zagreb, croatia, 4 december 2013 subtitling (captioning) gion linder head of subtitling swiss txt...

Zagreb, Croatia, 4 December 2013

Subtitling (captioning)

Gion LinderHead of subtitling SWISS TXTChairman Eurovision Access

Services Experts [email protected]

Regional Meeting for Central and Eastern Europe organized by International

“eAccessibility in Television Broadcasting in Central and Eastern Europe”

(HRT Academy, Zagreb, Croatia) – 3-4 December 2013)

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Topics

• What are subtitles?• Target groups• Legal issues• Technology• Input technologies• Content access• Reception of subtitles• Subtitling market• Quality• Profession subtitler/respeaker• Subtitles on all devices• Added values• International

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What are subtitles?

Subtitles are is a textual version of the dialog or commentary … [in audiovisual media]. (Wikipedia)

• Intra- / interlingual subtitles

• Closed / open subtitles

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Target groups

Hearing impaired (WHO: 5% or 360’000’000)

• Deaf• Hard of hearing

• age-related• profound

• Late deafened• Deaf children

Foreign language comprehension• Learners

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Legal issues (1/2)

There would be no such service without legislation(except the US)

Fields:• Only broadcast or online as well?• Subtitles, signed programs,

clean audio

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Legal issues (2/2)

• European directives• EU encourages member states

• National legislation• Voluntary service

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Technology

• Server• Transmission system

• DVB, Teletext or online• Exchange format: STL EBU TT

• Equipment providers• Screen (Sysmedia)• FAB• Softel• Cavena (Scantitling)

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Input technologies (1/10)

Keyboard• Ordinary Keyboard• Stenotype

• only in the UK and US (and Italy)• Short key systems

• e.g. Norway• Fast typers

• e.g. Austria• Dual keyboards

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Voice recognition• Respeaking

• Dragon and IBM• Available in English, French, German, Spanish,

Italian and Dutch

• Respeaking with correction• France (correct sentences vs. delay)

• Automatic voice recognition

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Automatic subtitling= recognition + creation of subtitles• for live programs, with subsequent

correction, alignment service• Problems that might occur• Challenges

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Automatic subtitling• NER value from different providers

Prepared Spontaneous German 87.5

90.3 94.9

81.1 83.1 82.9

French 93.6 91.5 94.4

Italian 93.0 90.8 86.6

92.3 86.9 85.0

analyzed with NERstar

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Automatic subtitling - Difficulties• Spoken vs. written language• Different from standard language• Background music/noise• Big variation within a program• Wrong recognized words

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Savas project• EU funded, 2 years• 6 languages: German, French, Italian,

Spanish, Portuguese and Basque• Goal: live subtitling of news programs

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Automatic subtitling - Conclusions• Not all kind of programs suit• Standard language• Without spontaneous speech• Homogenous program format• Noise and background sound

standardized

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Automatic subtitling• Possible area of use• Local programs• Automatic recognition with postponed

correction• Subtitles available on the internet and

HbbTV

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Content access

• Prerecorded programs• Access to content as early as possible• Convert to low res (+ meta data)• Distribution• Attach to data base or copy on MXF

• Live programs• Access to news desk• Access to prerecorded videos• Near live: access to audio at least

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Reception of subtitles (1/5)

• Display on screen• Common sense

• 2 lines, on the bottom• Double height• Only bright colors• Duration chps or wpm

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• Processing live subtitles• Scrolling vs. blocks• Time spent on images

Source: Pablo Romero-Fresco

Blocks Scrolling Hearing 33.3% 11.7% Hard-of-Hearing 33.2% 11.4% Deaf 31.7% 14.3%

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Subtitling market

• Prerecorded programs• Hard competition• Easy to enter the market

• Live programs• Follow the value chain• Costs for a broadcaster

• Different ways to fulfill: With or without an own staff

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Quality (1/7)

• Definition of quality• Pretty easy for prerecorded programs

• Correctly, regarding content and grammar• Word order and key words• Verbatim as long as possible• Description of non visible sounds• Linguistic nuances, ambiguities, irony• In sync and frame accurate

• Easy language?

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Quality (2/7)

• Definition of quality• For live programs

• Verbatim vs. slight synthesis• Scrolling vs. block• Real live vs. postponed editing (delay!)

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Quality (3/7)

• Quality assessment• For live programs

• Word error rate• NER model

• Assessment in the UK• So far: WER• New: NER model

• 90 minutes per year per channel• News, entertainment and sports• Supervision by Roehampton University

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Quality (4/7)

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Quality (5/7)

• NER model: error examples• Serious

he’s having problems with the cheques instead ofhe’s having problems with the Czechs

• Normalhe’s a buy you a bull asset instead ofhe’s a valuable asset

• MinorSimon brown has been appointed new chairman of Rolls Royce instead ofSimon Brown has been appointed new chairman of Rolls Royce

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Quality (6/7)

NERstar tool• All you need:

• video, subtitle, transcript• Calculates the NERvalue and the delay

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Quality (7/7)

NER model• British Ofcom plans:

• 6 videos, 5 minutes each for news, entertainment and sports

• Supervising Roehampton university

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Profession subtitler

• Ordinary subtitler• Respeaker• In the future only corrector?• Precarious work situation

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Subtitles on all devices

• From linear to non linear• New format EBU TT• On all devices?

• On the own webpage?• On HbbTV?• On TV service providers like Zattoo?• On mobile devices?

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Added values

• Subtitles may improve• the search in the own archives• the search for video search engines

• Subtitles may be useful • for recognition software

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International

• Awareness• EBU: Eurovision Access services

experts group• Knowledge exchange• Interfere when necessary

• ITU: Focus Group• Other stakeholders

Thank you!

[email protected]

Geneva, Switzerland, 24 October 2013 36

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