Re: 答复: MediaStreamTrack behaviuor

On 07/05/2012 11:13 AM, Sunyang (Eric) wrote:
> Are you sure?

I'm sure that was the intention when it was written :-).

>
> Since we do not construct new mediastreamtrack, so I mute it in 1st  mediastream, it will change the object status.
> Since it is the same object referenced in 2nd mediastream, so I think it is also muted.
>
> SO do you mean that if we construct a new mediastream using existing mediastreamtrack, it will be a new object?
Yes, that is what I mean.

>
> Yang
> Huawei
>
>
> -----邮件原件-----
> 发件人: Stefan Hakansson LK [mailto:stefan.lk.hakansson@ericsson.com]
> 发送时间: 2012年7月4日 21:43
> 收件人: public-media-capture@w3.org
> 主题: Re: MediaStreamTrack behaviuor
>
> On 07/04/2012 02:35 PM, Tommy Widenflycht (ᛏᚮᛘᛘᚤ) wrote:
>> Hi,
>> I am a bit confused regarding the latest draft regarding how
>> MediaStreamTracks should behave when they are part of more than one
>> MediaStream.
>>
>> It used to be that when a MediaStream was created with a list of Tracks
>> one created new tracks that had the same underlying data source as the
>> input tracks. Basically one cloned the tracks.
>>
>> Now the draft says that the new MediaStream should add the same Tracks
>> to its lists. That means that the same Track can now belong to more than
>> one MediaStream. This has an unfortunate effect that if one disables a
>> Track, the Track gets disabled in all MediaStreams. It is no longer
>> possible to have independent enabled stated, and for example this basic
>> use case is impossible:
>>
>> A LocalMediaStream is created by getUserMedia. The user creates a new
>> MediaStream with the video track from the LMS. The LMS is attached to a
>> video tag for self view, and the MS is added to a PeerConnection. The
>> user wants to implement a video mute function for outgoing video and
>> therefore disables the video track in the MS. This now disables the
>> video track in the LMS as well whereas before this was doing the right
>> thing.
>>
>> What is the reasoning behind this change?
>
> To me it sounds like an editing mistake. One of the purposes of being
> able to create new MS's from track(lists) of existing MS's is to be able
> to disable a specific track in one MS without disabling the "same" track
> (i.e. the track representing the same source) in the other MS.
>
> So, the way it used to be is the way it should be IMO.
>
> Stefan
>
>>
>> /Tommy
>>
>> --
>> Tommy Widenflycht, Senior Software Engineer
>> Google Sweden AB, Kungsbron 2, SE-11122 Stockholm, Sweden
>> Org. nr. 556656-6880
>> And yes, I have to include the above in every outgoing email according
>> to EU law.
>
>
>

Received on Friday, 6 July 2012 07:01:14 UTC