Clarification about media2 AudioEncoder2Configuration

[seimonw]

I'm a little confused about the AudioEncoder2Configuration in media2.

The Profile T specification says "Encoding – The encoding used to compress audio. See the IANA MIME Type Name reference for a full list of values". And the spec links to https://www.iana.org/assignments/media-types/media-types.xhtml for a list of all of the values.

But the xsd schema restricts this to a subset of only four values. This doesn't appear to be mentioned anywhere else, I'm wondering what I should be setting it to if I'm sending G.711A / PCMA format audio?

[svefredrik]

See the annotation for AudioEncoder2ConfigurationOptions: "Audio Media Subtype for the audio format. For definitions see tt:AudioEncodingMimeNames and IANA Media Types." So basically both the IANA list and the enumarations in tt:AudioEncodingMimeNames can be used. Typically, tt:AudioEncodingMimeNames is used for special cases for backward compatiblity.

[seimonw]

Thanks. In your reply you refer to AudioEncoder2ConfigurationOptions, whereas I am looking at AudioEncoder2Configuration which has xs:restriction specified to limit it to only four options.
The annotation there says "Audio Media Subtypes as referenced by IANA (without the leading "audio/" Audio Media Type and except for the audio types defined in the restriction)". Not sure how to parse "and except for" in this context.
Are you saying that the xs:restriction shouldn't really be there?

[svefredrik]

There's a similar sentence in the annotation for Encoder in AudioEncoder2Configuration: "Audio Media Subtype for the audio format. For definitions see tt:AudioEncodingMimeNames and IANA Media Types."
https://github.com/onvif/specs/blob/22.12/wsdl/ver10/schema/onvif.xsd#L1316

[seimonw]

Ah, I see yes. The MimeTypes are restricted, but the Encoding is just a string. Thanks very much for explaining it.

[svefredrik]

Sure no problem!