MKV skipping or dropping video frames. Audio is fine


#1

I’ve had this problem with DIVX/XVID before, I believe because of warppoints, but I don’t believe I’ve experienced it with with MKV before. Now I have an entire series of 1080p episodes (BBC LIFE) that are difficult to look at.

I’m using a WDTV Live.

I took a quick clip and put it on youtube to hopefully convey what is happening: http://www.youtube.com/watch?v=Ke30bWA9g54

The ducks should be moving smoothly but about once per second they jump ahead, It’s probably very tough to see in the video.

I ran mediainfo on the file and here is the result:

General
Format : Matroska
File size : 6.08 GiB
Duration : 58mn 33s
Overall bit rate : 14.9 Mbps
Encoded date : UTC 2009-12-20 10:47:38
Writing application : mkvmerge v2.9.8 ('C'est le bon') built on Aug 13 2009 12:49:06
Writing library : libebml v0.7.7 + libmatroska v0.8.1

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4.1
Format settings, CABAC : Yes
Format settings, ReFrames : 4 frames
Muxing mode : Container profile=Unknown@4.1
Codec ID : V_MPEG4/ISO/AVC
Duration : 58mn 33s
Bit rate : 14.2 Mbps
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Frame rate : 25.000 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.275
Stream size : 5.70 GiB (94%)
Writing library : x264 core 80 r1376M 3feaec2
Encoding settings : cabac=1 / ref=4 / deblock=1:-3:-3 / analyse=0x3:0x113 / me=umh / subme=10 / psy=1 / psy_rd=1.0:0.2 / mixed_ref=0 / me_range=32 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=0 / chroma_qp_offset=-3 / threads=12 / sliced_threads=0 / nr=0 / decimate=1 / mbaff=0 / constrained_intra=0 / bframes=5 / b_pyramid=0 / b_adapt=2 / b_bias=0 / direct=3 / wpredb=1 / wpredp=2 / keyint=250 / keyint_min=25 / scenecut=40 / rc_lookahead=40 / rc=2pass / mbtree=1 / bitrate=14240 / ratetol=1.0 / qcomp=0.60 / qpmin=10 / qpmax=51 / qpstep=4 / cplxblur=20.0 / qblur=0.5 / vbv_maxrate=50000 / vbv_bufsize=50000 / ip_ratio=1.40 / aq=1:1.00
Language : English

Audio
ID : 2
Format : AC-3
Format/Info : Audio Coding 3
Mode extension : CM (complete main)
Codec ID : A_AC3
Duration : 58mn 33s
Bit rate mode : Constant
Bit rate : 640 Kbps
Channel(s) : 6 channels
Channel positions : Front: L C R, Side: L R, LFE
Sampling rate : 48.0 KHz
Bit depth : 16 bits
Stream size : 268 MiB (4%)
Language : English

Text
ID : 3
Format : UTF-8
Codec ID : S_TEXT/UTF8
Codec ID/Info : UTF-8 Plain Text
Language : English

Menu
00:00:00.000 : en:00:00:00.000
00:10:38.680 : en:00:10:38.680
00:17:09.480 : en:00:17:09.480
00:27:17.000 : en:00:27:17.000
00:40:28.280 : en:00:40:28.280
00:47:56.000 : en:00:47:56.000

I’m thinking maybe the 2 Format Settings in the video are to blame but I’m really clueless when it comes to looking at the details like this… Can anyone suggest what the problem is or better yet a solution? This happens on usb as well as over network.

I apologize if this has been covered… I looked through and tried to search but most thread titles are just “Not working correctly” instead of an actual description, and what I did see was related to .avi


#2

That kinda looks like Pulldown issues, but it’s VERY VERY minor, at least what I can see in the Youtube clip.

Can you set your WDTV to 25fps and see if that makes any difference?


#3

I was set on 1080p 23.976Hz and have options for 24, 50 and 60.

Switched it to 60 and it seems to be running awesomely (50 was a slight improvement and 24 did nothing)

Thank you so much! I already had it in my head that I would be re-compressing these, would have never thought I could fix it by changing settings =]


#4

Really, you shouldn’t have to do that…  There’s a HUGE vote going for “Auto Detect Framerate” in the IDEAS LAB.  Go vote for it.

The idea there is that the WD will examine the file, look for the frame rate, then adjust the HDMI settings to match.

I leave mine set at 60, and I don’t either notice or am not bothered by those Judders, as it’s called.