able to search for and upload subtitles by movie name or series name, which can make finding perfectly synced subtitles for your specific video files somewhat troublesome. OpenSubtitles native applications like FileBot instead use a hash derived from the specific video file content itself (and not the filename) so that perfectly matched subtitles can be downloaded fully automatically.



Exact Search: Lookup by Hash
When looking up subtitles via hash FileBot will only use a 8 byte hash computed from the video file content as well as the file size (e.g. hash=15597dfefd704c45, size=3636599158) to find perfectly matched subtitles. Since hash+size uniquely identifies a specific video file the subtitles a guaranteed to be perfectly synced.

:!: Notably, only subtitles that have been uploaded with hash+size for that specific video file by OpenSubtitles native applications like FileBot can be retrieved via hash+size. FileBot therefore requires you to select video file / subtitle file pairs when uploading subtitles.


Fuzzy Search: Lookup by Name
If FileBot cannot lookup perfectly matching subtitles via Exact Search then it will fallback to searching for subtitles by name using information available in the video filename, such as movie name, series name, episode numbers, etc (e.g. series=Firefly, season=1, episode=1) similar to what a human user would do when looking up subtitles manually. FileBot will try to guess the best matching subtitles but perfectly matching subtitles cannot be guaranteed in this case.

:!: Fuzzy Search fallback is enabled by default if use the Image Exact Search feature in the Desktop application. However, if you are using the filebot command-line tool, then the -non-strict flag must be specified explicitly to enable Fuzzy Search.

:arrow: If you find subtitles for your video files via Fuzzy Search and have confirmed that the subtitles are perfectly synced to your video files, then please upload the subtitles again with FileBot so that the missing hash+size information can be added to OpenSubtitles to make subtitle lookup more straight-forward for the next guy.
:idea: Please read the FAQ and How to Request Help.
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