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[justsomeguy]

Is this possible with MC12. 

I have a lot of mp3's that had mp3gain run on them that actually modifies the mp3 its self instead of writing the replaygain info to the tag.  I also have a lot of mp3's that were not done this way.  Basically I want to use the currently accepted method of analyzing and writing to tags instead of modifying the mp3.

Problem is I have a couple hardware mp3 players that do not support the replaygain tags.  So obviously the volume on a mix of songs can vary drastically.  Is there a way to have MC actually modify the mp3 its self based on the replaygain tag on the fly as it transfers the files to an external device like a hardware player or usb flash drive.  I have read that foobar can actually modify the files but I'd like to stick with using MC for everything.

Thanks for any help   

[justsomeguy]

Well I'm guessing this can't be done, at least I can't see a way of doing it.  Seems to be a 2 step and 2 application process at minimum.  Will transfer the songs to my usb device then use foobar to actually modify those files with the correct replaygain.  This seems to me that it would be a useful feature for many people.  Maybe MC13.......

[dlmax63]

Although this would be useful to some,... I think if it is implemented it should not be very easily accessed if the sound quality is changed. Re-encoding mp3 files, as I understand it, would inherently change the SQ of the file. I wouldn't want people to inadvertently lessen the quality of their music.

[justsomeguy]

I agree that it shouldn't be a default setting but an option.  As I understand it though, applying the replaygain physically to the mp3 doesn't actually re-encode the file.  The program mp3gain did something similar and did not actually re-encode anything and was completely reversible and therefor considered "lossless".  foobar however doesn't provide a way of undoing the changes, I'm not sure why.

[dlmax63]

I thought you said that you had some hardware players that didn't recognize replay gain and that you wanted the file itself to have the volume modified. I don't know that reducing the actual overall volume of the file can be accomplished without re-encoding the file. (Someone closer to the coding of MC will have to answer that.) My point is that if the MP3 is actually re-encoded, it would be dangerous since the SQ would be reduced.

[justsomeguy]

that is right I want to modify the mp3 directly.  I don't claim to know the technicals behind it all but basically I believe that some of the data in the mp3 is used to specify the "volume" level of each sample in the song.  mp3gain and maybe foobar, but I'm not sure, modify this data directly which only alters the "volume" of the sample.  There is no decoding/encoding happening.  Here's a link to the mp3gain site http://mp3gain.sourceforge.net/index.php, I think it has more specifics on how this is accomplished.  I have tested mp3gain by modifying an mp3 then undoing the change and the before and after files are bit for bit identical.  mp3gain has been around for many years and has been well proven and tested.

I still agree that it is an option that shouldn't be enable by default because there could be some gotcha's that people wouldn't be aware of.  If for some reason the mp3 from the external device got transferred back to the main library somehow that may not be good.

[Alex B]

The mentioned programs can change the file volume levels so that all MP3 decoders use the changed volume level. AFAIK, they adjust a scale value inside each frame in the MP3 file. The process is practically lossless, because it does not change the encoded data anyhow. Only the resulting output volume is adjusted. This kind of scale adjustment is not known to cause any audible problems, like audibly decraded S/N ratio.

Foobar uses the same (or at least very similar) software code as MP3Gain, but it has less available options.

I think the command line MP3Gain program could be called by a plugin if someone would like to investigate the possibility to create one. Perhaps also the JRiver developers would be interested in finding out if that kind of feature could be integrated in MC. The MP3Gain source code is freely available. For example, a feature to automatically volume level synched MP3 files during the sync (with any portable) would be a nice add to MC13's feature list.

For now, it is quite possible to adjust the files after "syncing" with an external program.

Personally, I first sync a virtual handheld on a local hard drive with MC12 so that I can adjust the synced files before using them with multiple devices. After adjusting the files I use MJ12 for syncing a couple of small flash memory devices and burning MP3 CDs for my car. I have set MJ12 to monitor only the virtual handheld location so its library is small and fast to use.

[justsomeguy]

A plug-in or integrated into MC would be awesome.  Would make an already outstanding program just that much better.  I kinda like the virtual hand held idea as a temp solution maybe.  Might be faster to adjust the files on the hard drive than on the external device itself.  I'm not lazy but it would really be nice to have this all automated behind the scenes.  Is there an official way to make a feature request or should I maybe put a link to here in the MC13 feature request thread?