Audio Video mismatch

[Prabhakar]

There is a Audio Video mismatch when editing mp4 videos, need assistance to rectify the same

[borate]

Mismatch when watching preview or after export?  More specifically, what type of mismatch - synchronization?

What version of Videopad is being used?

The best way to sort this out is to share your project.  Someone will check it out.

Here's how...  http://nch.invisionzone.com/topic/23659-tips-for-getting-help-on-this-forum/

If it contains sensitive material you can link it in a personal message (PM) to me, via the envelope above.  Be sure to FILE|SAVE PORTABLE PROJECT AS, not simply SAVE PROJECT, and don't forget to share it.

[italiangen]

Hi Borate,  I have the same issue.  The exported mp4 file is by the end of the video, out of sync (lagging) by about 7 seconds.  The project previews are in sync.  The video and audio files are the original linked recording.  I'm using 6.29 and can not use any other version for now.  The entire video is about 1.5 hours.  Since I only have 8GB of memory I did increase the Page file.  Here is the link.

https://drive.google.com/drive/folders/1sI4sugFhCUj22g247AhW0U9ORgWyBHqA?usp=sharing

Thanks for your support as always!

Peter D

 

[borate]

Requested access, but be aware that this should not be necessary.

Simply make the link public and, if you want it kept private, include it in a Personal Message to me.  Click the envelop at the top-right of the window and type in my name.

[borate]

It's likely that the many individual speed changes are causing sync to slip.  Doubt that it's a bug.  Still, the fact that preview is in sync and export is out has been noted to the developers.

This may be the best and simplest solution...

Build the entire project with effects but without any speed changes on the speaker's linked A/V tracks. (If needed, speed changes on the video overlays shouldn't affect tracks 1.)

When editing is complete SAVE as a project and then export as an Mp4.

Restart VP and load that Mp4 file.  Now apply the speed change overall to that single file, with the "add frames" box checked.

As a test, verify results by exporting at lowest resolution.  If that looks good, then up the res to the desired value and export again.  Let us know.

[italiangen]

Thanks Borate. 

When I finished the last edits and exported the mp4, should that mp4 be at a higher res or lower res?  Then that mp4 is loaded as a new project and it's speed reduced.  What does the "Add Frames" box do?

 

[borate]

Auto--match is but a suggestion.  Since high quality isn't an issue here, it might be best to use the lowest res and frame rate that looks acceptable for both the initial Mp4 export and  the final speed-reduced export..  Check the Insert transition frames check-box to add blended frames to help with the transition between video frames when the speed is reduced.

Not much more you can do with the original 101 project, but try the above suggested procedure on your next effort - and shoot with better lighting.

And here's another approach to mess with when you're in an experimental mood...

Complete editing with NO speed changes except possibly to a few overlay clips and SAVE PROJECT AS with a unique name, should there be a need to restore.

Click the + sign on the Sequence 1 tab above the tiimeline, to create a new blank sequence.

With that blank Sequence 2 chosen, click the SEQUENCES tab in the bin, right-click on the Sequence 1 folder and PLACE CLIP ON SEQUENCE AT START.

Sequence 2 is now a composited single clip of Sequence 1.  Though the overlays and audio track won't be visible, they're there.

Apply the speed change to Sequence two and export it  See if it remains in sync.

[italiangen]

Going back to my comment about the "Add Frames" box, here is the situation.  I loaded a final mp4 version as a new project then made the change speed adjustments.   Waited a bit then previewed it and it was good and on time until the end.  Exported the MP4 and it was out of sync.  

The lower res quality is not good enough for me to use.  I tried 1280x720 and as you know it was out of sync.  I'm going to try reductions to see if and at what point syncing occurs. 

I have not tried your 2 track 2 sequences yet.  Are these syncing issues due to my hardware limitations?

Thanks for the continued support.

Peter D

 

[borate]

Perhaps there is a hardware element, but can't say.  Upload the PORTABLE project before the speed change and share it here if possible.  We'll continue to investigate.

What is the speed-reduction factor?

[italiangen]

Here are two portable versions.  

https://drive.google.com/file/d/1eseEcmSv_1sdO1GimRDrNmUzMrgNxTrP/view?usp=sharing        With speed change so that you can see that in Preview viewing it is in sync.

https://drive.google.com/file/d/1ZEIJSWITMyyEvmPcgbQYEEaWQn3ei5Rl/view?usp=sharing          Without speed changes

These two files are the entire project.  Will you be using 6.29 to analyze this issue?

Peter D

[borate]

Those appear to be the final output, so that won't help.

But on further examination it appears that the issue is one of "keeping pitch unchanged."  UNcheck that box and the project should stay in sync, though the voice may be a bit too manly at 85%.  As a compromise try 90-95.

Whether this is a bug or not is unclear, but it has been reported.  On isolated clips, with minimal speed change, any sync deviation likely wouldn't be noticed.

[italiangen]

 

https://drive.google.com/drive/folders/1qNAi4fFnu-SPKQBOX-pMat-qHwQ-XIh1?usp=sharing

[borate]

Tested the new project using version 7.53 with the Sequence 2 method outlined above at 93% speed and "retain pitch" box UNchecked.  It stayed in sync and sounded much better.

[italiangen]

Thanks Borate. 

1. What is the difference between version 6.29 and 7.53?  Where can I find the release notes that explain the differences.

2.  I'll try the Sequence 2 method with 6.29 and let you know it it works.

2. Does 7.53 suggest or require more Ram or other specs?  

3. Do you think that due to my recording length, that I should divide the recording into 3 or 4 parts and process them independently? 

Peter D

[Nationalsolo]

Hi

".... What is the difference between version 6.29 and 7.53?  Where can I find the release notes that explain the differences. "

There is a list here with various changes listed....

https://www.nchsoftware.com/videopad/versions.html

Nat

[borate]

7.53 likely won't require more resources, but don't quote me on that.

For licensed users upgrades are free for up to six months.  After that, VP will continue to fully function but a fee will be required in order to register the newest.

Don't think there's a need to break up the project;  wasn't here ... and it remained in sync.

[italiangen]

Borate,  Do I need to wait for sequence 2 to buffer (green timeline) before I make the speed change?  Then I need to wait for the change to complete?  If so, what is the indicator that tells me its completed?  When you say export, you mean that the export contains both seq1 and seq2 as the overlay?

Peter

[borate]

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Do I need to wait for sequence 2 to buffer (green timeline) before I make the speed change?

Perhaps not necessary, but it might be wise to always wait for cachiing ... to allow a smoother preview.

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When you say export, you mean that the export contains both seq1 and seq2 as the overlay?

An export outputs only the sequence that is currently displayed on the timeline - all tracks.

If Sequence 2 has been added, as instructed above, it will be the entirety of Sequence 1 as a single clip.  You won't see overlays or audio waveform, but they're present.

Then export Sequence 2, after making the speed change.

You can also try it the way you did in the first instance, making speed changes on each Sequence 1 clip, but that wouldn't be my preference.

[italiangen]

Borate,  Thank you for all your help.  I did as you instructed and it was good enough for this project.  Allow me to just ask a question or two.

1.  When I created seq2 with seq1 where seq1 was an mp4 of all effects (exp,pos,overlay), why does a seq2 better handle the speed change without keeping the pitch?  Is there some sort of priority given to seq2???

2.  I totally agree that seriously improving the quality of capturing video at the source is essential.  So is it that I'm asking VP to do so much global changes that it is my hardware that is probably the major bottleneck?  

3.  If memory serves me correctly, I purchases VP in Nov of 2018.  When I need to reinstall VP I downloaded 6.29 when in fact I could have dl'd 7.05.  Am I correct on this given the 6 months free updates?  I was in a way, pleasantly surprised to see all the updates and fixes from 6.29 and 7.51.

Again, thanks for you help.

Peter D

 

[borate]

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Why does a seq2 better handle the speed change without keeping the pitch?  Is there some sort of priority given to seq2?

Doubt that it handles it better.  The Seq 2 method takes in all tracks and may make it easier to troubleshoot whether numerous speed changes, as in your case, are causing a problem.

A global change can be applied to Seq 1 by first selecting all (<crtl-a>) and clicking on GROUP CLIPS but it's not as easy to work with, and can be problematic.

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Is it that I'm asking VP to do so much global changes that it is my hardware that is probably the major bottleneck?  

Hardware is certainly a factor with resource intensive video editing.  But don't think there will be a problem if the PITCH box is unchecked.  Developers are looking into the issue.

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Am I correct on this given the 6 months free updates?

Yes, updates are free within six months of purchase.  Of course, you can always test non-registered versions, to see if you like them.