Jerky movement on DVD rips

[pwrogers]

I have been successfully transferring DVDs to MKV files which I store on a NAS and view using a Dune Smart D1 player. However, recently (maybe since the latest release), MKV rips from DVDs are playing back with jerky - "sticky" motion. Sound is continuous and smooth, but the vision keeps hesitating (throwing in repeated fields) and then playing normally again, having dropped a field to keep in sync.

The Dune player seems to be having trouble playing new DVD conversions in real time although other video players (eg. VLC) can play them smoothly.

The issue has nothing to do with data rate because old DVD-MKV rips still play fine on the same equipment. Furthermore, new BD-MKV rips are not affected by this problem and play back fine.

It seems to me that something is wrong in the file structure of MKV conversions of DVDs since the latest version of makemkv which is upsetting my Dune player when played back in real time (going to half-speed on the Dune does not exhibit any jerkiness). Is anyone else having this problem, and can anyone suggest what might be going wrong?

Phil

Further info: I am in the UK so I am converting 720 x 576 25 fps DVDs. I am running makemkv v 1.8.10 on Mac OS 10.6.8. All my previous rips using makemkv prior to v1.8.10 still play perfectly. I have also tried using a different, external optical drive from which to read the DVDs and the problem persists. Everything points to the recent release of makemkv 1.8.10...

[ndjamena]

MakeMKV started flagging all it's DVD rips as Variable Frame Rate, maybe your player is taking it seriously and switching modes or something. Or maybe it's a time-codes issue. You could try remuxing the files with MKVToolNix, that tends to set them back to CFR and may solve the problem.

[pwrogers]

ndjamena - Thanks for the suggestion... but the last thing I want to have to do is start re-muxing. The beauty of makemkv was that it just worked; now it doesn't (as far as my player is concerned, anyway). Is this Variable Frame Rate flag on MPEG2 streams a bug or an intended "feature"? Hopefully, the developers will look at this issue, because there are lots of Dune player users out here!

[ndjamena]

I have no idea actually. I'm not even sure it's the actual problem. I only noticed this VFR thing existed because suddenly my Video stream names were missing the FPS component and I had to rewrite my program to grab the nominal FPS to compensate. I just checked my latest acquisition, Doctor Who - Invasion of the Dinosaurs. I still have all the original MakeMKV rips and all but the first episode are flagged as Variable Frame Rate. The final remuxed versions are all Constant Frame Rate.

Check the problem files with MediaInfo just to see if I may be on to something. If you remux just one of problem files and see if it plays properly afterwards, it will at least give us something to work with.

[pwrogers]

I'll do as you suggest to gather more information ... in the meantime, I have gone back to v1.8.8 (the last version I had before 1.8.10) and the problem has gone away.

Developers - please look into this!

[ndjamena]

Hmmm, I can't actually find anything in the Matroska Header that specifies any kind of FrameRate other than Default Duration. I'm not entirely sure where MediaInfo is getting Variable Frame Rate from, but if I remux it with MKVToolNix it reverts to Constant. I'm pretty sure Mike has some idea what the problem is already, but it can't hurt to check your files too.

[ndjamena]

Well, all I've learned today is that time-codes are stored as unsigned integers (I'm assuming that integer is divided by the timescale in the Segment Info header), the one millisecond differences in the time-codes of some of the video frames is caused through it sharing a time-code with an audio frame (I'm assuming it's shifted a millisecond so they don't clash), and that MakeMKV writes its Video frames in Group Blocks and Audio/Subtitle Frames in Simple Blocks where MKVMerge writes everything into Simple Blocks (but since episode one is always constant frame rate, that's not causing this).

At least I know more now than I knew yesterday.

[ndjamena]

Code: Select all

General 
Unique ID : 199402161959828712033084632417365060793 (0x9603759FC95925BDD1F1F86C0A6AECB9) 
Complete name : E:\Make\Young Justice\Season 01\Young Justice - 01x05.mkv 
Format : Matroska 
Format version : Version 2 
File size : 795 MiB 
Duration : 21mn 24s 
Overall bit rate mode : Variable 
Overall bit rate : 5 191 Kbps 
Movie name : Young Justice - 01x05 
Encoded date : UTC 2014-05-30 08:24:43 
Writing application : MakeMKV v1.8.10 win(x64-release) 
Writing library : libmakemkv v1.8.10 (1.3.0/1.4.1) win(x64-release) 

Video 
ID : 1 
Format : MPEG Video 
Format version : Version 2 
Format profile : Main@Main 
Format settings, BVOP : No 
Format settings, Matrix : Custom 
Codec ID : V_MPEG2 
Codec ID/Info : MPEG 1 or 2 Video 
Bit rate mode : Variable 
Bit rate : 4 896 Kbps 
Maximum bit rate : 9 800 Kbps 
Width : 720 pixels 
Height : 576 pixels 
Display aspect ratio : 16:9 
Frame rate mode : Variable 
Original frame rate : 25.000 fps 
Standard : PAL 
Color space : YUV 
Chroma subsampling : 4:2:0 
Bit depth : 8 bits 
Scan type : Interlaced 
Scan order : Top Field First 
Compression mode : Lossy 
Time code of first frame : 00:59:58:00 
Time code source : Group of pictures header 
Language : English 
Default : No 
Forced : No 

Audio 
ID : 2 
Format : AC-3 
Format/Info : Audio Coding 3 
Format profile : Dolby Digital 
Mode extension : CM (complete main) 
Format settings, Endianness : Big 
Codec ID : A_AC3 
Duration : 21mn 24s 
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 
Compression mode : Lossy 
Stream size : 29.4 MiB (4%) 
Title : Stereo 
Language : English 
Default : Yes 
Forced : No 

Text 
ID : 3 
Format : VobSub 
Muxing mode : zlib 
Codec ID : S_VOBSUB 
Codec ID/Info : The same subtitle format used on DVDs 
Language : English 
Default : No 
Forced : No 

Menu 
00:00:00.000 : en:Chapter 01 
00:02:26.440 : en:Chapter 02 
00:08:20.720 : en:Chapter 03 
00:14:20.200 : en:Chapter 04 
00:20:52.480 : en:Chapter 05 

See, frame-rate mode - Variable. MakeMKV hasn't even finished with the disc yet, so nothing else has touched this file. Why is it doing that? What's changed?