[gst-devel] Re: [vorbis-dev] HTTP streaming / mime type

Wim Taymans wim.taymans at chello.be
Mon Jul 31 23:21:00 CEST 2000


"Myers W. Carpenter" wrote:
> 
> Anthony Arcieri wrote:
> >
> > > The only way to check would be with the MIME type or give each plugin
> > > the first few kbytes of the stream and see which one can decode the
> > > audio.
> >
> > The media architecture I'm developing tests for which codec to use using
> > leading context, either by magic numbers or by an identification function.
> > This leading context is buffered until a positive match has been made, at
> > which point the buffered data is passed on to the proper module.

Exactly as gstreamer does it.

> >
> > On a similar note, I was wondering if anyone could think of a case where a
> > fixed amount of leading context would be unworkable for identifying a
> > stream.

You are not able to identify the contents of an MPEG2 stream with a fixed amount
of leading data. Subtitles for example arrive after maybe a few MB of
video/audio
data has been decoded. You need a system where the threads and decoders can be
insterted into the pipeline while it is playing. IFO files can help too.

btw. I have been working on the plugins on the 071500 snapshot. I have some cool
changes pending: MPEG2 subtitle decoding, general speedups and I'm reworking the
wine Windows codecs loading. Hopefully I'll be able to do DivX encoding soon.
I have not tried to make the new state handling work but I will try to do so
when
I have finished what I want to do now. So don't panic if there are no CVS
commits
for a while...

Wim


-- 
In just seven days, I can make you a man!
		-- The Rocky Horror Picture Show




More information about the gstreamer-devel mailing list