Multicast streaming problem

[fredj21]

Hello !

I have one multicast server and some Rapberry player and IPTV Box players.This equipments are in a simple Vlan of level 2 network
Since a migration from my server, I encounter some problems when I diffuse 3 streams multicast from my Ubuntu server.

My new server configuration :

• Distribution : Ubuntu server 16.04.3 LTS (xenia)

• kernel version : 4.4.0-93-generic #116-Ubuntu SMP Fri Aug 11 21:17:51 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux

• VLC media player 2.2.2 Weatherwax (revision 2.2.2-0-g6259d80)

My simple script to start 3 streams :

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#/bin/sh cvlc -v /media/video_1.ts --sout-keep --loop --sout="#gather:standard{mux="ts",access="udp",dst="239.101.0.60"}" & cvlc -v /media/video_2.ts --sout-keep --loop --sout="#gather:standard{mux="ts",access="udp",dst="239.101.0.61"}" & cvlc -v /media/video_3.ts --sout-keep --loop --sout="#gather:standard{mux="ts",access="udp",dst="239.101.0.62"}" &

Several problems :

1/ when i start VLC with option -vvv, I can see a lot of this messages :

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[00007fd420001f98] udp access out debug: packet has been sent too late (1178642004) [00007fd420001f98] udp access out debug: packet has been sent too late (1178623358) [00007fd420001f98] udp access out debug: packet has been sent too late (1178604708) [00007fd420001f98] udp access out debug: packet has been sent too late (1178586058)

and

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[00007fd420001f98] udp access out debug: late packet for UDP input (1178623167) [00007fd420001f98] udp access out debug: late packet for UDP input (1178604509) [00007fd420001f98] udp access out debug: late packet for UDP input (1178585853) [00007fd420001f98] udp access out debug: late packet for UDP input (1178567198)

2/ sometimes, during the streaming, I see this other messages:

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[00007f22e0001f98] udp access out warning: send error: Resource temporarily unavailable [00007f22e0001f98] udp access out warning: send error: Resource temporarily unavailable [00007ff92c001f98] udp access out warning: send error: Resource temporarily unavailable [00007ff92c001f98] udp access out warning: send error: Resource temporarily unavailable

3/ when I analysis with Wireshark, I can observe what the UDP packet are sent ONLY each 20ms :



I looking for a solution

I think what problems are a same route cause --> Linux kernel doesn't send quickly enough UDP Packet into the network !
I think the IP stack buffer did not drain quickly enough by the Kernel --> some packets are dropped between VLC process and Linux IP Stack

But Why ?

[fredj21]

Hi !
nobody seems inspired !

I have just make a new test : to compare the new VLC version ( 2.2.2 ) and my old version ( 2.0.8 ) in my new server : Ubuntu Kernel 4.4

VLC 2.2.2 --> VLC send only every 20ms :





VLC 2.0.8 --> VLC send UDP packets one to one --> the frequency is of course more important , but linear !




Do you have an explanation for this difference of comportment ?
Is there a particular configuration to schedule UDP into the network ?


Cdt,
Fred.

[Jean-Baptiste Kempf]

Use multicat for this?