Stereo Tool
https://forums.stereotool.com/

MicroMPX errors
https://forums.stereotool.com/viewtopic.php?t=30595		 Page 1 of 1
Author:  radiohead [ Mon May 03, 2021 8:44 pm ]
Post subject:  MicroMPX errors
I'm soak testing our two transmitter network. Getting some errors as below. I'd really value some suggestions. I can't find any documentation on error correction for Micro MPX - can anyone advise or point me to the manual? I'm not really worried about delay, reliability is king, so if more delay is needed that is not a problem.

Bitrate: 320kbs
Keyframe interval 0.5s
Span 128 packets
Overhead 16 packets
Limit rate below 460kbs

Delay 6s

Studio send PC - Pentium i7 CPU 40% RAM 60%

TX 1 - I'm getting lots of "Buffer out of range - resetting" errors, and the odd "Soundcard is playing too fast or too slow" errors. Pentium i5, running CPU 15% and RAM 46%

TX 2 - is having too many packets missing and sliences of 6 seconds or above. Pentium i5 running CPU 14% and RAM 51%.

Both TX's are at different physical locations and different WAN connections. The errors don't seem to coincide, suggesting the studio send PC is not the problem.

Any suggestions, especially with explaination would be greatfully accepted!

Thanks
Author:  radiohead [ Fri May 07, 2021 11:27 pm ]
Post subject:  Re: MicroMPX errors
Bump
Author:  hvz [ Wed May 26, 2021 11:03 am ]
Post subject:  Re: MicroMPX errors
Sorry for the slow response.

TX 1
"Soundcard is playing too fast or too slow" - that's your problem. One of the sound cards is not behaving correctly. (The error should indicate if it's the incoming stream - then it's on the encoder side - or on the actual sound card on the decoder side). Since TX 2 doesn't say this it's most likely the decoder sound card.

Sound cards clocks typically run within 0.01% of the set frequency. This error occurs if it deviates more than 0.1%. So basically, if you tell it to run at 192000 Hz it runs below 191808 or above 192192 Hz. Which is a quite extreme offset.

TX 2
That would indicate network issues. 128/16 should normally be more than enough though, and with keyframes every 0.5 seconds, even if you would loose more than 16 packets the audio should come back after at most 0.5 seconds. So if you loose audio for 6 seconds, that seems to indicate that the whole network drops for multiple seconds. Are you sending loads of data over this network?
Author:  radiohead [ Sun May 30, 2021 10:22 pm ]
Post subject:  Re: MicroMPX errors
Thanks Hans,

I'm still getting this issue, and now we've started test transmissions I can hear it as audible glitches on-air. It's strange because both transmitters use the same type of CM6631A sound card and same type of i5 PC. The only difference is different ISP's at the TX end.

It's really worrying me, not sure what to try next!
Author:  radiohead [ Sun May 30, 2021 11:17 pm ]
Post subject:  Re: MicroMPX errors
This might be stupid and nothing to do with it, but unless it's a coincidence, leaving the uMPX console open in Chrome Browser seems to have settled it down! No more errors yet after an hour.
Author:  hvz [ Tue Jun 01, 2021 12:45 pm ]
Post subject:  Re: MicroMPX errors
That really shouldn't matter. What type of glitches do you hear, and does MicroMPX report any errors?
Author:  radiohead [ Wed Jun 02, 2021 9:29 pm ]
Post subject:  Re: MicroMPX errors
I can confirm, in this specific situation, leaving a Chrome window open DEFINITELY almost eliminates the glitches compared to closing it! Same when I changed to the inetrnal instead of external sound card. God knows why opening the console in Chrome improves it!

There seems to be a time or temperature correlation. (Recently it has been hot here in the days - the situation improves overnight - is that due to temperature or internet performance??!)

I'm building a new uMPX decoder on totally different hardware to see if that changes anything
Page 1 of 1 All times are UTC+02:00
Powered by phpBB® Forum Software © phpBB Limited
https://www.phpbb.com/