Muzikbrowzer ReplayGain Volume Leveling

ReplayGain is a proposed standard for volume leveling. Numerous applications have begun adopting it. ReplayGain works by analyzing each audio file and creating a ReplayGain adjustment factor for it. That factor is then written into a metadata tag in the file. The audio portion of the file is unaltered.

Muzikbrowzer provides a degree of support for ReplayGain Volume Leveling. In order to use volume leveling in Muzikbrowzer you must use another software application to analyse your audio files and create ReplayGain tags in your files. Once you have done this you may enable ReplayGain Volume Leveling in Muzikbrowzer's Menu/Settings/General tab and Muzikbrowzer will read the ReplayGain tag value from your audio files and adjust the volume accordingly as each song is played.

There are numerous software applications that perform ReplayGain analysis, but this functionality is not completely standardized. I.e. the various software applications use different tagging schemes and even different analysis algorithyms. In this first effort to support ReplayGain Muzikbrowzer supports a single ReplayGain tagging scheme. As this technology matures and upon users requests additonal support will be included in Muzikbrowzer. Let us know.

Muzikbrowzer looks for the following ReplayGain tags based upon audio file type, along with known thirdparty software that generates the correct tag:

For some reason MediaMonkey isn't writing the REPLAYGAIN tags .wma files. MediaMonkey documents that they use Microsoft Access for their database and therefore it should be possible to roll out a script to read those tags from their db and to write the tags directly into .wma files.

Foobar2000 also creates REPLAYGAIN_TRACK_GAIN tags in .ogg, .flac and .wma files. However for mp3 id3v2 tags, foobar2000 only writes version id3v2.4 tags. Muzikbrowzer can read foobar2000's REPLAYGAIN tags in ogg,flac and wma files but not from foobar2000's mp3 files. See the chapter on Tags for further information.

Using ReplayGain Volume Leveling

Once you have added ReplayGain tags to your files and enabled ReplayGain Volume Leveling in Muzikbrowzer/Menu/Settings/General Muzikbrowzer will adjust the volume as each song begins playing.

When you enable ReplayGain in Muzikbrowzer the volume is set to 75%. That's Muzikbrowzers volume control, not the Windows control. This is used as the base volume level which is used for calculating the adjusted volume as each song begins playing. It is recommened that you leave the volume set at or near 75%. The reason for this is to allow Muzikbrowzer to adjust the volume up or down as each song is played. As each song is played you will notice that the volume control actually moves up or down appropriately. This is Muzikbrowzers response to the ReplayGain values read from the audio file as it begins playing.

To arrive at the adjusted volume level this formula is used:

volume = BaseVolumeLevel + (Multiplier x ReplayGainValue)

Where ReplayGainValue is the value read from the ReplayGain tag and BaseVolumeLevel is as discussed above. Volume ranges from 0% to 100% (not DBs) and the RGVs are supposed to range between -51db and +51db according to the Replay Gain spec, but RGVs are normally between -20db and +20db.

Multipler is the value set in Settings / Replay Gain Multiplier.

You may adjust the volume yourself but in doing so you are resetting the base volume level for subsequent ReplayGain volume leveling. For example if you manually adjust the volume level to 100% then there is no room to adjust up for quieter songs.

In Muzikbrowzer you can view the individual ReplayGain values in your files by right clicking on a song then Edit Tag then Display Tag Data.

Why do we need this volume leveling business anyway?

For this we have our illustrious recording industry to thank. Just do an internet search for "Loudness Wars" and/or "ReplayGain".