On Sat, Mar 14, 2020 at 12:20:11AM +0200, Yorick Hardy wrote: > You are correct. I threw together a NetBSD audio driver based on the oss > driver, but it had exactly the same problem. Strangely, I have been unable to > reproduce the problem on an old i386 netbook (so far). > > I wrote a test program to try and reproduce what ffmpeg is doing, and > (I am not sure yet) it seems like non-blocking reads is causing the > distortion. The same test program with blocking reads seems to work > okay. > > I will look into it a bit more, and then report back.
Right, /dev/audio doesn't support non-blocking I/O. But you're supposed to do short enough reads and writes that it shouldn't matter. That might be the cause of the worst of the problems. Do you want to work on this together somewhere?
