26345 2014-07-15 23:02:06 +0000 [MSE] order of activeSourceBuffers underspecified 2014-07-24 20:13:34 +0000 1 1 1 Unclassified HTML WG Media Source Extensions unspecified PC All RESOLVED FIXED P2 normal CR 1 jer.noble acolwell acolwell mike public-html-media public-html-bugzilla oldest_to_newest 108975 0 jer.noble 2014-07-15 23:02:06 +0000 2.1 Attributes, activeSourceBuffers "activeSourceBuffers of type SourceBufferList, readonly Contains the subset of sourceBuffers that are providing the selected video track, the enabled audio track(s), and the "showing" or "hidden" text track(s)." The order of entries in the SourceBufferList are underspecified. Intuitively, activeSourceBuffers should have the same order as sourceBuffers, but a naive implementation may order them depending on what SourceBuffer reached a "Add the SourceBuffer to activeSourceBuffers" step first. 109249 1 acolwell 2014-07-24 17:46:54 +0000 Why does order matter here? I don't particulary object to mandating that the order match sourceBuffers, but I don't really understand why it matters. Won't the application always have to manually inspect the lists if sourceBuffers.length != activeSourceBuffers.length? Why let the application treat the == case differently? 109251 2 jer.noble 2014-07-24 17:50:47 +0000 (In reply to Aaron Colwell from comment #1) > Why does order matter here? Well, honestly, because WebKit's implementation fails some of the proposed W3C Media Source testsuite tests which expect a particular order. Specifically, the mediasource-buffered.html will fail if the order of activeSourceBuffers is not the same as sourceBuffers. 109252 3 jer.noble 2014-07-24 17:53:09 +0000 Also, the general trend toward array-like objects in W3C specs, and particularly in the Text Track specs, has been to give those arrays an explicit, deterministic order. 109253 4 acolwell 2014-07-24 17:58:44 +0000 Ok. Fair enough. I'll make the change. Thanks for your input. 109263 5 acolwell 2014-07-24 20:13:34 +0000 Change committed. https://dvcs.w3.org/hg/html-media/rev/13056a200b38