TMT 5 Stuttering Blu-Ray playback

[eagle63]

I’d love to revive this thread as I’m having the same problem as the OP.  The stuttering/juddering is not nearly as bad as his was, but it’s definitely noticeable.  

I’m running Win7 MC with a core i3 550 CPU (clarksdale), using the onboard Intel Graphics via HDMI.  My TV is an LG LCD 120Hz.  (less than a year old)  I’m using TMT5 (the latest version, downloaded a few days ago) for blu-ray playback.  Playback of Live and Recorded TV is generally very smooth for me.  

I have my refresh rate set to 60Hz both in Windows as well as WMC.  (1920×1080)  I have the latest Intel driver for my graphics card, and supposedly this latest version includes some improvements for 24p.  (apparently it now supports 23.976hz instead of 24hz)  Regardless, bluray playback has never been particularly smooth for me no matter which driver I use.  When playing a bluray my CPU sits at about 32% so that’s not the problem.  

Anyone have any ideas?  I’m kind of a noob when it comes to the nitty gritty details of refresh rates, 24p, etc, and frankly I don’t really care that much if it’s 24p or not – I just want it to look nice and smooth like it does when I playback blurays on my PS3. 

[Aaron Ledger]

To learn a little more about 24p, read this. For video sources, you should use 59Hz, not 60Hz though it will probably be difficult to perceive the difference due to the small error introduced by 60Hz. For Intel boards, you not only need the driver update, but you also need the BIOS update as mentioned earlier in this thread. It may be possible that you have downloaded a version of TMT5 that is automatically setting a 24Hz setting while watching BD. You will want to verify that this is not occurring. You either should watch at a 23Hz rate or 59Hz rate (with accompanying telecine judder).

[eagle63]

[quote=Aaron Ledger]

To learn a little more about 24p, read this. For video sources, you should use 59Hz, not 60Hz though it will probably be difficult to perceive the difference due to the small error introduced by 60Hz. For Intel boards, you not only need the driver update, but you also need the BIOS update as mentioned earlier in this thread. It may be possible that you have downloaded a version of TMT5 that is automatically setting a 24Hz setting while watching BD. You will want to verify that this is not occurring. You either should watch at a 23Hz rate or 59Hz rate (with accompanying telecine judder).

[/quote]

Wow, thanks a ton Aaron.  I think I need to re-read the 24p article a few more times before it sinks in, however, but great stuff nonetheless.  A few more questions/comments:

1.  I checked my BIOS version, and it appears as though I have the latest.  (dated 10/19/2011) 

2.  Are there some hidden settings in TMT somewhere that can adjust the framerate, or does it take care of all that automatically?  Furthermore, do the refresh rate settings in WMC even matter when playing back a bluray in TMT?  In other words, does TMT “take over” and assert it’s own refresh rate?

3.  Wow, really 59.95hz?  And here this whole time I thought 60Hz was correct.  So I need to change that both in Windows as well as WMC right?

4.  I keep reading about disabling UAC.  I assume that’s the user account control thing in windows?  What in the world would that have to do with the refresh rate on a graphics card?? 

Thanks again for the help!

[Aaron Ledger]

1. Regarding your BIOS, I just want to make sure you have an Intel branded board. If it’s not manufactured by Intel, I am not sure if manufacturers have implemented the same fixes for 24p as Intel has for SandyBridge graphics.

2. It may depend on your version of TMT5. I know in the original release of the feature, you had to disable by a registry entry. I have not tried the latest. TMT5 does “take over” when it begins playing and WMC is no longer responsible for what TMT5 chooses to do with the refresh rate.

3. 59.94Hz to be exact. You can have different display settings between Windows desktop and WMC, but if you don’t have any good reason for doing so, it’s probably best to leave them the same. If you’re interested in some more info on refresh rates and frame rates, this article is a good starting point.

4. Before Intel implemented the fix in their BIOS and graphics drivers for SandyBridge processors, the graphics engine would only output 24p appropriately if UAC was disabled. On a non-updated system with UAC enabled, a 23Hz setting would be the same result as a 24Hz setting (24.000Hz), but enabling UAC would allow the 23Hz setting to approach the proper 23.976Hz. I do not know technically why this was the case.

Your TV may be able to help you determine if TMT5 is changing the refresh rate if it displays information about the incoming video so you may want to check your TV manual.

[eagle63]

Thanks again Aaron.  My board is an Intel board, specifically the DH57JG.  Keep in mind this is a Clarksdale board not a Sandy Bridge board.  I’m not sure if that matters as far as this 24p stuff is concerned??  (my impression is it’s the same underlying bug in both architectures, but I could be wrong)  

I’ve started to read some threads over at the TMT5 site and I’ve seen their support guy tell people to use 60hz.  I’m not sure why that would matter if TMT is overriding that with it’s own refresh rate.  

I’ll check and see if my TV provides any info about the refresh rate getting displayed.  Does the TV need to have specific support for 24p for this all to work?  I didn’t think that was the case..  Again, if I playback the same bluray on the same TV using my PS3 everything is smooth as butter.  I have no idea if it’s in 24p or not, but that’s really a secondary concern – the main goal is to get the judder to stop when playing bluray’s on my HTPC.  

[Aaron Ledger]

I’m not sure if Clarkdale has been fixed to allow 23.976 Hz when 23 Hz is selected. When I used to have a Clarkdale board, this was not a reality.

TMT5 will use the desktop refresh rate setting. If the desktop supports 24p, some versions of TMT5 will change the rate to 23/24 Hz depending on version and source material and then change back to the desktop refresh rate when it is finished.

Your TV may not support 24p at all or it may support it in at least a couple of ways. If your TV accepts 24p input, it may simply telecine to 59.94 Hz. This is common on lower-tier TVs for the past few years. Many TVs also now support “proper” 24p playback which means playing the 24p frames in an even cadence.

There can be many causes of “judder”. First, there is telecine judder (AKA pulldown judder). This is when 24p material is displayed with uneven cadence. You may or may not notice this and is also more apparent in certain types of scenes. Second, there is a specific issue with Intel graphics that may exist in some circumstances where 23Hz is selected, but the hardware actually displays at 24Hz which creates a repeated frame about every 45 sec. or so which may or may not be noticeable depending on content. Third, there is a specific issue with TMT5 where some versions select 24Hz even if 23Hz setting is available. It is probably best to rule out the above causes and then see if there is some other cause.

[mpatnode]

Note if you want to try the auto-refresh rate change in TMT, you need to add

Refresh23HZ=1

 under the [GENERAL] section to the [USER]AppDataRoamingArcSoftArcSoft TotalMedia Theatre 55.2PlayDVD.ini

And then make sure the “Automatic refresh rate switching” checkbox is checked in the video settings.    Note there’s another PlayDVD.ini file if you are launching from Windows Media Center and I assume the feature works there as well.

That said, I have yet to ever see TMT play a BD without stuttering or losing audio sync somewhere along the line.    I strongly recommend having a standalone BD player as a backup for those times where all you really want to do is watch the movie…

[mpatnode]

Check out this post on the Arcsoft TMT Forum.   (Ignore the subject) They go into the 23 vs 24 issue in detail.

You have to force the refresh to 23.976 once the movie has started, otherwise you get the usual frame skip every 40s or so as TMT plays it at 24hz irrespective of the 23hz setting (we’ve already discussed this and my hopes are high that in a future update the 23 hz setting in TMT will also apply to 3D movies).

Interesting that Jason@Arcsoft just runs at the default 24Hz and says he never sees a problem.  

[eagle63]

@mike and @aaron

Thanks to both of you for the info.  I had some time this weekend to fiddle around with settings and watch some blurays.  I discovered that the “auto frame rate refresh” setting in TMT5 was NOT checked.  This was the source of my problems.  After checking that box, playback was almost perfect.  I watched Inception and Star Wars – Attack of the Clones over the weekend and both looked fantastic.  

I did not make that “Refresh23Hz=1” tweak, nor did I do the other thing mentioned on the arcsoft forum link for forcing 23.976 after playback begins.  To be honest, things looked good enough that I didn’t feel like messing around any more.  I’m sure I’m getting the skipped frame every 40 seconds, but I don’t recall even noticing it.  I’ll have to watch another blurry this week and see if I can detect it.  Bottom line though, is that simply checking that “auto frame rate refresh” checkbox in TMT5 dramatically improved playback.  

As for my TV, I did some research and discovered that it actually does support 24p.  It’s an LG set, and LG calls it “Real Cinema” mode.  Here’s the blurb from the manual:  “Makes video clips recorded in film look more natural by eliminating judder effect.  DVD and Blu-Ray movies are filmed at 24 frames per second.  With LG Real Cinema, every frame is consistently processed 2 times in 1/24 of a second pro ducting 48fps, thus totaling eliminating the judder effect.”  (apparently this is “2:2 pulldown”??)

Here’s something interesting:  There’s a setting in the TV’s advanced menu which shows you if Real Cinema mode is enabled or not.  When watching a blu-ray disc, it automatically gets switched on.  (Tv must realize it’s getting a 24 fps signal and turns on real cinema mode?)  However, when I watch some ripped blu-rays I have the TV is NOT turning on real cinema mode.  Hmmm.  The movies are actually not “ripped”, they’re uncompressed MKV’s (using makemkv) that I then converted into WTV files using dvrmstoolbox.  So maybe somewhere along the line, the frame rate got messed up and the TV doesn’t recognize it as 24p material??  This is lesser concern for me, but definitely something I need to do some research on.  

[Aaron Ledger]

2:2 pulldown is what your TV can do in Real Cinema mode. It just means that for each frame, it displays the frame twice in 1/23.976 seconds. The final refresh rate of the display ends up being ~48Hz.

From what you describe, it sounds as if your PC’s refresh rate is not being set to 23Hz or 24Hz. You can perform a quick check by simply setting your desktop display refresh rate to 23Hz and observing that the Real Cinema option is enabled.

[eagle63]

[quote=Aaron Ledger]

2:2 pulldown is what your TV can do in Real Cinema mode. It just means that for each frame, it displays the frame twice in 1/23.976 seconds. The final refresh rate of the display ends up being ~48Hz.

From what you describe, it sounds as if your PC’s refresh rate is not being set to 23Hz or 24Hz. You can perform a quick check by simply setting your desktop display refresh rate to 23Hz and observing that the Real Cinema option is enabled.

[/quote]

I set my desktop refresh rate to 23hz (I had a choice of 23 or 24, and I think 23 actually means 23.976) but it made no difference – the TV setup doesn’t show real cinema mode as enabled.  But since I’m playing back these movies via media center, wouldn’t I have to set my refresh rate in media center (not desktop) to 23hz?  I tried this, but of all the 38 modes, none of them had a refresh rate of 23.  (or 24 for that matter)  They were all either 60, 59.94, or 30.  Since the Intel graphics support 24 (and now 23hz), should’t I see this as an option in media center?

[eagle63]

@Aaron,  I just tried to post a reply to you but it got flagged as “inappropriate content”.  I have no idea why, in fact this is the 2nd time it’s happaned in as many days.  Hopefully someone can restore my post?

[Aaron Ledger]

I was not suggesting to play the content back–merely to set the desktop refresh rate to 23hz to understand if the Real Cinema option is there. If you did try that and it didn’t work, perhaps the display requires YCbCr.

As for WMC, I have not tried to use it for 24p playback as I use external players for that content. I wouldn’t be surprised if WMC prevents it as it isn’t compatible with TV standards.

[eagle63]

[quote=Aaron Ledger]I was not suggesting to play the content back–merely to set the desktop refresh rate to 23hz to understand if the Real Cinema option is there. If you did try that and it didn’t work, perhaps the display requires YCbCr. As for WMC, I have not tried to use it for 24p playback as I use external players for that content. I wouldn’t be surprised if WMC prevents it as it isn’t compatible with TV standards.[/quote]

Ok, I see what you mean.  I just closed MC and set the desktop refresh rate back to 23hz.  The TV settings now DO show that cinema mode is enabled.  So yes, it appears your theory was correct.  A few final (maybe) questions:

1.  So the reason cinema mode works when playing a blu-ray disk via TMT5 is because TMT is setting the refresh rate itself.  (going outside of MC’s settings)  But if I’m playing back a ripped DVD or blu-ray, that is being handled my MC’s player which is subject to MC’s refresh rate settings.  What happens to movies that are broadcast via cable/satellite/OTA with regard to the refresh rate?  Since HD is 59.94hz, but the original film was 23.976hz, what happens exactly?  Does the cable or satellite provider adjust the framerate to 59.94?  Or is it being broadcast correctly but then MC is adjusting it to fit within it’s refresh rate settings?

2.  Are there any decent tools that I can install which will show my precisely what framerate is being rendered?  I don’t think my TV has anything like that, but maybe there’s something I can install on my HTPC?  

[Aaron Ledger]

RE #1: Yes. You’ve got it correct. Regarding what happens with broadcast encoding of movies, believe it or not, ATSC allows broadcasters to send 720/24p and 1080/24p though I am unaware of any that actually do. Most 24p content (this includes movies and many TV shows) just telecine the content to 720/59.94 frames/sec. or 1080i/59.94 fields/sec. Technically, the 24p could also potentially be recovered via Inverse Telecine algorithm and played back properly at 24p though it is rarely implemented. WMC is only responding to the content the way most devices out there that deal with TV broadcasts do.

As a side note, while it is well-known that BD films are always 24p, DVDs are also almost all 24p as well. Some DVDs were authored with a “hard telecine”, but most just had MPEG flags that told the player to telecine. The “progressive” DVD players actually were capable of playing the DVD back at 24p and there are some software players on the PC that will allow this as well.

RE #2: Yes. MPC-HC is one such tool. It is actually an open-source software player. You can see  just about all the details of the renderer when playing back in MPC-HC.

[Author]

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