24895 2014-03-03 00:36:03 +0000 Be explicit in dealing with UA preference settings for audioTracks and videoTracks 2014-04-27 01:00:08 +0000 1 1 1 Unclassified WHATWG HTML unspecified PC All RESOLVED FIXED P2 normal Unsorted 24859 1 silviapfeiffer1 ian cyril.concolato hbbtvjon ian mike pal contributor oldest_to_newest 101733 0 silviapfeiffer1 2014-03-03 00:36:03 +0000 UAs want to introduce settings to pre-activate audioTracks and videoTracks, e.g. to always have an "audio description" audio track enabled in parallel to the default audio track (AudioTrack.kind()="descriptions"), or to always pick the video track with burnt in captions over the "main" video track (VideoTrack.kind()="captions"), or to auto-activate the audio track with the correct dubbing (AudioTrack.kind()="translation"). The spec currently does not mention this possibility and does not deal well with it. In the section that describes the tasks to do after media fetch (in point 4 of [1]) it says: "If either the media resource or the address of the current media resource indicate a particular set of audio or video tracks to enable, then the selected audio tracks must be enabled in the element's audioTracks object, and, of the selected video tracks, the one that is listed first in the element's videoTracks object must be selected. All other tracks must be disabled." So, the possibility of the browser enabling specific audio or video tracks from UA preferences doesn't seem to be taken care of. I think it would be worth adding another step after step 11, something similar to what is in the text track section. E.g. "If the user has expressed an interest in having an audio or video track enabled based on its kind, language, or label, then the selected audio tracks must be enabled in the element's audioTracks object, and, of the selected video tracks, the one that is listed first in the element's videoTracks object must be selected." [1] http://www.whatwg.org/specs/web-apps/current-work/#concept-media-load-resource 101751 1 hbbtvjon 2014-03-03 09:10:51 +0000 As the originator of #24859, this issue is not just about the user expressing an interest. There may be audio tracks which differ only by the number of channels (stereo, 5.1, 7.1) but are otherwise equivalent. There may be audio and video tracks which differ only by the codec. e.g. AVC vs HEVC for video and HE-AAC vs Dolby vs DTS for audio. It should be clear if the UA can choose between these based on the characteristics of the device without user input. The quoted language in the spec can be reasonably be interpreted as excluding the UA making these kind of choices as well. 101764 2 ian 2014-03-03 18:53:32 +0000 Yeah we can add something to step 11 there that more explicitly allows the user agent to apply some intelligence to the track selection. (My intent was that "the media resource ... indicate[s] a particular set" would cover this, e.g. the media says "this track is 5.1 channel, this track is 2 channel", and the user agent says "well I need the 5.1-channel version".) 102337 3 ian 2014-03-13 23:32:29 +0000 Reopen if this isn't enough. Thanks. 102338 4 contributor 2014-03-13 23:33:10 +0000 Checked in as WHATWG revision r8543. Check-in comment: Try to elaborate on why the UA might pick particular media tracks http://html5.org/tools/web-apps-tracker?from=8542&to=8543 102549 5 hbbtvjon 2014-03-18 11:31:20 +0000 Reopened as we think that the proposed wording could be improved. The proposed wording is; if the user agent has information that enabled it to select specific tracks for optimal performance We think any of the following would be clearer (although we prefer the first two); 1) "if the user agent has information that enabled it to select specific tracks" (i.e. delete "for optimal performance") 2) "if the user agent has information that enabled it to select specific tracks for a better user experience" (i.e. replace "optimal performance" with "a better user experience") 3) "if the user agent has information that enabled it to select specific tracks for optimal results" (i.e. replace "performance" with "results") 102588 6 ian 2014-03-18 18:00:23 +0000 Ok, how's this?: 102589 7 contributor 2014-03-18 18:00:56 +0000 Checked in as WHATWG revision r8552. Check-in comment: Try to improve wording for track selection text. http://html5.org/tools/web-apps-tracker?from=8551&to=8552 102623 8 hbbtvjon 2014-03-19 09:25:10 +0000 Sorry but the URL doesn't work. "No result." Also the email in the commit-watchers archive says; "/home/ianh/svn/webapps/hooks/commit-email.pl: `/usr/bin/svnlook diff /home/ianh/svn/webapps -r 8552' failed with this output: svnlook: Can't write to file '/tmp/tempfile.2.tmp': No space left on device" and the version of the spec that I can see doesn't have a change (although I may be looking in the wrong place). 102801 9 silviapfeiffer1 2014-03-24 02:02:45 +0000 Jon: check again - the URL works now 103272 10 hbbtvjon 2014-04-02 13:24:30 +0000 (In reply to contributor from comment #7) > Checked in as WHATWG revision r8552. > Check-in comment: Try to improve wording for track selection text. > http://html5.org/tools/web-apps-tracker?from=8551&to=8552 That change works for us.