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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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Input technologies (2/10)
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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Input technologies (4/10)
Automatic subtitling= recognition + creation of subtitles• for live programs, with subsequent
correction, alignment service• Problems that might occur• Challenges
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Input technologies (5/10)
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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Input technologies (6/10)
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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Input technologies (7/10)
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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Input technologies (9/10)
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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Input technologies (10/10)
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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Reception of subtitles (2/5)
• 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 (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