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Re: What does a track contain?

From: Peter Thatcher <pthatcher@google.com>
Date: Wed, 24 Feb 2016 10:34:18 -0800
Message-ID: <CAJrXDUG6bwAxikceEYQmbQcScVT_sQtCDC0cYLZofE3kHoeEAg@mail.gmail.com>
To: Martin Thomson <martin.thomson@gmail.com>
Cc: "public-media-capture@w3.org" <public-media-capture@w3.org>
FYI, someone answered my question with this:

http://simpl.info/videoalpha/

Works in Chrome, but not Firefox.

On Wed, Feb 24, 2016 at 8:28 AM, Peter Thatcher <pthatcher@google.com>
wrote:

> I don't know enough about <video> to know the answer to this:  if it has
> an alpha channel in it, and it's rendered on top of other web elements, is
> it supposed to render such that you potentially see through the video to
> the other web elements below?  In other words, could I use a <video> to
> make a video of a translucent ghost fly around a web page?  Is that the
> kind of thing we're going for here?   canvas -> track -> <video> -> ghost?
>
> On Wed, Feb 24, 2016 at 8:20 AM, Martin Thomson <martin.thomson@gmail.com>
> wrote:
>
>> On 24 February 2016 at 08:13, Peter Thatcher <pthatcher@google.com>
>> wrote:
>> > What do you mean "throughout the media pipeline"?  Do you expect a track
>> > sent through a PeerConnection to have the alpha channel intact when it
>> comes
>> > out the remote side?
>>
>> Well, we know that RTP video is generally incapable of handling alpha
>> channels, so no.  Unless and until we find a codec that supports an
>> alpha channel (APNG perhaps).
>>
>> But the simple example of <canvas> piped to <video> presents something
>> of a challenge.
>>
>
>
Received on Wednesday, 24 February 2016 18:35:25 UTC

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