23.976 fps vs 24 fps

[gcoupe]

I raised this in another thread, but rather than continue sidetracking that thread, I thought I might try and get some further help here in a new dedicated thread...

The background is that the playback behaviour of TMT5 has changed with the latest release. Instead of adopting the refresh setting of the Desktop, it seems to use the refresh rate of the original media. So, whereas TMT version 5.0.1.87 would use whatever refresh rate was set on the desktop (e.g. 24 Hz/50 Hz/60 Hz), TMT version 5.0.1.114 uses 23.976 fps (Hz), because that's what most Blurays are encoded at.

In the previous version of TMT, I could see slight jerkiness during panning shots, but now with version 5.0.1.114, there is a very noticeable pause every 40 seconds, when the video freezes, and then jumps to catch up with the audio (which has continued uninterrupted).

For example, during the opening space scenes of Avatar, with the two rotating modules on the spaceship, with TMT 5.0.1.87 I could see a slight jerkiness as they rotated through the scene. Now with TNT 5.0.1.114 they move as smooth as silk, which is good, but then I get the full stop every 40 seconds on the video, which is horrendous.

Richard was good enough to explain that this event every 40 seconds is caused by converting from 23.976 to 24 fps, when an extra frame is introduced every 40 seconds.

But, here's my gripe: I don't think I'm being abnormally sensitive to this extra frame, but it literally seems to freeze the video for almost a second. Surely I can't be the only person to think that this is totally unacceptable? Very slight juddering during panning, I can live with; but this freezing every 40 seconds is intolerable. Is there something else happening to exacerbate this issue? Perhaps the TV, or the Catalyst video driver working against the TMT5 stream?

Any help gratefully received.

[richard1980]

The conversion from 23.976 to 24 fps should only cause a stutter that lasts approximately .04 seconds...barely anything, but still noticeable to the trained/sensitive eye (and technically it's not a stutter...its a duplicate frame, which you will perceive as a stutter). It should absolutely not result in a 1-second delay in video playback. My guess is whatever is doing the conversion from 23.976 to 24 is having problems. Without knowing the exact settings you are using and what hardware is involved, my only suggestion is to start the process of elimination until you can identify exactly what part of the chain is giving you the problem. A few possible things that could be giving you the problem:

TMT
Windows
GPU
Home theater receiver
TV

Of course, this is only the case if my theory is correct. The 40-second interval is 100% consistent with 23.976 to 24.000 conversion, but perhaps something else could be causing the issue instead.

[gcoupe]

Thanks, Richard. Yep, .04 seconds I doubt that I'd notice, so something else is going on, but I think you are correct that it's linked to the conversion. I think I have to try a long process of elimination flicking various settings in various places in what will probably be a fruitless attempt to find out what's causing this.

There are times when I hanker back to the days when I had a standalone Bluray player and everything just worked...

[richard1980]

Have you tried setting TMT and/or Windows to output at 23.976?

[gcoupe]

Have you tried setting TMT and/or Windows to output at 23.976?

I can't see any way of setting the fps in TMT. I'll try fiddling with the Catalyst settings and see if I can hit a stable combination. Thanks.

[gcoupe]

I've just had a reply back from Arcsoft support:

Thank you for using our products.
Regarding your issue, our engineer has reproduce your issue:it is a known issue that playback will stutter when TMT5 play the movie with ATI 5XXX graphic card.
we will fix this issue in further patch.
Sorry for the inconvenience.
Thank you for your understanding and interest in our product.

Interesting...

[fuminggorilla8]

Does the very same thing with the ATI HD 6xxx card.

[gcoupe]

Further to this, I read elsewhere that downgrading the Catalyst drivers from 11.8 to 11.4 would resolve this issue. I tried this, and am pleased to report that the pause every 40 seconds has gone, and playback is smooth. There is the extra frame being inserted every 40 seconds, but as Richard points out, this causes a delay of only 0.04 seconds, which is barely noticeable to me.

[richard1980]

Glad you got it fixed!