If anyone is interested, I have written a small command line r128gain scanner/tagger implementation to fill the lack of such tool.
Its written in Python and uses FFmpeg for decoding and R128 loudness analysis.
* writes tag using the ReplayGain format (follows ReplayGain v2 specification), or the R128_XXX_GAIN format as described in the Opus RFC
* should work with any file/tag format (my automated tests cover AAC, FLAC, Opus, MP3, Vorbis, WavPack)
* extremely fast (compared for example to vorbisgain) by using file based parallism and/or FFmpeg threaded decoding
I still have a few features to add before releasing a v1.0, but after a few weeks of testing with different file formats, both as a command line tool and a library for some of my projects, it seem to work quite well.
It's not a lot a code and I use it myself frequently so I intend to maintain it in the long run.
It's quite possible to come up with a graph that tries to be more exact rather than heuristic. igorc's graph from 2014 would be more of a starting point for such an endeavor. It'd need to be updated for Opus 1.2, and it would benefit from more listening test evidence.
Because some codecs' performance depends so much on the difference, one really would need at least two separate graphs - one for fullband stereo music and one for speech.
I've been using Opus 1.2.1 @~64 on iOS foobar2000.
* Version 3.4.0
- Fixed display of '&' symbol in playlist.
- Fixed admin rights detection in install scripts when Server service is disabled.
- Fixed crush when album art size is set to 0.
- Changed volume control handling to better match with foobar2000 volume control behaviour.
- Fixed memory leak in album art handler.
The UMX reader is for UT99.ooh ok yeah I don't have that installed...
It's interesting to observe that 4 members have mentioned Opus@80kbps as point where is hard to spot artifacts for them.
Opus ~80 kbps is roughly equivalent to LAME ~130 kbps (V5) which lands in an "excellent" area of quality (MOS 4.5+) http://listening-tests.hydrogenaud.io/sebastian/mp3-128-1/results.htm
So one could say that Opus 80 kbps is "excellent" at least for an average listener. It's clear that an experienced listeners can spot artifacts at much higher rates.
I never noticed any artifacts at 80kbps though, though I haven't tried to find any either.
I tried it and for me it's 80 kbit.
I'll be honest, I struggled to ABX at 64kbps. 80kbps is enough for me.
80kbps is pretty much my limit as well, can't be bothered listening to killer samples all the time.
Last post by kode54 -
I was only suggesting it in case of the weird possibility of a Phillips ADC that encodes HDCD information, however rare that may be.