Does the playback file exist on a slow storage device? I have a few usb sticks that pause with cd quality wav files because of the slow I/O of the device. But the same file compressed to flac or mp3 on the same storage device will play without pauses. Or the cd quality file on any "faster" device, even sdhc cards plays without pauses. It could be a power management issue and hardware related. Swapping around the ports that things are plugged into or using a powered hub can help, sometimes. Try running something like nmon when you trigger the issue. With "L" for cpu, it can be a little more informative. With a blue "w" when it's waiting on something from the system. Which might indicate hardware type issues like bus speed or swap usage. Also check dmesg for indications of hardware issues (iffy connections). - James On 1/15/17, Fabian Keller <contact@xxxxxxxxxxxxxxxxx> wrote: > Hi all, > > While developing an audio software based on PortAudio, I discovered a > surprising problem related to ALSA: I'm getting short pauses in the > audio playback (sounding like typical buffer underruns) depending on > the audio amplitude. > > As a test, I have generated two wave files containing pure white > noise. One of them with an amplitude of 0.5 the other one using a full > range amplitude of 1.0. I'm playing both files with aplay, but I'm > getting the same behavior with other players and also with the > software I'm developing: The 0.5 amplitude files plays without any > issues. But the 1.0 amplitude file plays with short breaks in the > audio stream. I'm getting about two of these breaks per minute, but > there does not seem to be a deterministic pattern. I would guess the > pauses are <100 ms in duration, which is why I was debugging in the > direction of buffer underruns for many days until I discovered this > amplitude effect. I have xruns logging enabled, so I'm pretty sure > this is not related to that. > > Do you have any idea what could be causing this? > > System specs: > - Ubuntu 14.04. with the default libportaudio2 (based on the last 2014 > release) > - Standard Intel onboard sound: PCH [HDA Intel PCH], device 0: ALC892 > Analog [ALC892 Analog] > > Another test: Amplitude 0.9 also has breaks, so it is not just the > full range amplitude. > > Thanks, > Fabian > > ------------------------------------------------------------------------------ > Developer Access Program for Intel Xeon Phi Processors > Access to Intel Xeon Phi processor-based developer platforms. > With one year of Intel Parallel Studio XE. > Training and support from Colfax. > Order your platform today. http://sdm.link/xeonphi > _______________________________________________ > Alsa-user mailing list > Alsa-user@xxxxxxxxxxxxxxxxxxxxx > https://lists.sourceforge.net/lists/listinfo/alsa-user > ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user
