6.2 Audio waveform often doesn't display

ELAN
1

Hi there,

I’ve recently downloaded 6.2 for Mac which definitely seems to have addressed some of the previous issues in 6.1 (thank you!). However, I’m having issues with the audio waveform that automatically displays when playing an MP4 video.

At times, the waveform will be there but will then just disappear and look like a straight line despite lots of sounds and that a waveform was visible in that segement beforehand.

Is anyone else having this issue or is this an issue that anyone has suggestions for?

Thanks!

2

Hi,

The cause of this problem lies in a low level AVFoundation function (namely copyNextSampleBuffer of the AVAssetReaderOutput), for which we haven’t found a good solution or workaround yet. In ELAN 6.1 this would freeze the application, in 6.2 the flat line that you mention is shown (allowing the user to save changes and close the file).

There are currently two options when this occurs (it doesn’t seem to occur on every macOS system):

  1. if waveform visualization is required, or at least desirable, extract a .wav file from the .mp4 and link it as a second media file. This was the only way to see the waveform in all ELAN versions until 6.0.

  2. disable the waveform via View->Viewer->Signal Viewer

We’ll continue to try to solve this issue (e.g. by looking for alternative methods).

-Han

1 Like
3

Hi Han,

That’s handy to know! Extracting the .wav file sounds like a good workaround for the now.

Thanks for the help!