Nan Errors for Small Files

[chsanford]

Hello,

I am using Ubuntu 17.10 with gstreamer 1.0. I've been using GST-PEAQ to estimate the divergence between audio files, and I occasionally obtain the following as output for the divergence between a pair of files when using the basic version of GST-PEAQ.

Objective Difference Grade: -nan
Distortion Index: nan

I cannot tell exactly what causes the error. It seems like it primarily happens when the audio clips are particularly short or when the file is almost silent. Do you have any insight into why this happens? I am happy to send you files that cause this behavior, if you would like.

Thanks.

[martinholters]

The PEAQ algorithm needs a certain amount of data for its averaging to make sense. Otherwise, some internal values will be calculated as 0/0, giving rise to NaN values which then propagate. Also, as there is no correct value to use in this case, the score simply cannot be calculated. Unfortunately, as the algorithm has some thresholds on where to start (and stop) considering the data in the input file, one cannot give a fixed minimum length of the input.

That being said, a more informative output would surely be in order here.