Re: Sourcing language information for media tracks

I'd actually be quite happy if somebody else took over as editor -
it's not been looked after well in the past.
Sergey - since you're working on it, could you spend some time
updating that spec also?

It's part of a community group, where change discussions usually
happen: https://www.w3.org/community/inbandtracks/
Also note: https://www.w3.org/community/inbandtracks/wiki/Main_Page .

Hope it finds some kind hands to work on!

Cheers,
Silvia.


On Tue, Mar 15, 2016 at 7:04 PM, Philip Jägenstedt <philipj@opera.com> wrote:
> I see, can you link to the repo from the spec itself?
>
> On Sat, Mar 12, 2016 at 4:19 AM, Silvia Pfeiffer <silviapfeiffer1@gmail.com>
> wrote:
>>
>> https://github.com/w3c/HTMLSourcingInbandTracks
>>
>> It's been there forever and maintained there also.
>>
>> Best Regards,
>> Silvia.
>>
>> On 11 Mar 2016 10:29 PM, "Yosuke Funahashi" <yosuke@w3.org> wrote:
>>>
>>> I can set up a Github repo for this spec under the W3C account If you
>>> prefer.
>>>
>>> Yosuke
>>>
>>> On 3/11/16 5:53 PM, Philip Jägenstedt wrote:
>>>>
>>>> Silvia, any chance of maintaining this spec on GitHub so that you can
>>>> accept
>>>> PRs? Not that I'm volunteering, of course, but this seems like the kind
>>>> of thing
>>>> where it'd be appropriate :)
>>>>
>>>> On Fri, Mar 11, 2016 at 8:26 AM, Sergey Volk <servolk@chromium.org
>>>> <mailto:servolk@chromium.org>> wrote:
>>>>
>>>>     Hi,
>>>>     I've been working on adding media track support in Chromium and was
>>>>     trying to use  the spec at
>>>>     https://dev.w3.org/html5/html-sourcing-inband-tracks/ for reading
>>>>     various media track properties.
>>>>     I've ran into a few issues (see the discussion at
>>>>     https://codereview.chromium.org/1735003004/ for details):
>>>>
>>>>     1. The current draft says that for MPEG-4 ISOBMFF files the language
>>>>     for audio/video tracks should be: "Content of the language field in
>>>>     the MediaHeaderBox."
>>>>     But according to various sources (e.g.
>>>>
>>>> https://developer.apple.com/library/mac/documentation/QuickTime/QTFF/QTFFChap2/qtff2.html,
>>>>     https://www.scribd.com/doc/10911307/26/mdhd-box, etc) the language
>>>>     field in MDHD box is a zero-padded 16-bit value that encodes a
>>>>     3-letter ISO 639-2/T language code:
>>>>     3-character code specifying language(see ISO 639-2/T); each
>>>> character
>>>>     isinterpreted as 0x60 + (5 bit) code to yield an ASCII character.
>>>>     Yet according to the HTML5 spec (see
>>>>
>>>> https://html.spec.whatwg.org/multipage/embedded-content.html#dom-audiotrack-language)
>>>>     A/V track language attributes must return BCP-47 language tag
>>>> strings,
>>>>     not the 3-character ISO 639-2/T codes.
>>>>     So the inband-tracks-sourcing spec should probably mention that the
>>>>     language read from MDHD.language field needs to be translated into
>>>>     BCP-47.
>>>>
>>>>     2. Again, according to multiple sources on the internet (for example
>>>>     see
>>>>
>>>> https://developer.apple.com/library/mac/documentation/QuickTime/QTFF/QTFFChap2/qtff2.html).
>>>>     There is a new way to specify language info for media tracks in MP4
>>>>     files, see the 'Extended Language Tag Atom' section in the link
>>>> above.
>>>>     The ELNG box is optional, but when present it will have a BCP-47
>>>>     language info. So when the ELNG box is present in the .mp4 file, it
>>>>     should probably be preferred over the language field of MDHD box.
>>>>
>>>>
>>>
>>> --
>>> Yosuke Funahashi
>>> Web and TV IG co-chair, Entertainment vertical champion,
>>> HTML Media Extensions WG team contact at W3C
>>> Project Associate Professor at Keio University
>
>

Received on Tuesday, 15 March 2016 09:25:51 UTC