{"action":"opened","issue":{"url":"https://api.github.com/repos/w3c/media-source/issues/76","repository_url":"https://api.github.com/repos/w3c/media-source","labels_url":"https://api.github.com/repos/w3c/media-source/issues/76/labels{/name}","comments_url":"https://api.github.com/repos/w3c/media-source/issues/76/comments","events_url":"https://api.github.com/repos/w3c/media-source/issues/76/events","html_url":"https://github.com/w3c/media-source/issues/76","id":155131156,"number":76,"title":"VideoPlaybackQuality is underdefined, leading to interop concerns","user":{"login":"wolenetz","id":11578819,"avatar_url":"https://avatars.githubusercontent.com/u/11578819?v=3","gravatar_id":"","url":"https://api.github.com/users/wolenetz","html_url":"https://github.com/wolenetz","followers_url":"https://api.github.com/users/wolenetz/followers","following_url":"https://api.github.com/users/wolenetz/following{/other_user}","gists_url":"https://api.github.com/users/wolenetz/gists{/gist_id}","starred_url":"https://api.github.com/users/wolenetz/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/wolenetz/subscriptions","organizations_url":"https://api.github.com/users/wolenetz/orgs","repos_url":"https://api.github.com/users/wolenetz/repos","events_url":"https://api.github.com/users/wolenetz/events{/privacy}","received_events_url":"https://api.github.com/users/wolenetz/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/w3c/media-source/labels/interoperability","name":"interoperability","color":"5319e7"}],"state":"open","locked":false,"assignee":null,"milestone":{"url":"https://api.github.com/repos/w3c/media-source/milestones/2","html_url":"https://github.com/w3c/media-source/milestones/V1","labels_url":"https://api.github.com/repos/w3c/media-source/milestones/2/labels","id":1358225,"number":2,"title":"V1","description":"","creator":{"login":"jdsmith3000","id":8323871,"avatar_url":"https://avatars.githubusercontent.com/u/8323871?v=3","gravatar_id":"","url":"https://api.github.com/users/jdsmith3000","html_url":"https://github.com/jdsmith3000","followers_url":"https://api.github.com/users/jdsmith3000/followers","following_url":"https://api.github.com/users/jdsmith3000/following{/other_user}","gists_url":"https://api.github.com/users/jdsmith3000/gists{/gist_id}","starred_url":"https://api.github.com/users/jdsmith3000/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/jdsmith3000/subscriptions","organizations_url":"https://api.github.com/users/jdsmith3000/orgs","repos_url":"https://api.github.com/users/jdsmith3000/repos","events_url":"https://api.github.com/users/jdsmith3000/events{/privacy}","received_events_url":"https://api.github.com/users/jdsmith3000/received_events","type":"User","site_admin":false},"open_issues":8,"closed_issues":17,"state":"open","created_at":"2015-10-15T21:12:39Z","updated_at":"2016-05-16T21:54:13Z","due_on":null,"closed_at":null},"comments":0,"created_at":"2016-05-16T21:54:13Z","updated_at":"2016-05-16T21:54:13Z","closed_at":null,"body":"While looking into #69, we discovered some concerns with the current specification of VideoPlaybackQuality:\r\n* The spec does not say what to do if values cannot be provided, potentially leading to interop issues and/or authors ignoring them.\r\n * For example: Firefox and Chrome always report corruptedVideoFrames as 0, meaning a value of 0 is meaningless to authors. If this value can’t be calculated by most implementations, maybe it should be removed from the spec. Otherwise, there should be a specification of how to do feature detection. For example, state that implementations should not expose an attribute it cannot support or otherwise indicate it is invalid (a nullable/optional value?).\r\n * If the implementations are inaccurate, it may be misleading authors.\r\n\r\nNote: Moving VPBQ out of MSE spec (per #69), would address this MSE bug.\r\n\r\nAs further indication that this feature is underdefined:\r\n* Is there no concern or parallel for corrupted __audio__ decode? (Perhaps this should be a MediaQualityObject.)\r\n* droppedVideoFrames covers both predecode drop and missing deadline drop:\r\n * is this distinction relevant to authors, and can all/most implementations cover both types of drops?\r\n * If not, this value would be unreliable and we need some sort of feature detection.\r\n* Optionality in whether to report corrupt frames as dropped: This allows implementation flexibility, but should implementations be consistent in reporting?\r\n"}}