Replay Gain Not Writing iTunes SoundCheck Tags Correctly

[garym]

Re: Replay Gain Not Writing iTunes SoundCheck Tags Correctly

Excellent work. I hope spoon can take a look at this and fix things on the dbpa side.

[cleatus356]

Re: Replay Gain Not Writing iTunes SoundCheck Tags Correctly

Just to be safe, I checked over what dBPa does with m4a files as well and that is not working quite right either. For this particular track, the calculated album gain is +2.33

dBPa ITUNNORM = 00000248 00000248 000005B4 000005B4 00024CA8 00024CA8 00007FFF 00007FFF 00024CA8 00024CA8 (imports to iTunes as -1.0 dB)
iVolume ITUNNORM = 00000252 00000252 000005CC 000005CC 00024CA8 00024CA8 00000000 00000000 00024CA8 00024CA8 (imports to iTunes as +2.3 dB)

I added bold to the parts of the field hex values that matter. If I change the dBPa bold values to be 00000000 00000000 as they are in the iVolume field, then the iTunes track imports correctly.

[cleatus356]

Re: Replay Gain Not Writing iTunes SoundCheck Tags Correctly

I did not see any further updates to this so I started experimenting again figuring it must be something in the way that dBPowerAmp and other programs are writing the tag. I manipulated iVolume so that it was writing the same volume as I was getting from dBPowerAmp. Here is how the ITUNNORM tags were written:

dBPowerAmp: 0000023A 0000023A 00000591 00000591 00024CA8 00024CA8 00007C24 00007C24 00024CA8 00024CA8 (imports as -0.7 dB for SoundCheck)
iVolume: 0000023D 0000023D 00000599 00000599 0000BD60 0000BD60 00000000 00000000 0000D0C8 00009138 (imports as +2.4 dB for SoundCheck)

As you can see, the first (4) hex sets of numbers almost the same and really are just rounding differences. The last (6) sets of hex numbers are completely different so I don't know what is going on there. The funny thing is that if I copy the hex numbers from iVolume tag to the dBPowerAmp file using MP3Tag, the SoundCheck value that comes up in iTunes does not change. So I then took it a step further and took the original file after dBPowerAmp did it's replay/gain calculation that had not been touched at all by MP3Tag and opened it in a hex editor. I then made the COMMENT ITUNNORM tag the same as what was written by iVolume and when I imported that file into iTunes it gave the right value.

So, given all of this I now know that dBPowerAmp IS NOT converting the Album Gain correctly to the hexidecimal numbers that iTunes uses. Using the same hex editor, I simply made all of the hex numbers the same 0000023A and iTunes showed the correct volume when I imported the tag (note that I did this because that is how MP3Tag writes the values for m4a files and that works). I'm not sure what all the different numbers are supposed to mean but it doesn't appear to matter. I also know from this experiment that MP3Tag IS NOT truly writing the COMMENT ITUNNORM tag as a comment which is why it did not work when I copied the COMMENT ITUNNORM field that iVolume wrote to a virgin track.

I hope this helps and that the Replay/Gain module can be fixed so that it works correctly so that there is a batch way of handling this from now on using the EBU R128 standard.

I just looked at these one last time after reviewing the m4a files and it literally is as simple as making the 8 digit hex values in the 7th and 8th position all zeroes (shown in bold above)...that worked for mp3 files as well. This seems like it would be an easy global change to the way dBPa is writing these values...

[Spoon]

Re: Replay Gain Not Writing iTunes SoundCheck Tags Correctly

Now fixed in latest beta:

https://forum.dbpoweramp.com/showthread.php?44192-dBpoweramp-R17-Windows-Beta

[mville]

Re: Replay Gain Not Writing iTunes SoundCheck Tags Correctly

Now fixed in latest beta:

https://forum.dbpoweramp.com/showthr...7-Windows-Beta

Has the Replay Gain R5 utility codec also been updated with the fix?

[Spoon]

Re: Replay Gain Not Writing iTunes SoundCheck Tags Correctly

If you install R17 beta it replaces the DSP which is used by the utility codec, fixing it also.

[cleatus356]

Re: Replay Gain Not Writing iTunes SoundCheck Tags Correctly

I have tested it out several times now and it appears to work correctly. Thanks for getting this updated so quickly Spoon...