1. SMPTE Timed Text in the UltraViolet™ Common File Format Mike Dolan (TBT)

2. © 2012 SMPTE · The 2012 Annual Technical Conference & Exhibition · www.smpte2012.org SMPTE Timed Text in the UltraViolet™ Common File Format Requirements & History Relationship to SMPTE Timed Text Extensions Profiles & Constraints Further Reading

3. © 2012 SMPTE · The 2012 Annual Technical Conference & Exhibition · www.smpte2012.org Requirements Subtitles –(language translation of dialog) –Comparable to DVD & Blu-ray functionality Closed Captions –(transcription of sound) –Comparable to CEA-708 as constrained by FCC 47CFR79.102

4. © 2012 SMPTE · The 2012 Annual Technical Conference & Exhibition · www.smpte2012.org Development History Subtitle design started in early 2009 DVB Subpictures first considered W3C TTML (known as DFXP then) proposed in late 2009 SMPTE-TT (with TTML) decided in early 2010 W3C TTML published in late 2010 SMPTE-TT published in late 2010 Refinements and constraints developed since

5. © 2012 SMPTE · The 2012 Annual Technical Conference & Exhibition · www.smpte2012.org Relationship to TTML & SMPTE-TT W3C TTML SMPTE-TT CFF-TT

6. © 2012 SMPTE · The 2012 Annual Technical Conference & Exhibition · www.smpte2012.org The Base “TT” Namespaces (1/3) W3C TTML –Designed to be general purpose for many use cases, not just subtitles and captions –A rich design destined to be subsetted for applications SMPTE-TT Extensions –Images –Metadata

7. © 2012 SMPTE · The 2012 Annual Technical Conference & Exhibition · www.smpte2012.org The Base “TT” Namespaces (2/3) SMPTE-TT Extensions – Images –Definition inline in the document or by external URI –PNG format –Inline encoding via “Base64” –Attributes to insert in a region and define justification

8. © 2012 SMPTE · The 2012 Annual Technical Conference & Exhibition · www.smpte2012.org The Base “TT” Namespaces (3/3) SMPTE-TT Extensions – Metadata –General metadata defined for television caption conversion: Source format (e.g. “CEA-608”) Conversion attributes –General data carriage Inline encoding via “Base64” Used for “tunneling” data (e.g. exact original CEA- 608 data byte pairs)

9. © 2012 SMPTE · The 2012 Annual Technical Conference & Exhibition · www.smpte2012.org CFF-TT Extension cff:forcedDisplayMode –Support for “forced” subtitles Even when subtitle track is not enabled, some special case text/images are displayed

10. © 2012 SMPTE · The 2012 Annual Technical Conference & Exhibition · www.smpte2012.org Example XML … This subtitle text is always displayed even when the subtitle track is not selected. …

11. © 2012 SMPTE · The 2012 Annual Technical Conference & Exhibition · www.smpte2012.org Profiles Text –708 FCC subset functionality –Well-defined Unicode for most Western languages –No image support Image –SMPTE-TT PNG file support Mainly intended for font glyphs –No text support

12. © 2012 SMPTE · The 2012 Annual Technical Conference & Exhibition · www.smpte2012.org Constraints - General Some TTML infrastructure complexity not needed to meet requirements Root container = video track width and height Only 4 Active Regions maximum within root container Simplified attribute syntax and semantics –e.g. media timebase, text metrics Detailed Rendering Model –Maximum document size –Character and Image buffer model –Character and Image rendering throughput

13. © 2012 SMPTE · The 2012 Annual Technical Conference & Exhibition · www.smpte2012.org Constraints – Text Profile (all image-related attributes and elements forbidden) Anamorphic text forbidden Blurred text forbidden

14. © 2012 SMPTE · The 2012 Annual Technical Conference & Exhibition · www.smpte2012.org Constraints – Image Profile (all text-related attributes and elements forbidden)

15. © 2012 SMPTE · The 2012 Annual Technical Conference & Exhibition · www.smpte2012.org Further Reading DECE CFF Specification –http://www.uvvu.com/uv-for-business.php SMPTE-TT PDA –https://www.smpte.org/PDA_On-demand/SMPTE-TT SMPTE-TT Standards Overview –https://www.smpte.org/sites/default/files/st2052-0- 2010.pdf W3C TTML 1.0 2 nd Edition (draft) –http://dvcs.w3.org/hg/ttml/raw- file/tip/ttml10/spec/ttaf1-dfxp.html

16. © 2012 SMPTE · The 2012 Annual Technical Conference & Exhibition · www.smpte2012.org Author - Michael Dolan, TBT –DECE Technical Working Group Co-Chair –Member of SMPTE 24TB and W3C TTWG –mailto:mdolan@newtbt.com Questions? The End