Related questions on this site that unfortunately don't match my use case:
- Compare two audio files
- How to use sox or ffmpeg to detect silence intervals in a long audio file and replace them by zeros (aka suppress background noise)?
The DSP Stack Exchange site has nothing of value to offer:
- Measuring how non-noisy a sound signal is has meaningless answers.
Problem:
I download files from the Internet (YouTube, Vimeo, etc.), or transcode stuff from my FM radio. I would like to be able to calculate (from the command line) the following:
- (ideally) a pair of numbers: average Signal-to-Noise-Ratio (SNR) and its variance for the recording as a whole
- (not so ideally) a sequence of SNR values for e.g. each time slice of the recording (a second, a tenth etc.)
- (would work at a pinch) a spectrogram for each time slice of the recording
...using only GNU/FOSS command line tools - FFmpeg and anything I can get in source tarball form.
P.S. Can I do it with sox?
soxoffers no definite solution (but allows one to get the spectrogram from the command line). ITU-R BS.468-4 standard filters should be used (unless one wants to go full U.S. of A with A-weighting). – Phil's sox May 08 '17 at 18:55