I installed the latest VLC 3.0 from the Ubuntu snap store yesterday which I assume is the official release version with the switch --devmode, to make VLC usable. I watched one 1080p movie with no major problems but playing a 2160p movie was different story altogether. The movie continuously stuttered the whole time, ie played a few seconds then stopped repeatedly with occasional white/pixalated screen. A look at the message log (below) shows a plethora of errors.
The PC runs ubuntu 17.10 with a intel i5-4430 CPU and no discreet graphics card and I am using X-11 display.
main debug: processing request item: 1 The Purge 2013.mkv, node: Playlist, skip: 0
main debug: rebuilding array of current - root Playlist
main debug: rebuild done - 4 items, index 3
main debug: starting playback of new item
main debug: resyncing on 1 The Purge 2013.mkv
main debug: 1 The Purge 2013.mkv is at 3
main debug: creating new input thread
main debug: Creating an input for '1 The Purge 2013.mkv'
main debug: requesting art for new input thread
main debug: using timeshift granularity of 50 MiB
main debug: using default timeshift path
main debug: looking for meta fetcher module matching "any": 1 candidates
main debug: `file:///media/pool/Entertainment/Movies%20Horror%20and%20Supernatural/The%20Purge/1%20The%20Purge%202013.mkv' gives access `file' demux `any' path `/media/pool/Entertainment/Movies%20Horror%20and%20Supernatural/The%20Purge/1%20The%20Purge%202013.mkv'
lua debug: Trying Lua scripts in /home/scott/snap/vlc/158/.local/share/vlc/lua/meta/fetcher
main debug: creating demux: access='file' demux='any' location='/media/pool/Entertainment/Movies%20Horror%20and%20Supernatural/The%20Purge/1%20The%20Purge%202013.mkv' file='/media/pool/Entertainment/Movies Horror and Supernatural/The Purge/1 The Purge 2013.mkv'
main debug: looking for access_demux module matching "file": 21 candidates
lua debug: Trying Lua scripts in /snap/vlc/158/usr/lib/vlc/lua/meta/fetcher
lua debug: Trying Lua scripts in /snap/vlc/158/usr/share/vlc/lua/meta/fetcher
main debug: no meta fetcher modules matched
main debug: looking for art finder module matching "any": 2 candidates
qt debug: IM: Setting an input
lua debug: Trying Lua scripts in /home/scott/snap/vlc/158/.local/share/vlc/lua/meta/art
lua debug: Trying Lua scripts in /snap/vlc/158/usr/lib/vlc/lua/meta/art
lua debug: Trying Lua playlist script /snap/vlc/158/usr/lib/vlc/lua/meta/art/00_musicbrainz.luac
lua debug: skipping script (unmatched scope) /snap/vlc/158/usr/lib/vlc/lua/meta/art/00_musicbrainz.luac
lua debug: Trying Lua playlist script /snap/vlc/158/usr/lib/vlc/lua/meta/art/01_googleimage.luac
lua debug: skipping script (unmatched scope) /snap/vlc/158/usr/lib/vlc/lua/meta/art/01_googleimage.luac
lua debug: Trying Lua playlist script /snap/vlc/158/usr/lib/vlc/lua/meta/art/02_frenchtv.luac
lua debug: skipping script (unmatched scope) /snap/vlc/158/usr/lib/vlc/lua/meta/art/02_frenchtv.luac
lua debug: Trying Lua playlist script /snap/vlc/158/usr/lib/vlc/lua/meta/art/03_lastfm.luac
lua debug: skipping script (unmatched scope) /snap/vlc/158/usr/lib/vlc/lua/meta/art/03_lastfm.luac
lua debug: Trying Lua scripts in /snap/vlc/158/usr/share/vlc/lua/meta/art
main debug: no art finder modules matched
main debug: looking for meta fetcher module matching "any": 1 candidates
lua debug: Trying Lua scripts in /home/scott/snap/vlc/158/.local/share/vlc/lua/meta/fetcher
lua debug: Trying Lua scripts in /snap/vlc/158/usr/lib/vlc/lua/meta/fetcher
lua debug: Trying Lua scripts in /snap/vlc/158/usr/share/vlc/lua/meta/fetcher
main debug: no meta fetcher modules matched
main debug: looking for art finder module matching "any": 2 candidates
lua debug: Trying Lua scripts in /home/scott/snap/vlc/158/.local/share/vlc/lua/meta/art
lua debug: Trying Lua scripts in /snap/vlc/158/usr/lib/vlc/lua/meta/art
lua debug: Trying Lua playlist script /snap/vlc/158/usr/lib/vlc/lua/meta/art/00_musicbrainz.luac
lua debug: Trying Lua playlist script /snap/vlc/158/usr/lib/vlc/lua/meta/art/01_googleimage.luac
lua debug: Trying Lua playlist script /snap/vlc/158/usr/lib/vlc/lua/meta/art/02_frenchtv.luac
lua debug: Trying Lua playlist script /snap/vlc/158/usr/lib/vlc/lua/meta/art/03_lastfm.luac
lua debug: Trying Lua scripts in /snap/vlc/158/usr/share/vlc/lua/meta/art
main debug: no art finder modules matched
main debug: no access_demux modules matched
main debug: creating access: file:///media/pool/Entertainment/Movies%20Horror%20and%20Supernatural/The%20Purge/1%20The%20Purge%202013.mkv
main debug: (path: /media/pool/Entertainment/Movies Horror and Supernatural/The Purge/1 The Purge 2013.mkv)
main debug: looking for access module matching "file": 26 candidates
main debug: using access module "filesystem"
main debug: looking for stream_filter module matching "prefetch,cache_read": 26 candidates
cache_read debug: Using stream method for AStream*
cache_read debug: starting pre-buffering
cache_read debug: received first data after 0 ms
cache_read debug: pre-buffering done 1024 bytes in 0s - 66666 KiB/s
main debug: using stream_filter module "cache_read"
main debug: looking for stream_filter module matching "any": 26 candidates
lua debug: Trying Lua scripts in /home/scott/snap/vlc/158/.local/share/vlc/lua/playlist
lua debug: Trying Lua scripts in /snap/vlc/158/usr/lib/vlc/lua/playlist
lua debug: Trying Lua playlist script /snap/vlc/158/usr/lib/vlc/lua/playlist/anevia_streams.luac
lua debug: Trying Lua playlist script /snap/vlc/158/usr/lib/vlc/lua/playlist/anevia_xml.luac
lua debug: Trying Lua playlist script /snap/vlc/158/usr/lib/vlc/lua/playlist/appletrailers.luac
lua debug: Trying Lua playlist script /snap/vlc/158/usr/lib/vlc/lua/playlist/bbc_co_uk.luac
lua debug: Trying Lua playlist script /snap/vlc/158/usr/lib/vlc/lua/playlist/cue.luac
lua debug: Trying Lua playlist script /snap/vlc/158/usr/lib/vlc/lua/playlist/dailymotion.luac
lua debug: Trying Lua playlist script /snap/vlc/158/usr/lib/vlc/lua/playlist/jamendo.luac
lua debug: Trying Lua playlist script /snap/vlc/158/usr/lib/vlc/lua/playlist/koreus.luac
lua debug: Trying Lua playlist script /snap/vlc/158/usr/lib/vlc/lua/playlist/liveleak.luac
lua debug: Trying Lua playlist script /snap/vlc/158/usr/lib/vlc/lua/playlist/newgrounds.luac
lua debug: Trying Lua playlist script /snap/vlc/158/usr/lib/vlc/lua/playlist/rockbox_fm_presets.luac
lua debug: Trying Lua playlist script /snap/vlc/158/usr/lib/vlc/lua/playlist/soundcloud.luac
lua debug: Trying Lua playlist script /snap/vlc/158/usr/lib/vlc/lua/playlist/twitch.luac
lua debug: Trying Lua playlist script /snap/vlc/158/usr/lib/vlc/lua/playlist/vimeo.luac
lua debug: Trying Lua playlist script /snap/vlc/158/usr/lib/vlc/lua/playlist/vocaroo.luac
lua debug: Trying Lua playlist script /snap/vlc/158/usr/lib/vlc/lua/playlist/youtube.luac
lua debug: Trying Lua scripts in /snap/vlc/158/usr/share/vlc/lua/playlist
main debug: no stream_filter modules matched
main debug: looking for stream_directory module matching "any": 0 candidates
main debug: no stream_directory modules
main debug: attachment of directory-extractor failed for file:///media/pool/Entertainment/Movies%20Horror%20and%20Supernatural/The%20Purge/1%20The%20Purge%202013.mkv
main debug: looking for stream_filter module matching "record": 26 candidates
main debug: using stream_filter module "record"
main debug: creating demux: access='file' demux='any' location='/media/pool/Entertainment/Movies%20Horror%20and%20Supernatural/The%20Purge/1%20The%20Purge%202013.mkv' file='/media/pool/Entertainment/Movies Horror and Supernatural/The Purge/1 The Purge 2013.mkv'
main debug: looking for demux module matching "mkv": 55 candidates
mkv debug: | + Seek head
mkv debug: | - info at 4151
mkv debug: | + Information
mkv debug: | | + TimecodeScale=1000000
mkv debug: | | + Muxing Application=libebml v1.3.5 + libmatroska v1.4.8
mkv debug: | | + Writing Application=mkvmerge v20.0.0 ('I Am The Sun') 64-bit
mkv debug: | | + Duration=5112171
mkv debug: | | + Date=Sun Jan 21 12:24:42 2018
mkv debug: | | + UID=1355435813
mkv debug: | - tracks at 4281
mkv debug: | + Tracks
mkv debug: | | + Track Entry
mkv debug: | | | + Track Number=1
mkv debug: | | | + Track UID=3682470927
mkv debug: | | | + Track Type=video
mkv debug: | | | + Track Lacing=0
mkv debug: | | | + Track CodecId=V_MPEGH/ISO/HEVC
mkv debug: | | | + Track Language=`zxx'
mkv debug: | | | + Track Video
mkv debug: | | | | + width=3840
mkv debug: | | | | + height=2160
mkv debug: | | | | + display width=3840
mkv debug: | | | | + display height=2160
mkv debug: | | | + Track CodecPrivate size=206
mkv debug: | | | + Track Default Duration=41708333
mkv debug: | | + Track Entry
mkv debug: | | | + Track Number=2
mkv debug: | | | + Track UID=1134574109
mkv debug: | | | + Track Type=audio
mkv debug: | | | + Track CodecId=A_DTS
mkv debug: | | | + Track Default Duration=10666667
mkv debug: | | | + Track Audio
mkv debug: | | | | + afreq=48000
mkv debug: | | | | + achan=6
mkv debug: | | | | + abits=24
mkv debug: | | + Track Entry
mkv debug: | | | + Track Number=3
mkv debug: | | | + Track UID=2954067057
mkv debug: | | | + Track Type=subtitle
mkv debug: | | | + Track Lacing=0
mkv debug: | | | + Track CodecId=S_TEXT/UTF8
mkv debug: | - cues at 55732196481
mkv debug: | + Cues
mkv debug: | - loading cues done.
mkv debug: | - tags at 55732351544
mkv debug: | + Tags
mkv debug: + Tag
mkv debug: | + Targets
mkv debug: | | + TargetTypeValue: 50
mkv debug: | | + TrackUID: 2150711113446984719
mkv debug: | | + LoadTag Unknown (N11libmatroska16KaxTagTargetTypeE)
mkv debug: | + Simple Tag
mkv debug: | | + Meta BPS: 82978083
mkv debug: | + Simple Tag
mkv debug: | | + Meta DURATION: 01:25:12.149000000
mkv debug: | + Simple Tag
mkv debug: | | + Meta NUMBER_OF_FRAMES: 122569
mkv debug: | + Simple Tag
mkv debug: | | + Meta NUMBER_OF_BYTES: 53024541080
mkv debug: | + Simple Tag
mkv debug: | | + Meta _STATISTICS_WRITING_APP: mkvmerge v20.0.0 ('I Am The Sun') 64-bit
mkv debug: | + Simple Tag
mkv debug: | | + Meta _STATISTICS_WRITING_DATE_UTC: 2018-01-21 12:24:42
mkv debug: | + Simple Tag
mkv debug: | | + Meta _STATISTICS_TAGS: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES
mkv debug: + Tag
mkv debug: | + Targets
mkv debug: | | + TargetTypeValue: 50
mkv debug: | | + TrackUID: 13379801169537284637
mkv debug: | | + LoadTag Unknown (N11libmatroska16KaxTagTargetTypeE)
mkv debug: | + Simple Tag
mkv debug: | | + Meta BPS: 4233094
mkv debug: | + Simple Tag
mkv debug: | | + Meta DURATION: 01:25:12.171000000
mkv debug: | + Simple Tag
mkv debug: | | + Meta NUMBER_OF_FRAMES: 479266
mkv debug: | + Simple Tag
mkv debug: | | + Meta NUMBER_OF_BYTES: 2705037612
mkv debug: | + Simple Tag
mkv debug: | | + Meta _STATISTICS_WRITING_APP: mkvmerge v20.0.0 ('I Am The Sun') 64-bit
mkv debug: | + Simple Tag
mkv debug: | | + Meta _STATISTICS_WRITING_DATE_UTC: 2018-01-21 12:24:42
mkv debug: | + Simple Tag
mkv debug: | | + Meta _STATISTICS_TAGS: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES
mkv debug: + Tag
mkv debug: | + Targets
mkv debug: | | + TargetTypeValue: 50
mkv debug: | | + TrackUID: 3786566977834941553
mkv debug: | | + LoadTag Unknown (N11libmatroska16KaxTagTargetTypeE)
mkv debug: | + Simple Tag
mkv debug: | | + Meta BPS: 47
mkv debug: | + Simple Tag
mkv debug: | | + Meta DURATION: 01:18:12.313000000
mkv debug: | + Simple Tag
mkv debug: | | + Meta NUMBER_OF_FRAMES: 954
mkv debug: | + Simple Tag
mkv debug: | | + Meta NUMBER_OF_BYTES: 27710
mkv debug: | + Simple Tag
mkv debug: | | + Meta _STATISTICS_WRITING_APP: mkvmerge v20.0.0 ('I Am The Sun') 64-bit
mkv debug: | + Simple Tag
mkv debug: | | + Meta _STATISTICS_WRITING_DATE_UTC: 2018-01-21 12:24:42
mkv debug: | + Simple Tag
mkv debug: MKV/Ebml Parser: m_el[mi_level] == NULL
mkv debug: | | + Meta _STATISTICS_TAGS: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES
mkv debug: MKV/Ebml Parser: m_el[mi_level] == NULL
mkv debug: loading tags done.
mkv debug: | + Information
mkv debug: | + Tracks
mkv debug: | + Cluster
mkv debug: NEW START CHAPTER uid=0
mkv debug: found 3 es
main debug: selecting program id=0
mkv debug: seek: preroll{ track: 1, pts: 0, fpos: 5590 }
mkv debug: seek: preroll{ req: 1, start-pts: 1, start-fpos: 5590}
mkv debug: Starting the UI Hook
main debug: using demux module "mkv"
main debug: looking for a subtitle file in /media/pool/Entertainment/Movies Horror and Supernatural/The Purge/
main debug: looking for video decoder module matching "any": 16 candidates
avcodec debug: using ffmpeg Lavc58.6.103
avcodec debug: CPU flags: 0x000fd3db
avcodec debug: allowing 5 thread(s) for decoding
avcodec debug: codec (hevc) started
avcodec debug: using frame thread mode with 5 threads
main debug: using video decoder module "avcodec"
main debug: looking for packetizer module matching "any": 24 candidates
main debug: using packetizer module "dts"
main debug: looking for audio decoder module matching "any": 20 candidates
main debug: reusing audio output
vlcpulse error: digital pass-through stream connection failure: Not supported
main error: module not functional
main debug: keeping audio output
main error: failed to create audio output
avcodec debug: using ffmpeg Lavc58.6.103
avcodec debug: CPU flags: 0x000fd3db
avcodec debug: codec (dca) started
main debug: using audio decoder module "avcodec"
main debug: looking for spu decoder module matching "any": 22 candidates
avcodec debug: using ffmpeg Lavc58.6.103
avcodec debug: CPU flags: 0x000fd3db
avcodec warning: refusing to decode non validated subtitle codec
subsdec debug: trying demuxer-specified character encoding: UTF-8
main debug: using spu decoder module "subsdec"
main debug: looking for meta reader module matching "any": 2 candidates
lua debug: Trying Lua scripts in /home/scott/snap/vlc/158/.local/share/vlc/lua/meta/reader
lua debug: Trying Lua scripts in /snap/vlc/158/usr/lib/vlc/lua/meta/reader
lua debug: Trying Lua playlist script /snap/vlc/158/usr/lib/vlc/lua/meta/reader/filename.luac
lua debug: Trying Lua scripts in /snap/vlc/158/usr/share/vlc/lua/meta/reader
main debug: no meta reader modules matched
main debug: `file:///media/pool/Entertainment/Movies%20Horror%20and%20Supernatural/The%20Purge/1%20The%20Purge%202013.mkv' successfully opened
main debug: Buffering 0%
main debug: Buffering 13%
main debug: Buffering 41%
main debug: Stream buffering done (334 ms in 0 ms)
dts debug: DTS samplerate:48000 bitrate:1536000
main debug: restarting module due to input format change
main debug: removing module "avcodec"
main debug: looking for audio decoder module matching "any": 20 candidates
main debug: reusing audio output
vlcpulse error: digital pass-through stream connection failure: Not supported
main error: module not functional
main debug: keeping audio output
main error: failed to create audio output
avcodec debug: using ffmpeg Lavc58.6.103
avcodec debug: CPU flags: 0x000fd3db
avcodec debug: codec (dca) started
main debug: using audio decoder module "avcodec"
main debug: reusing audio output
pulse debug: using ? channel map
pulse debug: changed buffer metrics: maxlength=4194312, tlength=138240, prebuf=0, minreq=46080
pulse debug: connected to sink alsa_output.pci-0000_00_1b.0.iec958-stereo
main debug: output 'f32l' 48000 Hz 3F2M/LFE frame=1 samples/24 bytes
main debug: looking for audio volume module matching "any": 2 candidates
main debug: using audio volume module "float_mixer"
main debug: input 's32l' 48000 Hz 3F2M/LFE frame=1 samples/24 bytes
main debug: looking for audio filter module matching "scaletempo": 16 candidates
scaletempo debug: format: 48000 rate, 6 nch, 4 bps, fl32
scaletempo debug: params: 30 stride, 0.200 overlap, 14 search
scaletempo debug: 1.000 scale, 1440.000 stride_in, 1440 stride_out, 1152 standing, 288 overlap, 672 search, 2400 queue, fl32 mode
pulse debug: changing sink 1: alsa_output.pci-0000_00_1b.0.iec958-stereo (Built-in Audio Digital Stereo (IEC958))
main debug: using audio filter module "scaletempo"
main debug: conversion: 's32l'->'f32l' 48000 Hz->48000 Hz 3F2M/LFE->3F2M/LFE
main debug: looking for audio converter module matching "any": 8 candidates
audio_format debug: s32l->f32l, bits per sample: 32->32
main debug: using audio converter module "audio_format"
main debug: conversion pipeline complete
main debug: conversion: 'f32l'->'f32l' 48000 Hz->48000 Hz 3F2M/LFE->3F2M/LFE
main debug: conversion pipeline complete
main debug: looking for audio resampler module matching "any": 3 candidates
main debug: using audio resampler module "samplerate"
avcodec debug: available hardware decoder output format 46 (vaapi_vld)
avcodec debug: available hardware decoder output format 119 (cuda)
avcodec debug: available software decoder output format 64 (yuv420p10le)
avcodec debug: trying format vaapi_vld
main debug: looking for text renderer module matching "any": 3 candidates
freetype debug: Building font databases.
freetype debug: Took -39018 microseconds
main debug: using text renderer module "freetype"
main debug: looking for video converter module matching "any": 23 candidates
swscale debug: 32x32 (32x32) chroma: YUVA -> 16x16 (16x16) chroma: RGBA with scaling using Bicubic (good quality)
main debug: using video converter module "swscale"
main debug: looking for video converter module matching "any": 23 candidates
yuvp debug: YUVP to YUVA converter
main debug: using video converter module "yuvp"
main debug: Deinterlacing available
main debug: deinterlace -1, mode auto, is_needed 0
main debug: looking for vout window module matching "qt,any": 4 candidates
qt debug: requesting video window...
main debug: using vout window module "qt"
main debug: looking for inhibit module matching "any": 2 candidates
dbus_screensaver debug: found service org.freedesktop.ScreenSaver
main debug: using inhibit module "dbus_screensaver"
main debug: Opening vout display wrapper
main debug: looking for vout display module matching "any": 11 candidates
main debug: VoutDisplayEvent 'resize' 3840x2160
main debug: looking for opengl module matching "any": 2 candidates
main debug: resized to 3840x2160
main debug: VoutDisplayEvent 'resize' 3840x2160
main debug: resized to 1869x1025
main debug: VoutDisplayEvent 'resize' 1869x1025
egl_x11 debug: EGL version 1.4 (DRI2) by Mesa Project
egl_x11 debug: extensions: EGL_CHROMIUM_sync_control EGL_EXT_buffer_age EGL_EXT_create_context_robustness EGL_EXT_image_dma_buf_import EGL_KHR_create_context EGL_KHR_fence_sync EGL_KHR_get_all_proc_addresses EGL_KHR_gl_renderbuffer_image EGL_KHR_gl_texture_2D_image EGL_KHR_gl_texture_cubemap_image EGL_KHR_image EGL_KHR_image_base EGL_KHR_image_pixmap EGL_KHR_surfaceless_context EGL_KHR_wait_sync EGL_MESA_configless_context EGL_MESA_drm_image EGL_MESA_image_dma_buf_export EGL_NOK_texture_from_pixmap EGL_WL_bind_wayland_display
main debug: using opengl module "egl_x11"
main debug: looking for glconv module matching "any": 3 candidates
main debug: using glconv module "glconv_vaapi_x11"
main debug: using vout display module "gl"
glconv_vaapi_x11 warning: Can't create Image KHR: kernel too old ?
main debug: removing module "gl"
main debug: removing module "glconv_vaapi_x11"
main debug: removing module "egl_x11"
main debug: resized to 600x420
main debug: VoutDisplayEvent 'resize' 600x420
main error: video output creation failed
dbus_screensaver debug: got cookie 633984152
main debug: removing module "dbus_screensaver"
qt debug: releasing video...
qt debug: Video is not needed anymore
main debug: removing module "freetype"
main debug: removing module "yuvp"
main debug: removing module "swscale"
main error: failed to create video output
main debug: looking for text renderer module matching "any": 3 candidates
freetype debug: Building font databases.
freetype debug: Took -10114 microseconds
main debug: using text renderer module "freetype"
main debug: looking for video converter module matching "any": 23 candidates
swscale debug: 32x32 (32x32) chroma: YUVA -> 16x16 (16x16) chroma: RGBA with scaling using Bicubic (good quality)
main debug: using video converter module "swscale"
main debug: looking for video converter module matching "any": 23 candidates
yuvp debug: YUVP to YUVA converter
main debug: using video converter module "yuvp"
main debug: Deinterlacing available
main debug: deinterlace -1, mode auto, is_needed 0
main debug: looking for vout window module matching "qt,any": 4 candidates
qt debug: requesting video window...
main debug: using vout window module "qt"
main debug: looking for inhibit module matching "any": 2 candidates
dbus_screensaver debug: found service org.freedesktop.ScreenSaver
main debug: using inhibit module "dbus_screensaver"
main debug: Opening vout display wrapper
main debug: looking for vout display module matching "any": 11 candidates
main debug: VoutDisplayEvent 'resize' 3840x2160
main debug: looking for opengl module matching "any": 2 candidates
main debug: resized to 3840x2160
main debug: VoutDisplayEvent 'resize' 3840x2160
main debug: resized to 1920x1080
main debug: VoutDisplayEvent 'resize' 1920x1080
egl_x11 debug: EGL version 1.4 (DRI2) by Mesa Project
egl_x11 debug: extensions: EGL_CHROMIUM_sync_control EGL_EXT_buffer_age EGL_EXT_create_context_robustness EGL_EXT_image_dma_buf_import EGL_KHR_create_context EGL_KHR_fence_sync EGL_KHR_get_all_proc_addresses EGL_KHR_gl_renderbuffer_image EGL_KHR_gl_texture_2D_image EGL_KHR_gl_texture_cubemap_image EGL_KHR_image EGL_KHR_image_base EGL_KHR_image_pixmap EGL_KHR_surfaceless_context EGL_KHR_wait_sync EGL_MESA_configless_context EGL_MESA_drm_image EGL_MESA_image_dma_buf_export EGL_NOK_texture_from_pixmap EGL_WL_bind_wayland_display
main debug: using opengl module "egl_x11"
gl debug: MAP_PERSISTENT support (direct rendering) enabled
main debug: resized to 1869x1025
main debug: VoutDisplayEvent 'resize' 1869x1025
main debug: using vout display module "gl"
main debug: original format sz 3840x2176, of (0,0), vsz 3840x2160, 4cc I0AL, sar 1:1, msk r0x0 g0x0 b0x0
main debug: removing module "freetype"
main debug: looking for text renderer module matching "any": 3 candidates
freetype debug: Building font databases.
freetype debug: Took -10486 microseconds
main debug: using text renderer module "freetype"
qt debug: Qt: Entering Fullscreen
main debug: Received first picture
main error: buffer deadlock prevented
main debug: Decoder wait done in 737 ms
pulse debug: cannot synchronize start
pulse debug: deferring start (9638 us)
pulse warning: starting late (-1610 us)
pulse debug: started
pulse debug: underflow
pulse debug: underflow
pulse debug: changing sink 1: alsa_output.pci-0000_00_1b.0.iec958-stereo (Built-in Audio Digital Stereo (IEC958))
pulse debug: underflow
pulse debug: underflow
pulse debug: underflow
main debug: auto hiding mouse cursor
main debug: picture might be displayed late (missing 12 ms)
main warning: picture is too late to be displayed (missing 29 ms)
main warning: picture is too late to be displayed (missing 37 ms)
main warning: picture is too late to be displayed (missing 20 ms)
main warning: picture is too late to be displayed (missing 21 ms)
main warning: picture is too late to be displayed (missing 42 ms)
main warning: picture is too late to be displayed (missing 35 ms)
main debug: auto hiding mouse cursor
main debug: auto hiding mouse cursor
main debug: picture might be displayed late (missing 1 ms)
main debug: picture might be displayed late (missing 8 ms)
main warning: picture is too late to be displayed (missing 27 ms)
main warning: picture is too late to be displayed (missing 75 ms)
main warning: picture is too late to be displayed (missing 96 ms)
main warning: picture is too late to be displayed (missing 54 ms)
main debug: picture might be displayed late (missing 13 ms)
main debug: picture might be displayed late (missing 12 ms)
main warning: picture is too late to be displayed (missing 77 ms)
main warning: picture is too late to be displayed (missing 102 ms)
main warning: picture is too late to be displayed (missing 60 ms)
main debug: picture might be displayed late (missing 19 ms)
main warning: picture is too late to be displayed (missing 25 ms)
main debug: killing decoder fourcc `subt'
main debug: removing module "subsdec"
main warning: picture is too late to be displayed (missing 98 ms)
main warning: picture is too late to be displayed (missing 148 ms)
main warning: picture is too late to be displayed (missing 106 ms)
main warning: picture is too late to be displayed (missing 66 ms)
main warning: picture is too late to be displayed (missing 25 ms)
main warning: picture is too late to be displayed (missing 52 ms)
main warning: picture is too late to be displayed (missing 78 ms)
main warning: picture is too late to be displayed (missing 128 ms)
main warning: picture is too late to be displayed (missing 131 ms)
main warning: picture is too late to be displayed (missing 90 ms)
main warning: picture is too late to be displayed (missing 90 ms)
main warning: picture is too late to be displayed (missing 51 ms)
main warning: picture is too late to be displayed (missing 84 ms)
main warning: picture is too late to be displayed (missing 45 ms)
main warning: picture is too late to be displayed (missing 64 ms)
main warning: picture is too late to be displayed (missing 68 ms)
main warning: picture is too late to be displayed (missing 89 ms)
avcodec warning: More than 11 late frames, dropping frame
main warning: picture is too late to be displayed (missing 48 ms)
avcodec error: more than 5 seconds of late video -> dropping frame (computer too slow ?)
avcodec error: more than 5 seconds of late video -> dropping frame (computer too slow ?)
avcodec error: more than 5 seconds of late video -> dropping frame (computer too slow ?)
avcodec error: more than 5 seconds of late video -> dropping frame (computer too slow ?)
avcodec error: more than 5 seconds of late video -> dropping frame (computer too slow ?)
avcodec error: more than 5 seconds of late video -> dropping frame (computer too slow ?)
avcodec error: more than 5 seconds of late video -> dropping frame (computer too slow ?)
avcodec error: more than 5 seconds of late video -> dropping frame (computer too slow ?)
avcodec error: more than 5 seconds of late video -> dropping frame (computer too slow ?)
avcodec error: more than 5 seconds of late video -> dropping frame (computer too slow ?)
avcodec error: more than 5 seconds of late video -> dropping frame (computer too slow ?)
main warning: picture is too late to be displayed (missing 42 ms)
main warning: picture is too late to be displayed (missing 135 ms)
main warning: picture is too late to be displayed (missing 106 ms)
main warning: picture is too late to be displayed (missing 147 ms)
main warning: picture is too late to be displayed (missing 189 ms)
main warning: picture is too late to be displayed (missing 64 ms)
main warning: picture is too late to be displayed (missing 27 ms)
main warning: picture is too late to be displayed (missing 22 ms)
main debug: picture might be displayed late (missing 4 ms)
main warning: picture is too late to be displayed (missing 26 ms)
main warning: picture is too late to be displayed (missing 32 ms)
main debug: picture might be displayed late (missing 5 ms)
main debug: toggling resume
dbus_screensaver debug: got cookie 123548342
main debug: toggling resume
pulse debug: changing sink 1: alsa_output.pci-0000_00_1b.0.iec958-stereo (Built-in Audio Digital Stereo (IEC958))
pulse debug: suspended
pulse debug: changing sink 1: alsa_output.pci-0000_00_1b.0.iec958-stereo (Built-in Audio Digital Stereo (IEC958))
main debug: auto hiding mouse cursor
main debug: auto hiding mouse cursor
UPDATE
Tried the same and other UHD movies on a 2nd 17.10 machine with a 1050 graphics card that had similar results.