[vdr] Re: [ANNOUNCE] vdr-xine-0.4.3 plugin

[Reinhard Nissl <rnissl@gmx.de>]

Hi,

Stefan Lucke wrote:

> > I wonder, however, if its possible/planned to enhance the plugin to play 
> > also other media types like divx or mp3?
> > It would be cool to have a plugin similiar to the mplayer-plugin to 
> > watch movies. Reencoding (mpeg-pes) wouldnt be needed anymore,
> > so performance should be better compared to the current mplayer approach.
> Such thing I would like too. To enable this cDevice should be extended to 
> selectCodec (vcodec,acodec), so that we vdr-xine and vdr-softdevice
> may select all of ffmpegs available codecs.
>
> We should make a feature request to Klaus.
> Whats your opinion Reinhard ?
Well, it's not that easy. xine has a multistage plugin architecture: input-, 
demuxer-, decoder-, postprocess- and output-plugins.

I've written a new input plugin which interfaces VDR. All other stages are 
handled by already available plugins in xine. Typically, at least the input 
plugin is selected by the mrl (vdr:) and optionally the demuxer might be 
selected (#demux:mpeg_pes). Otherwise it is detected by looking on some sample 
data, which the input plugin must provide in that case. The demuxer relies on 
the input plugin to provide data in a certain format (e. g. MPEG PES packets) 
and then decides, which data is contained in the packets (e. g. 
BUF_VIDEO_MPEG, BUF_AUDIO_MPEG, BUF_AUDIO_A52). After that, xine decides which 
decoder to use.

I think, that a different demuxer must be choosen to support divx respectively 
mp3 transparently. The problem is, that unlinke the decoder, the demuxer 
cannot be changed on the fly. It is determined when the stream is opened. So 
you might suggest to close and open the stream again to choose a different 
demuxer, but this is almost impossible, as it is typically done by the 
frontend application (e. g. xine, fbxine, ...) which might hold some extra 
data to manage playback of a stream.

I've seen, that xine can be instructed to remote control the currently active 
xine process, but I don't think that this would be a good way to go, as it 
puts a strict dependency on using xine.

Finally, I hope that I could point out, why it is not that easy to support 
other formats transparently. But if someone finds a solution, I'll do my best 
to include it into my plugin.

Bye.
--
Dipl.-Inform. (FH) Reinhard Nissl
mailto:rnissl@gmx.de