[gst-devel] IEC958 caps

[pl bossart]

Hi,
some HDMI implementations can use the EDID information to find out
what is supported by the audio receiver. The idea is that a sanity
check is run before actually playing, to make sure a given stream is
supported downstream. One issue with gstreamer is that such a check
isn't really possible: even though some existing elements support
IEC958 formats, such as ac3iec958 and alsasink, they all rely on the
same "audio/x-iec958" capability. Nice, but limited, since the actual
payload format is lost. There's no way to signal that the data is
actually an AC3, E-AC3, DTS or MPEG format, and as a consequence no
means for the sink to check it can actually handle the data.

So the question is: how does one go about extending capabilities? Can
I just go ahead and define new fields, eg "audio/x-iec958,
payload=<val>", using the values defined by the IEC or CEA standards?
Or do I need a new cap per format such as "audio/x-iec958-eac3"? Or
are the capabilities listed somewhere in some central location to
ensure consistency?
Thanks for your time,
-Pierre