[Theora-dev] Directshow filters 0.64.7878

illiminable ogg at illiminable.com
Tue Oct 5 04:03:32 PDT 2004

----- Original Message ----- 
From: "Thomas Vander Stichele" <thomas at apestaart.org>
To: "illiminable" <ogg at illiminable.com>
Sent: Saturday, September 25, 2004 6:14 PM
Subject: Re: [Theora-dev] Directshow filters 0.64.7878

> Hi Zen,
> On Sat, 2004-09-25 at 10:08, illiminable wrote:
>> Updated again... theora works and seeks properly (not to keyframe) in WMP 
>> 9
>> and 10.
>> You can encode from a bunch of onew input types like RGB32, RGB24, IYUV 
>> etc.
>> And fixed a bug that was stopping the filters being used in a activeX
>> control in an IE browser.
>> www.illiminable.com/ogg/
> Still, thanks for all the work you're doing on this.

No worries...

> We are releasing our server next month, and we're wondering what your
> timeline is wrt. having the ds filters play network streams nicely as
> well.  We'd like to be able to recommend that people install your
> filters to watch streams.

I had a good look at it today... and have found that it's actually extremely 
difficult to reconfigure a running graph even under ideal conditions. Doing 
it properly for homogenous chains in all cases... is really hard... doing it 
for arbitrary chains looks like way way more trouble than it's worth... and 
i don't think any other player can do that yet anyway, so i'm not going to 
lose any sleep over that.

I've found a world class dodgy way to do it for single stream vorbis network 
stream... which seems to have worked... i've been listening to virgin radio 
through 10 or so transitions and it seems to work (though it does look like 
WMP is getting a bit confused about what time it should be showing)

I'm pretty sure i can do the same for a theora stream... though i can see 
some potential for losing sync particularly if one stream is actually longer 
than the other, but i'm sure i can hack my way around that.

Is there a test server somewhere with a theora+vorbis stream ?

The conditions under which i can get chaining to work with this hack are...

a) The stream is non-seekable.
b) Each chain contains the same number and type of codecs with the same 
settings (ie can't change the samplerate or the number of channels)
c) The stream is valid.

Which as far as i know this means it should be fine for icecast.

I'm unsure at this stage what the effect is if the codebook changes mid 
stream... i'd have to check with conrad about what libfishsound will do in 
that situation. I've a feeling it's just dropping the extra headers.

It's pretty likely i can do the same for speex, but flac looks like it will 
be much harder... but that's not really streamed often anyway.

Also something i noticed on virgins 
site(http://www.virginradio.co.uk/thestation/listen/ogg.html)... which may 
interest you wrt to this... is that they supply links as .pls files. However 
WMP doesn't support .pls files (though winamp and iTunes do)... there may be 
a special filter around somewhere for it... but it's not instaled by 
default... so that may be something to keep in mind.

In order to play the stream you need to save the .pls file and copy/paste 
the naked link out of the file into WMP. I think there's probably another 
playlist format that is windows friendly... maybe .m3u ?



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