Welcome Guest ( Log In | Register )

LENGTH (running time field), TLEN in ID3 ?? in FLAC, [TOS #6: moved from General Audio]
post Aug 29 2012, 08:49
Post #1

Group: Members
Posts: 18
Joined: 20-August 12
Member No.: 102509

I have a bunch of MP3s, some have a TLEN file, some don't, haven't come across any problems so far.

Some intertubes references say this can be important for "proper seeking with VBRs" whatever that means.

Other places say don't worry about it.

The newer part of my collection is mostly FLAC, and that seems to have no issue, but if the value is important when converting to MP3, will FB2K handle this automagically or should I embed a "LENGTH" field say via MP3Tag?

And I realize this may be a heretical question here, but is there a free toolset (in either/both senses) better than FB2K on windoze for converting from FLAC to MP3, I'm trying to get all the tags over and am finding I have to change quite a few of MP3Tag's default mappings in order to get the ID3 tags converted properly (e.g. CONTENT GROUP rather than CONTENTGROUP). And of course the coverart would be nice.
Go to the top of the page
+Quote Post
Start new topic
post Sep 3 2012, 07:53
Post #2

Group: Members
Posts: 18
Joined: 20-August 12
Member No.: 102509

Thanks to you both for the clear and unambiguous answer.

I don't know much about this stuff (obviously) so please correct my below interpretation if I'm wrong.

The TLEN field only pertained to MP3, and (its equivalent LENGTH) has never been relevant wrt to FLAC files.

Perhaps the field's spec was created back when VBR encoding was the new hotness, some players couldn't display the "time remaining" accurately without it.

However, all modern mainstream players retrieve the precise length value from the MP3-specific internal "?header" (in any case someplace not having anything to do with user-maintained tags) and therefore having a TLEN field is redundant, not just unnecessary but possibly misleading.

Therefore the consensus recommendation is to delete this field and its value wherever it may be found, at least in FLAC and MP3 files.
Go to the top of the page
+Quote Post
post Sep 3 2012, 10:46
Post #3

Group: Super Moderator
Posts: 5275
Joined: 23-June 06
Member No.: 32180

I think you’re pretty much right-on with the background. But, via a blast from the past…
…I don’t know whether always deleting it is a good idea, either. tongue.gif I think the situation is that you needn’t worry about adding it manually, whether to MP3 (whose encoder will do that if it judges it to be advisable) or to FLAC (which has its own format), – but going through your MP3s and removing it might conceivably cause issues with reliant players (like the one you imagined), whereas it’ll almost certainly do no harm if left in place, being ignored in the worst-case scenario.

I’m glad you thought my answer was helpful, but please allow me to defer to anyone with better knowledge of MP3/TLEN than myself, just in case I’ve omitted or mistaken something! smile.gif

This post has been edited by db1989: Sep 3 2012, 10:47
Go to the top of the page
+Quote Post

Posts in this topic

Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:


RSS Lo-Fi Version Time is now: 26th November 2015 - 02:08