IMSC 1 Implementation Report

Introduction

This implementation report is now frozen and closed.

Please refer to the IMSC1 Test suite and implementation page for current information.

The following is the implementation report for the IMSC 1 specification based on the IMSC 1 test suite.

This implementation report is used to demonstrate implementation experience for IMSC 1 transition to Proposed Recommendation.

IMSC1 introduces extensions to TTML1, as well as incorporates extensions specified in ST2052-1 and EBU-TT-D. Tests cover every feature defined in IMSC1 not already present in TTML1. Refer to the list of extensions added in IMSC1 in section 6.7, section 6.10, section 7.4, section 8.4 and in Appendix F. [http://www.w3.org/TR/ttml-imsc1/#features-and-extensions

Tests are listed in the table below.

Do not hesitate to direct questions and/or results to the IMSC1 Editor (Pierre-Anthony Lemieux <pal@sandflow.com>) and/or the TTWG mailing list [1] with [imsc] at the start of your email's subject.

Tests

Test	Features	Description	Companies/Implementations
			Company-1	GStreamer Prototype (BBC R&D)	Green International Consulting (GIC) <henry.gu at giconline.net>	castLabs GmbH	SKYNAV
			Implementation-1	Implementation-2	Implementation-3	castLabs Android Player SDK (v2)	TTV, TTX, TTXV
Synchronization (Section 6.6)
frameSync1.ttml	Text Profile	When played against a 24 fps related video object (see [2] for example), each subtitle should appear on the frame specified in its text, with frame 0 corresponding to the related video object frame at t=0s within the instance document timeline.	FAIL	Not tested	Not tested	PASS	PASS
ittp:aspectRatio (Section 6.7)
aspectRatio1.ttml	Text Profile, ittp:aspectRatio	Maintains 4:3 aspect ratio when rendering the caption	PASS	Not tested	Not tested	PASS	PASS
aspectRatio2.ttml	Text Profile, ittp:aspectRatio	Maintains 16:9 aspect ratio when rendering the caption	PASS	Not tested	Not tested	PASS	PASS
aspectRatio3.ttml	Image Profile, ittp:aspectRatio	Maintains 4:3 aspect ratio when rendering the caption	PASS	Not tested	Not tested	PASS	PASS
aspectRatio4.ttml	Image Profile, ittp:aspectRatio	Maintains 16:9 aspect ratio when rendering the caption	PASS	Not tested	Not tested	PASS	PASS
aspectRatio5.ttml	Text Profile, ittp:aspectRatio	Fills the related video object when rendering the caption	PASS	Not tested	Not tested	PASS	PASS
aspectRatio6.ttml	Image Profile, ittp:aspectRatio	Fills the related video object when rendering the caption	PASS	Not tested	Not tested	PASS	PASS
ittm:altText (Section 6.7.4)
altText1.ttml	Image Profile, ittm:altText	The contents of altText should not be displayed	PASS	Not tested	Not tested	PASS	PASS
itts:forcedDisplay (Section 6.7.3)
forcedDisplay1.ttml	Text Profile, itts:forcedDisplay	The display of one of the two captions is controlled through the displayForcedOnlyMode application parameter	Not tested	Not tested	Not tested	PASS	PASS
ebutts:linePadding (Section 7.4 - Extensions)
linePadding1.ttml	Text Profile, ebutts:linePadding	See Annex D at https://tech.ebu.ch/docs/tech/tech3380.pdf The rendered captions should match linePadding1_16x9.png assuming a 16:9 ratio root container or linePadding1_4x3.png for a 4:3 root container; the font does not need to be identical.	FAIL	PASS	Not tested	PASS	PASS
ebutts:multiRowAlign (Section 7.4 - Extensions)
multiRowAlign1.ttml	Text Profile, ebutts:multiRowAlign	See Annex C at https://tech.ebu.ch/docs/tech/tech3380.pdf The rendered captions should match multiRowAlign1_16x9.png assuming a 16:9 ratio root container or multiRowAlign1_4x3.png for a 4:3 root container; the font does not need to be identical.	FAIL	PASS	Not tested	PASS	PASS
ittp:progressivelyDecodable (Section 6.7.2)
progressivelyDecodable1.ttml	Text Profile, ittp:progressivelyDecodable	The presence of the ittp:progressivelyDecodable parameter should not affect rendering	PASS	Not tested	Not tested	PASS	PASS
Reference Fonts (Section 7.3)
referenceFonts1.ttml	Text Profile, Reference Fonts	The rendered captions should match referenceFonts1-reference.png	FAIL	Not tested	Not tested	PASS	PASS
Maximum rate subtitles (640px x 480px) created from Solekai022_854_29_640x75_MaxSdSubtitle_v7_subtitles (Section 8.4 - Extension @)
track5-frag0-sample1-subs0.ttml	Image Profile	[3]	Not tested	Not tested	Not tested	PASS	PASS
track5-frag1-sample1-subs0.ttml	Image Profile	[4]	Not tested	Not tested	Not tested	PASS	PASS
track5-frag2-sample1-subs0.ttml	Image Profile	[5]	Not tested	Not tested	Not tested	PASS	PASS
track5-frag3-sample1-subs0.ttml	Image Profile	[6]	Not tested	Not tested	Not tested	PASS	PASS
track5-frag4-sample1-subs0.ttml	Image Profile	[7]	Not tested	Not tested	Not tested	PASS	PASS
track5-frag5-sample1-subs0.ttml	Image Profile	[8]	Not tested	Not tested	Not tested	PASS	PASS
track6-frag0-sample1-subs0.ttml	Text Profile	[9], view results in video	Not tested	Not tested	PASS	PASS	PASS
Maximum rate subtitles (1920px x 1080px) created from Solekai023_1920_23_1x1_MaxHdSubtitle_v7_subtitles (Section 8.4 - Extension @)
track5-frag0-sample1-subs0.ttml	Image Profile	[10]	FAIL	Not tested	Not tested	PASS	PASS
track5-frag1-sample1-subs0.ttml	Image Profile	[11]	FAIL	Not tested	Not tested	PASS	PASS
track5-frag2-sample1-subs0.ttml	Image Profile	[12]	FAIL	Not tested	Not tested	PASS	PASS
track6-frag0-sample1-subs0.ttml	Text Profile	[13], view results in video	FAIL	Not tested	PASS	PASS	PASS

NOTE: The complete test suite contributed by DECE, translated to IMSC1, is available at [14]. The corresponding test procedures are located at [15].