Audio description :making it work

Nick Tanton

BBC

Synopsis

• Authoring

• Playout

• Coding

• Receivers

• End-to-end

BBC involvement

• working on AD since early 90’s• working on AD for DTV since 1997• defined signal formats in 1998• broadcasting on DTT since 1999• regular service since 2000• provided technical support to

manufacturers and other broadcasters• pro-active participation in

standardisation

BBC activity now

• AD on over 11% of programmes (Q1-Q3 2007) for all relevant BBC public service digital TV channels

• AD on our HD service

• UK Digital Switchover Help Scheme

• Authoring and playout by RedBEE

• Coding by Siemens

Authoring 1

1998

Authoring 2

1999

2008

Authoring 3

Authoring 4

Authoring 5

• keep file format as flexible as possible– e.g. multiple WAV and ESEF

• anticipate– archiving– re-edits and re-versioning– new delivery platforms and standards

Playout

• ensure that if you’ve scheduled AD – it gets played-out as scheduled,– correct AD is associated with video etc.

before TX,– it is accurately labelled in the metadata

included with the delivered signal,– you’ve kept an accurate as-delivered log.

Coding

• ensure– the signal gets transmitted as scheduled,– it is correctly signalled in the service

information (SI),– you’re able to identify failures to deliver

and rectify them as promptly as possible,– coders can identify and respond

appropriately to errors in the incoming signal.

Receivers 1

• ensure– clear and complete definition of expected

receiver behaviour,– user-interface is appropriate for B&PS,– test and representative streams are

available and used– thorough testing (preferably with some

independent oversight)

Beware regression

Receivers 2

Remote controls• Easy-to-use remote

controls are important for everyone (especially the blind and partially sighted)

DedicatedAD & ST buttons

Receivers 3

• Most manufacturers know what is involved in including AD with their product.

• A number of manufacturers have product with AD (iDTVs and stbs) or are working on including it

End-to-end (e2e ?)

• ensure– everyone involved in the process of

delivery understands how important AD is to the blind and partially sighted user,

– monitoring is designed-in ab-initio (and for executive action not just for reporting),

– the service requirements are paramount.

A culture based solely on “service level agreements” & “key performance indicators”

will almost certainly produce a poor user-experience.

Thanks for your attention

nick.tanton@bbc.co.uk

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