Latest post Fri, Jun 14 2019 7:42 AM by Lachie-VC. 7 replies.
Page 1 of 1 (8 items)
Sort Posts: Previous Next
  • Fri, Apr 12 2019 3:21 PM

    • rosstucks
    • Not Ranked
    • Joined on Wed, Oct 3 2018
    • Posts 4
    • Points 40

    exception legend audio communications error hardware underrun reason:klukaerr_underrun

    I have recently been getting this error popping up on a project I have been working on. 

    All footage was shot on same camera and settings, yet it only seems to happen when playing certain interviews. The Rushes play fine but when its in a sequence with lots of layers and audio it pops up with the error 

    exception legend audio communications error hardware underrun reason:klukaerr_underrun

    Now all the other interviews with the same amount of layers and everything play fine but its just one or 2 of the interviews that do it!

    I am running a Dell T7910 with 2x E5-2670 v3 processors and 64GB ram. Rushes are on shared storage running over network (speed is fine). The PC is connected to a Nitris DX feeding a Sony broadcast monitor over SDI

    I have been scratching my head over this one for days and can't work it out!

    Any Ideas?

  • Mon, Apr 22 2019 3:28 PM In reply to

    • Marianna
    • Top 10 Contributor
    • Joined on Thu, Oct 13 2005
    • Avid
    • Posts 10,666
    • Points 223,900
    • Avid Beta Moderators
      Avid Customer Advocate
      Avid Developer Moderator
      BlogAuthor
      SystemAdministrator

    Re: exception legend audio communications error hardware underrun reason:klukaerr_underrun

    Hey Ross - apologies for the delay in responding....  almost caught up after 8 days at NAB.

    I would take a look at this document....

    http://avid.force.com/pkb/articles/en_US/Error_Message/Exception-Legend-Audio-Communications-error-Hardware-Underrun-with-Nitris-DX-or-Mojo-DX?retURL=%2Fpkb%2Farticles%2Fen_US%2Ftroubleshooting%2Fen241207&popup=true

    Hope that helps.

    marianna

    Director of Online Communities and Forums/Customer Advocate [view my complete system specs]

    marianna.montague@avid.com

    mobile 813-493-6800

    Twitter:  avidmarianna

    Facebook: Marianna Montague

    www.avidcustomerassociation.com   |  Connect 2019 | April 6-7 | Aria, Las Vegas, NV

    WWLD

  • Wed, Apr 24 2019 10:20 AM In reply to

    • rosstucks
    • Not Ranked
    • Joined on Wed, Oct 3 2018
    • Posts 4
    • Points 40

    Re: exception legend audio communications error hardware underrun reason:klukaerr_underrun

    Hi, thanks for the reply

    I have actually found this document already and worked my way through it. None of it helped unfortunately.

    Everything works fine on most clips apart from this one multicam interview like I said. If I unplug the Nitris DX it doesn't seem to happen. I thought I had solved it as it didn't happen all day yesterday until the late afternoon when it started to do it again on the same clips so it is very inconsitant as to when it happens!

    Any other idea's I can try as it is very difficult to edit and show the client the edit when it pops up all the time

    Thanks

  • Thu, Apr 25 2019 7:22 PM In reply to

    • Marianna
    • Top 10 Contributor
    • Joined on Thu, Oct 13 2005
    • Avid
    • Posts 10,666
    • Points 223,900
    • Avid Beta Moderators
      Avid Customer Advocate
      Avid Developer Moderator
      BlogAuthor
      SystemAdministrator

    Re: exception legend audio communications error hardware underrun reason:klukaerr_underrun

    Hey Ross

    I also sent you a long-winded email to your MyAvid email.  

    According to our Audio engineer, the Audio Hardware Underrun occurs when the code that fills the audio playback buffers does not run in time, and therefore audio is not available when the hardware wants to play it out.  The fill is done by a high priority thread, and is the last step in the audio signal chain for Nitris DX. If the hardware underrun occurs, it is because something higher priority on the system is interfering, or something running in the fill thread takes too long.  The things that typically come out higher priority are direct memory access through attached devices, or other real-time programs running on the same machine.  Also, AAX Track Effects are run in the high priority buffer filling thread, and if you have too many, the audio hardware underrun will occur.

    I sent you 4 things you can try via email..... Please check that and report back.

     

    Marianna

    Director of Online Communities and Forums/Customer Advocate [view my complete system specs]

    marianna.montague@avid.com

    mobile 813-493-6800

    Twitter:  avidmarianna

    Facebook: Marianna Montague

    www.avidcustomerassociation.com   |  Connect 2019 | April 6-7 | Aria, Las Vegas, NV

    WWLD

  • Fri, Apr 26 2019 10:27 AM In reply to

    • rosstucks
    • Not Ranked
    • Joined on Wed, Oct 3 2018
    • Posts 4
    • Points 40

    Re: exception legend audio communications error hardware underrun reason:klukaerr_underrun

    Okay great I will work through what you have suggested and get back to you.

    Just out of interest if it was to be something wrong with our Nitris DX what other alternatives to it would you suggest? It is only being used to feed a broadcast monitor over SDI and 2 speakers over XLR really. I have a Black magic PCIe card that could do the the SDI output but its the speakers that I am struggling to work out as they only have XLR inputs.

    Sorry for all the questions but this was all setup before I joined the company so was not involved in the setup!

  • Mon, Jun 10 2019 9:23 AM In reply to

    • jberrr
    • Not Ranked
    • Joined on Tue, Sep 12 2017
    • Posts 17
    • Points 225

    Re: exception legend audio communications error hardware underrun reason:klukaerr_underrun

    Hi Marianna,

    We are seeing this exact same issue as well, on qualified z840s with a Nitris DX running Media Composer 2018.12.5.

    Could you send me the lists of things to try as well?

    Thanks,

    Jonathan

  • Tue, Jun 11 2019 6:15 PM In reply to

    • Marianna
    • Top 10 Contributor
    • Joined on Thu, Oct 13 2005
    • Avid
    • Posts 10,666
    • Points 223,900
    • Avid Beta Moderators
      Avid Customer Advocate
      Avid Developer Moderator
      BlogAuthor
      SystemAdministrator

    Re: exception legend audio communications error hardware underrun reason:klukaerr_underrun

    Jonathan....

    According to our audio engineer, Audio Hardware Underrun occurs when the code that fills the audio playback buffers does not run in time, and therefore audio is not available when the hardware wants to play it out.  The fill is done by a high priority thread, and is the last step in the audio signal chain for Nitris DX.  If the hardware underrun occurs, it is because something higher priority on the system is interfering, or something running in the fill thread takes too long. The things that typically come out higher priority are direct memory access through attached devices, or other real-time programs running on the same machine.  Also, AAX Track Effects are run in the high priority buffer filling thread, and if you have too many, the audio hardware underrun will occur.

     The good news is that there’s lots of diagnostic code in place to analyze what’s happening.  This engineer personally specified how the hardware would work, and wrote all the code at the driver and thread level that makes this work, and he knows it very well.

    The bad news is that in most cases we’ve never been able to figure out why it happens. The audio hardware underrun is, in many ways, one of our worst fears, because when they occur they are hard to isolate and solve.

    There are a couple things you can do and I think #1 is the answer.

    #1  The console command “audiobuffertime” can be used to increase the latency and in some cases make the underruns stop.  The only downside to increasing the audio buffer time is increased control latency when doing automation gain recording, and possibly an increase in JKL responsiveness (although I’ve never detected any perceptible difference there). The default value of 150000 gives 150 milliseconds for real-time interrupts and AAX effects to complete their tasks.  The default value in Media Composer version 8.4 might only be 75000, as I know I doubled the default some time ago. You can increase this up to the point you start to get some kind of “out of memory” errors on start of play, I think that happens around 300000 or so. (I will attempt to find out the limit once I get my DX up and running again.) This command is stored in MCSTATE and once set will persist on that machine until changed.  This is the most likely path to success, and if it works, this is a suitable long-term solution.

    #2 If you are using a lot of compute-intensive AAX effects, consider mixing down some tracks and deactivating the ones that have heavy effects on them.

    #3 The EVENTLOG.LOG file automatically records a lot of useful information whenever an audio hardware underrun occurs.  If you could capture some of these for me, and can see if the problem you are experiencing is a consistent one, meaning something inside Media Composer is causing it, or inconsistent, suggesting something outside of Media Composer.

    #4 If you MUST, there is a console command to simply turn off hardware error detection.  We use this command during development so that we can pause the software to examine its state without triggering an error. If you do this, the hardware underruns will manifest themselves and clicks and pops in the audio, or short repeated blips, but they will not stop playback. Do this only when you get into the “I’m so annoyed please stop” state, and definitely never, ever in a cut to tape or to air.  That command is “debugadm 2” and it is not persisted, it needs to be re-issued each time you launch Media Composer.

     Let me know how it goes.

    Marianna

    Director of Online Communities and Forums/Customer Advocate [view my complete system specs]

    marianna.montague@avid.com

    mobile 813-493-6800

    Twitter:  avidmarianna

    Facebook: Marianna Montague

    www.avidcustomerassociation.com   |  Connect 2019 | April 6-7 | Aria, Las Vegas, NV

    WWLD

  • Fri, Jun 14 2019 7:42 AM In reply to

    • Lachie-VC
    • Not Ranked
    • Joined on Thu, Jun 21 2018
    • Posts 2
    • Points 20

    Re: exception legend audio communications error hardware underrun reason:klukaerr_underrun

    This is an interesting post for me, we have run into this in the past with our systems. 

    I work for an broadcast rental and engineering company and I did a job last year where we encontered 'Legend Audio communications error, Hardware underrun' quite badly. Our set up was 12x edit suites (mix of z840 and z440's) with Nitris DX IO's. Storage was Nexis Pro 40TB with three chassis running 2018.6.1 in a single storage group with CISCO 4900M switches. The MC's were 2018.5 on win 7 pro. The machines had either Intel pro 1000 nic's or Myricom 10G-PCIE2-8C2-2S Nic's, around six and six. The codec we were using was DNxHD120 1080/50i. All kit was built more or less to the Avid spec (PCI-E slots, ram, cpu, switch config etc)

     

    We stated to run into the error on the machines with the Myricom NIC's even though they pathdiag and benchmarded with flying colours. No errors on the switch ports or network errors on the Nexis NIC. The error didn't occor on the machines with the Intel pro 1000's. The error would often occur just scrubbing through a single steam of video or even playing it back. After having slightly unhappy editors for a day I moved all machines over to Intel Pro 1000's and didn't run into the error again for the duration on the job.

    Not sure if anyone has seen anything similar?

     

     

     

Page 1 of 1 (8 items)

© Copyright 2011 Avid Technology, Inc.  Terms of Use |  Privacy Policy |  Site Map |  Find a Reseller