Preview playback speed.

[john4647]

VS 2018 Ult.
When previewing clips I notice that the preview runs slowly (about 25% slower than real time). As a result the audio 'stutters' and the clip is out of synch.
Is there a way to control the preview playback speed?

[lata]

Hi John
You do not give any info regarding your clips
Smart Proxy
Make sure you are using Smart Proxy –Settings Smart proxy – Enable is checked
Then right click the clips on the timeline for Create Smart proxy, this may take some time, once created you should see a small double icon on the clip as image below

click image for larger view

[john4647]

Thanks for the reply.
I have smart proxy enabled and all the files in the timeline have the smart proxy icon.
They are .MTS files from my Panasonic Camcorder.
The speed problem is only apparent when viewing clips in the preview window. Viewing the whole project is o/k.

[RobertOZ]

Hi John,
Are you therefore saying that in Project Mode the video plays at the correct speed, but in clip mode the speed reduces

[john4647]

Hi John,
Are you therefore saying that in Project Mode the video plays at the correct speed, but in clip mode the speed reduces

Exactly that Robert.

[lata]

Hi
Clip playback uses the source files on the hard drive to play the video, Project playback is assisted by smart proxies.
I have seen this in the past with test clips where my pc struggled to play the clip, most media players struggled to play the files and that showed when using Video Studio in clip mode.

Can you tell us the type and properties of the clips, right click the clip from the timeline and choose properties, what are they?

So do you have any issues playing these files on your pc, not using Video Studio.

[john4647]

These are the clip properties. I set the project properties to be 'same as'

I do not have any issues playing these clips on my PC or TV or indeed the rendered video, just in clip preview mode.

[lata]

Hi John
My Panasonic records to the same as your video although I tend to use 50i (25fps) if I need a Bluray Disc.
I have to say that I found 50P easier to edit than 25fps, my older pc needed Smart Proxy for 25fps but got away without using SP with 50P

Just added 15 clips to 2018, no problems in playing in both modes without Smart Proxy
I am at a loss as to understand why those video files do not play correctly for you in clip playback.

I do have K-Lite codec pack installed which was recommended on the Corel Knowledge Base for problem HD video, although that was not the reason for me to install and I cannot say that it made any difference, I suppose worth a try.

Post updated

If you play the clips from within the library are they better or the same -- poor playback

[john4647]

If I play the clips direct from the library, the result is the same.
This is probably not scientific or even the best way to illustrate my point.
However, I filmed what is happening and have posted the film here:https://drive.google.com/file/d/1VhCVoQ ... sp=sharing
I hope this works.
If it does, you will see that for the first 15 seconds of the clip all appears to be well. Then progressively the video slows down by about 20/25%. If you compare the counter on the clip preview with the VLC (or other) counter this is apparent.
Also I notice that the audio part of the clip finishes some time before the video part.
(I do have the K-Lite Codec pack)

[canuck]

Could you upload the clip (used in your example) so that we can download it and do some tests?

[john4647]

Could you upload the clip (used in your example) so that we can download it and do some tests?

No problem, here is the clip:

https://drive.google.com/file/d/1oN3j5A ... sp=sharing

However, this problem occurs with all my .MTS clips, not just this one.

[Ken Berry]

Over the years, I have never set much store by VS's preview in Clip mode, regardless of the version and regardless of my computer setup. IMHO it has been a weak point of VS, for me at least. But I accept it as I still get a pretty clear idea of what I need to edit in it. And since all my projects are never much more than 20 minutes long, I'm prepared to use Project mode or even test render the project to get a better idea of what might need doing to it.

You'll see from my Profile under my avatar that my computer has a similar CPU and RAM to yours, though a different GPU.

I've played your clip a couple of times, and essentially it played OK in the sense that the video and audio stayed in sync throughout, and it did not slow down. However, it jumped a couple of times when I played it, though the jumps were at different points in the two playbacks -- and I have found this to be fairly common with all my playback of HD or 4K video for which I have not made a SmartProxy copy. I never used SmartProxy for these playbacks. When the very brief jumps occurred, the audio also jumped and stayed in sync with the video. In both cases, the audio ceased at the same time as the video, and as far as I could see, the audio was matching the speaker's lips throughout. Apart from the jumps, the speed remained the same throughout.

[tletter]

However, I filmed what is happening and have posted the film here:https://drive.google.com/file/d/1VhCVoQ ... sp=sharing

There is stuttering shown in your video but when I download "00017.MTS" and play it in VS2018, it plays fine even w/o Smart Proxy. As you are using Smart Proxy, perhaps the proxy file is corrupt and should be recreated, or turn off Smart Proxy and see how it plays. What does Task Manager show that your system is doing when the stuttering occurs?

I note that in your video, you've separated the audio track for "00017.MTS", yet you also have the audio enabled in the video track, i.e. you have duplication of the audio.

tletter
https://www.youtube.com/user/tletter

[john4647]

However, I filmed what is happening and have posted the film here:https://drive.google.com/file/d/1VhCVoQ ... sp=sharing

There is stuttering shown in your video but when I download "00017.MTS" and play it in VS2018, it plays fine even w/o Smart Proxy. As you are using Smart Proxy, perhaps the proxy file is corrupt and should be recreated, or turn off Smart Proxy and see how it plays. What does Task Manager show that your system is doing when the stuttering occurs?

I note that in your video, you've separated the audio track for "00017.MTS", yet you also have the audio enabled in the video track, i.e. you have duplication of the audio.

tletter
https://www.youtube.com/user/tletter

I don't think that all my MTS smart proxy files could be corrupt, in any case, if I turn smart proxy off there is no difference.
I have not looked at Task Manager during the stuttering. I will do this and respond.
I re-enstated the audio for the purposes of my example. In the final cut it would be muted and the audio split would come into play.
As a matter of course I split out the audio in all my clips to assist in adjusting the music track volume, however playing the clip only (as per my example) would not bring the audio track into use (i don't think)

[lata]

Hi John
Thanks for the original sample of 0017.mts
I have no problems in playing that clip in Clip Playback
Compared to the recording it is as smooth as a babies bum.

I also wondered why you split audio but assumed you need to tweak the levels to remove the engine sounds
Not that will be an issue as you are having problems with Clip Playback and not Project Playback

In addition to other suggestions here can you de-select your Hardware Acceleration options via Preferences (F6) – Performance tab,
some users have complained that using acceleration has affected render quality.
Worth a try…
And should it improve things try without Smart Proxy.