[Galaxy Note II Q&A, Help & Troubleshooting] vanijane:
I've been using MXPlayer to play video files on my phone and while it usually doesn't have a problem playing most of the files, there have been a few where it would only play the sound and not the video. I never had problems of the video not playing at all, though. And also, there are some files which play both sound and video but the video is quite laggy.

I'm not familiar with how phones and codecs and whatnot work (when I still had a desktop, I would watch my videos there and when the videos didn't play right, all I had to do was download and install codec packs but I'm not sure if you could do that with a phone...). Anyway, to make things a bit simpler (I think), I've posted below the media info of the video files that only played sound and no video, and the laggy one.

NO VIDEO, JUST SOUND (Also, these won't show subs)

General
Unique ID : 182338066429087365776864735620848566423 (0x892D08C23B632384A297E5F4018E4097)
Complete name : H:\# Unsorted Downloads\[Anime-Koi] Karneval - 01 [h264-720p][E619A01C].mkv
Format : Matroska
Format version : Version 4 / Version 2
File size : 373 MiB
Duration : 23mn 39s
Overall bit rate : 2 202 Kbps
Encoded date : UTC 2013-04-05 02:25:56
Writing application : mkvmerge v6.0.0 ('Coming Up For Air') built on Jan 20 2013 09:52:00
Writing library : libebml v1.3.0 + libmatroska v1.4.0
Attachment : Yes / Yes / Yes / Yes / Yes / Yes / Yes / Yes / Yes

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High 10@L4.0
Format settings, CABAC : Yes
Format settings, ReFrames : 9 frames
Codec ID : V_MPEG4/ISO/AVC
Width : 1 280 pixels
Height : 720 pixels
Display aspect ratio : 16:9
Frame rate mode : Variable
Original frame rate : 23.976 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 10 bits
Scan type : Progressive
Title : H.264 720p HDTV [10bit]
Writing library : x264 core 125 r2200+677M 3a754e7
Encoding settings : cabac=1 / ref=9 / deblock=1:1:1 / analyse=0x3:0x113 / me=umh / subme=8 / psy=1 / fade_compensate=1.00 / psy_rd=0.70:0.00 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=1 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=0 / chroma_qp_offset=-2 / threads=12 / lookahead_threads=2 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / fgo=0 / bframes=3 / b_pyramid=2 / b_adapt=2 / b_bias=0 / direct=3 / weightb=1 / open_gop=0 / weightp=2 / keyint=250 / keyint_min=23 / scenecut=40 / intra_refresh=0 / rc_lookahead=70 / rc=crf / mbtree=1 / crf=17.0000 / qcomp=0.70 / qpmin=0 / qpmax=81 / qpstep=4 / ip_ratio=1.40 / aq=3:0.70
Language : Japanese
Default : Yes
Forced : Yes
Color primaries : BT.709
Transfer characteristics : BT.709
Matrix coefficients : BT.709

Audio
ID : 2
Format : AAC
Format/Info : Advanced Audio Codec
Format profile : LC
Codec ID : A_AAC
Duration : 23mn 39s
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 48.0 KHz
Compression mode : Lossy
Title : AAC LC 2.0 192Kbps
Language : Japanese
Default : Yes
Forced : Yes

Text
ID : 3
Format : ASS
Codec ID : S_TEXT/ASS
Codec ID/Info : Advanced Sub Station Alpha
Compression mode : Lossless
Title : Main Track [Softsub Karaoke]
Language : English
Default : Yes
Forced : Yes

Menu
00:00:00.000 : en:Prologue
00:00:37.787 : en:Part A
00:02:49.043 : en:Part B
00:11:13.839 : en:Part C
00:19:46.852 : en:Part D
00:21:54.604 : en:Ending Song
00:23:24.569 : en:Preview
00:23:39.376 : en:End

General
Unique ID : 195443306720641913050768616422467911184 (0x930902FDBE99D920B101FA2128E33E10)
Complete name : H:\# Unsorted Downloads\Persona 4 The Animation [Dual Audio] [Blu Ray]\Persona 4 The Animation Ep.01 - You're myself, I'm yourself.mkv
Format : Matroska
Format version : Version 2
File size : 386 MiB
Duration : 29mn 56s
Overall bit rate : 1 803 Kbps
Movie name : You're myself, I'm yourself
Encoded date : UTC 2012-12-10 08:40:38
Writing application : mkvmerge v5.5.0 ('Healer') built on Apr 6 2012 21:43:24
Writing library : libebml v1.2.3 + libmatroska v1.3.0
Attachment : Yes / Yes / Yes / Yes / Yes / Yes / Yes / Yes / Yes

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High 10@L4.1
Format settings, CABAC : Yes
Format settings, ReFrames : 9 frames
Muxing mode : Header stripping
Codec ID : V_MPEG4/ISO/AVC
Duration : 29mn 56s
Width : 1 280 pixels
Height : 720 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
Title : Episode 1 - You're myself, I'm yourself
Writing library : x264 core 124 r2197 69a0443
Encoding settings : cabac=1 / ref=9 / deblock=1:0:0 / analyse=0x3:0x113 / me=umh / subme=10 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=24 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-2 / threads=3 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=9 / b_pyramid=0 / b_adapt=2 / b_bias=0 / direct=1 / weightb=1 / open_gop=0 / weightp=1 / keyint=240 / keyint_min=24 / scenecut=40 / intra_refresh=0 / rc_lookahead=40 / rc=crf / mbtree=1 / crf=18.0 / qcomp=0.60 / qpmin=0 / qpmax=81 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00
Default : Yes
Forced : No

Audio #1
ID : 2
Format : AAC
Format/Info : Advanced Audio Codec
Format profile : LC
Codec ID : A_AAC
Duration : 29mn 56s
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 48.0 KHz
Compression mode : Lossy
Delay relative to video : 9ms
Title : English 2.0 AAC
Language : English
Default : Yes
Forced : No

Audio #2
ID : 3
Format : AAC
Format/Info : Advanced Audio Codec
Format profile : LC
Codec ID : A_AAC
Duration : 29mn 56s
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 48.0 KHz
Compression mode : Lossy
Delay relative to video : 945ms
Title : Japanese 2.0 AAC
Language : Japanese
Default : No
Forced : No

Text #1
ID : 4
Format : ASS
Codec ID : S_TEXT/ASS
Codec ID/Info : Advanced Sub Station Alpha
Compression mode : Lossless
Title : English Lyrics/Signs
Language : English
Default : Yes
Forced : No

Text #2
ID : 5
Format : ASS
Codec ID : S_TEXT/ASS
Codec ID/Info : Advanced Sub Station Alpha
Compression mode : Lossless
Title : English Subtitles
Language : Japanese
Default : No
Forced : No

Menu
00:00:00.000 : en:Prologue
00:01:27.963 : en:eek:pening
00:02:58.136 : en:Part 1
00:18:34.113 : en:Part 2
00:26:53.695 : en:Ending
00:28:08.687 : en:Preview
00:28:24.703 : en:Ending Credits

General
Unique ID : 238416833271108914671198131772825344211 (0xB35D696EA074F0DF82BF62388C5518D3)
Complete name : H:\Anime\Brave 10\[Final8]Brave 10 - 01 (BD 10-bit 1280x720 x264 AAC)[114F9F2D].mkv
Format : Matroska
Format version : Version 2
File size : 365 MiB
Duration : 23mn 41s
Overall bit rate : 2 154 Kbps
Encoded date : UTC 2012-09-20 16:22:54
Writing application : mkvmerge v4.9.1 ('Ich will') built on Jul 11 2011 23:53:15
Writing library : libebml v1.2.1 + libmatroska v1.1.1
Attachment : Yes / Yes / Yes / Yes / Yes / Yes / Yes

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High 10@L5.1
Format settings, CABAC : Yes
Format settings, ReFrames : 16 frames
Muxing mode : Header stripping
Codec ID : V_MPEG4/ISO/AVC
Duration : 23mn 41s
Width : 1 280 pixels
Height : 720 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 122 r2184 5c85e0a
Encoding settings : cabac=1 / ref=16 / deblock=1:0:0 / analyse=0x3:0x113 / me=umh / subme=10 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=32 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=0 / chroma_qp_offset=-2 / threads=12 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=12 / b_pyramid=2 / b_adapt=2 / b_bias=0 / direct=1 / weightb=1 / open_gop=0 / weightp=2 / keyint=240 / keyint_min=23 / scenecut=40 / intra_refresh=0 / rc_lookahead=50 / rc=crf / mbtree=1 / crf=16.0 / qcomp=0.60 / qpmin=0 / qpmax=81 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00
Default : Yes
Forced : No

Audio
ID : 2
Format : AAC
Format/Info : Advanced Audio Codec
Format profile : LC
Codec ID : A_AAC
Duration : 23mn 41s
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 48.0 KHz
Compression mode : Lossy
Delay relative to video : 9ms
Default : Yes
Forced : No

Text
ID : 3
Format : ASS
Codec ID : S_TEXT/ASS
Codec ID/Info : Advanced Sub Station Alpha
Compression mode : Lossless
Default : Yes
Forced : No

Menu
00:00:00.000 : :Intro
00:00:23.000 : :eek:P
00:01:52.500 : :Part A
00:10:24.000 : :Part B
00:21:42.000 : :ED
00:23:11.000 : :Preview

PLAYS VIDEO AND SOUND, BUT VIDEO IS LAGGY

General
Unique ID : 226338877801338539278156801268788804665 (0xAA47484077141735ACDFD3C191F4BC39)
Complete name : H:\Anime\Durarara!!\[Coalgirls]_Durarara!!_01_(1280x720_Blu-ray_FLAC)_[537A4BA3] [8bit].mkv
Format : Matroska
Format version : Version 2
File size : 440 MiB
Duration : 24mn 30s
Overall bit rate mode : Variable
Overall bit rate : 2 510 Kbps
Movie name : Durarara!! 01
Encoded date : UTC 2012-10-21 15:36:55
Writing application : mkvmerge v5.8.0 ('No Sleep / Pillow') built on Sep 2 2012 15:37:04
Writing library : libebml v1.2.3 + libmatroska v1.3.0
Attachment : Yes / Yes / Yes / Yes / Yes / Yes / Yes / Yes / Yes / Yes / Yes / Yes / Yes

Video
ID : 5
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L3.1
Format settings, CABAC : Yes
Format settings, ReFrames : 4 frames
Muxing mode : Header stripping
Codec ID : V_MPEG4/ISO/AVC
Duration : 24mn 30s
Width : 1 280 pixels
Height : 720 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 : 8 bits
Scan type : Progressive
Writing library : x264 core 128 r2216 198a7ea
Encoding settings : cabac=1 / ref=1 / deblock=1:1:1 / analyse=0x3:0x113 / me=hex / subme=2 / psy=1 / psy_rd=0.40:0.00 / mixed_ref=0 / me_range=16 / chroma_me=1 / trellis=0 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=0 / threads=3 / lookahead_threads=1 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=5 / b_pyramid=2 / b_adapt=1 / b_bias=0 / direct=1 / weightb=1 / open_gop=0 / weightp=1 / keyint=250 / keyint_min=23 / scenecut=40 / intra_refresh=0 / rc_lookahead=10 / rc=crf / mbtree=1 / crf=18.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / ip_ratio=1.40 / aq=1:0.60
Language : English
Default : Yes
Forced : No

Audio #1
ID : 1
Format : FLAC
Format/Info : Free Lossless Audio Codec
Codec ID : A_FLAC
Duration : 24mn 30s
Bit rate mode : Variable
Channel(s) : 2 channels
Sampling rate : 48.0 KHz
Bit depth : 16 bits
Title : [FLAC 2.0]
Writing library : libFLAC 1.2.1 (UTC 2007-09-17)
Language : Japanese
Default : Yes
Forced : No

Audio #2
ID : 2
Format : FLAC
Format/Info : Free Lossless Audio Codec
Codec ID : A_FLAC
Duration : 24mn 30s
Bit rate mode : Variable
Channel(s) : 2 channels
Sampling rate : 48.0 KHz
Bit depth : 16 bits
Title : [FLAC 2.0]
Writing library : libFLAC 1.2.1 (UTC 2007-09-17)
Language : English
Default : No
Forced : No

Text #1
ID : 3
Format : ASS
Codec ID : S_TEXT/ASS
Codec ID/Info : Advanced Sub Station Alpha
Compression mode : Lossless
Title : [ASS]
Language : English
Default : Yes
Forced : No

Text #2
ID : 4
Format : ASS
Codec ID : S_TEXT/ASS
Codec ID/Info : Advanced Sub Station Alpha
Compression mode : Lossless
Title : [ASS] [FOR DUB]
Language : English
Default : No
Forced : No

Menu
00:00:00.000 : en:eek:pening
00:01:30.048 : en:Part A
00:11:58.551 : en:Part B
00:22:46.532 : en:Ending
00:24:15.476 : en:Preview

I wanna know if there's something I can do so that I can watch these files on my phone (coz my media player can't play most of these files, either). Can I download codecs or may be a specific player off the market or do I have to do some video conversions?