More > JRiver Media Center 19 for Windows
NEW: Improved audio analysis and volume leveling (R128)
Vocalpoint:
--- Quote from: 6233638 on August 19, 2013, 01:25:00 pm --- "Broadcast" includes radio - in fact that's where R128 has had the most adoption so far,
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Haven't heard any radio stations here (Canada) that sound like they are using it - but I guess I should have specifically said television when I said "broadcast". With all the new "loudness" rules in effect here now - TV is where I notice LOTS of leveling has now occurred.
Radio has too many compressors and other doodads to make R128 worth the effort. And I do not thinking anyone is complaining about ads or music on the radio being too loud but I know (since I have actually called to complain) that ads on TV were out of control. I expect R128 plays a big role in that transition since it has become law now.
--- Quote from: 6233638 on August 19, 2013, 01:25:00 pm ---Looking through the analyzed files in my library, 60% (of 15,000 files) require more headroom than -15 LUFS provides.
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I do not understand this - Can you explain how headroom a factor in applying an LUFS value?
Cheers,
VP
mwillems:
--- Quote from: 6233638 on August 19, 2013, 01:25:00 pm ---"Broadcast" includes radio - in fact that's where R128 has had the most adoption so far, I believe. Looking through the analyzed files in my library, 60% (of 15,000 files) require more headroom than -15 LUFS provides.
I thought it was generally recommended to not use the "process independently of independent volume" option for anything that is processing the audio, and it's just for visualizers/analyzers.
The issue is that, because volume leveling happens first, if it's going to run into clipping, it does not level fully.
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I think you might have it backwards (but I'm open to correction). You're right that it is recommended not to use "process independently of internal volume," but in the recommended state (off), internal volume is happening before DSP modules. Turning "process independently" on undoes internal volume for that module, which means that internal volume would otherwise happen first. That's why setting the internal volume lower gives you more headroom for DSP that involve boost, like EQ or convolution. Matt, I think, has confirmed that internal volume gives you more DSP headroom in the PEQ and convolution contexts. Otherwise it would be impossible to use any DSP that involved boost without constant risk of engaging clip protection, right?
--- Quote ---If Media Center's internal volume control adjusted the target level, reducing the volume control would give you additional headroom:
With the volume control at 100%, the track will still play back at 0dB, which is 6dB quieter than the target level.
If you reduce volume to 88% (-6dB) and that adjusts the target to -29 LUFS, it will still play back at 0dB, but other tracks will be up to 6dB lower, because the adjustment gave you an extra 6dB of headroom.
If you reduced the volume control to 76% (-12dB; -35 LUFS) then that track would be played back at -6dB. (because it's supposed to be +6dB from the leveling target)
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My understanding is that internal volume already gives you additional headroom, at least with other DSP modules (but I believe for volume leveling too). For example, I have +5 dB shelf that, if it were processed before internal volume, would cause clipping all the time. So I set my maximum internal volume -6 dBFS, with the result that I've never observed clipping in the analyzer even with very loud material. It's possible that PEQ and Volume leveling are different in this respect?
Thanks for the additional explanation, I'm a little dense sometimes ;D I'd be curious if one of the devs could confirm one or the other.
6233638:
--- Quote from: Vocalpoint on August 19, 2013, 01:56:57 pm ---I do not understand this - Can you explain how headroom a factor in applying an LUFS value?
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1. R128 Peak level cannot be higher than -1.0 dBTP to avoid inter-sample clipping. (this is to account for some variance in the inter-sample peak calculation)
2. -23 LUFS is the target volume for leveling.
Using a real world example, you might have a track which has a [Peak Level (R128)] of -0.8 dBTP, and a [Volume Level (R128)] of 4.0 LU.
This means that the track needs to be played back at +4dB to sound like it's the same volume as other tracks.
Because clipping protection does not allow the peak level to exceed -1.0 dBTP, the track actually gets played back at -0.2 dB.
So to level this track properly, you need an additional 4.2dB of headroom; the target for leveling needs to be reduced to -27.2 LUFS, rather than -23 LUFS, for it to play back at the same perceived level as other tracks - either that or you just accept that this track is 4.2dB quieter than everything else.
If the target level was changed from -23 LUFS to -15 LUFS, this particular track would now be 12.2 dB quieter than any other track which is able to be normalized without clipping.
--- Quote from: mwillems on August 19, 2013, 02:17:45 pm ---I think you might have it backwards (but I'm open to correction). You're right that it is recommended not to use "process independently of internal volume," but in the recommended state (off), internal volume is happening before DSP modules.
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Volume Leveling seems to happen first. This is the track I mentioned above, which is supposed to play at +4.0 dB:
--- Quote from: mwillems on August 19, 2013, 02:17:45 pm ---Turning "process independently" on undoes internal volume for that module, which means that internal volume would otherwise happen first.
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It's not an option for Volume Leveling.
EDIT:
In my library, I actually have a track (classical music) that needs an additional 7dB of headroom to be leveled properly, which would require the target be reduced to -30 LUFS!
But overall, -23 LUFS seems like a good target, as only 1% of my library (151 tracks) require more headroom than it provides.
This expression will let you see how much headroom your tracks require. (it could probably be cleaned up - but it works)
--- Code: ---Delimit(if(isempty([Peak Level (R128)]),,formatnumber(math(removecharacters(left([Peak Level (R128)],5),/ /+,0)+RemoveCharacters([Volume Level (R128)],/ LU,0)+1),1)),/ dB,)
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So if you were thinking about changing the target level to -15 LUFS rather than the current -23 LUFS, you would count all tracks that are -8.0 dB or greater. (note: positive values sort to the end of the list for some reason)
While -23 LUFS seems like a good target for music, video seems like it will require at least -30 LUFS to level properly, and we really need some way to analyze downmixed audio if multichannel files are being played back in stereo, for proper leveling.
mwillems:
--- Quote from: 6233638 on August 19, 2013, 02:31:54 pm ---Because clipping protection does not allow the peak level to exceed -1.0 dBTP, the track actually gets played back at -0.2 dB.
So to level this track properly, you need an additional 4.2dB of headroom; the target for leveling needs to be reduced to -27.2 LUFS, rather than -23 LUFS, for it to play back at the same perceived level as other tracks - either that or you just accept that this track is 4.2dB quieter than everything else.
If the target level was changed from -23 LUFS to -15 LUFS, this particular track would now be 12.2 dB quieter than any other track which is able to be normalized without clipping.
Volume Leveling seems to happen first. This is the track I mentioned above, which is supposed to play at +4.0 dB:
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Oh that ties that up; you're right (I was just looking at DSP studio myself and noticed what you describe). Internal volume happens before almost everything else, but not volume leveling. I have large number of tracks/albums that need positive volume leveling adjustments but have near 0 dBFS peaks, and it sounds like they're unlikely to get the correct adjustments unless internal volume is applied first. The vast majority of my listening happens at around 20% internal volume, so I'd have all the headroom I could ever need under those circs.
mojave:
--- Quote from: 6233638 on August 19, 2013, 02:31:54 pm ---Using a real world example, you might have a track which has a [Peak Level (R128)] of -0.8 dBTP, and a [Volume Level (R128)] of 4.0 LU.
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Do you have very many real world examples in your library where the Peak Level (R128) doesn't have enough headroom to adjust for Volume Level (R128)? In my library of 6400 audio tracks I found just three and it only made a 1.6 dB or less difference. I also would never play back those tracks without the entire album so it wouldn't matter anyway. The one needing the most Volume Level (R128) measures 15.8 and it has a Peak Level (R128) of -15.1 dBTP. The actual adjustment is 14.1 dB.
Only 200 tracks of mine need a positive volume adjustment (.03%). Out of those 200, there are only 4 tracks that I would play in a mixed playlist.
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