'ello all!
I’ve been searching the manual for how to locate max and min samples in a project track.
Any clues would be appreciated.
David
you can find out how tall the max is by using amplify
it will tell you how far you can go until you clip so you are that many db down from FS. i see no easy way to tell how to find the min. or where the max was located. i guess if you expanded the wave form enough that you could slowly scroll through it and find those points though. maybe if you used the find silence feature it could find the min if you used a narrow enough gap but it could depend on the noise level so would not be really useful.
Thanks for your suggestion Womper.
I just realised that by min. val. sample, I should have said “maximally negative.”
They can’t be hard to find. I wonder whether anyone else has a use for such info…
I’m interested in finding them to make some editing decisions prior to normalising the track, so as to achieve an overall higher mean amplitude.
I’m not really interested in doing it by hand/sight as that can’t be batched.
Does the dev. team read any of this or should I email them specifically?
cheers,
David
The Amplify effect will indicate the max OR min of a selection.
The default amplification is to bring the peak level to 0dB … that’s +/- 1.0
If you use Audacity 1.3 and you set “View menu > Show Clipping”, and then amplify to 0dB, the place(s) where the waveform touches +/- 0dB will be indicated by a red vertical line.
<<<If you use Audacity 1.3 and you set “View menu > Show Clipping”, and then amplify to 0dB, the place(s) where the waveform touches +/- 0dB will be indicated by a red vertical line.>>>
Since “0” is a valid number, I thought they turned red if the samples exceeded 0.
Koz
Unless you are using 32 bit, then it can’t exceed +/- 1.0
That’s what makes digital clipping so nasty. 1 bit over +1 and you are suddenly at -1
Audacity therefore triggers the clip indicator at 0dB.
In the case of one or two single lines, it’s no problem. Where the audio attempts to exceed 0dB (or for 32 bit, if it does exceed 0dB, then there will be a whole wodge of red lines with the appearance of thick red lines and that indicates there is a problem.
tried that in 1.3.9 and did not get the red line.
it shows during recording. did not see it when i allowed clipping and overamplified the signal to force clipping.
You’ve broken it 
Post a full description of the problem including repeatable steps of how to reproduce the issue in a new topic.
Don’t forget all the usual information that is required in a good error report.
is there a template for a good error report?
this one did work after all .
it was hidden temporarily.
it started out as max at the very beginning so the line got pushed off display. had to scroll back to see it. and at 0.1 db over clipping it was very thin.
feature request? optionally be able to put fatter yellow line around the thin red lines to help spot the very short clipping spots.
and maybe a spot with a fixed flag that turns on when there is clippign anywhere to alert the fact that it happened.
Audacity doesn’t give you direct access to that data (it’s a feature request that it should give you a text export of it).
Wavosaur will give you a text read out of the amplitude of each sample.
As for Audacity, if you save a project, you can look in the .aup file. Each blockfile will show values for negative peak, positive peak and RMS (average) volume. That’s quite a lot of data to wade through to find whether the highest peak of all is positive or negative.
Gale
Thanks Steve - that’ll do what I require very nicely.
For the record, there is also an Analyse/Find Clipping routine, which seems to be more generic. Presumably it can also be used in batch mode. See [u]http://manual.audacityteam.org/index.php?title=Analyze_Menu[/u].
This tool is also useful to analyse the “band of vertical red lines” issue Steve refers to.
Thanks to all for help. I hope this is useful to others too.
David