You may experience slow or choppy...

I think it is a H264 video, but I still get that warning.

The video info is as following:

General
Format : Matroska
Format version : Version 4 / Version 2
File size : 1.00 GiB
Duration : 24mn 12s
Overall bit rate mode : Variable
Overall bit rate : 5 943 Kbps
Encoded date : UTC 2013-09-19 08:10:00
Writing application : mkvmerge v6.2.0 (‘Promised Land’) built on Apr 28 2013 12:22:01
Writing library : libebml v1.3.0 + libmatroska v1.4.0

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High 10@L5
Format settings, CABAC : Yes
Format settings, ReFrames : 13 frames
Codec ID : V_MPEG4/ISO/AVC
Duration : 24mn 12s
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 23.976 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 10 bits
Scan type : Progressive
Writing library : x264 core 136 r2348+704+51 d1baef6 tMod [10-bit@4:2:0 X86_64]
Encoding settings : cabac=1 / ref=13 / deblock=1:-2:-2 / analyse=0x3:0x133 / me=tesa / subme=10 / psy=1 / fade_compensate=0.00 / psy_rd=0.60:0.15 / mixed_ref=1 / me_range=32 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=0 / chroma_qp_offset=-3 / threads=12 / lookahead_threads=3 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / fgo=0 / bframes=12 / b_pyramid=2 / b_adapt=2 / b_bias=0 / direct=3 / weightb=1 / open_gop=0 / weightp=2 / keyint=480 / keyint_min=1 / scenecut=40 / intra_refresh=0 / rc_lookahead=60 / rc=crf / mbtree=1 / crf=17.0000 / qcomp=0.75 / qpmin=0:0:0 / qpmax=81:81:81 / qpstep=5 / ip_ratio=1.40 / aq=3:0.80 / aq-sensitivity=10.00 / aq-factor=1.00:1.00:1.00 / aq2=0 / aq3=0
Language : English
Default : Yes
Forced : No
Color range : Limited
Color primaries : BT.709

Audio #1
ID : 2
Format : FLAC
Format/Info : Free Lossless Audio Codec
Codec ID : A_FLAC
Duration : 24mn 12s
Bit rate mode : Variable
Channel(s) : 2 channels
Sampling rate : 48.0 KHz
Bit depth : 24 bits
Writing library : libFLAC 1.3.0 (UTC 2013-05-26)
Language : Japanese
Default : Yes
Forced : No

Audio #2
ID : 3
Format : AC-3
Format/Info : Audio Coding 3
Mode extension : CM (complete main)
Format settings, Endianness : Big
Codec ID : A_AC3
Duration : 24mn 12s
Bit rate mode : Constant
Bit rate : 640 Kbps
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 48.0 KHz
Compression mode : Lossy
Stream size : 111 MiB (11%)
Language : Japanese
Default : No
Forced : No

Audio #3
ID : 4
Format : AC-3
Format/Info : Audio Coding 3
Mode extension : CM (complete main)
Format settings, Endianness : Big
Codec ID : A_AC3
Duration : 24mn 12s
Bit rate mode : Constant
Bit rate : 640 Kbps
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 48.0 KHz
Compression mode : Lossy
Stream size : 111 MiB (11%)
Language : Japanese
Default : No
Forced : No