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Rockbox mail archiveSubject: Re: junk in idv2 tagsRe: junk in idv2 tags
From: Bill Napier <napier_at_pobox.com>
Date: 16 Sep 2002 11:25:50 -0400 On Mon, 16 Sep 2002 12:45:02 +0200, "Danijel Ilisin" <d.ilisin_at_wtnet.de> said: > Hi again, i just tried a different id3 tag editor (named ID3 Edit) > and guess what: After the ID3V2 data there is plenty of zero > bytes. Mp3check says this: > E:\ftp\linus>mp3check -e *.mp3 [01] Roger Sanchez - Another > Chance.mp3: 419 bytes of junk before first frame header valid id3 > tag trailer v1.1 found > I mean, that's better than Winamp's version: > E:\ftp\linus>mp3check -e *.mp3 [01] Roger Sanchez - Another > Chance.mp3: 626 bytes of junk before first frame header valid id3 > tag trailer v1.1 found > So it seems there are many tools out there that work that way. I did some further investigation of my own and found out that mp3check (at least version 0.7.3) doesn't seem to know about id3v2 headers. 2 examples: Examples 1: C:\Documents and Settings\bnapier\Desktop\id3>mp3check -e "Guns N' Roses - Appetite For Destruction - 01 - Welcome To The Jungle.mp3" Guns N' Roses - Appetite For Destruction - 01 - Welcome To The Jungle.mp3: 355 bytes of junk before first frame header valid id3 tag trailer v1.0 found napier_at_billspc:~/rockbox/id3$ ./id3 Guns\ N\'\ Roses\ -\ Appetite\ For\ Destruction\ -\ 01\ -\ Welcome\ To\ The\ Jungle.mp3 version: 3 headerlen: 355 title : Welcome To The Jungle artist: Guns N' Roses album : Appetite For Destruction track#: 1 Example 2: C:\Documents and Settings\bnapier\Desktop\id3>mp3check -e "04 I Dreamed a Dream. mp3" 04 I Dreamed a Dream.mp3: 2174 bytes of junk before first frame header napier_at_billspc:~/rockbox/id3$ ./id3 04\ I\ Dreamed\ a\ Dream.mp3 version: 2 headerlen: 2174 title : I Dreamed a Dream artist: Exaltshow Ltd. album : (null) track#: 0 So what mp3check is reporting as "junk" is really the id3v2 header at the beginning. And yes, there is a large area of zero's at the beginning (to simplify changes, as another poster has already pointed out). But in both of the files I looked at, that area of zero's was included as part of the id3v2 header (the length of the id3v2 header was *CORRECT*). If you are going to chop of the id3v2 header from the beginning, check the length field and trust it. I even used winamp which did pad out some extra space, but did also adjust the length tag to get it right. Long story short: trust the id3v2 length tag, it seems to usually be correct. BTW - Linus, I would be interested to see (at least the beginning) of the mp3 file that had the padding where the length tag was wrong. I was unable to produce any files like that (even using the blasted winamp that you seem to dislike so much). b -- If it happens once, it's a bug. If it happens twice, it's a feature. If it happens more than twice, it's a design philosophy.Received on 2002-09-16 Page template was last modified "Tue Sep 7 00:00:02 2021" The Rockbox Crew -- Privacy Policy |