[linux-dvb] Re: First release: DVBVideoLAN

[Markus Winkler <markus.winkler@gmxpro.de>]

At 08:48 07.12.2001 +0000, you wrote:
>On Thursday 06 December 2001 16:06, Frank Klingenhoefer wrote:
> > I had a look on the "Linux-part" of your project.
> > I have one question:
> >
> > In my eyes the "Linux-part" is based on D.Chapman's dvbstream, which
> > is based on ...
> > Why did you remove the copyright info?
>
>Markus has left some of the copyright information in, but not all.  However,
>I don't think he's infringing the GPL.  All I would ask would be that he
>renames dvbstream to something else to avoid confusion with my version (which
>I am still developing).
>
>He has made quite a few changes to dvbstream - the main functional change is
>that his Windows client needs a Program Stream instead of the Transport
>Stream that my original dvbstream broadcasts.
>
>Markus has also added command-line options to indicate the input source (DVB
>card, file, stdin), and output target (network, file, stdout).  He uses ts2ps
> >from mpegtools in a pipe between two instances of dvbstream.
>
>I've read on the Elecard website that their MPEG-2 decoder can handle
>Transport Streams.  Markus - is there a reason why you decided not to use
>this feature?
>
>The main reason I chose to multicast transport streams was so that I could
>potential transmit a whole transponder over a LAN (it multiple TV channels),
>and then the client could choose which service to receive.

A little bit of history:
My little project started about 6 weeks ago. First, I only wanted to be 
able to watch TV on my notebook, then, I heard from a project witch is in 
development at my university. It's about a mutimedial lecture auditorium. 
In short words, my DVBVideoLAN turned into a student research project. And 
theres the reason for the conversion of the ts to ps: we use capture cards 
for encoding in mpeg2ps. Thats why.
Another thing, I was in hurry to get it working, because my last final 
excams are knocking on the door. Because of that the code, I produced, 
doesn't look very nice to me. To get it work was 1st prio (at least as an 
alpha version :-) ).

Ok, and now some additional remarks to DVBVideoLAN:
It seems, that it's not working everywhere :-( It's very important, that 
there isn't to much packet loss, at least in the beginning. For those of 
you, not famliar with DirectShow (I wans't it neither some weeks ago). 
DirectShow uses a Filtergraph for getting the stream, demuxing, decoding 
and playpack.

That's how it should be:
[My sourcefilter] --> Elecard Mpeg2 Demuxer --> Elecard Mpeg2 Decoder --> 
Video Renderer
                                 |
                                 |--> Mpeg Audio Decoder --> Default 
DirectSound Device

This graph after the Sourcefilter is built automatically (rendered). The 
only thing I set is the Source Filter. If there is to much packet loss the 
stream can't be identified correctly. If the Viewer dectects a problem, he 
restarts the graph building from the beginning.

Another point is the speed of your processor. I believe, that 750MHz is the 
minimum for the viewer (at least at the moment). Who says that only games 
need fast computers...

Tip: Some channels cause more problems than others. Sat1 and ProSieben are 
working without serious problems (at least here).

Best regards,

Markus Winkler

PS: a normal Viewer.log:

Init DVBVideoLan Viewer...
OK   : Filter created.
OK   : Filter added to GraphBuilder.
OK   : RTPSource Out found.
OK   : Rendered from RTPSource.
Error: Could not bind to window!
Close: pMC Stopped
Close: Interfaces3.
Close: CloseInterfaces
Close: Finish
PANIC: Retrying to build filtergraph. Attempt: 1
OK   : Filter created.
OK   : Filter added to GraphBuilder.
OK   : RTPSource Out found.
OK   : Rendered from RTPSource.
Error: Could not bind to window!                       <--Error at 
decoder/video renderer
Close: pMC Stopped
Close: Interfaces3.
Close: CloseInterfaces
Close: Finish
PANIC: Retrying to build filtergraph. Attempt: 2
OK   : Filter created.
OK   : Filter added to GraphBuilder.
OK   : RTPSource Out found.
OK   : Rendered from RTPSource.
OK   : Put_Owner.                                      <--Yeah
...
Exiting cleanly.

PPS: I gave the source filter a bigger buffer. You'll find it on 
http://pulp.mine.nu/dvbvideolan.

>Best wishes,
>
>Dave.
>
>
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