Proposal VuMeter Upgrades

From Audacity Wiki
Revision as of 11:27, 8 July 2007 by Suf (talk | contribs) (Updating link to "Feature Requests")
Jump to: navigation, search

What features should a VU Meter have?

Where should it live? Should it be fixed size and fit in the toolbar or should it be resizable?

  • LED type (with sticky peaks) in the mixer toolbar.
  • Analogue option

Some things it might/should have:

  • be positioned near the record level control (you are obviously going to use the level control to adjust the levels!)
  • clipping indication -- this is why we want meters, isn't it? But is it possible?
    • 4 or more contigouus samples at max (0 dB) is regarded as clipping ("over") in Red-Book-Audio
    • very special: some soundcards (eg. Soundblaster) cannot record up to 0dB. They limit (non-linear attenuation) the signal at about -4dB to - 2dB, so there should be an adjustable offset for the dB-scale.
  • a scale in dB (eg 1 bar per dB, assuming a bar type meter), Why not use Log Scale as in VU Meters. (dB is a logarithmic scale..)
  • multi-channel (eg. distinct left & right meters for stereo), Yes, very Important, and only a single meter for mono or 1-meter in a pair grayed out.
  • phase-error indicator (if absolute averages of (L-R) > (L+R) then your inputs are probably out of phase)
    • What if you were recording with a true stereo microphone, I think the sounds on the Left would show an out of phase condition when both channels are compaired. like wise the sounds on the Right side. (phase-error indicators are mainly to show if you have your inputs wired incorrectly).
    • Equation strictly is |L-R| > |L+R|, i.e. ignore the signs on the results. Hence for a blumein or similar crossed pair, this will only occur if the sound is outside the V of the pair of microphones at the side. This is equivalent to side on sound in a Mid / Side microphone setup. Either way the key thing is that mono listeners to the result will get little or no sound, which is very confusing. Any recording produced like this is likely to get a poor reception if played in mono.
    • An alternative implementation of this is based on an X-Y display of the inputs turned through 45 degrees, which will show horizontal or vertical depending on the phase of the inputs.
  • Given the above, maybe it should be possible to send the mix to the meters as well as the inputs to the meters.

Very easy to cause by crossing leads inside balenced audio connectors.

  • As well as a peak meter, it would be very useful to have an RMS meter (as seen in Wavelab).
  • The best meter (from the radio point of view) is a PPM meter. This would be very useful. Currently use a freeware one(http://www.darkwood.demon.co.uk/PC/meter.html) but would be much easier/better to have one built into the recorder.

See Feature Requests