Still about "id" format

On Wed, Nov 13, 2013 at 6:03 AM, Jon Piesing <Jon.Piesing@tpvision.com>wrote:

>  Brendan,
>
> > MPEG-2 TS
> > readonly attribute DOMString id;
> > The contents of the component_tag  field in the
> stream_identifier_descriptor in PMT.
> > This seems like an odd choice. Why not the PID?
>
> In DVB networks, my (limited) understanding is that PIDs are changed as a
> TS passes through the distribution network but component tags remain
> unchanged. Certainly if you look in the DVB-SI specification, references
> from descriptors to elementary streams normally use a component tag and not
> a PID.
>
>
I think this discussion raises two questions:

- what is the use case we are trying to address by exposing these info via
the track ID attribute? Is the only think we care is to have something that
unique locally to the application (in that case it may not matter much if
the PID changes along the broadcast value chain as far as each track as a
unique PID at the end) or are we trying to convey some other type of
information?

- depending on the answer above, do we also need to consider regional
variations of the standards?

/g