[linux-dvb] How to stream DVB-S2 channels over network?

Artem Makhutov artem at makhutov.org
Mon Dec 22 12:16:41 CET 2008


Hello,

BOUWSMA Barry schrieb:
> On Sun, 21 Dec 2008, Artem Makhutov wrote:
> 
>> I just checked it out. It looks interesing, but I need UDP streaming,
>> as the STB can only receive UDP-Streams.
> 
> What sort of UDP do you need -- an RTP Transport Stream,
> an RTP Program Stream, a simple raw Transport stream, or
> what?

It needs a raw MPEG-TS encapsulated in UDP packets.

> Unless you're using a different `dvbstream' than I, it
> sends out RTP (partial or not) Transport Streams, with
> UDP packet size equal to the TS frame size (I hacked this
> to fill as much of an ethernet frame as possible).
> 
> I don't know if your `szap2' program simply sets up the
> frontend to the desired frequency, or if it also sets
> hardware PID filters on your card -- I've always been able
> to use other utilities with bog-standard `t/szap' to work
> on the entire TS.

It also sets the PID's.

> If bandwidth is an issue, a HD H.264 stream is likely to
> weigh in around 10 to 20Mbit/sec; a full S2 transport
> stream is higher (DVB-S streams from Astra are on the
> order of 36Mbit/sec; S2 will likely be slightly more).

No, bandwith is not an issue. I have a peak traffic of 20.51 MBit/s and
an average traffic of 13.24 MBit/s.

> Add the overhead for UDP encapsulation of the 188-byte
> packets, and I wouldn't be surprised if you push close
> to some hardware limits of a 100Mbit/sec network, given
> the unreliable nature of UDP, and that a single dropped
> or corrupt packet can appear as a video stream error.
> 
> Although, as you said, your 'Doze works, so the sum of
> your hardware should be able to handle the traffic.
> 
> Something I just learned a few seconds ago, dvbstream:
> -net ip:prt IP address:port combination to be followed by pids 
> list. Can be repeated to generate multiple RTP streams
> 
> This will filter your ~50Mbit/sec transponder down to a
> manageable size.  Be sure to specify all the PIDs for
> ASTRA HD or whatever; for the DVB-S Eins Festival that
> will start tomorrow (Mo) with non-upscaled 720p content
> again, that should be
> 0  1600  -v 1601   -a 1602   1603  1606
> (as arguments to standalone `dvbstream')
> 
> 
> Just some additional things to keep in mind...
> 
> 
> By the way, I also received some personal mail which I
> don't think made it to the list, and this may be of use
> to you, so I'll quote from that here, so that others may
> benefit:
> DUBOST Brice wrote:
> ``You can try mumudvb : http://mumudvb.braice.net, I think it will answer
> your needs''

I will give it a try later.

Thanks, Artem




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