Re: Action item. definition and use of Clean audio in European television

On Sun, May 15, 2011 at 11:25 AM, Janina Sajka <> wrote:
> Amazing how much easier it is to find information when you can search on
> the name everyone else has been using! Thanks, Sean, for ferreting out
> this critical datum.
> Yes, I believe we should adjust our docs and requests. No reason to go
> against the flow.

OK, I've done it in our wiki page with the requirements.

We should discuss again whether we want it in the list of @kind names
given this different situation.

> With respect to independently adjusting volume of channels (or their pan
> positions, etc), may I suggest we've asked for that in our User
> Requirements?
>     * (DV-5) Allow the author to independently adjust the volumes of
>     * the audio description and original soundtracks.
>          * (DV-6) Allow the user to independently adjust the volumes of
>          * the audio description and original soundtracks, with
>                 the user's settings overriding the author's.
>                                  * (DV-8) Allow the author to provide * fade and pan controls to be
>                                  * accurately synchronised with the * original soundtrack.
>     * (DV-11) Support the simultaneous playback of both the described * and non-described audio tracks so that one may be
>            directed at separate outputs (e.g., a speaker and headphones).

Well, we have asked for it for audio descriptions. With clean audio,
our description is about multi-channel, but our requirements about
multi-track.We have made sure to achieve separate control for
multi-track. However, when it is in multi-channel data, there is no
access to individual channels and it would be rather difficult to
build that into the media elements.

However, we have the Web Audio API, which indeed exposes individual
channels to Javascript. So, we can do all of the fancy channel-based
manipulation through the Web Audio API.

If we want to have it additionally as a separate track type (@kind), I
would almost suggest to just call it "speech", because that's what it
is according to the DVB spec: the speech-only provided as separate
data with a possibility to increase its gain independently from the
other channels.


Received on Sunday, 15 May 2011 02:06:52 UTC