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14. Changes from RFC 3984

14. Changes from RFC 3984​

Following is the list of technical changes (including bug fixes) from RFC 3984. Besides this list of technical changes, numerous editorial changes have been made, but not documented in this section. Note that Section 8.2.2 is where much of the important changes in this memo occurs and deserves particular attention.

  1. In Sections 5.4, 5.5, 6.2, 6.3, and 6.4, removed that the packetization mode in use may be signaled by external means.

  2. In Section 7.2.2, changed the sentence

    There are N VCL NAL units in the de-interleaving buffer.

    to

    There are N or more VCL NAL units in the de-interleaving buffer.

  3. In Section 8.1, the semantics of sprop-init-buf-time (paragraph 2), changed the sentence

    The parameter is the maximum value of (transmission time of a NAL unit - decoding time of the NAL unit), assuming reliable and instantaneous transmission, the same timeline for transmission and decoding, and that decoding starts when the first packet arrives.

    to

    The parameter is the maximum value of (decoding time of the NAL unit - transmission time of a NAL unit), assuming reliable and instantaneous transmission, the same timeline for transmission and decoding, and that decoding starts when the first packet arrives.

  4. Added media type parameters max-smbps, sprop-level-parameter-sets, use-level-src-parameter-sets, in-band-parameter-sets, sar-understood, and sar-supported.

  5. In Section 8.1, removed the specification of parameter-add. Other descriptions of parameter-add (in Sections 8.2 and 8.4) were also removed.

  6. In Section 8.1, added a constraint to sprop-parameter-sets such that it can only contain parameter sets for the same profile and level as indicated by profile-level-id.

  7. In Section 8.2.1, added that sprop-parameter-sets and sprop-level-parameter-sets may be either included in the a=fmtp line of SDP or conveyed using the fmtp source attribute as specified in Section 6.3 of [9].

  8. In Section 8.2.2, removed sprop-deint-buf-req from being part of the media format configuration in usage with the SDP Offer/Answer model.

  9. In Section 8.2.2, made it clear that level is downgradable in the SDP Offer/Answer model, i.e., the use of the level part of profile-level-id does not need to be symmetric (the level included in the answer can be lower than or equal to the level included in the offer).

  10. In Section 8.2.2, removed that the capability parameters may be used to declare encoding capabilities.

  11. In Section 8.2.2, added rules on how to use sprop-parameter-sets and sprop-level-parameter-sets for out-of-band transport of parameter sets, with or without level downgrading.

  12. In Section 8.2.2, clarified the rules of using the media type parameters with SDP Offer/Answer for multicast.

  13. In Section 8.2.2, completed and corrected the list of how different media type parameters shall be interpreted in the different combinations of offer or answer and direction attribute.

  14. In Section 8.4, changed the text such that both out-of-band and in-band transport of parameter sets are allowed, and neither is recommended or required.

  15. Added Section 8.5 (informative) providing example methods for decoder refresh to handle parameter set losses.

  16. Added media type parameters max-recv-level and level-asymmetry-allowed and adjusted associated text and examples for level upgrade and asymmetry.

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