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It seems, that many RedHat developers have rather unique world views. When PulseAudio introduces random crackles and scratches in sound output, they claim, tha

It seems, that many RedHat developers have rather unique world views. When PulseAudio introduces random crackles and scratches in sound output, they claim, that I have a misbehaving sound card. It does not "misbehave", when I use the same applications with ALSA, but whatever. When rdrand fails to produce high-quality entropy — again and again, over and over — Poettering complains about buggy CPUs. I hope, that this particular group never ends up working on network hardware.

Avamander 6y ago
> It does not "misbehave", when I use the same applications with ALSA, but whatever. I mean RDRAND is a great example here, if you never use it, you never encounter these bugs. It's not impossible that PulseAudio tries to play higher quality audio or simply uses the device differently. > I hope, that this particular group never ends up working on network hardware. I'd kinda love it, probably quite a few fun hardware bugs will be found.
- Dylan16807 6y ago
  I'm reminded of this story about hidden network card bugs. Working in a bunch of tests doesn't mean something is correct, especially when it's complex. https://devblogs.microsoft.com/oldnewthing/20050512-48/?p=35653 https://devblogs.microsoft.com/oldnewthing/20050512-48/?p=35...
- vetinari 6y ago
  > It's not impossible that PulseAudio tries to play higher quality audio or simply uses the device differently. Pulseaudio mixes sound from several applications, unlike Alsa. Alsa just configures your soundcard for that one stream, Pulseaudio has no such luxury. In order to mix relatively small buffers (because latency), it needs to do timing. If your soundcard has problem with timing (and many do!), you will get crackling. The good news is, that the problem with timing can be only at specific frequencies; in the past, I had a computer with Nvidia Ion and it did this with 44,1kHz audio. With 48kHz, everything was OK. So fixing the output at 48kHz by forcing Pulse to mix at this frequency fixed the crackling.
  - frankling_ 6y ago
    Alsa has had software mixing via dmix since 2003. https://www.alsa-project.org/wiki/Main_Page_News https://www.alsa-project.org/wiki/Main_Page_News
    - vetinari 6y ago
      Yes, and it was off by default, because it had even bigger problems than PA.
      - frankling_ 6y ago
        I'll skip the usual list of personal anecdotes about PA failing in surprising ways I've never seen in 15+ years of using Alsa, but I will say that since a few applications have started depending on it, "apt-get purge pulseaudio" seems to always be in my shell history.
        vetinari 6y ago
        You know, that by doing that, you are trading short term gain for long term pain? Dmix for alsa was buggy, because just like PA, it didn't know about quirks of the hardware out in the field. And it stayed buggy, because nobody used it in return. Yes, PA was forced on users, but in the result the quirks were found, implemented and today, we all are better off. I didn't have any problem with PA since 2012 or so, but quite enjoyed the features it brought to the desktop.
deleted 6y ago
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Avamander 6y ago

> It does not "misbehave", when I use the same applications with ALSA, but whatever. I mean RDRAND is a great example here, if you never use it, you never encounter these bugs. It's not impossible that PulseAudio tries to play higher quality audio or simply uses the device differently. > I hope, that this particular group never ends up working on network hardware. I'd kinda love it, probably quite a few fun hardware bugs will be found.

Dylan16807 6y ago
I'm reminded of this story about hidden network card bugs. Working in a bunch of tests doesn't mean something is correct, especially when it's complex. https://devblogs.microsoft.com/oldnewthing/20050512-48/?p=35653 https://devblogs.microsoft.com/oldnewthing/20050512-48/?p=35...
vetinari 6y ago
> It's not impossible that PulseAudio tries to play higher quality audio or simply uses the device differently. Pulseaudio mixes sound from several applications, unlike Alsa. Alsa just configures your soundcard for that one stream, Pulseaudio has no such luxury. In order to mix relatively small buffers (because latency), it needs to do timing. If your soundcard has problem with timing (and many do!), you will get crackling. The good news is, that the problem with timing can be only at specific frequencies; in the past, I had a computer with Nvidia Ion and it did this with 44,1kHz audio. With 48kHz, everything was OK. So fixing the output at 48kHz by forcing Pulse to mix at this frequency fixed the crackling.
- frankling_ 6y ago
  Alsa has had software mixing via dmix since 2003. https://www.alsa-project.org/wiki/Main_Page_News https://www.alsa-project.org/wiki/Main_Page_News
  - vetinari 6y ago
    Yes, and it was off by default, because it had even bigger problems than PA.
    - frankling_ 6y ago
      I'll skip the usual list of personal anecdotes about PA failing in surprising ways I've never seen in 15+ years of using Alsa, but I will say that since a few applications have started depending on it, "apt-get purge pulseaudio" seems to always be in my shell history.
      - vetinari 6y ago
        You know, that by doing that, you are trading short term gain for long term pain? Dmix for alsa was buggy, because just like PA, it didn't know about quirks of the hardware out in the field. And it stayed buggy, because nobody used it in return. Yes, PA was forced on users, but in the result the quirks were found, implemented and today, we all are better off. I didn't have any problem with PA since 2012 or so, but quite enjoyed the features it brought to the desktop.

deleted 6y ago

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