Replay Gain is buggy

[Maxim Kurbatov]

Hi. I have noticed, that Replay Gain in Poweramp sometimes not works. If I open settings, go to replay gain settings menu, disable and enable replay gain, it can (not always) start working again.

Also, if it stopped working, I can't absolutely hear difference, when I change RG preamp and Tracks-Without-RG-Tags preamp.

[ScratMan]

I confirm replay gain does not work.

[andrewilley]

Seems to work for me, could you upload a couple of sample files which are set up for Replay Gain ? (I assume you do know that RG only applies a single gain boost to a whole track, to bring its peak level point up to a maximum volume - it does not normalise on the fly within a track)

Andre

[Maxim Kurbatov]

There are 1 normal track and 2 silent tracks:

https://drive.google.com/drive/folders/0B3LaKvcoO-_5dEYyYnpuZHY3YnM?usp=sharing

They all have track_replaygain tags, also their volume is THE SAME, when I listening them in DeaDBeeF-0.7.2 on linux,

but when I listening them on Poweramp on my Android, Waltari and Soundgarden tracks are more silent, than Radiohead track.

[andrewilley]

I can't see the sample files in the link you provided, only a .png image?

If you are needing +23dB of gain though, I think I would re-rip them to be honest!

Andre

[Maxim Kurbatov]

Oh, sorry, wrong link.

Samples are there: https://drive.google.com/drive/folders/0B3LaKvcoO-_5dEYyYnpuZHY3YnM?usp=sharing

Ripping a big collection of music is very durable process, anyway Replay Gain should add exactly +23dB to some tracks, but it's not.

[andrewilley]

I'll have a look.

I assume the extreme boost values in your files were created just for testing purposes though, as those files peak at -33dB as uploaded.

Andre

[Alpha-Toxic]

Just for reference: 

The stable version also has problems with replaygain. I have no idea if they are connected, but perhaps it's worth a look.

Example tracks linked in the other thread.

 

[andrewilley]

I know that some more obscure formats (e.g. Opus) were not detecting the enable/disable of RG correctly, but MP3 files should would OK. I think your problem may be related to the extreme gain settings though?

I created a series a test files based on the same piece of music, which has a fairly consistent high level from the start, as testing with different tracks is never going to make it very easy to compare.

The master copy peaks at nearly 100% digital level (quite common in modern recordings, less noise but it doesn't allow much headroom for subsequent EQ/etc control). By default, Replay Gain looks to set all track levels to a reference point of around -10dB, and in this case FooBar2000 chose a -7.9dB gain value for the MP3 file. (If you don't like this by the way, and you prefer maximum volumes and don't intend to add any EQ, you can create a fixed RG preamp boost in Poweramp to compensate, I wouldn't go beyond about 9-10dB though)

I then created four more MP3 versions of the same track in Adobe Audition, digitally scaled to -15dB, -20dB, -30dB and -40dB. Then FooBar2000 created Replay Gain values of +7dB, +12dB, +22dB and +32dB on those files respectively, which is what I would have expected.

Playing in Poweramp, the five MP3 files without any embedded ReplayGain values started off very loud and each one got progressively quieter, as expected. The versions with ReplayGain values set played a little quieter than the full 100% version (as expected, due to that -10dB target figure) except for the last two (with the +22dB and +32dB gains) which played as if RG was turned off.

So it looks to me as though RG values of more than around +20dB are being ignored (perhaps treated as spurious data, as that is a LOT of gain boost). I've uploaded my test files anyway, so perhaps you'd like to give them a try and see if you get the same results? https://www.dropbox.com/sh/0z8ljzan30sb6ph/AAAYQlcPvconAYsCLqPA7fria?dl=0 If you find the same, I'll report these findings through to Max and see if the approx 20dB RG limit is by design or is a bug.

Andre

[Maxim Kurbatov]

Andre, I have tested and I have the same behaivor as you, +22dB and +32dB are almost the same with or without RG. I believe, that Poweramp should not limit RG level, but should use it as is. If it is by design, there should be some option, to disable this behavior and ignore theese limits.

Thanks for your huge research, Andre! 

[andrewilley]

Are those files of yours that are recorded at about -30dB genuine audio files? I assumed you created them as a test. To be honest I don't think I'd try to use ReplayGain to fix such badly encoded audio files, I'd just re-encode them properly (even if only via something like MP3Gain)

Andre

[Maxim Kurbatov]

Those files are created for test, but I have very old tracks, which originally recorded with too low volume.

[zlodey]

On 19.10.2016 at 1:36 PM, Maxim Kurbatov said:

Those files are created for test, but I have very old tracks, which originally recorded with too low volume.

i would suggest you to make a copy of these files in a different folder, and then APPLY the replaygain values to the copied files: not just add the RG tag, but APPLY these RG values to the file, and so all players would recognize the loudness as you want. I used to do this for iPhone, because Apple's SoundCheck is such a piece of crap.

But this operation will ALTER your files, and you woun't be able to undo it, so this is why i suggested you to make a copy of these files. Move these copied files to your phone then, and this way the original files will remain intact on your PC.

The opperation of applying these RG values to the music files can be done very quickly and easely via Foobar's menu "Apply track/album ReplayGain to file content", or via MP3tag.

Not the best way though, but a very decent workaround

[andrewilley]

Yes, that's what I suggested in my post above. That method sets a gain value to each and every MP3 frame in the file (i.e. the small packets of compressed audio data) but I believe it does so without actually re-encoding the compressed audio (which would be a bad thing). It is very similar to using a ReplayGain gain offset, but as you say you can't the turn it off again like you can a RG tag.

Andre

[zlodey]

23 minutes ago, andrewilley said:

but I believe it does so without actually re-encoding the compressed audio

yes, it does NOT re-encode the compressed audio. It adds a sort of ”header” to the file, which tells every player the loudness it should play.

[andrewilley]

ReplayGain defaults to less than maximum volume as its target level (-6dB rings a bell, but it's been a while since I looked at it) so any tracks that are already encoded at 100% will become quieter if you then use ReplyGain. That target value is adjustable in Poweramp though.

[Edit] Actually the target should be -14dB from full-range, according to the ReplayGain wiki. Remember ReplayGain is not about making stuff LOUDER per se, but about trying to make it consistent.

Andre