mp4 demux: VPX: invalid PTS output by the demux

[000000014303a930] main encoder error: no suitable encoder module for fourcc `jpeg'.
VLC probably does not support this image format.
Assertion failed: (frame->i_pts != VLC_TICK_INVALID), function Decode, file vpx_alpha.c, line 513.
Process 40981 stopped
* thread #54, name = 'vlc-dec-video', stop reason = hit program assert
    frame #4: 0x000000010e982afc libvpx_alpha_plugin.dylib`Decode.cold.3 at vpx_alpha.c:513:13 [opt]
   510 	       }
   511 	       else
   512 	       {
-> 513 	           assert(frame->i_pts != VLC_TICK_INVALID);
   514 	           vlc_vector_push(&p_sys->missing_alpha, frame->i_pts);
   515 	       }
   516 	
Target 0: (vlc-osx-static) stopped.
warning: libvpx_alpha_plugin.dylib was compiled with optimization - stepping may behave oddly; variables may not be available.
(lldb) bt
* thread #54, name = 'vlc-dec-video', stop reason = hit program assert
    frame #0: 0x0000000185e56a60 libsystem_kernel.dylib`__pthread_kill + 8
    frame #1: 0x0000000185e8ec20 libsystem_pthread.dylib`pthread_kill + 288
    frame #2: 0x0000000185d9ba30 libsystem_c.dylib`abort + 180
    frame #3: 0x0000000185d9ad20 libsystem_c.dylib`__assert_rtn + 284
  * frame #4: 0x000000010e982afc libvpx_alpha_plugin.dylib`Decode.cold.3 at vpx_alpha.c:513:13 [opt]
    frame #5: 0x000000010e982090 libvpx_alpha_plugin.dylib`Decode(dec=<unavailable>, frame=0x0000600000727ea0) at vpx_alpha.c:513:13 [opt]
    frame #6: 0x000000010068ec04 libvlccore.dylib`DecoderThread_DecodeBlock(p_owner=0x00000001441a3e00, frame=0x0000600000727ea0) at decoder.c:1627:15 [opt]
    frame #7: 0x000000010068b7ec libvlccore.dylib`DecoderThread_ProcessInput(p_owner=<unavailable>, frame=<unavailable>) at decoder.c:1753:9 [opt] [artificial]
    frame #8: 0x000000010068c6cc libvlccore.dylib`DecoderThread(p_data=0x00000001441a3e00) at decoder.c:1867:9 [opt]
    frame #9: 0x0000000185e8ef94 libsystem_pthread.dylib`_pthread_start + 136

[000060000325a140] mp4 demux debug: elst (0) gives 0ms (movie)-> 0ms (track)
[000060000325a140] mp4 demux debug: track[Id 0x1] using Sync Sample Box (stss)
[000060000325a140] mp4 demux debug: stss gives 0 --> 0 (sample number)
[000060000325a140] mp4 demux debug: track[Id 0x1] sync point found sample 0(-0)
DEMUX MP4: MP4_ChunkGetSampleCTSDelta: count_pts=0 offset_pts=0
DEMUX MP4: Cannot MP4_ChunkGetSampleCTSDelta
[000060000325a140] mp4 demux debug: elst (0) gives 0ms (movie)-> 0ms (track)
[000060000325a140] mp4 demux debug: track[Id 0x2] preroll offset: -1 samples
DEMUX MP4: MP4_ChunkGetSampleCTSDelta: count_pts=0 offset_pts=0
DEMUX MP4: Cannot MP4_ChunkGetSampleCTSDelta
DEMUX MP4: UNKNOWN_DELTA
[000000013b076000] main input debug: program(0): using clock source: 'audio'
[000000013b076000] main input debug: Buffering 0%
DEMUX MP4: i_current_nzdts=0 dts=1
DEMUX MP4: i_current_nzpts=-9223372036854775808 pts=0
DEMUX MP4: MP4_ChunkGetSampleCTSDelta: count_pts=0 offset_pts=0
DEMUX MP4: Cannot MP4_ChunkGetSampleCTSDelta
DEMUX MP4: MP4_ChunkGetSampleCTSDelta: count_pts=0 offset_pts=0
DEMUX MP4: Cannot MP4_ChunkGetSampleCTSDelta
DEMUX MP4: UNKNOWN_DELTA
DEMUX MP4: i_current_nzdts=0 dts=1
DEMUX MP4: i_current_nzpts=0 pts=1
DEMUX MP4: MP4_ChunkGetSampleCTSDelta: count_pts=0 offset_pts=0
DEMUX MP4: Cannot MP4_ChunkGetSampleCTSDelta
DEMUX MP4: MP4_ChunkGetSampleCTSDelta: count_pts=0 offset_pts=0
DEMUX MP4: Cannot MP4_ChunkGetSampleCTSDelta
DEMUX MP4: i_current_nzdts=23219 dts=23220