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Media file formats

Audio files

REST API and UAS API applications can play media files that have been uploaded to an account's media file storage on Aculab Cloud. Similarly they can record media files to an account's media file storage.

Aculab Cloud plays and records Microsoft wav format (.wav) media files compressed using:

  • G.711 A-law (default)
  • G.711 mu-law
  • OKI ADPCM
  • IMA ADPCM
  • signed 16-bit PCM
  • unsigned 8-bit PCM

Only single channel or mono recordings are supported.

G.711 A-law or G.711 mu-law are preferred since they are reasonably small and provide the best quality for telephony use.

The supported sampling rates are:

  • 8000Hz (default)
  • 6000Hz
  • 11000Hz
  • 11025Hz

8000Hz is preferred since it matches the sampling rate used on calls and therefore provides the best quality.

Media files matching this specification can be uploaded to Aculab Cloud via the File Management web service or the File Management page.

Fax files

REST API and UAS API applications can send fax files that have been uploaded to an account's media file storage on Aculab Cloud. Similarly they can receive and save fax files to an account's media file storage.

Fax files to be sent or that are received are stored in the Tagged Image File Format (.tif).The compression schemes supported are:

  • CCITT Group 3 1-Dimensional Modified Huffman run length encoding (RLE). Also known as MH or CCITT 1D.
  • CCITT T.4 bi-level encoding as specified in section 4, Coding, of ITU-T Recommendation T.4. Also known as MR2D, CCITT Group 3 fax encoding or CCITT Group 3 2D.
  • CCITT T.6 bi-level encoding as specified in section 2 of ITU-T Recommendation T.6. Also known as MMRT6 or CCITT Group 4 fax encoding.

These compression schemes do not support colour or greyscale. Images are black and white only.

The page widths supported are:

  • A4 (1728 pixels, 21.95cm)
  • B4 (2048 pixels, 26.01cm)
  • A3 (2432 pixels, 30.89cm)

See Sending & Receiving Faxes for more details.

Media files matching this specification can be uploaded to Aculab Cloud via the File Management web service or the File Management page.