Integrated Dynamic Range (DR) measurment tool

[Robert J. H.]

Thank you Koz, it is interesting, as usual.
I have to check where I've seen this comparison of loudness recommendations.
Strange enough, The (mostly german-speaking) TV industry has adapted the -23 LUFS (or better, the gradual transition toward it) in 2012.
I remember the announcement some 3 or 4 years back. However, the switching from normal program to comercials still makes me jump... and so does switching from public to private stations. Radio broadcasting companies do not seem to have yet agreed on the introduction of R128.

Despite of my forbodings, implementing the DR14 algorithm seems to be the easier starting point. Mainly because it has neither filtering nor gating in it. The Loudness Range has included those but without the subtraction of the dBTP (true peak), it uses instead the integrated LUFS (loudness unit in relation to full scale). Both algorithms take just some part of the RMS values (if weighted or not). DR14 needs percentiles 80 to 100, whereas LRA uses those from 10 to 95 (but with a lot already removed due gating).

[unfa]

I'm bumping the thread.

There's a video by Ian Shepherd showing his online DR meter in action:
http://productionadvice.co.uk/how-to-ma ... song-loud/

I think it's a rather simple thing calculating the range between the peak and RMS with some easing. What do you think about that?

Also I'd like to remind again that the ofline meter is implemented in an open source project called DR14 T.tmeter:
http://dr14tmeter.sourceforge.net/index.php/Main_Page

How hard would it be to extract the analysis code and add it to Audacity's "Analysys" menu?
This way user could analyze any selection for the DR value. That would be extremely handy when checking album masters.

[unfa]

I've found an interested paper about the EBU R 128 (-23 LUFS) standard, I think it might be a big help in implementation:

http://lac.linuxaudio.org/2011/download/lm-pres.pdf

[unfa]

I've realized there's Ebumeter:

http://kokkinizita.linuxaudio.org/linux ... guide.html
http://kokkinizita.linuxaudio.org/linux ... index.html

It (nearly?*) complies to the EBU R 128 specification.
*I'm not sure if it measures inter-sample peaks yet.

It's not as easy to read as JKMeter, but given a bit of reading can really give nice results.
Maybe it'd be a good idea to incorporate some features of it into Audacity?

[steve]

There's a video by Ian Shepherd showing his online DR meter in action:

Good video.

[steve]

I've found an interested paper about the EBU R 128 (-23 LUFS) standard, I think it might be a big help in implementation:

http://lac.linuxaudio.org/2011/download/lm-pres.pdf

That answers my first question

It (nearly?*) complies to the EBU R 128 specification.

A "loudness meter" does not have to comply with EBU R-128 to work effectively as a loudness meter. It only needs to comply with EBU R-128 to be an "EBU R-128 compliant loudness meter".

There are weaknesses in the EBU R-128 specification that allow different (compliant) meters to produce significantly different measurements, and for measurement that are wildly different from "perceived loudness". Because of these weaknesses, for an "equal loudness normalization effect", I probably would not use EBU R-128. Similarly, for "mastering" a mix I would not rely on an absolute measurement from an EBU R-128 compliant meter - better to use "ears". However, having said that, EBU R-128 is probably the most widely accepted standard* for loudness measurement, so if Audacity were to have a "loudness" or "dynamic range" meter, then it would make sense for it to be compliant with EBU R-128.
(* not actually a "standard". EBU R-128 is a "recommendation" based on ITU-R BS1770)

How hard would it be to extract the analysis code and add it to Audacity's "Analysys" menu?

According to that paper:

• An instrument or software application conforming to R-128 should allow the user
  to display either M or S. Update rate must be at least 10 times per second.
• The maximum values for either must be displayed as well.
• For a graphical display two ranges should be provided: one from -18 to +9 LU,
  the second from -36 to +18 LU.
• The user should be able to select either the relative (LU) scale, or the absolute
  (LUFS) one.

So this appears to be primarily targeted at a real-time meter. In which case, it shouldn't it really be a new toolbar (like the standard meters) rather than something in the Analyze menu?

[steve]

I've realized there's Ebumeter:

http://kokkinizita.linuxaudio.org/linux ... guide.html

The good news is that it can be used with Audacity (http://youtu.be/MG4VYW6yChU)
The bad news, probably only on Linux.