RE: A new proposal for how to deal with text track cues

Hi Silvia,

Thanks for your email... I've commented in-line below. (>>)

As I state below, please do not misunderstand, I am not against the implementation of another subtitle / caption *output* format. I am concerned however about an output format that seeks to 'gloss over' the potential inadequacies of the caption / subtitle authoring. Captions and subtitles should never be considered 'second rate' ancillary content that can be fixed up by a 'clever' browser. For accessibility there is a clear ethical desire to have the best authored content. For translation, (where as much as 90% of the audience may need a quality translation experience) the commercial driver for high quality subtitles is even more important. Garbage in , garbage out. My primary concern with WebVTT is that far too much attention is being paid to supporting a 'garbage in' mentality.

Best regards,
John

John Birch | Strategic Partnerships Manager | Screen
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P Before printing, think about the environment-----Original Message-----
From: Silvia Pfeiffer [mailto:silviapfeiffer1@gmail.com]
Sent: 14 June 2013 11:14
To: John Birch
Cc: Glenn Adams; public-tt
Subject: Re: A new proposal for how to deal with text track cues

Hi John,

On Thu, Jun 13, 2013 at 1:30 AM, John Birch <John.Birch@screensystems.tv> wrote:
> Hmmm... I don't know where to start with this one. The following comments may seem harsh, but they do reflect my **personal** perspective of WebVTT.

It is indeed sad that there is so much misinformation about VTT out there and so much prejudice. Hopefully I can help to clarify some aspects here.

> Email threads can only go so far... and promoting a half-finished strawman as a standard and inviting people to comment / fix it does not seem to be an efficient route to a clear and effective standard either?

Be honest to yourself: how much further is TTML? It doesn't have a rendering algorithm yet, it doesn't have a JavaScript API that browsers would need to implement it properly (so application developers can manipulate the format), it still has bugs that prevent interoperable implementations in details. WebVTT even has a validator:
http://quuz.org/webvtt/.

>>TTML is a **markup** language. It is intended to contain the necessary structure to convey the intention of an author as to how text should appear timed against external content. It does NOT define a specific rendering implementation, the referenced rendering aspect is illustrative of the specification, and any rendering implementation is permitted. This has been the case since inception (over 10 years). It has been unequivocal how TTML should be interpreted, (barring a few corner cases that are well documented and will be resolved in the next edition). BTW. SMPTE-TT has more to say about practical rendering implementations in the captioning sense than TTML. For many of the use cases that TTML was intended, it is much further along than WebVTT. It has formed the base for many other standards.

Please don't get me wrong: I'm not trying to attack TTML - HTML is another example of a format that continues to change. I'm just trying to put this statement into perspective. All formats always evolve to support more features. Bugs continue to be found and fixed. That doesn't mean that the format is a "half-finished strawman", which, incidentally, is rather derogatory language and doesn't sound very welcoming to anyone trying to work with WebVTT .

>> I stand by my ("half-finished strawman") statement. I have followed the public **incremental** development of the WebVTT standard. I have had no inclination to attempt implementation against a moving target. All formats do not evolve to support more features. The better the requirements analysis and scoping phase is, the less radical evolution is required in the specification. Writing the spec should be the easy part - working out what to put in it is the difficult trick. By comparison to WebVTT, TTML had a long gestation, but the published standard was IMHO clearer and has certainly not evolved so much since publication.

> (Especially when there are other open public standards that may be
> more advanced in progress and may have followed a more conventional
> route?)

The route in which standards are created has nothing to do with the quality of the outcome. Many de-facto standards and industry standards were created over the years that are of high quality, and many specifications that "real standards bodies" following "real standardisation processes" have created have come out bloated and unusable and were never implemented.
>> I don't disagree. But my comment was more about why it seemed necessary to develop a standard that effectively contests some of the same space as TTML? Especially when TTML was already well formed and published at the time that WebVTT was conceived? If WebVTT had been positioned and defined as a rendering environment for TTML (which is now being discussed) we would not be having this discussion.

> RE: lack an evident appreciation of current captioning /subtitling workflows and conventions.
> There seems to be no cognisance of the wider community of captioning / subtitling... no sense of how WebVTT content might be created by conversion from other formats (like 608/708, or from Teletext etc).

You may have missed that there is an actual spec for this:
https://dvcs.w3.org/hg/text-tracks/raw-file/default/608toVTT/608toVTT.html
Other conversions are planned, but have not been required yet.

>> I must have missed the announcement last week! ;-) BTW, from an admittedly cursory look I have reservations about mapping 608 row positions to (recurring) fractional percentages. The potential problems this can create is one of the reasons why the TTML standard includes a cell positioning concept.

> There does not seem to be a huge awareness of the role of a professional captioner or subtitler. Or of the role of commercial subtitling and captioning organisations, or of the existence of (internal) quality standards for caption / subtitling services that are adopted (insisted upon) by those organisations.
> The professional captioning and subtitling profession is largely ignorant of WebVTT.

If this statements implies that professional captioning and subtitling organisations are ignoring WebVTT, then you may have overlooked that some are already supporting it and others are keeping a close eye.
They don't seem to be making a big fuss about it though. For example:

http://www.cpcweb.com/webcasts/webcast_samples.htm#WebVTT
http://www.automaticsync.com/captionsync/captionsync-delivers-webvtt-output/
http://www.synchrimedia.com/
http://www.longtailvideo.com/support/jw-player/29360/basic-vtt-captions/
http://www.wowza.com/forums/content.php?498-How-to-stream-WebVTT-subtitles-to-iOS-for-closed-captioning

>> Most of the organisations you mention are not captioning or subtitling companies operating in the TV / Film / Content creation marketplace. They are mostly organisations involved in the **redistribution** of media (excluding CPC). Captioning and subtitling (as creative activities) takes place at (or on behalf of) content owners / creators as well as at re-distributors. It is this former (professional level) authoring community that I do not believe WebVTT is connected with.

> IMHO to be adoptable by the commercial / professional community:
>
> WebVTT (as a standard) needs to:
>         clearly and directly express the professional author's intent (not indirectly).
>         support current conventions (positioning, style, timing).
>         result in implementations that allow content to be identically displayed regardless of which implementation is rendering it.

Agreed (though I don't know what you mean by "indirectly expressing author's intent"). WebVTT as it is specified does all these things, minus bugs.
>>Captions should be positioned, styled and timed using a concise, structured and partitioned framework. It should not be necessary to have an in depth knowledge of an arcane set of rules in order to achieve these requirements.

Hope this clarifies some of the misunderstandings that this group has with WebVTT.
>> My biggest reservations about WebVTT are that it appears that it is being promoted as a container for subtitling and caption content at the **authoring and archive** level. In truth I have no problem with WebVTT as a delivery format to be interpreted by a browser or agent, although clearly I would prefer that there was only one such format. However, WebVTT is late in the game, and it does not IMHO address the requirements of authoring and archive. This may be due to a lack of appreciation of the number of phases that subtitle and caption content goes through in a 'professional' broadcast environment. Like video, subtitles and captions exist in different 'silos' and are transformed (often repeatedly) depending on the final target application. The US captioning model (that of captioning near output or creating caption master tapes) is NOT representative of captioning globally, nor is it at all representative of subtitling (multiple language translation) workflows. I hope that clarifies my reservations about WebVTT.

Best Regards,
Silvia.



> Best regards,
> John
>
> John Birch | Strategic Partnerships Manager | Screen Main Line : +44
> 1473 831700 | Ext : 270 | Direct Dial : +44 1473 834532 Mobile : +44
> 7919 558380 | Fax : +44 1473 830078 John.Birch@screensystems.tv |
> www.screensystems.tv | https://twitter.com/screensystems
>
> Visit us at
> Broadcast Asia 2013, 18 - 21 June 2013, Booths 5E4-01 & 5E4-02, UK
> Pavillion, Marina Bay Sands, Singapore
>
>
> P Before printing, think about the environment-----Original
> Message-----
> From: Silvia Pfeiffer [mailto:silviapfeiffer1@gmail.com]
> Sent: 12 June 2013 14:06
> To: John Birch
> Cc: Glenn Adams; public-tt
> Subject: Re: A new proposal for how to deal with text track cues
>
> On Wed, Jun 12, 2013 at 10:50 PM, John Birch <John.Birch@screensystems.tv> wrote:
>> I'm not personally over concerned with where or who does this kind of
>> work, but am far more concerned with how it is done.
>>
>>
>>
>> For me, a process that involves substantial requirements analysis
>> performed with the involvement of all potentially interested parties
>> seems far more likely to result in a workable specification.
>
> Agreed. That's what the email threads are after.
>
>
>> If WebVTT is targeted at commercial use cases, it does IMHO seem to
>> lack an evident appreciation of current captioning /subtitling
>> workflows and conventions.
>
> Please explain. What workflows and conventions does WebVTT break?
>
> Best Regards,
> Silvia.
>
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This message may contain confidential and/or privileged information. If you are not the intended recipient you must not use, copy, disclose or take any action based on this message or any information herein. If you have received this message in error, please advise the sender immediately by reply e-mail and delete this message. Thank you for your cooperation. Screen Subtitling Systems Ltd. Registered in England No. 2596832. Registered Office: The Old Rectory, Claydon Church Lane, Claydon, Ipswich, Suffolk, IP6 0EQ

Received on Friday, 14 June 2013 11:37:57 UTC