Item loudness graph doesn't respond to channel selection

timzibrat · 05-06-2024, 01:38 AM

I've been trying to use the loudness graph on media items, which is a super great feature, but I've run into a dead end, where I use multichannel files and explode them to mono items. The loudness graph shows the same value on all of the items although it's very clear that the waveform is different. Is this a bug or something that cannot be changed? Spectrograms and spectral peaks all respond to channel selection naturally, how come not the loudness graph?

Also the tooltip does the same thing. The peaks under mouse is displayed correctly, while the loudness is for the whole source file.

Let me know if you need more info.

schwa · 05-06-2024, 05:01 AM

This is unfortunately a live-with-it situation. In general loudness values are measured by combining all channels, which is fundamentally different from how spectral information works. In other words REAPER stores a single loudness value for all channels combined, so it's not possible to back out the loudness value for a subset of the source media channels, without recalculating the peaks.

timzibrat · 05-06-2024, 12:38 PM

I see. So the only way to truly get the right info would be render to mono. I have the same issue with ARA, where "radix auto align post 2" always refers to the whole file not the selected channel. You have any suggestion for that type of workflow potentially? Is rendering/glueing the only option? Thanks for the info.

(maybe you could add a note when only certain channels are selected, that the graph might not be accurate?)

05-06-2024, 01:38 AM	#1
timzibrat Human being with feelings Join Date: Jan 2019 Location: Ljubljana, Slovenia Posts: 80	Item loudness graph doesn't respond to channel selection I've been trying to use the loudness graph on media items, which is a super great feature, but I've run into a dead end, where I use multichannel files and explode them to mono items. The loudness graph shows the same value on all of the items although it's very clear that the waveform is different. Is this a bug or something that cannot be changed? Spectrograms and spectral peaks all respond to channel selection naturally, how come not the loudness graph? Also the tooltip does the same thing. The peaks under mouse is displayed correctly, while the loudness is for the whole source file. Let me know if you need more info.

05-06-2024, 05:01 AM	#2
schwa Administrator Join Date: Mar 2007 Location: NY Posts: 17,814	This is unfortunately a live-with-it situation. In general loudness values are measured by combining all channels, which is fundamentally different from how spectral information works. In other words REAPER stores a single loudness value for all channels combined, so it's not possible to back out the loudness value for a subset of the source media channels, without recalculating the peaks.

05-06-2024, 12:38 PM	#3
timzibrat Human being with feelings Join Date: Jan 2019 Location: Ljubljana, Slovenia Posts: 80	I see. So the only way to truly get the right info would be render to mono. I have the same issue with ARA, where "radix auto align post 2" always refers to the whole file not the selected channel. You have any suggestion for that type of workflow potentially? Is rendering/glueing the only option? Thanks for the info. (maybe you could add a note when only certain channels are selected, that the graph might not be accurate?)