R128GAIN: An EBU R128 compliant loudness scanner Options

[pbelkner]

I've just uploaded on sourceforge a first version of r128gain, an EBU R128 (http://tech.ebu.ch/loudness) compliant loudness scanner:

http://sourceforge.net/projects/r128gain/files/

• process single files (tracks):
  
  • In order to just scan and analyze one file (WAV, FLAC or WV):
    
    CODE
    r128gain <file>
  • In order to scan, analyze and tag one file (currently only FLAC, result will be in <directory>):
    
    CODE
    r128gain <file> <directory>
  • In order to scan, analyze one file (WAV, WV) and encode and tag into FLAC (result will be in <directory>):
    
    CODE
    r128gain <file> <directory> flac
• recursively process directories (the content of a directory is considered an album):
  
  • In order to just recursively scan and analyze a directory:
    
    CODE
    r128gain <directory>
  • In order to recursively scan, analyze and tag a directory:
    
    CODE
    r128gain <directory> <directory>
    r128gain <directory>/* <directory>
  • In order to recursively scan, analyze a directory and encode and tag into FLAC:
    
    CODE
    r128gain <directory> <directory> flac
    r128gain <directory>/* <directory> flac

Tagging is currently supported only for FLAC:

• REPLAYGAIN_REFERENCE_LOUDNESS: always -23 LUFS (corresponding to EBU R128)
• REPLAYGAIN_TRACK_GAIN: loudness difference to -23 LUFS in LU measured for this track
• REPLAYGAIN_TRACK_PEAK: true peak measured at 192 kHz for this track
• REPLAYGAIN_ALBUM_GAIN: loudness difference to -23 LUFS in LU measured for the whole album
• REPLAYGAIN_ALBUM_PEAK: true peak measured at 192 kHz for the whole album

These tags should be honored by each Replay Gain compliant media player.

[googlebot]

I think you both have a valid point.

I also think that it is not very probable, that just because there is a tool now and some forum people decide to agree on a R128 tagging format, that there will be only a fraction of RG's device and player support anytime soon. It was different, when David started, because it filled a gap at its time, for which there were no solutions.

Until RG evolves into something allowing versioning, it can take ages. It might even never happen, since ID3 is such a mess. (The world of tagging could be such a better place without mp3.)

=> For an user with complete control over his own music library, it could be an attractive hack to rescan his library and write R128 estimated, but RG compatible, tags to his music collection. He would then have the benefits of both worlds, probably better loudness estimation due to gating, and instant playback support for most available hardware. RG enabled players don't really care what RG means or how the values were calculated. They just apply gain and prevent clipping.

Jdoering's approach to just use ref_pink.wav to get a relative offset between both approaches is very reasonable.

PS An additional tag could indicate, that the values are R128 based. A user could then choose to rescan all tracks, which do not have that, yet.

This post has been edited by googlebot: Jan 12 2011, 13:17

[pbelkner]

PS An additional tag could indicate, that the values are R128 based. A user could then choose to rescan all tracks, which do not have that, yet.

R128GAIN solves this by design:

• It takes a directory tree as input and copies the hole tree structure reursively into a second, r128 tagged tree structure.
• The original tree is preserved. The created r128 tree is structural equivalent to the original tree.
• If you interrupt R128GAIN and later on restart it, it will continue where you've interrupted (you should interrupt only during analysis not during encoding).