MKV Pixilation

Recently I have had several MKV’s that have had minor to major pixilation. Here is the odd part, the pixilation is on the bottom 1/2 of the screen about 90% of the time. Perhaps just coincidental. I have found no pattern to these rips. Some are from bluray, some DVD, some are 1080 and most are 720. I believe all those should be insignificant to my issue.

Please advise.

**Answere to a couple of questions up front.

  1. Yes this is from the WD drive, not a network drive.

  2. No there is no additional load on the drive to slow it down.

  3. 1TB WDTV Live Hub

Here is a photo of the pixilation. The media info is below:

Here is the info for the latest MKV having issues:

Complete name                    : W:\Movies!kids\clean up\Animated.Movies.2011.RoSubbed.DVDRip.and.720p-ES\720p\06.Tinker.Bell.And.The.Lost.Treasure.2009.720p.BluRay.DTS.x264-titul\Movie\Tinker.Bell.And.The.Lost.Treasure.2009.720p.BluRay.DTS.x264-titul.mkv
Format                           : Matroska
File size                        : 4.21 GiB
Duration                         : 1h 20mn
Overall bit rate                 : 7 504 Kbps
Encoded date                     : UTC 2009-12-24 17:51:04
Writing application              : mkvmerge v2.9.7 (‘Tenderness’) built on Jul 16 2009 20:46:29
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        : 8 frames
Muxing mode                      : Container profile=Unknown@4.1
Codec ID                         : V_MPEG4/ISO/AVC
Duration                         : 1h 20mn
Bit rate                         : 5 205 Kbps
Nominal bit rate                 : 5 352 Kbps
Width                            : 1 280 pixels
Height                           : 720 pixels
Display aspect ratio             : 16:9
Frame rate                       : 23.976 fps
Resolution                       : 8 bits
Colorimetry                      : 4:2:0
Scan type                        : Progressive
Bits/(Pixel*Frame)               : 0.236
Stream size                      : 2.91 GiB (69%)
Writing library                  : x264 core 68 r1183M f21daff
Encoding settings                : cabac=1 / ref=8 / deblock=1:-3:-3 / analyse=0x3:0x133 / me=umh / subme=9 / psy_rd=0.7:0.0 / mixed_ref=1 / me_range=32 / chroma_me=1 / trellis=0 / 8x8dct=1 / cqm=0 / deadzone=8,8 / chroma_qp_offset=-2 / threads=6 / nr=0 / decimate=1 / mbaff=0 / bframes=5 / b_pyramid=1 / b_adapt=1 / b_bias=0 / direct=2 / wpredb=1 / keyint=250 / keyint_min=25 / scenecut=40 / rc=2pass / bitrate=5352 / ratetol=1.0 / qcomp=0.60 / qpmin=10 / qpmax=51 / qpstep=4 / cplxblur=20.0 / qblur=0.5 / vbv_maxrate=30000 / vbv_bufsize=38000 / ip_ratio=1.40 / pb_ratio=1.30 / aq=1:0.80
Language                         : Russian

Audio #1
ID                               : 2
Format                           : DTS
Format/Info                      : Digital Theater Systems
Codec ID                         : A_DTS
Duration                         : 1h 20mn
Bit rate mode                    : Constant
Bit rate                         : 1 510 Kbps
Channel(s)                       : 6 channels
Channel positions                : Front: L C R, Surround: L R, LFE
Sampling rate                    : 48.0 KHz
Resolution                       : 24 bits
Stream size                      : 867 MiB (20%)
Language                         : English

The problem is your encodes.

The one you posted the MediaInfo for says that the file has been encoded with 8 ReFrames.

The WDTV can only handle 4 ReFrames.  ("@L4.1")

You’ll have to re-encode any “bad” media, using settings that the WDTV can actually play.

I should be a little more clear…

In the WDTV’s Supported Formats section, it says:

MPEG-4.10 (H.264) MP@L4.1 and HP@L4.1 up to 1920x1080p24, 1920x1080i30, or 1280x720p60 resolution (constrained to match BDand HD-DVD specifications)

The “4.1” part of the “L4.1” indicates which “Level” of the H.264 standards the encoder and playback device need to meet.

The H.264 specifications specify 4 reference frames for level 4 (and level 4.1) encodings, despite the fact that there can, in theory, be up to 32 reference frames in H.264 streams.

Even though the encoder has tagged the file as “High@L4.1”, the file does NOT meet the H.264 level 4.1 specs, since it has 8 reference frames.

The WDTV’s Sigma chip only has the physical space to keep track of 4 reference frames while it’s decoding streams.  The chip meets L4.1 playback specs.

But since the file was encoded out of spec, with 8 reference frames, the resulting video is garbled, because it’s expecting the decoder to remember 8 different frames of video at any one time, and providing difference information from those 8 frames.  Since the WDTV can only keep track of 4 frames at any one time, it knows that some pixels are different than what was in ReFrames 5-8, but it no longer knows what ReFrames 5-8 look like, so it can’t properly decode the picture.

Thank you for the detailed response. I appreciate your help and understand what you’re saying.

With that…this is another very very frustrating part of this product. I understand it can’t be perfect and do everything, even though that is what our expectation levels are. But **bleep**…not being able to do a codec? Even a “specific type of MKV”,  I mean they seriously could not put a chip in this thing that is capable of processing codecs for the next 5 years? I mean the thing can’t even stay connected to a windows network share w/out having to do all kinds of [deleted] These are just “basic” functions that I can say…a MAJORITY of the user base continues to have frustrations with. I’m done. More headache and hassle than it’s worth.

Wait…I’m probably totally out of line here. I’m sure we all thought, while standing there holding this in our hands before we bought it,…“Yea…I"m sure I’ll have to reencode videos to play them. Sounds good. Ring me up!”.

I tend to sit on the fence, and bash WD with one hand, and defend WD with the other. :wink:

… but in WD’s defence, the decoding capabilities of the chip (or lack thereof) are set by the chip manufacturer, Sigma Designs, and WD can’t really do anything about any inherent limitations.

That photo looks like classic “Macroblocking.”

I would try playing it on another player and see if you get clean results in the same stream.

It may have something to do with whoever encoded that video setting BITRATE limits, and not doing two-pass encoding to find the bounds for the bitrates.

RoofingGuy wrote:

I should be a little more clear…

 

In the WDTV’s Supported Formats section, it says:

 

MPEG-4.10 (H.264) MP@L4.1 and HP@L4.1 up to 1920x1080p24, 1920x1080i30, or 1280x720p60 resolution (constrained to match BDand HD-DVD specifications)

 

 

The “4.1” part of the “L4.1” indicates which “Level” of the H.264 standards the encoder and playback device need to meet.

 

The H.264 specifications specify 4 reference frames for level 4 (and level 4.1) encodings, despite the fact that there can, in theory, be up to 32 reference frames in H.264 streams.

 

Even though the encoder has tagged the file as “High@L4.1”, the file does NOT meet the H.264 level 4.1 specs, since it has 8 reference frames.

 

The WDTV’s Sigma chip only has the physical space to keep track of 4 reference frames while it’s decoding streams.  The chip meets L4.1 playback specs.

 

But since the file was encoded out of spec, with 8 reference frames, the resulting video is garbled, because it’s expecting the decoder to remember 8 different frames of video at any one time, and providing difference information from those 8 frames.  Since the WDTV can only keep track of 4 frames at any one time, it knows that some pixels are different than what was in ReFrames 5-8, but it no longer knows what ReFrames 5-8 look like, so it can’t properly decode the picture.

Ok, I have calmed down…a little, and am willing to try and work within the scope of the WDTV Live Hub.

What is the correct steps to take with mkvmerge to change it to 4 reference frames? What application do you recommend, free or not.  I just did a simple remux and it did not fix it. I’m assuming there are specific tags that I need to use.

What type of player might you suggest? It plays perfect on the PC and looks amazing using MPC.

Ok, not to trying blow your response out of the water here but…I am really trying to figure this out.

Here is another video tested…Peter.Pan.1953.720p.HDTV.x264.mkv, with the following media info…showing “9” reframes. It plays perfect. Not a hiccup. Please advise.

General
Complete name                    : W:\Movies!kids\clean up\Animated.Movies.2011.RoSubbed.DVDRip.and.720p-ES\720p\01.Peter.Pan.1953.720p.HDTV.x264.RoDubbed-NoGrp\Peter.Pan.1953.720p.HDTV.x264-NoGrp.mkv
Format                           : Matroska
File size                        : 2.16 GiB
Duration                         : 1h 17mn
Overall bit rate                 : 3 990 Kbps
Encoded date                     : UTC 2011-02-25 21:23:53
Writing application              : mkvmerge v4.5.0 (‘Speed of Light’) built on Feb  1 2011 02:10:32
Writing library                  : libebml v1.2.0 + libmatroska v1.1.0

Video
ID                               : 1
Format                           : AVC
Format/Info                      : Advanced Video Codec
Format profile                   : High@L4.1
Format settings, CABAC           : Yes
Format settings, ReFrames        : 9 frames
Muxing mode                      : Container profile=Unknown@4.1
Codec ID                         : V_MPEG4/ISO/AVC
Duration                         : 1h 17mn
Bit rate                         : 3 350 Kbps
Width                            : 960 pixels
Height                           : 720 pixels
Display aspect ratio             : 4:3
Frame rate                       : 23.976 fps
Color space                      : YUV
Chroma subsampling               : 4:2:0
Bit depth                        : 8 bits
Scan type                        : Progressive
Bits/(Pixel*Frame)               : 0.202
Stream size                      : 1.77 GiB (82%)
Writing library                  : x264 core 79 r1347M 5ddd61b
Encoding settings                : cabac=1 / ref=9 / deblock=1:-2:-2 / analyse=0x3:0x113 / me=esa / subme=10 / psy=1 / psy_rd=0.6:0.0 / mixed_ref=1 / me_range=24 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / chroma_qp_offset=-2 / threads=6 / nr=0 / decimate=0 / mbaff=0 / constrained_intra=0 / bframes=8 / b_pyramid=2 / b_adapt=2 / b_bias=0 / direct=3 / wpredb=1 / wpredp=2 / keyint=250 / keyint_min=25 / scenecut=40 / rc=2pass / mbtree=0 / bitrate=3350 / ratetol=1.0 / qcomp=0.60 / qpmin=10 / qpmax=51 / qpstep=4 / cplxblur=20.0 / qblur=0.5 / ip_ratio=1.40 / pb_ratio=1.30 / aq=1:0.60 / pulldown=0 / nal_hrd=0
Language                         : English

Audio #1
ID                               : 2
Format                           : AC-3
Format/Info                      : Audio Coding 3
Mode extension                   : CM (complete main)
Codec ID                         : A_AC3
Duration                         : 1h 17mn
Bit rate mode                    : Constant
Bit rate                         : 192 Kbps
Channel(s)                       : 2 channels
Channel positions                : Front: L R
Sampling rate                    : 48.0 KHz
Bit depth                        : 16 bits
Video delay                      : 20ms
Stream size                      : 106 MiB (5%)
Language                         : Romanian

Audio #2
ID                               : 3
Format                           : AC-3
Format/Info                      : Audio Coding 3
Mode extension                   : CM (complete main)
Codec ID                         : A_AC3
Duration                         : 1h 17mn
Bit rate mode                    : Constant
Bit rate                         : 448 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                      : 248 MiB (11%)
Language                         : English

Text
ID                               : 4
Format                           : UTF-8
Codec ID                         : S_TEXT/UTF8
Codec ID/Info                    : UTF-8 Plain Text
Language                         : English

I mis-spoke.  I’m sorry.  I was working with bad information.

It appears the chart I’d looked at was wrong.  1920*1080 is indeed limited to 4 ReFrames, under level 4.1, but 1280*720 is allowed 9 ReFrames under 4.1, not the 4 that my source incorrectly stated.

So I’d look into Tony’s suggestion about the bitrate being out-of-bounds.