pcutmp3 tool, properly/perfect cut mp3 Options

[SebastianG]

Hi !

I got quite a few PMs about the mp3 splitter (read more here). Because of that and the fact that it seems to be doing what it's supposed to I decided to make the current beta version public.

A Java Runtime Environement 1.4 or higher.is needed. You can call the application in the commandline via:
java -jar pcutmp3.jar <parameters>
(Leave parameters blank to see a help screen)

Splitting with a cue sheet is pretty simple. Here's an example:
java -jar pcutmp3.jar --cue something.cue something.mp3

WARNING:
Your player needs to properly support the LAME tag. If it doesn't you'll hear gaps. I tested it with Foobar 0.8.3 and Foobar 0.9 beta 5. Unfortunately the older one ignores encoder delay values above 1152 in the LAME tag (edit: see post #5 for Foobar 0.8.3). Since pcutmp3 usually creates mp3 files with encoder delays of around 2000 samples it won't work in Foobar 0.8.3. In combination with Foobar 0.9 beta 5 it works like charm. WinAMP + otachan's in_mpg123 + some good output-plug probably also works fine. So, use this app only if it makes sense to use it. The number of players which properly interpret the LAME tag is pretty low !! If your player does you can use pcutmp3 to do sample granular cuts.

How it works:
This app analyzes the source mp3 file and its Xing/Info/LAME tag and allows cutting it at *any* positions through the use of the LAME tag's encoder_delay/padding fields. It generates for each track you crop out of the large source file a new Xing/Info/LAME tag frame filled appropriately and resolves the problem of missing bitreservoir data via a "silence frame" (holding the missing data) that directly follows the Xing/Info/LAME tag frame. This additional delay (due to this "silence frame") is also compensated via the encoder_delay setting which explains the high values it produces (576...2879). It should be possible to rejoin files losslessly (not yet implemented).

Sebi

direct link to version 0.95 beta (I'm sorry, this is a dead link)
Feedback is appreciated.

This post has been edited by SebastianG: May 31 2008, 10:29

[SebastianG]

Hello y'all !

does it also work when cutting CBR non Lame files? Let's say FhG? Will those files get a Lame Header or what?

Yes. pcutmp3 simply defaults to an encoder delay of 576 samples and writes the LAME tag. The LAME tag is really an intergral part of the whole pcutmp3 idea ... So, it's added if it wasn't there before and this is being done with the "LAME" string as some kind of LAME-tag marker for maximum support. This of course might fool some applications to think the mp3 has been encoded via LAME. As I said before, I don't think there's a better way of doing things here because of the LAME tag format specification not specifying any good way of determining its presence.

Edit: works great with VBR files. However, I noticed that the Music CRC doesn't match with the actual Music CRC. The original file is fine. The Lame-Header CRC matches...

This is intentional. According to the LAME tag specification the Music CRC is something that should not be altered. If we don't alter it, this Music CRC serves as an ID with which it is possible to automatically gather pieces of the same original track. This and the special PCUT tag together allows automatic rejoining. Something for the future development.

here is another little bug: pcutmp3 assumes that every cue sheet starts at 0:00.00,  therefore, if you have a cue sheet that starts at 0:05.00 for instance, pcutmp3 will still start to cut @ 0:00.00

This is intentional as well. I'm not a fan of throwing anything away. The CUE split function was supposed to partition the original mp3 without loosing the pregap. This I thought makes most sense, doesn't it ?

Sebi

This post has been edited by SebastianG: Jan 17 2006, 10:08

[Jojo]

thanks for your answer.

here is another little bug: pcutmp3 assumes that every cue sheet starts at 0:00.00,  therefore, if you have a cue sheet that starts at 0:05.00 for instance, pcutmp3 will still start to cut @ 0:00.00

This is intentional as well. I'm not a fan of throwing anything away. The CUE split function was supposed to partition the original mp3 without loosing the pregap. This I thought makes most sense, doesn't it ?

I guess it does make sense, however, I changed a cue sheet and just wanted portions of a song. That is no problem when being done in the middle of the file, however, since it was at the beginning I ran into trouble. I ended up adding an extra track to the cue sheet and that worked like a charm.

Anyway, heads up for your great program. Thank you.

This post has been edited by Jojo: Jan 18 2006, 07:00