I am the assigned Gen-ART reviewer for this draft. For background on Gen-ART, please see the FAQ at < http://wiki.tools.ietf.org/area/gen/trac/wiki/GenArtfaq>. Please wait for direction from your document shepherd or AD before posting a new version of the draft. Document: draft-ietf-codec-opus-14 Reviewer: Elwyn Davies Review Date: 3 June 2012 IETF LC End Date: IESG Telechat date: 7 June 2012 Summary: As far as the textual part of the document is concerned this version addressed my last call comments and apparently adequately describes the structure of the codec. My review at last call was concentrated on this textual part and I did not have time to significantly dip into the large body of code that makes up the normative part of the draft. I cannot therefore say that there is an exact correspondence between the description and the code, but the description does seem to give a good view (significantly better then before Last Call IMO) of the way the codec operates. I would like to thank the authors for the speedy and effective way that they addressed the comments that I made - to an uninformed neophyte in codecs this seems to be an excellent piece of work. Having had a little time to dip into code since doing the last call, the one serious comment that I would make is that it is a great pity that the code did not incorporate Doxygen or similar code documentation comments. Being able to extract a Doxygen comment document would significantly enhance the understandability of some very complex code and potentially allow the code to be tied back to the textual comments in a way that would (I suspect) help future implementors trying to generate alternative versions. I appreciate that is a lot of work at this late stage but it would help a lot. Regards, Elwyn Davies