- From: Steev James <steev.a.james@gmail.com>
- Date: Wed, 16 Apr 2014 22:19:05 +0530
- To: Stefan Håkansson LK <stefan.lk.hakansson@ericsson.com>
- Cc: Adam Bergkvist <adam.bergkvist@ericsson.com>, "kiran.guduru@samsung.com" <kiran.guduru@samsung.com>, "public-media-capture@w3.org" <public-media-capture@w3.org>
- Message-ID: <CAB1_PA7EdL9QvoZuhdsAVFDLOez1Q0Apszkt-K2WNTRAwcSQkw@mail.gmail.com>
+1 This change seems to be fine for me. On Wed, Apr 16, 2014 at 7:27 PM, Stefan Håkansson LK < stefan.lk.hakansson@ericsson.com> wrote: > On 16/04/14 09:51, Adam Bergkvist wrote: > > OK, let's try to get this into the spec. > > > > Since the media element resource load algorithm says that a media > > resource can indicate a set of audio and/or video tracks to enable, > > perhaps that's what we should do and nothing more. Then we would leave > > it up to the media element spec take care of the rest (setting > > AudioTrack.enabled, VideoTrack.selected and > VideoTrackList.selectedIndex). > I agree, the only thing we should change is the section: > > "Set the VideoTrackList.selectedIndex to the index of the first > VideoTrack, in the VideoTrackList, that corresponds to a > MediaStreamTrack that has readyState 'live'. If no such VideoTrack > exists, set the selectedIndex attribute to -1." > > The rest seem OK IMO. > > > > > > > /Adam > > > > On 2014-04-16 07:42, Stefan Håkansson LK wrote: > >> On 16/04/14 06:03, Kiran Kumar Guduru wrote: > >>> Samsung Enterprise Portal mySingle > >>> > >>> Some more comments regarding relation between "live" and "muted" state > >>> of a MediaStreamTrack. > >>> > >>> This has been discussed earlier in [1] and concluded that "muted" and > >>> "disabled" tracks should be considered as "live". > >>> > >>> [1] https://www.w3.org/Bugs/Public/show_bug.cgi?id=22259 > >>> > >> OK, so we should be able to use "live". > >>> ------- *Original Message* ------- > >>> > >>> *Sender* : Kiran Kumar Guduru<kiran.guduru@samsung.com> Lead > >>> Engineer/SRI-Bangalore-TZN/Samsung Electronics > >>> > >>> *Date* : Apr 16, 2014 12:32 (GMT+09:00) > >>> > >>> *Title* : Re: Re: [Bug 25275] VideoTrackList.selectedIndex > >>> initialization confilicts with HTML5 spec, "if no track is selected". > >>> > >>> Yes It is done by modifying the statement. > >>> > >>> I agree that the relation between 'live' and 'muted' is not defined in > >>> the spec. Since muted is not present in the readyState of the > >>> MediaStreamTrack, I thought that "muted" and "disabled" are part of > >>> "live" state only. > >>> > >>> ------- *Original Message* ------- > >>> > >>> *Sender* : Stefan Håkansson LK<stefan.lk.hakansson@ericsson.com> > >>> > >>> *Date* : Apr 15, 2014 22:12 (GMT+09:00) > >>> > >>> *Title* : Re: [Bug 25275] VideoTrackList.selectedIndex initialization > >>> confilicts with HTML5 spec, "if no track is selected". > >>> > >>> On 2014-04-15 14:36, Kiran Kumar Guduru wrote: > >>>> +1 for "not take the muted/disabled of the MediaStreamTrack into > >>> account". > >>>> I would like to polish this "just select one of the video tracks > >>>> regardless of it being muted/disabled or not" with > >>>> > >>>> "First available MediaStreamTrack with MediaStreamTrack.readyState > >>>> "live", (Since live includes muted and disabled), If no such track > >>>> available set it to -1. > >>> This would work for me. That would mean that we replace the sentences > >>> > >>> "Set the VideoTrackList.selectedIndex to the index of the first > >>> VideoTrack, in the VideoTrackList, that corresponds to a > >>> MediaStreamTrack that is not muted or disabled. If no such VideoTrack > >>> exists, set the selectedIndex attribute to 0." > >>> > >>> with > >>> > >>> "Set the VideoTrackList.selectedIndex to the index of the first > >>> VideoTrack, in the VideoTrackList, that corresponds to a > >>> MediaStreamTrack that has readyState 'live'. If no such VideoTrack > >>> exists, set the selectedIndex attribute to -1." > >>> > >>> and we're done? > >>> > >>> (The caveat seem to be that the relation between 'live' and 'muted' is > >>> not defined.) > >>> > >>> > >>>> ------- *Original Message* ------- > >>>> > >>>> *Sender* : Stefan Håkansson LK > >>>> > >>>> *Date* : Apr 15, 2014 20:20 (GMT+09:00) > >>>> > >>>> *Title* : Re: [Bug 25275] VideoTrackList.selectedIndex initialization > >>>> confilicts with HTML5 spec, "if no track is selected". > >>>> > >>>> On 2014-04-15 11:33, Kiran Kumar Guduru wrote: > >>>> > It is true that MediaElement spec is not specifying anything about > >>>> > initialization of selectedIndex. > >>>> > > >>>> > In MediaStreams spec, we will come across this scenario, "if no > >>> track is > >>>> > selected", after removing the selected track from VideoTracks > >>> (and when > >>>> > not selecting any other tracks in the list). > >>>> > >>>> Re-reading the html draft, I get to the following understanding: > >>>> > >>>> * For audio, any new tracks (tracks that are added to a MediaStream > that > >>>> is being played in a media element) gets status disabled in the media > >>>> element's AduioTrackList. I.e. the application has to enable them > >>>> (enabled=true) to have their audio played (mixed in with the other > audio > >>>> tracks). > >>>> * For video, any new track (tracks that are added to a MediaStream > that > >>>> is being played in a media element) gets status not-selected in the > >>>> media element's VideoTrackList. I.e. the application has to select it > >>>> (selected=true) to have its video played. > >>>> * For audio, removing a track does not affect the remaining tracks > >>>> (their enabled property in the AudioTrack of the AudioTrackList of the > >>>> media element remains). > >>>> * For video, removing a track does not affect the remaining ones, > >>>> meaning that if the track being removed is the currently selected one, > >>>> then no track will be selected after removal (and selectIndex of the > >>>> media elements VideoTrackList will return -1). > >>>> > >>>> I think there are no ambiguities so far. > >>>> > >>>> The only outstanding thing would be the resource fetch phase. The > >>> text says > >>>> "If either the media resource [...] indicate a particular set of audio > >>>> or video tracks to enable, or if the user agent has information that > >>>> enabled it to select specific tracks for optimal performance, 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." > >>>> > >>>> What this means for a MediaStream is up to this group to define. What > is > >>>> currently said is that for all MediaStreamTracks of kind audio, the > >>>> media element's corresponding AudioTrack should be initialised to > >>>> "enabled" (and not take the enabled attribute of the corresponding > >>>> MediaStreamTrack into account). > >>>> > >>>> For video, it is said: "Set the VideoTrackList.selectedIndex to the > >>>> index of the first VideoTrack, in the VideoTrackList, that corresponds > >>>> to a MediaStreamTrack that is not muted or disabled. If no such > >>>> VideoTrack exists, set the selectedIndex attribute to 0." I think '0' > >>>> should be changed to '-1', but otherwise this is quite clear IMO. We > >>>> could consider simplifying by not take the muted/disabled of the > >>>> MediaStreamTrack into account, and just select one of the video tracks > >>>> regardless of it being muted/disabled or not. > >>>> > >>>> Stefan > >>>> > >>>> > >>>> > >>>> > > >>>> > ------- *Original Message* ------- > >>>> > > >>>> > *Sender* : Steev James > >>>> > > >>>> > *Date* : Apr 14, 2014 22:24 (GMT+09:00) > >>>> > > >>>> > *Title* : Re: [Bug 25275] VideoTrackList.selectedIndex > initialization > >>>> > confilicts with HTML5 spec, "if no track is selected". > >>>> > > >>>> > Hmm, > >>>> > My reay intention is "if none of the tracks are selected" has no > >>> room in > >>>> > MediaStreams spec. > >>>> > > >>>> > > >>>> > On Mon, Apr 14, 2014 at 6:15 PM, Stefan Håkansson LK > >>>> > > > wrote: > >>>> > > >>>> > On 2014-04-14 14:15, Steev James wrote: > >>>> > > Stefan, > >>>> > > This link is just specifying that AudioTracks / VideoTracks > >>>> can have > >>>> > > multiple tracks and, > >>>> > > "The|VideoTrackList.selectedIndex|attribute must return > >>> the index > >>>> > of the > >>>> > > currently selected track, if any. If the|VideoTrackList > >>>> > > > >>>> > |object > >>>> > > does not currently represent any tracks, or if none of the > >>>> tracks are > >>>> > > selected, it must instead return −1." > >>>> > > >>>> > Hm, we must be talking past each other. I read your comment > >>>> > 'MediaElement spec has not mentioned anything about "how" to > >>> select a > >>>> > track.', and responded to it because I think that is precisely > >>>> what you > >>>> > _can_ do with the enabled (audio) and selected (video) > >>> attributes. > >>>> > > >>>> > > > >>>> > > > >>>> > > It is not mandating the default initialization to first > >>> track. But > >>>> > > MediaStreams is mandating it to initialize it to '0' track > >>> of the > >>>> > list. > >>>> > > So "if none of the tracks are selected" has no room in > >>>> > MediaStreams spec. > >>>> > > > >>>> > > > >>>> > > > >>>> > > On Mon, Apr 14, 2014 at 5:02 PM, Stefan Håkansson LK > >>>> > > > > >>>> > > > >> wrote: > >>>> > > > >>>> > > On 2014-04-14 08:58, bugzilla@jessica.w3.org > >>>> > > >>>> > > > > wrote: > >>>> > > > https://www.w3.org/Bugs/Public/show_bug.cgi?id=25275 > >>>> > > > > >>>> > > > steev > > >> > >>>> > > changed: > >>>> > > > > >>>> > > > What |Removed > |Added > >>>> > > > > >>>> > > > >>>> > > >>>> > >>> > ---------------------------------------------------------------------------- > >>>> > > > CC| > >>>> > > |steev.a.james@gmail.com > >>>> > > > >>>> > > > > >>>> > > > --- Comment #5 from steev > > >>>> > > > >> --- > >>>> > > > MediaElement spec has not mentioned anything about > >>> "how" to > >>>> > > select a track. > >>>> > > > >>>> > > > >>>> > > >>>> > >>> > http://www.w3.org/TR/html5/embedded-content-0.html#media-resources-with-multiple-media-tracks > >>>> > > details this. > >>>> > > > >>>> > > > Is > >>>> > > > there any special interst for specifying this in > media > >>>> > streams spec? > >>>> > > > > >>>> > > > >>>> > > > >>>> > > > >>>> > > >>>> > > >>>> > > > >
Received on Wednesday, 16 April 2014 16:49:33 UTC