@MatN QEMU vm configuration (I left the default): - Hypervisor: KVM (strange: I had read that for 32-bit guests KVM could not work) - CPU Model: EPYC-Rome (I wish! I actually have a Ryzen 3700X) - Virtual Net: Default (NAT) - Mouse and Keyboard: PS/2 - Screen: Server Spice - Video: QXL (does not work with other options!) - Audio: HDA (ICH9) - USB: USB3 I didn't touch Debian or the VM. I just had to install some dependencies that, apparently, bld_prepare.sh didn't have installed. Maybe the fault is the DE used (LxQT) which is really minimal and unstable. Anyway the build from git works fine, video and audio. I only have problems with AV1. I have tried VP8, webm, Vorbis and h264, mkv. The only strange messages on the terminal are: FFMPEG::open_decoder: some stream times estimated: /home/test-deb/Video/1280.webm int MWindow::load_filenames(ArrayList<char*>*, int, int, int): [...] FFMPEG::open_decoder: some stream times estimated: /home/test-deb/Video/sample_1280x720_surfing_with_audio.mkv int MWindow::load_filenames(ArrayList<char*>*, int, int, int): But everything seems to work fine (remember: in the build, not appimage).