Audio Synch out after Conversion

Xenofex2 wrote on 2/20/2018, 7:20 AM

In my latest 'quick project' I have been trying to edit a 32 minute football video taken by one of the 'Dad's' over the weekend in which our young grandson played. I have actioned a basic edit - snip and cut - and not touched anywhere the unlocking of audio tracks. I have about 60 clips joined together - no fades etc - and reduced the length by about 10 minutes.

Play it within MEP and there is no problem. Now I have tried to export to MPEG4 a number of times and every time it is obvious when playing the exported movie within some 20 - 30 seconds that the audio comments made by spectators is out of synch with what is happening and this is not the case if I watch within MEP the project file.

Now I think I may have found the reason although nowhere expert in understanding the meaning of frames per second.

Above are two screenshots. One on the left shows, I think, the Object Properties of the original movie and what I have been trying to export my edited version to - 29.97! The one on the right shows the actual properties of the exported movie which shows, again I think, the Object Properties of the MPEG4 file and shows that the fps is not what I had originally set up MEP to export it to, but 25fps. Is that the reason why the audio is out of synch when playing the mpeg file?

Okay not a frequent user of MEP, I have not encountered this problem before, apart from the previous week. Again doing exactly the same thing with last weeks football video downloaded from youtube, MEP crashed just as I was having a last look before exporting. Lesson reminder - must do frequent saves. Went through the whole process of editing again and this time the audio was out of synch. Gave up and tried a third time, again from scratch and this time the exported movie was okay.

MEP was re-installed again a few months back after further Windows problems. MEP version is 17-0.2 159.

Any suggestions please?

George

Comments

johnebaker wrote on 2/20/2018, 9:10 AM

Hi George

. . . . video taken by one of the 'Dad's' . . . .

Do you know what camera/device was used to record the video?

Can you analyse the original video clip with MediaInfo and post the results back from the Tree view of MediaInfo.

I think you are on the right lines looking at the framerates, however I suspect the problem is in the original recording and an educated guess would be that the video is variable framerate whereas MEP works best with a constant framerate - the MediaInfo data will either confirm this or give an indication of what the problem is.

HTH

John EB

Xenofex2 wrote on 2/20/2018, 10:01 AM

John

Attached is a screenshot of the particular section in MediaInfo I think you want. I don't know if this would help but I do have Movavi Video Converter 18 Premium.

George

johnebaker wrote on 2/20/2018, 12:33 PM

Hi George

My suspicions about the framerate of the source video being Variable are confirmed, try running the source video through a Video converter to change the video framerate to Constant and then import this into MEP.

I and several other members here use MovAvi (paid for) for conversion, however there are other freeware converters available - avoid using Handbrake it is IMHO not easy to use.

HTH

John EB

Xenofex2 wrote on 2/20/2018, 2:09 PM

John

Thankyou for the feedback and suggestion as to how to proceed. I assume by this information that two or more cameras recorded the initial match which caused this variable frame rate although having downloaded one file from youtube, it was not something that I had thought was possible?

Following a problem around a year ago when I had collected individual videos from different sources for a project, it was as a result of this Forum, and probably yourself, that I was first introduced to the Movavi program and now also have the paid for version.

Thankyou again for your help.

George

johnebaker wrote on 2/20/2018, 2:39 PM

Hi george

. . . . I assume by this information that two or more cameras recorded the initial match which caused this variable frame rate . . . .

I personally have not come across a good camera that records variable framerate, however some cheap cameras and a lot of mobile devices, eg smartphones, do record video with a variable framerate to save space on the recording media.

AFAIK videos from Youtube are constant framerate - I have a couple of FullHD (1920x1080) webm format that were downloaded from YT, howeverI have seen comments that some may be variable framerate.

HTH

John EB

Xenofex2 wrote on 2/20/2018, 3:03 PM

John

Interestingly I have just heard from our son who was on the touchline. He tells me that it was recorded on one camera. In light of your further comments, probably a smartphone.

Thankyou again. Something else I've learnt.

George