Video and extracted Audio don't match

Hi,

i keep running into a strange problem. When importing video, the extracted audio and video don’t have the same length.
This happens on both MP4 and MOV Files, mostly 25fps. Doesn’t matter whether AVC Coding, H264, photo JPG.
Most times audio is longer than video.
It doesn’t always happen. I have two different videos here, same client, same project, same export settings, both MP4 (AVC coding), one is fine, on the other audio is longer than video.
Can anybody tell me how to fix this? Do you run into the same problem?`

Best,
Oli

Samplerate mis-match?

(Video should always be 48kHz)

Fredo

no, all concerning projects are 48 khz.

i uploaded a project on my server. Video F1 is ok, on video “F2” audio is longer than video after importing video with extracting audio on import.
Can you replicate the same problem?
http://www.diefaktur.de/download/nuendo-test-project.zip

audio in this project is not the final version btw. It’s just a layout version :slight_smile:

What happens if you disable “extract Audio from video file” on import, and do the extract audio after the video file is in the Pool?

I had a look at the project and this looks like a rounding error.
From the first video, the audio is equal length, o, the second one (Public) the audio is 1 frame longer.

But, the audio is exactly 10 seconds, while the video is one frame shorter than 10 seconds.
So it looks like it is a rounding error in video and/or audio.

Since there is no BITC, and since it is a mp4 encoding, it is impossible to know where the problem comes from.

Fredo

I exported F2 in Quick Time Player to a Foto JPEG Codec. Then imported it into Nuendo and …and yes, now Picture and Audio are same lengh.
Makes a point for what Fredo proposes that its sort of a MP4 rounding error. (Its that one black frame at the end of the movie that is neglected in MP4 version…)


Oswald

ok, so the beginning of the two should match, and i just don’t care about the ending?
I will check again with Photo JPEG, although i remember having the same problem with it.
But if it is only the last frame, that is missing, but up to the frame before, video and audio are in sync, that is fine with me.
Rounding error, ok.

What seems certaine here is that I can see that 1 black frame at the end of the movie when opening the video in QT player. Imported in Nuendo that 1 black frame is gone…
And audio is exactly that 1 frame longer. That makes me think: We have one of this cases where sound is right but picture is wrong.

Oswald

ok, thanks for all your input.