Hi Dale, On Tue, Oct 12, 2021 at 8:53 PM Dale R. Worley <worley@xxxxxxxxxxx> wrote: > > It looked like there was some controversy about this, so I decided to > take a look. It does seem to me that if it wants to claim an IETF mime > type rather than a vnd. one, at the least the exposition needs to be > clarified. > > The introduction of the draft itself references various features of the > encoding but seems to be more oriented toward the connoisseur of image > encoding formats than users. The documents are wishy-washy regarding > compatibility and extensibility, as if these are current snapshots of > something that is expected to evolve organically. > > For instance, section 4 "Interoperability Considerations" includes "The > container is RIFF-based and allows extension via user defined chunks" > but does not mention this statement in the referenced document: "Older > readers may not support files using the lossless format." > > If we aren't just assigning a code for a vendor's product, we need to > put a stake in the ground that is definitive what the format is and > isn't, that we expect to stay in the same place for at least five years. > The format is finalized. Lossless and animation were added in 2012 [1] and 2013 [2], respectively. The comment is in reference to older Android releases [3] as those features were being rolled out. RIFF as a container is extensibile, but that would be done at an application level and wouldn't affect the implementation of the frame's compression. The core chunks to the format are stable and will not be changed. [1] https://chromium.googlesource.com/webm/libwebp/+/refs/tags/v0.2.0/NEWS [2] https://chromium.googlesource.com/webm/libwebp/+/refs/tags/v0.3.0 [3] https://developer.android.com/guide/topics/media/media-formats#image-formats > Dale -- last-call mailing list last-call@xxxxxxxx https://www.ietf.org/mailman/listinfo/last-call
