Initialization Segment: Ftyp compatibility

haudiobe commented 4 years ago

John Simmons: The language about the file type box containing a major_brand or compatibility _brand the user agent does not support should include, for CMAF, a structural brand the user agent does not support.

haudiobe commented 4 years ago

I believe this is a mix of CMAF structural brands and the fields in the ISO BMFF. So I do not agree on that one to be changed.

haudiobe commented 4 years ago

ISO BMFF byte stream format is wrong, should only throw error if none of the brands are supported/understood.
throw an error if none of the structural brands are present (but they are not mandated)
difficult to say anything

Example

only iso6 brand present (but the file track conforms to CMAF) => browser only supports CMAF
only cmfc brand present (but the file track conforms to ISO6) => browser only supports ISO6

Would be good that user agent shall support the following brands. Does a browser support the profiles parameter in the RFC6381 mimeType? Media Capabilities: anything about brands?

The existing text is wrong, so we do not inherit this, but are silent for now. We add a note addressing the issue. Bring this to the attention of W3C.

haudiobe commented 4 years ago

(2020/05/05 CTA WAVE): Ask Cyril for comments

haudiobe commented 4 years ago

Nothing needs to be done. If you believe differently, please speak up.

cta-wave / CMAF-Byte-Stream

Initialization Segment: Ftyp compatibility #2