Project Renders with Out of Sync audio

[Paul33]

This is a new one for me !

Have quite a big project made up of around 50 short (c.30 seconds) clips, all at 1080 25fps and from same source. Project hangs together fine in Videostudio 2020 Ultimate with a few titles added and I can watch it through and all is good but ...... when I render the project on a "Same As First Clip" MPG basis, I end up with a video that has out of sync audio in the second half of the video.

I have tried all sorts, including reloading the full video, splitting the audio, splicing it at the first known out of sync clip and sliding the audio until it is back in sync ...... all looks good again but then it goes out of sync again when I re-render it. I even had one file that was close enough to live with, uploaded it to You Tube and it went further out of sync on there !!!!

The only clues I can offer here are ........

1. I can hear very slight "popping" / "clicking" on the audio where it seems to go out of sync as though there was some interference at that point.

2. When I render in VS2020, it hangs on 99% for an age before confirming it is complete ..... something seems to be upsetting it at 99% !

Having made about a dozen renders now of a 22GB file, I'm ready to give up but if anybody has any ideas then I'd love to hear them or even fool proof ways to get around the issue would do !

[Ken Berry]

First off, you say your project consists of 50 clips of around 30 seconds each. That would make the overall project around 25 minutes to half an hour long. 22GB sounds rather large for that. So are the original clips mp4, mov or something else?

In the render, do you have SmartRender enabled? If so (and I think it is ticked in the Share screen by default), then turn it off and try rendering again.

Have you tried setting the Project Properties to what you want and then rendering Same As Project Settings or even without that box ticked and just letting it render with the settings which appear in the Properties box on that Render page?

[lata]

Hi
Can you right click one of the clips on the timeline and choose properties, what are they
You say 50 clips at 30 seconds each, that's 25 minutes, 22Gb seems pretty large

Is it possible that the video is using a variable frame rate, just thinking out loud

I would try rendering again but deselect Smart Render, will take longer to complete but may fix the audio sync issue

Post updated
Sorry Ken missed your reply

[Paul33]

Yes, sorry, the 50x30secs was a bit misleading as a small number of the clips are longer. The total output MP4 was 21.6GB and the length was 45 minutes.

I have tried switching off Smart Render, Encode Acceleration, Both and without any change.

Typical clip properties attached.

As all my clips come from the same smartphone source with same settings, I always figured that "Same As First Video Clip" was the way to go but happy to learn otherwise here. If I use Project Settings, what should I use as the options confuse me and don't appear to offer what I want which I guess is MP4 output at 1920x1080 25fps.

Must admit, I don't necessarily understand the "Same As First Video Clip" settings that pop up on the SHARE screen - especially the NTSC reference. The rendering properties read ......

NTSC non-drop frame (30 fps)
MPEG-4 Files
24 bits, 1920 x 1080, 25.007 fps
Frame-based
H.264 Baseline Profile Video: 75217 Kbps
44100 Hz, 16 Bit, Stereo
MPEG AAC Audio: 256 Kbps

In fairness, I don't usually have any issues with rendering or audio sync and I suspect this is down to damaged audio track containing clicks from a faulty mic that are momentarily stalling the audio ..... but always happy to learn as I'm fairly new to all this !!!

[lata]

Hi Paul
Those properties look a little odd maybe VS is struggling to read those files correctly
Can you use a program called Media Info
https://mediaarea.net/en/MediaInfo
This will give more accurate details of your files

The Frame Rate appears to be variable, notice the rate as 25.007fps, that should be 25fps - Video Studio can struggle using a variable rate.
The data rate is particularly high at 75217 when 15000 would be more appropriate, hence the large file size at 21Gb

Not sure about the NTSC reference, that may be Video Studio, but Media Info should show correctly.

With the NTSC showing I was wondering if changing the Project Properties to use 30fps, then render same as project properties would improve the sync.
I assume your project properties are using 25fps?

As rendering with no Smart Render did not help it is becoming more apparent that converting the video to another format may be the way to go
However others have had success doing that and others made no difference.

Same as First Clip options
From Preferences F6 there is a check box for Show Messages, should be selected
From a new project when we add the first clip a message should prompt us to match the project properties, this sets the timelines to match the video in particular the frame rate. Do you see that message, you will have to start a new project to test.
If you do not get this message then VS is not liking your video files.
Generally from Share the option “same as project” and “same as clip” should be identical
Viewing the properties panel compare the two what do you see?
It is possible that VS does not read the video correctly and cannot set the project properties to match, in which case Same as First Clip may be available, a quick option to render the files using the same properties usually retains quality.

Quite difficult to pin down the problem and as I say converting the video may be the quickest option

[Paul33]

Thanks Trevor.

The video clips are from my smartphone and using software on the phone called FILMIC PRO. The only setting I see in there that MIGHT be causing issues is the one relating to Video Encoding which offers a Standard / Filmic Quality / Filmic Extreme. Extreme is what I am using and that states "The app sets a target of 100mbps for 2k, 3k and 4k. At 1080p this target is is 50mbps" whereas Filmic Quality states "At 1080p, FiLMiC Quality is 32mb per second for improved image quality, detail and color information". Is that where the high data rate comes from ? Maybe I need to switch away from "Extreme" as it probably makes little difference to the final product ...... or am I wrong ?!!!

Also is the "variable rate" something I can control/change. Is that something at source (ie: on camera) or in VS ? I've never consciously chosen "variable rate" to the best of my knowledge !

I get the suggested message on adding first clip every time so that works. I remain confused about "same as project" settings ..... does that derive from the project in some way or purely from manual input ?

The properties for "save as project" read .......

NTSC non-drop frame (30 fps)
MPEG-4 Files
24 bits, 1920 x 1080, 25.008 fps
Frame-based
H.264 Baseline Profile Video: 9579 Kbps
44100 Hz, 16 Bit, Stereo
MPEG AAC Audio: 256 Kbps

When I tried this setting, it produced a small file that looked awful so presumably something went wrong in that one !!!

[Ken Berry]

First off, where in the world are you? In an NTSC area or PAL?

Next, it is pretty clear to me, after seeing that your smartphone produces variable frame rates, that that is the problem. As Trevor has already said, VS has difficulty with that. It can only deal with video which fits precisely into international video frame rate standards. And for PAL those are essentially 25 fps and 50 fps exactly (plus one or two others which are not relevant here); and for NTSC they are 30 fps and 60 fps exactly. (In point of fact, the exact NTSC rates are 29.97 fps and 59.94 fps -- don't ask me why; it's historical and complex. But these are usually called 30 and 60 fps, even though processed as 29.97 and 59.94...)

Now the 0.7 or 0.8 seconds that your smartphone is adding to 25 fps is the source of the current problem. It might sound miniscule, but if VS is rendering -- as it is -- with an exact 25 fps but the audio is going through at its original 25.7 or 25.8 fps, then gradually over the project the difference will build up until it becomes obvious and then serious.

You won't like this, but people in this situation are usually only successful when they run their original video through an outside video converter program like the freeware Handbrake or Format Factory. You set it to produce mp4 with virtually the same properties (though perhaps a lower bitrate than 72000 -- say 15000 or even 25000 or 30000) and a fixed framerate of 25 fps. This may take time given all your videos in the project, but it may save you experiencing this problem.

[Paul33]

I'm in the land of PAL (UK) !

I'm a bit confused about this one. I've created many projects of similar length before without any sync issues and I've also got the frame-rate set as 25fps in Filmic Pro with is a top level piece of software for phone video so would expect it to be producing 25fps !

[Ken Berry]

Is there any way of telling Filmic to use a constant 25 fps? I suspect there probably isn't such a command in the smartphone's video setup...

[Paul33]

Not that I can see.

I'm trying to get input from the Filmic "experts" as I try to resolve this. There seems to be reference to some software not being able to work with VFR so is this something that VideoStudio lags behind the rest on (eg: Final Cut, Premiere) ?

[Paul33]

I'm also puzzled by the relevance of VFR to audio sync issues because surely on a clip by clip basis, the video and audio are in sync. If I split the audio of any clip in Videostudio then the fps is the same for both the video and audio track.

I get that my project is made up of multiple clips that vary from about 24.9 fps to 25.1 fps but so long as the audio and video are in sync PER CLIP then how does that result in deteriorating sync as the project progresses ? It also doesn't explain why there are no sync issues when I watch the full project in Videostudio but there are when I view it outside of videostudio after rendering.

[lata]

Hi Paul
Now that you have re-installed Quicktime, i assume only the codec and not the player

Has this improved the audio sync of your rendered files.

[Paul33]

No ..... same problem with yesterday's project !

Having so much time on my hands has allowed me to really focus on this one. I'm finding reasons but I don't have the knowledge to understand those reasons so I'm going to lean on you all again !

The audio sync issue is 100% down to video bit-rate. I have compared (mediainfo) old files without audio sync issues and those more recent with audio sync issues and the one difference is bit rate.

The video clips that make up the project are coming off the phone camera at around 34000kbps (34mbps). If I render with this on a "same as first clip" basis then I get bad audio sync problems late in the project. This is not visible when viewing the project in videostudio (smart proxy files) but the resulting render has the sync issues ...... and the file is 10x the size of the older files.

If I simply don't use any "same as" setting (ie: leave it unticked) then it creates a file with a bit rate of 15000kbps but the audio sync issue is still there ..... just not so bad.

If I click on "same as project settings" (which I have never set so don't know how those settings are derived), it renders at 5000kbps which is in line with my older files. There are no audio sync problems at all with the resulting file.

I would be interested to know what all that adds up to but I'm more interested in what I am supposed to be losing by rendering 34000kbps files at 5000kbps. With my limited knowledge, I would have assumed that quality would bomb but although it may be marginally lower quality on a big monitor, it is not hugely noticeable. Would it have been better to shoot at a lower bit rate or is there some benefit to downscaling the bit rate when rendering ?

If I'm shooting to watch the files both on YouTube at HD1080 but also on a 50" TV, should I be aiming for a certain bit rate ? I've seen reference to 10,000kbps for YouTube HDR uploads at standard frame rates.

Over to you experts !!!

[lata]

Hi Paul
First I think that Video Studio is not reading your video correctly and may not like the videos codec.
I do not think the data rate will cause the audio sync issues I would suspect the Frame Rate.

When we add a video to the timelines normally the videos frame rate will be the same as the timelines frame rate.
If the video has a higher frame rate than the timeline then VS will drop frames to allow the video to fit, if the video has a lower rate then frames will be duplicated, added

If Video Studio cannot read the video correctly how can we be sure that same as First Clip is going to use the correct properties

What does media Info show the frame rate as, VS showed 25.07fps which we think is variable, by the way the timeline has to use a constant frame rate.
Set your project properties to use the same frame rate as shown using MediaInfo.

Then Share Same As Project Properties
And yes I am clutching at straws as I do not know how to fix the audio sync.
You may be best to try a video converter, even so that may not correct things.

[Paul33]

I've re-rendered four projects now that had audio sync problems and have set the project settings with a 10MBps bit rate and all have rectified the audio sync problem that I was getting with the "same as first clip" setting. The only difference showing in mediainfo appears to be the bit rate.

All of the source files are coming in as VFR around the 25fps - some slightly higher, some slightly lower - which I can't see would result in a steadily declining audio sync but then maybe I just don't understand it !!!

Whatever the case, I now seem to have a solution that works so I'll have to sit with that and not worry about understanding why.

Thanks for your help on this one.