Works like a charm. Thanks Frode.
Code:
$ grep -e rate -e sync FS-UAE.log.txt | grep -v opengl
video_sync = auto
fs_emu_set_video_frame_rate: 50
g_fs_emu_video_sync_to_vblank = 1
g_fs_emu_video_allow_full_sync = 1
frame rate (50) does not equal screen refresh (0)
fs_ml_video_sync_enable(0)
detected refresh rate: 49
checking video sync mode
will sync video updates to vblank
detected refresh rate: 49
assuming refresh rate: 49 (20408 usec per frame)
GL_ARB_sync extension found
deciding video sync method
- using default sync method
wait_for_frame_no_netplay: new frame rate 50 (time: 20000)
fs_emu_set_video_frame_rate: 50
g_fs_emu_video_sync_to_vblank = 1
g_fs_emu_video_allow_full_sync = 1
frame rate (50) close enough to screen refresh (49)
fs_ml_video_sync_enable(1)
SERIAL: period=372, baud=9600, hsyncs=16, bits=8, PC=fc2234
However I had to almost double the audio_buffer_target_bytes (14336). With the default settings I get buffer underruns.
Edit: At 50.3Hz I can set the audio_buffer_target_bytes to down 512 without any underruns.
Edit2: But only if vsync is enabled.