[Discuss-gnuradio] UDP sources blocking flowgraph when network is discon

From:

Nigel Orr

Subject:

[Discuss-gnuradio] UDP sources blocking flowgraph when network is disconnected

Date:

Thu, 21 Jun 2012 11:43:00 +0100

I am working on a gnuradio application which takes feeds from other
sources over Ethernet. There is a possibility that the source will be
disconnected occasionally due to intermittent network failures, when
that happens I'd like the audio to go silent, and come back when the
source is reconnected. In short, I'd like it to behave like an analogue
audio connection :-) UDP looks like the closest option to that, so
that's what I've tried so far.

I currently connect the UDP blocks with something like
udp_in = gr.udp_source((gr.sizeof_float*1), "0.0.0.0", 1234, 1472, True,
True)
and then connect them into the flowgraph.

I have tried various options (all 4!) of the Boolean settings for Wait
for data and empty packet = EOF, but it doesn't seem to do what I need.
At best (with the above settings), the flowgraph pauses when the UDP is
disconnected, so all the local sources which are still connected buffer
up, resulting in long delays when the UDP comes back.

Is it possible to get 'analogue-like' performance from a network socket
connection, if so how should I do that within gnuradio? Is there
something clever I can do with Throttle or Valve or something which will
decouple loss of a UDP audio stream from the rest of the flowgraph?

Thanks,

Nigel

Nigel Orr

Chief Technologist

Tel: +44 (0) 1224 775700

Fax: +44 (0) 1224 775800

Email: address@hidden

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I am working on a gnuradio application which takes feeds from other sources over Ethernet. There is a possibility that the source will be disconnected occasionally due to intermittent network failures, when that happens I'd like the audio to go silent, and come back when the source is reconnected. In short, I'd like it to behave like an analogue audio connection :-) UDP looks like the closest option to that, so that's what I've tried so far. I currently connect the UDP blocks with something like udp_in = gr.udp_source((gr.sizeof_float*1), "0.0.0.0", 1234, 1472, True, True) and then connect them into the flowgraph. I have tried various options (all 4!) of the Boolean settings for Wait for data and empty packet = EOF, but it doesn't seem to do what I need. At best (with the above settings), the flowgraph pauses when the UDP is disconnected, so all the local sources which are still connected buffer up, resulting in long delays when the UDP comes back. Is it possible to get 'analogue-like' performance from a network socket connection, if so how should I do that within gnuradio? Is there something clever I can do with Throttle or Valve or something which will decouple loss of a UDP audio stream from the rest of the flowgraph? Thanks, Nigel
Nigel Orr Chief Technologist Tel: +44 (0) 1224 775700 Fax: +44 (0) 1224 775800 Email: address@hidden Website: www.nautronix.com

This email is sent and received in accordance with the terms and conditions as defined on our website. To view click here Nautronix Limited is head-quartered at Nautronix House, Howe Moss Ave, Kirkhill, Dyce, Aberdeen, AB21 0GP. Nautronix is part of Nautronix Group Limited which is registered in Scotland, registered office: 66 Queens Road, Aberdeen, AB15 4YE. Registered Number: SC372837.Nautronix Limited which is registered in Scotland, registered number SC062293, with a registered office at 66 Queens Road, Aberdeen, AB15 4YE is part of Nautronix Group Limited. Nautronix (Holdings) Limited which is registered in Scotland, registered number SC225116, with a registered office at 66 Queens Road, Aberdeen, AB15 4YE is part of Nautronix Group Limited.