Re: [Gnash-dev] 2nd try: How can Internet Archive flash script pick codec to use?

[strk]

I started a wiki page on the matter.
Next thing to research to implement the draft is support for
this in gstreamer and ffmpeg:

http://wiki.gnashdev.org/MediaCapabilities

Comments and help are welcome.

--strk;

On Mon, Sep 22, 2008 at 10:42:42AM +0200, strk wrote:
> Added swfdec developer in Cc.
> 
> Ben, we're trying to define a way for an SWF movie to tell which
> containers and codecs are supported by a flash player.
> 
> John's drafty draft (below) looks fine to me. What do you think ?
> 
> --strk;
> 
> On Mon, Sep 22, 2008 at 01:19:42AM -0700, John Gilmore wrote:
> 
> > Adobe's description of Flash Lite doesn't say, of course, what the
> > mime types are returned for popular formats.  Indeed, this interface
> > just looks like it documents the container types, not the codecs.
> > There's confirming info about this in a tutorial:
> > 
> >   http://mobiforge.com/designing/story/flash-lite-and-video-streaming
> > 
> > which shows "video/3GP" as a returned type, and also describes the
> > wide variety of codecs usable within that type.  Dumb.  
> > 
> > I suggest that we add a parallel interface,
> > 
> >   System.capabilities.videoDecoderTypes
> >   System.capabilities.audioDecoderTypes
> >   System.capabilities.videoEncoderTypes
> >   System.capabilities.audioEncoderTypes
> > 
> > which would return the necessary info.
> > 
> > Then a Flash movie would be able to check for both container support
> > and for codec support (for both video and audio, potentially) if it
> > wanted to select among copies of a movie in various formats.
> > 
> > We should also draft a spec for such an interface, put it in the
> > public Gnash documentation, and feed it to Adobe for consideration in
> > future revisions of Flash.  We can implement it regardless of what
> > they do, but at least we'll be doing OUR part to avoid needless
> > incompatability.
> > 
> > Very drafty draft (from this, you already know I don't understand
> > ActionScript syntax): In a system with Gnash, configured to use ffmpeg
> > or gstreamer, in which the configured media library contains these
> > decoders.  (Depending on what other codec plugins are available, lots
> > more will also be described in these arrays.)
> > 
> >   System.capabilities.videoMIMETypes ["video/ogg"] will be true.
> >   System.capabilities.audioMIMETypes ["audio/ogg"] will be true.
> >   System.capabilities.audioDecoderTypes ["vorbis"] will be true.
> >   System.capabilities.audioDecoderTypes ["speex"] will be true.
> >   System.capabilities.audioDecoderTypes ["flac"] will be true.
> >   System.capabilities.videoDecoderTypes ["theora"] will be true.
> > 
> > The codec names should generally be in lowercase, so people won't have
> > to case-match them.  (We may be stuck with random cases in the MIME
> > types, like the above "video/3GP", but at least we can do better in
> > our own interface.)  Some will be nonintuitive, e.g. MP3 won't be
> > called mp3 because it's real name is something else; mp3 is a
> > high-speed collision between a container format and a codec.
> 
> 
> 
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