Originally just Audio Files, we have migrated to a more generic model, MediaFile. This is extensible to any type of media; currently only Audio is in common use, but anticipated future use includes Images and Videos.

Database Models


The MediaFile model itself is fairly generic, having only a few built-in columns.

Field Description
file The file. In Django, a FileField object holding the file. In the database, the path to the file relative to MEDIA_ROOT.
user Who owns the file
type Reference to MediaTypes - indicates Audio, Image, Video, etc.
active Only used in very specific situations, but basically ‘should this file be used in processing’
alias Display name of the file
uploadDate For diagnostics / logging / tracking - when was the file uploaded.
sensor Null by default, or a reference to which Sensor collected this file
library Which Library contains this file
realStartTime The datetime at which the recording begain, if known
md5 MD5 Checksum of the file (may be explicitly set and used for validation of proper import, or automatically computed during import.


The MediaFileMetaData is a key/value system for having extensible metadata for MediaFiles. This allows flexibility for specific Projects, though a core set of MetaData will likely be necessary for each MediaFileType (though software should check and gracefully fail if the necessary data isn’t available).

Field Description
mediaFile Reference to the MediaFile
name Name of the Datum
value Value of the Datum
userEditable Whether the user is free to edit this data (for example, users should be able to freely edit Audio File length data)

MetaData for Audio Files

Here’s a typical list of Metadata that is expected for AudioFiles

  • Not User Editable (generally required by ARLO)
    • fileSize
    • validRIFFsize
    • validDATAsize
    • dataStartIndex
    • dataSize
    • wFormatTag
    • numChannels
    • sampleRate
    • nAvgBytesPerSec
    • nBlockAlign
    • bitsPerSample
    • numBytesToTailPad
    • numFrames
    • durationInSeconds
  • User Editable (generally NOT required, i.e., not used directly by ARLO. Most of these are being removed now that we have the UserMetaData)
    • subjectName
    • startTime (necessary for some ARLO functions)
    • age
    • id_number
    • sunrise
    • sunset
    • contextInfo
    • microphoneType
    • microphonePlacement
    • numSpecies
    • weatherConditions
    • birdSpecies
    • latitude
    • longitude