Editing MPEG, audio out of sync

[TAMc]

I've been wading through the 3042 search results from the above key words , and hoping there might be a solution. I normally work in AVI but have an old family MPEG file which I'd like to reduce in length but it loses audio sync when imported into VideoStudio X9 Ult Pro. The problem doesn't arise with short clips. Interestingly, the video tutorial on importing in Corel's website demonstrates an MP4 file being imported & edited in the software so I'm guessing the problem here is about progressive loss through the extended time? I've tried rendering the file into AVI but that doesn't change the problem.

[Ron P.]

I haven't read about this OOS problem in quite some time, years in fact. I did do a search using the term "out of sync", and me being the author, which provided 94 results. Out of Sync. This was a problem when editing MPEG 2 video way back in the VS10,11, 12 era. It seems that those versions had a problem editing compressed video files. The current version should not have this problem, since it is designed to handle much more compressed video than MPEG-2. Whoa, ok I just re-read your post. You didn't specify what version of MPEG. So let's start at the beginning.

What are the properties of your video file? Right-click on it, copy and paste them to the forum.
What are your Project Properties ?
Since you're located in a PAL area, is this MPEG video file PAL or NTSC? They don't play well together. PAL video standard is 25fps, while NTSC is 29.97fps.

Back when this was a common issue, there were some third-party utilities we would recommend as a work around. I'm not sure if they currently exist though.

[TAMc]

Thanks so much, Ron, & good to hear from you. The system won't allow me to copy/paste the file's properties dialogue box but the general tab shows it as a 23.2GB MP4 video. On importing it into X9 the properties shown are:
Microsoft AVI files
24 bits, 720 x 576, 16:9, 25 fps
Lower Field First
DV Video Encoder -- type 1
DV Audio -- PAL, 32.000 kHz, 12 Bit, Stereo

I tried changing these to HDV/MPEG but the problem remains.
From the 2008 posts I followed a couple of links to other software but the pages are no longer available.

The MP4 file was created a few days ago, after re-linking an old .VSP edit to the nearest thing I have to original material, a series of MPEG clips made by my son from his original Digital 8 material which he's over-recorded!

[Ken Berry]

You keep using the term "import" in relation to this video. What exactly are you doing. If the original video is mp4, why not just insert that from wherever it is stored into the VS timeline for editing (right click in the timeline or library window and click on "Insert Video".

It seems that by "importing" you are going something else to transform mp4 into DV/AVI.

I am also wondering about the mp4 part. If the original video came from an old Digital 8 camcorder, the video from it was much more likely to be mpeg-2 or if it were a Sony Digital 8 with Firewire, then possibly DV/AVI -- though I note you say the original Digital 8 tape has been over-recorded.

If in fact your relinking of the old VSP brought in mpeg-2 or DV/AVI files, then an added problem -- which might in itself explain the out of sync problem -- might be that these files would have been Lower Field First. If you then produced the mpeg-4 from them, I suspect you may have used default mpeg-4 properties, which use Upper Field First.

In other words, we need more information about the Properties of the relinked files *before* conversion to mpeg-4, plus the properties you used for that conversion to mp4.

[John-T-Smith]

Does your video use a constant frame rate, or a variable frame rate?

Exactly what is INSIDE the video you are editing?
Report back with the codec details of your file, use the programs below
Free programs to get file information for PC/Mac http://mediaarea.net/en/MediaInfo/Download you should VIEW IN TREE VIEW

[MrJohnny]

Tam

1 What are the properties of the "old family MPEG" video file, as Ron P requested? Use the link John T gave.
2 Does the "old family MPEG" video/audio play in sync in an external program, eg Windows Media Player/VLC?
3 The short clips that play OK - are they cut from the "old family MPEG" file? If so, can you chop up the "old family MPEG" and use them in VS?
4 Can you separate the "old family MPEG" audio from the video using VS or VirtualDub (using FFMPEG plugin) or some other program. If yes - do the times given for video and audio match?

John

[TAMc]

Really appreciate all your help with this, folks - thanks so much. Going away for a week or so and will catch up with this when back & time to explore further. Trevor M

[TAMc]

Hi folks, & appreciate your patience. I've attached the MediaInfo report which will hopefully shed some light on this. The file plays correctly in Media Player; the problem arises when it's inserted into VS and edited. I'm now able to recreate 95%+ of the project by using the earlier several MPEG files, and these seem to be going ok, but for reasons I've not yet been able to discover there's a closing clip in the 'rogue' MP4 file not included in the earlier files which I'd really like to recover/retain. However, I realise this is a bit of a mess and might have to settle for what I can get, benefit from the learning, and move on.
I've also captured 4 screenshots of the MP4 file's Windows right-click properties which I'll endeavour to attach later if that's of any help, but these attachments aren't being accepted just now as they exceed the acceptable pixcel range.

[MrJohnny]

Trevor

Looks like the "old family MPEG" is a variable frame rate file (just)!
To resurrect the "rogue" file(s) try converting it to constant frame rate. The folks around here seem to recommend Handbrake, don't use it myself - I use FFMPEG/Winff, anyway looks like conversion one way or another. Good to know you have got most of the video you require.

John

[TAMc]

Looks like you absolutely 'nailed it' John. thanks so much to you & others who helped along the way. Handbrake did the trick, allowing me to capture the final clip I needed & stitch it all together. I now have the outcome I'd hoped for but began to think not achievable.