(gdb) run --hwdec=vaapi --vo=vaapi --vf=vavpp:deint=motion-adaptive ~/x264-letters.mkv
Starting program: /mnt/sdb1/Gits/mpv-build/mpv/build/mpv --hwdec=vaapi --vo=vaapi --vf=vavpp:deint=motion-adaptive ~/x264-letters.mkv
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/libthread_db.so.1".
[New Thread 0x7fffedb31700 (LWP 29578)]
Playing: /home/andy/x264-letters.mkv
[New Thread 0x7fffed330700 (LWP 29579)]
[Thread 0x7fffed330700 (LWP 29579) exited]
 (+) Video --vid=1 (*) (h264)
[New Thread 0x7fffed330700 (LWP 29580)]
[New Thread 0x7fffecb2f700 (LWP 29581)]
[New Thread 0x7fffe7fff700 (LWP 29582)]
libva info: VA-API version 0.38.1
libva info: va_getDriverName() returns 0
libva info: Trying to open /usr/lib/dri/radeonsi_drv_video.so
libva info: Found init function __vaDriverInit_0_38
libva info: va_openDriver() returns 0
Opening video filter: [vavpp deint=motion-adaptive]
[Thread 0x7fffe7fff700 (LWP 29582) exited]
Using hardware decoding (vaapi).
VO: [vaapi] 720x576 => 1024x576 vaapi
mpv: vl/vl_deint_filter.c:452: vl_deint_filter_render: Assertion `filter && prevprev && prev && cur && next && field <= 1' failed.

Program received signal SIGABRT, Aborted.
0x00007ffff13695c8 in raise () from /lib/libc.so.6
(gdb) bt
#0  0x00007ffff13695c8 in raise () from /lib/libc.so.6
#1  0x00007ffff136aa4a in abort () from /lib/libc.so.6
#2  0x00007ffff13623e7 in __assert_fail_base () from /lib/libc.so.6
#3  0x00007ffff1362492 in __assert_fail () from /lib/libc.so.6
#4  0x00007fffe72c7132 in vl_deint_filter_render (filter=<optimized out>, prevprev=<optimized out>, prev=<optimized out>, cur=cur@entry=0x1e749d0, next=<optimized out>, field=field@entry=2) at vl/vl_deint_filter.c:452
#5  0x00007fffe72a9b54 in vlVaApplyDeint (drv=0x7fffe825f330, drv=0x7fffe825f330, context=0x1e267f0, field=2, current=0x1e749d0, param=0x1feba40) at postproc.c:218
#6  vlVaHandleVAProcPipelineParameterBufferType (drv=drv@entry=0x7fffe825f330, context=context@entry=0x1e267f0, buf=buf@entry=0x206f4c0) at postproc.c:275
#7  0x00007fffe72a740e in vlVaRenderPicture (ctx=<optimized out>, context_id=<optimized out>, buffers=<optimized out>, num_buffers=<optimized out>) at picture.c:328
#8  0x000000000051065a in render (vf=vf@entry=0x1e25c60, in=in@entry=0x1ff7720, flags=18) at ../video/filter/vf_vavpp.c:232
#9  0x0000000000510e90 in output_frames (vf=0x1e25c60) at ../video/filter/vf_vavpp.c:266
#10 filter_ext (vf=0x1e25c60, in=<optimized out>) at ../video/filter/vf_vavpp.c:342
#11 0x000000000050b3a2 in vf_do_filter (vf=0x1e25c60, img=0x20129d0) at ../video/filter/vf.c:366
#12 0x000000000050b4c8 in vf_output_frame_until (c=c@entry=0x1e25090, until=0x1e258e0, eof=false) at ../video/filter/vf.c:421
#13 0x000000000050b59e in vf_output_frame_until (eof=<optimized out>, until=<optimized out>, c=0x1e25090) at ../video/filter/vf.c:400
#14 vf_output_frame (c=c@entry=0x1e25090, eof=eof@entry=false) at ../video/filter/vf.c:434
#15 0x00000000004e0424 in video_filter (mpctx=mpctx@entry=0x1ddddb0, eof=eof@entry=false) at ../player/video.c:489
#16 0x00000000004e05de in video_decode_and_filter (mpctx=mpctx@entry=0x1ddddb0) at ../player/video.c:559
#17 0x00000000004e1c60 in video_output_image (endpts=-9.2233720368547758e+18, mpctx=0x1ddddb0) at ../player/video.c:709
#18 write_video (mpctx=mpctx@entry=0x1ddddb0, endpts=endpts@entry=-9.2233720368547758e+18) at ../player/video.c:1194
#19 0x00000000004ddd3e in run_playloop (mpctx=mpctx@entry=0x1ddddb0) at ../player/playloop.c:945
#20 0x00000000004d9262 in play_current_file (mpctx=0x1ddddb0) at ../player/loadfile.c:1225
#21 mp_play_files (mpctx=mpctx@entry=0x1ddddb0) at ../player/loadfile.c:1378
#22 0x00000000004da12c in mpv_main (argc=<optimized out>, argv=0x7fffffffe0f8) at ../player/main.c:517
#23 0x00007ffff13565e0 in __libc_start_main () from /lib/libc.so.6
#24 0x000000000047fd49 in _start ()