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Music streaming and downloading: an introduction
Richard Ranft
The British Library Sound Archive
IAML Annual Study Weekend – April 2006
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Principles: file sizes,
audiences, copyrights
Audio file types
Preparing sound files
Delivery methods
Examples
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Digital audio
“Music is a time-frequency wave function with tonal qualities pleasing to the human ear” – ALICE
Digital audio files are large… In a simple text file (Windows Notepad), one character or
space requires 1 byte storage The 325 letters and spaces on this page occupies 325
bytes This same text as recorded speech = 1,000 x larger
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File sizes & data rates
8 bits = I byte
Data storage sizes measured in bytes CD 650 MB 1 minute @ CD quality ~ 10MBytes Typical desktop computer hard drive 60 GBytes
Data transfer rates measured in bits per second
CD quality stereo 1,411 kbit/s
Modem connection up to 56 kbit/s
Broadband connection from 256 kbit/s
LAN from 10 Mbit/s
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A quart into a pint pot
Downloading Playback cannot start until entire file received by user Playback is continuous (no buffering) Transfer high quality, uncompressed files
Compression Lossless compression, e.g. MLP, FLAC, 50% reduction Lossy compression (“data reduction”), e.g. mp3, AAC, RealAudio, >80%
reduction Used for streaming media
Streaming Fast delivery, but lower quality than downloading Useful for previewing Instant playback: plays when you click Can use to discourage copying Buffering: used to control network interruptions Live streaming used in ‘broadcasting’ radio shows
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Your audience
Why deliver sound?
Who are your audiences?
What content do want to deliver?
How to deliver content?
Accessing the content
Rights issues
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File types
Uncompressed files WAV AIFF 3-minute song (32 MB): several hours to download over modem
Compressed files MPEG-1 layer III .mp3 (typically 10:1 compression at 128 kbps) Ogg Vorbis .ogg Quicktime Windows Media Audio .wma Choice of bitrates
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Preparing files
Master files v. access files
Digitisation & editing Use high quality files during preparation Edit with e.g. Wavelab (Steinberg), Adobe Audition (Adobe),
SoundForge (Sony), Audacity (freeware)
Conversion from WAV to access version file Batch conversion tools Batch renaming e.g. Rename4u
Upload to server
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Delivery
Simple web page
Choice of file types and qualities
Streaming & streaming servers
Podcasts
Preventing piracy:
Use short samples or low resolution
Watermarking, encryption, streaming
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www.arkive.org
3 file types offerred (with video), each at 2 bitrates
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Click to add title
Cylinder Preservation & Digitization Project: http://cylinders.library.ucsb.edu
3 file types offerred: Quicktime for streaming; mp3 and wav for downloads
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Examples
British Library Sound Archive
5 million recordings: musical works, interviews, recordings of plays and poetry, wildlife sounds, oral history, sound effects
580,000 hours (excluding second copies)
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66 years non-stop listening 6 years added per year
Most of the recordings are
in copyright
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Access
Access: CD publications,
exhibitions & talks, radio
broadcasts, copying service;
listening services
- where rights can be cleared,
or where BL owns rights
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Listening access in three arenas:
Off site, all web users, via BL website Collect Britain (1,400 sounds), plus 800
other sounds, where copyright permissions have been granted or are in public domain (older than 70 years).
Off site, selected web users, to FE & HE communities in the UK Archival Sound Recordings Project:
12,000 sounds by September 2006.
On-site access unrestricted (3 million sounds…)
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www access to British Library sounds
Before 2006: RealAudio streaming format RealServer Surestream
Now: WMA streaming using MMS Windows 2000 server software 45 simultaneous users, but can accommodate many more 400 GB server storage capacity
Downloads not yet available Mp3 downloads of Archival Sound Recordings Project
recordings from September 2006
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www.bl.uk/nsa
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On-site access
For IPR reasons, continuing requirement to provide on-site access
Manual Listening & Viewing Service, appointments-based
Many recordings too fragile to be handled by listeners
Headphone listening in soundproof study carrels
Limited number of carrels Cannot meet increasing demand from
playwrights, media researchers, oral historians, musicologists, etc
Risk of handling damage
2020
SoundServer
A new service, providing instant
access to many sounds in selected
Reading Rooms
Access to digital surrogates of
recordings stored on webserver
‘Point & Click’ delivery from self-
service workstations in reading rooms
Use of ‘leak-proof’ self-muting
headphones on selected Reading
Room terminals
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How does SoundServer work?
Staff receive request for CD listening
On-demand encoding to mp3 files
Files transferred to Windows 2003 server
Personal playlist created by staff using a web form
Playlist links to mp3s and to Sound Archive catalogue
Listeners wait 5 working days for pre-ordered custom playlists
Listener accesses their personal list via Reader number
Sounds relayed over 100 Mbps network to Media Player Classic
player on web browser
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SoundServer: benefits
Removes need for appointments
Semi-automated service - listener-controlled playback
Potentially many simultaneous users
Increasing on-line data bank of audio
Reduced wear on collection items
Entire SoundServer collection accessible to any visitor via
‘Jukebox’ pages
Runs in parallel with existing appointments service, using
existing staff resources
Low cost: capital costs of £14k for server store, headphones &
2 workstations, but rest of service uses existing simple, low-
cost technology, & existing staff
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SoundServer: disadvantages
Lower sound quality of surrogates – but acceptable to most users
Highly dependent on IT infrastructure/reliable network to add and access content
Users wishing to read sleeve notes and view artwork must still make an appointment – but audio-only access acceptable
Need to continue existing appointments-based manual service in parallel for ‘difficult’ audio formats and for sleeve notes and video viewing.
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Progress so far
Nine PC terminals
Currently limited to CD
recordings
A growing collection - now
3,000 recordings -
accessible by any readers
browsing the Jukebox
- including our most
frequently requested items
Feedback from listeners is
very positive
2525
SoundServer developments
Extra SoundServer terminals in reading rooms and in public areas of building
100,000 files in 4 years
Adding e.g. BL CD publications: ‘try before you buy’
Integration with other electronic audio resources, other BL electronic resources (e.g. Oral History transcripts, Naxos on-line library)
Introduce improved playback facilities (bookmarking, saved searches)
Submitting playlist requests via a webform
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Growth in listening and viewing use
0
20
40
60
80
100
120
140
07/08/05 07/10/05 07/12/05 07/02/06 07/04/06
date
nu
mb
er/
we
ek L&V appointments-
excluding SoundServer
Weekly L&V (inc. SS)totals
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Click to add title
Thanks for listening.
Questions?
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