[vdr] VDR and multicast streaming

Artem Makhutov artem at makhutov.org
Tue Oct 21 17:25:22 CEST 2008


Hi,

On Tue, Oct 21, 2008 at 04:44:20PM +0200, Frank Schmirler wrote:
> On Tue, 21 Oct 2008 14:46:52 +0200, Artem Makhutov wrote
> > The ADB-Boxes use Multicast-TS. I have captured a transmission from 
> > my IPTV provider. So you can take a look on it:
> > 
> > http://www.makhutov.org/downloads/adb/
> 
> The .pcap file is not accessible. Would it contain the IGMP traffic, too?

Ah, sorry, I fixed the permissions.
Yes, you can the the IGMP traffic there.

Packet #4 is the IGMG Join Group packet. After this one the stream
starts. Packet 1,2 and 3 not relevant, they are used for other multicast
stuff.

Packet #23114 is the IGMP Leave, after this packet the ISP stops the
multicast transmission.

> > The boxes send IGMP Join / Leave Group messages, if you switch or 
> > turn on a channel.
> > 
> > Streamdev could listen for such messages an enable/disable the streams.
> > 
> > The IGMP Join Group messages are send in an interval (1 
> > messege/minute). If an IGMP Leave Group message is recieved, or if 
> > no Join Message was received during 2 minutes then the stream sould 
> > be stopped.
> 
> Makes sense - that's the way how it's supposed to work when subscribing to an
> Internet multicast stream, i.e. accross router boundaries. With streamdev,
> each channel would become a multicast group of its own. Multicast IPs are not
> an issue here. The IPv4 Local Scope for multicast addresses is large enough.
> But how do you configure them in the box? Or does it listen to some sort of
> announcements (getstream2 sends SAP/SDP packets)?
> 
> > The boxes also support HTML, so then can post data to a webpage, if the
> > channel was switched. I am not sure if all boxes support this. At least
> > the ADB boxes can do this.
> 
> Some sort of user interface would be fine anyway.

Yes, sure, this would be great.

Regards, Artem



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