Archiving Digital Audio Files

Victoria SloyanfutureArch Project

Graduate Library Trainee Scheme

Project Showcase

7th July 2010

Aims

Select a container format

Determine best way to capture audio

Decide how to deliver audio to users

Types of format

Uncompressed: Sound and silence are encoded at the same number of bits/second

Lossless: Use fewer bits/second to encode silence. Sound data is an exact replica, but the file size is reduced

Lossy: Entire file is compressed. The result is very similar, but not identical to the pre-compressed data. File size is significantly reduced

Which file format?

Uncompressed Open source Standardised Recommended by Library of

Congress and British Library

Exact Audio Copy (EAC)

Metadata

Record ID Collection name Disk number Date record created Case or sleeve label Physical disk label Media type Brand Capacity Capacity used File format Encoding schema Sample rate Bit depth Bit rate

Duration Extraction software used Hardware configuration Drive used Disk folder name Disk number of tracks Errors of disk Date extracted Date ingested Date of recording Genre Contributors Scope and content Rights information Access restrictions

Delivering Audio

Master WAVE

Large, uncompressed file

Original quality and size

Preservation

Processed WAVE

Uncompressed and processed

Better sound quality

Users who require WAVE format

Optimised MP3

Compressed and processed

Better sound quality and small file size

Most users

Processing Files

Conclusion

Select a container format WAVE

Determine best way to capture audioRip it using a secure ripper (EAC)

Decide how to deliver audio to usersUse processed files and access them by streaming