Rockbox mail archiveSubject: Re: replaygain and id3v2 / RGAD tag?
Re: replaygain and id3v2 / RGAD tag?
From: BlueChip <cs_bluechip_at_webtribe.net>
Date: Wed, 10 Aug 2005 19:11:41 +0100
AHA! I had not previously realised a difference between MP3Gain and
ReplayGain ...thanks for correcting me :)
>err... MP3Gain (not ReplayGain) stores the ReplayGain gain (rounded to the
>closest 0.5dB) in each MP3 packet and adds replaygain info (as APEv2 tags,
>which still aren't yet supported by rockbox but ask me for a patch) to the
>ReplayGain is just the way you compute these gains (using the so-called
>"equal loudness" heuristic) plus some recommendations on how to store this
>in a few file formats:
>(this link was in my original message)
>-MPC, Ogg and APE have native ReplayGain support.
>-MP3 has no native support for the ReplayGain tags (thus the use of
>mp3gain is recommended), but such tags can be read by the player from the
>id3v2 or APEv2 tags. Rockbox supports id3v2 tags. Foobar2000 supports
>APEv2 and id3v2 tags.
>-for WAV, you can either use APEv2 tags (anything after the end of the
>"data" chunk should be ignored), of store the gains in an extra RIFF chunk.
>>>>I would need that part which parses binary replaygain info to implement
>>>>replaygain on WAV files too, so if id3v2 should use it also then that
>>>>binary parsing function should be done in replaygain.c I guess.
>>>Where would the tag be stored for wavs? But extracting the values from
>>>the RGAD frame and converting them to something usable for replaygain.c
>>>should be easy enough... (And I'll soon commit something that should
>>>make it a little bit easier :).
>>ReplayGain is a tool to tweak MP3 packet headers, as such it only works
>>with MP3's. I suppose you could implements a system that will work with
>>WAV files, but it will not be "ReplayGain" it will be "Magnus' WavGain" -
>>although if Rockbox pick it up as a new standard, it might stand a chance
>>of reaching the public eye :)
Received on 2005-08-10