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Is there a specification? I think "de facto standard" is a more appropriate phrase for Flash.
by pohl 17y ago
Is there a specification?
I think "de facto standard" is a more appropriate phrase for Flash.
- vetinari 17y agoYes, there is (http://www.adobe.com/devnet/swf/ http://www.adobe.com/devnet/swf/). It is even available gratis (H.264 specification is not).
- blasdel 17y agoFlash isn't an open standard by any useful definition. Sure they specified the container format and data structures (just like with the MS Office formats), but everybody had figured that part out a long time ago because it's obvious and easy to capitalize on by developing an extractor. The runtime APIs are incredibly hard to reverse-engineer, comprise the vast bulk of the Flash implementation, and are the entire reason for the plugin's instability.
- kierank 17y agoH.264 specification is available gratis: http://www.itu.int/rec/T-REC-H.264-200903-S/en http://www.itu.int/rec/T-REC-H.264-200903-S/en
- vetinari 17y agoI stand corrected, thanks.
- pohl 17y agoInteresting, but I don't see how one could create a complete implementation without a spec for the Sorensen Spark codec.
- wmf 17y agoSorenson Spark == H.263 (not a typo), which is documented. The problem with Flash is VP6, although FFMPEG reverse engineered it.
- vetinari 17y agoActually, it is based on a draft h.263, not the final h.263. One of the older flash specification did document it. The svq3 specification was removed from swf specs around time it was made available under more liberal license (Sorenson probably didn't agree with wider specs availability).
- kierank 17y agoFFmpeg has reverse engineered it and there is an open source decoder and some documentation.