qemu git && 4.2: timed audio issues with sb16, gus not working?

[David Miller]

I have built [both] current git, and 4.2.0, there are issues with audio/soundhw for both.

Specifics:

Linux nullrig 5.3.0-24-generic #26-Ubuntu SMP Thu Nov 14 01:33:18 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux

Out of source build, successful for both:

../configure --prefix=/opt/qemu --target-list=i386-softmmu,mips64el-softmmu ---enable-sdl --enable-sdl-image --enable-lzo --enable-bzip2 --enable-avx2 --enable-kvm --enable-membarrier --enable-plugin

Call:

./qemu -machine pc,accel=kvm,usb=off -cpu pentium -m 64 -rtc base=localtime -parallel none -soundhw sb16,adlib,pcspk -device cirrus-vga,bus=pci.0 -drive id=disk1,file=doom.cow,format=qcow2,if=virtio -audiodev pa,id=pa

Audio for sb16 sounds ok, however if i switch to a timer based audio: -audiodev wav

The output is wrong.. I had assumed it was all timer based audio, however it seems to be limited to sb16.

So I then tried the next popular/compatible audio device for dos games: gravis ultrasound [gus].

I get no output at all for it.
I have tried more than one piece of software, DOOM shareware is any easy example.

I realize there are better solutions for playing DOS games, however I am interested in snapshot support which many of them lack.

I am willing to put the work into fixing it myself if need be, however i'm not very familiar with the audio backend. Specifically, it is already mixed into a single buffer, if 'adlib' driver is already working: (audio_pcm_ops.write() output is correct on timer based output) I failed to see how it affects emulation of the sound blaster.

[David Miller (zezuspam)]

./qemu is a symlink to qemu/build/i386-softmmu/qemu-system-i386

[David Miller (zezuspam)]

It seems this might be related to buffer/sample size, spice works and uses timed audio with a larger buffer.
GUS I have not gotten to work.

[Laurent Vivier (laurent-vivier)]

Fixed here:
https://git.qemu.org/?p=qemu.git;a=commitdiff;h=fdc8c5f4717f