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ilia3101 / MLV-App

All in one MLV processing app.
https://mlv.app/
GNU General Public License v3.0
283 stars 29 forks source link

Audio sync according to first video frame time stamp #77

Closed bouncyball-git closed 6 years ago

bouncyball-git commented 6 years ago

This is the continuation of this thread: LINK

Look how precise this sync is:

BookSync.MLV. It is synced to 1milisecond + 12samples = 60 samples all. This long zeros been added in the beginning of the audio data. booksync

BikeSync.MLV. There have been cut 558miliseconds at the beginning bikesync

BUT, there is very ugly mistake made in this example! If you will look at the left and right channel waveforms of original and synced wav very carefully you will see that they are swapped ;)

I'm doing rounding to even number of bytes, but I had to do 4byte rounding to account both channels correctly, one stereo sample = 4bytes not 2... ehh... have to do my math again :)

Edit: This also concerns to cut-in alignment. It have to be 4 bytes instead of 2.

masc4ii commented 6 years ago

The article about ffmpeg and GPU is very interesting! Will try that out!

masc4ii commented 6 years ago

Maybe another export option for h264 / h265?

bouncyball-git commented 6 years ago

Yes why not.

masc4ii commented 6 years ago

For you it was working? I only get crashes without any error message. Maybe may graphics card is not able to do that :-(

masc4ii commented 6 years ago

Ah... -loglevel 0... hehehe. Unknown encoder 'h264_nvenc' Is there a newer ffmpeg version necessary?

masc4ii commented 6 years ago

It seems that needs CUDA >= 2.0, I have 1.0. :-(

bouncyball-git commented 6 years ago

I was lucky to use the ffmpeg version with nvenenc on windows. On Linux I got the same error you have despite I have GTX1080. We have to compile for macos and Linux. ffmpeg included In Win64 version of MLV App has all these features compiled.

bouncyball-git commented 6 years ago

This issue should be fixed now after commit 3255c70d411b04d1f291a4b08bae7b181cae92c5.

bouncyball-git commented 6 years ago

I hope I ironed out last bug causing crash on some long delayed audio MLVs, so I'm gonna close this issue for now.