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.

[pbelkner]

On a completely other note... What about patents?

I'm no lawyer, but the least I can say is the following: At the time of this writing the implementation of R128GAIN is exclusively based on information publicly available from the following documents:

1. ITU-R BS.1770 ‘Algorithms to measure audio programme loudness and true-peak audio level’
2. EBU Technical Recommendation R 128: Loudness normalisation and permitted maximum level of audio signals
3. EBU Tech Doc 3341: ‘Loudness Metering ‘EBU Mode’ metering to supplement loudness normalisation in accordance with EBU R 128’
4. EBU Tech Doc 3342 ‘Loudness Range: A descriptor to supplement loudness normalisation in accordance with EBU R 128’

None of them contain any reference to a patent, especially not in their list of references.

What is the license for the tool?

Is it safe to use your tool in other projects?

It's GPLv3 (http://www.gnu.org/licenses/gpl.html)

[mudlord]

It's GPLv3 (http://www.gnu.org/licenses/gpl.html)

Any reason why? To suit "Free" software uses only? Doing so restricts other players like FB2K from using that code, even if a different implementation is made....>_>

[pbelkner]

It's GPLv3 (http://www.gnu.org/licenses/gpl.html)

Any reason why? To suit "Free" software uses only?

R128GAIN is heavily based on SoX (uses SoX IO, re-sampler, filters, chain architecture etc.)

IO will probably be re-implemented in order to support most of the existing codecs using FFmpeg.

Both, SoX and FFmpeg, are GPLed, hence R128GAIN is "GPL infected".

Doing so restricts other players like FB2K from using that code, even if a different implementation is made....>_>

Yep.

[Soap]

Both, SoX and FFmpeg, are GPLed, hence R128GAIN is "GPL infected".

ffmepg is v2.1 or later. Is there a reason you went to v3?

[pbelkner]

Both, SoX and FFmpeg, are GPLed, hence R128GAIN is "GPL infected".

ffmepg is v2.1 or later. Is there a reason you went to v3?

Not really.

[Soap]

ffmepg is v2.1 or later. Is there a reason you went to v3?

Not really.

Your call, not mine, but unless you're worried about Tivoation (however you spell it) or one of the other corner cases covered in new by v3, removing v2 becomes a (significant?) restriction on uptake.

[pbelkner]

ffmepg is v2.1 or later. Is there a reason you went to v3?

Not really.

Your call, not mine, but unless you're worried about Tivoation (however you spell it) or one of the other corner cases covered in new by v3, removing v2 becomes a (significant?) restriction on uptake.

I've heard about some discussions regarding v3 but I'm not aware of the details. Maybe it's a good idea to relax to v2 later on.

[saratoga]

ffmepg is v2.1 or later. Is there a reason you went to v3?

Not really.

Your call, not mine, but unless you're worried about Tivoation (however you spell it) or one of the other corner cases covered in new by v3, removing v2 becomes a (significant?) restriction on uptake.

I've heard about some discussions regarding v3 but I'm not aware of the details. Maybe it's a good idea to relax to v2 later on.

I strongly recommend using a "v2 or later" type GPL license, rather then explicitly going v3. It makes it MUCH easier for other people to use your code, and the added protections in the v3 aren't particularly relevant here anyway.

That said, for this kind of code using a GPL front end and an LGPL backend for the actual DSP library makes a lot of sense since it keeps your tool GPL but still allows a wider range of people to use your code without having to re-implement it.

[cpchan]

That said, for this kind of code using a GPL front end and an LGPL backend for the actual DSP library makes a lot of sense since it keeps your tool GPL but still allows a wider range of people to use your code without having to re-implement it.

I totally agree with this.