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.
Yes this is from the WD drive, not a network drive.
No there is no additional load on the drive to slow it down.
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
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.
… 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.
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.
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.
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
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.
