@Ronoco

Hi

In addition to @CubeAce comment, audio going out of sync can occur when the audio sample rate of the source video is different to the standard 48kHz for video.

John EB
Forum Moderator

Hey @CubeAce and @johnebaker.

Thank you for the replies. I am using an external hard drive to store the video files, fortunately.

To correct myself a bit from my last post, I meant to say that the video and audio ARE in synch at the very start of the project, but go way out of synch over time.

Also, I'm not the one who records the footage, so I'm trying to figure that out now from the person I get the footage from about the audio sample rate. As far as I know, the settings on their end haven't changed between my using Video Pro X 12 on my Windows 10 machine to now on my Windows 11 machine. I didn't have a problem with it on the old machine cause I had to set the Display Option to use the Compatibility Mode for the arranger. I tried that for the new one, but no dice unfortunately.

@Ronoco

Hi.

Both @johnebaker and I understand the problem and took it as you have further explained it.

Did you download MediaInfo and look at the exif data of a file or at the very least right clicked one of the audio portions of one of the files and selected properties to check the audio sample rate?

Did you check the project movie settings match the settings of the files used as at least it seems that playback is also affected?

Can you copy and paste the text view from MediaInfo here please?

Nearly this type of problem is always a problem with the files but without further information is impossible to diagnose further or rule out causes.

The standard renderer should be working just fine with your computer specs with no need to use compatibility mode for any reason.

When you say an external hard drive, is it an SSD or SATA drive and is it connected to either a USB3 port or USB-C port? If SATA what is it's spindle speed and cache memory size? If you don't know that, what make and model is it? I doubt that is the problem though.

If the person has reinstalled OBS Studio or done an update it is possible the files are now variable frame rate as that is it's default recording mode.

If you have an old project to hand that you could reload, it that project still OK?

Ray.

@Ronoco

Hi

AS @CubeAce has commented - use MediaInfo to analyse the OBS recording, see this tutorial on how to set up and get the required information.

In the Audio section of the analysis, locate this line

Sampling rate                            : ??.? kHz

where ??.? represents the sample rate value.

If this is not 48 kHz or 44.1 kHz then this may be the cause of the audio going out of sync.

The Display options settings have no influence on the issue you are having.

. . . . I am using an external hard drive to store the video files, fortunately. . . . .

Assuming you are actually working from the external hard drive and the video files have a maximum resolution of Full HD 1920x1080 and the drive supports USB 3 connected to a USB 3 port then, this should be OK.

From experience, working with a USB 2 connected drive, or higher resolution video eg 4K UHD 3840 x 2160 is not, IMHO, very satisfactory in terms of playback of the timeline which can give the appearance of audio lag, however it is usually accompanied by lagging/jerkiness in the video playback. In my case, as soon as the warranty on my laptop expires (soon), I will be adding a second internal drive.

John EB

@CubeAce @johnebaker

Thank you for your patience. I appreciate the help.

Yes.  I made sure the project movie settings matched the settings of the file, at 720p and 60 fps.

Yep, just installed MediaInfo now.  Here are the results:

As for the external drive, it is a 2 TB Toshiba Canvio Advance SATA with USB 3.2.  I've also moved the video file to the internal NVMe SSD just in case and still had the same results.

As for my old projects, they seem to be having the same issue.

I see what you mean now, it looks like that yes, the initial recording was set to variable and the audio is at 44.1 Hz. Does this mean that I cannot use the video file as is?

I apologize for all the simple questions. I'm not very tech literate so a lot of this new to me.

@Ronoco

Hi.

Personally I would have thought both the program and the computer specs would have made both more tolerable of both variable frame rate video and a different sampling frequency of the audio as the improvement of more recent components / programs should mean better more capable processing but that does not seem to be the case. Older systems and programs seemed to be more tolerant. the vfr is only 4fps on the video side which is small. The longer the clip as well the more it will drift over time.

The audio frame rate per second on your file's data also seems not to be standard which at 48kHz at least would be 46.857 fps. So any one of those could be throwing out the audio to video on playback over time.

The hard drive I'm not familiar with but if USB 3.2 compatible should be fine for this.

The files can be converted to constant frame rates and a higher sampling frequency / fps with a bunch of free programs such as Handbrake but other members such as @johnebaker or @AAProds would be better at guiding you to a selection of programs than myself.

For future use though and I don't know how many people you do this for, please get them to use my OBS settings I put in my first post for future recordings and that should alleviate the problem at source.

The data from one of my OBS recordings.

Ray.

@Ronoco

Hi

Thanks for the MediaInfo.

The VFR range difference is relatively low at 4fps and is IMHO acceptable.

The audio 44.1kHz sample rate is supported by VPX and causes no issues with sync when the video component is Constant Frame Rate (CFR).

I suspect that the combination of Variable Frame Rate (VFR) and the lower audio sampling rate are causing the sync issue.

@AAProds has a tutorial, which I cannot find at the moment, on using Avidemux.

John EB

@Ronoco

Hi.

I should have added there are no stupid questions if you don't know the answers. Don't feel bad. Most of us have been in the same position or had different problems in the past. That is what the forums are for.

Ray.