Hello florian, > I wanted to ask for a long time if your ebulm Linux loudness > meter has seen an upgrade to include True Peak Metering? > And does it use the -10 relative gate for integrated loudness?
The last release (july 2012) uses the -10 dB relative gate. The current development version includes the true peak metering. It uses 4 times oversampling and measures both the original signal and the same with a DC removed (first order highpass, 5 Hz). I just need to decide how to display this. Currently there is an indicator that flashes yellow for 1 second when the peak level reaches -1 dB, and turns red permanently (until reset) at 0 dB. Suggestions to improve this are welcome ! BTW, the upsampling is kind of tricky. Using a standard resampling filter designed to avoid aliasing (say -80 dB at 0.5 * FS and -3 dB at 0.48 * FS), peaks are underestimated in some test cases, e.g. for a single sample. OTOH, one could argue that any real-life D/A converter will probably do the same. The standard doesn't address this issue AFAIK. Another issue is what to do for 96 and 192 kHz. Assuming there will be no significant energy above 25 kHz or so, 2 times upsampling would be enough for 96 kHz, and 192 would require none at all. Ciao, -- FA A world of exhaustive, reliable metadata would be an utopia. It's also a pipe-dream, founded on self-delusion, nerd hubris and hysterically inflated market opportunities. (Cory Doctorow) _______________________________________________ Sursound mailing list [email protected] https://mail.music.vt.edu/mailman/listinfo/sursound
