HydrogenAudio

Lossy Audio Compression => Other Lossy Codecs => Topic started by: YouGoByeBye on 2012-09-28 09:44:18

Title: .celt files
Post by: YouGoByeBye on 2012-09-28 09:44:18
I'm new at this whole thing, but I want to convert a .celt file into an MP3. The whole reason for doing this is because of a game I am playing. It has sound files that are stored inside of an .fsb file (This part doesn't matter to much because I already got them separated). In that .fsb file there are .celt files and from what I understand those are the actual sounds from the game. I need a simple way to convert those to a .mp3. Now I've read another post on here that says that they are now under Opus... I have no idea what that means, I searched it and came up with some .exe files that I have no idea how to use. So if some one can please give me a tutorial on how to convert a .celt file to a .mp3 file in simple English that would be amazing.
Title: .celt files
Post by: Dynamic on 2012-09-28 10:00:56
Opus has superceded CELT but is not compatible with CELT files, which were always experimental. The bitstream got as far as a soft freeze, but early .celt files might be incompatible with later decoders.

I'd suggest the easiest way*, if you have a Windows PC, might be to obtain foobar2000 media player/converter and download and install the foo_input_celt plugin (http://www.foobar2000.org/components/view/foo_input_celt).

If it plays the .celt files properly, then you can right click the file(s) and Convert... to use any encoder you've set up.

Search these forums or knowledgebase (Wiki) for how to set up LAME as an MP3 encoder for foobar2000 (also known as fb2k). A VBR quality setting from -V5 (~130kbps) to -V2 (~190kbps) should provide pretty good sound quality, and foobar2000 will warn you that transcoding from lossy to lossy will not increase quality, and may make it audibly worse, but will still let you do it.

(* The celt-codec.org site only contains source code as far as I'm aware, so tracking down a commandline decoder binary might be tricky - it's not on rarewares.org, though I didn't check reallyrarewares)
Title: .celt files
Post by: ExUser on 2012-09-28 15:09:15
What game?
Title: .celt files
Post by: YouGoByeBye on 2012-09-28 16:11:56
Opus has superceded CELT but is not compatible with CELT files, which were always experimental. The bitstream got as far as a soft freeze, but early .celt files might be incompatible with later decoders.

I'd suggest the easiest way*, if you have a Windows PC, might be to obtain foobar2000 media player/converter and download and install the foo_input_celt plugin (http://www.foobar2000.org/components/view/foo_input_celt).

If it plays the .celt files properly, then you can right click the file(s) and Convert... to use any encoder you've set up.

Search these forums or knowledgebase (Wiki) for how to set up LAME as an MP3 encoder for foobar2000 (also known as fb2k). A VBR quality setting from -V5 (~130kbps) to -V2 (~190kbps) should provide pretty good sound quality, and foobar2000 will warn you that transcoding from lossy to lossy will not increase quality, and may make it audibly worse, but will still let you do it.

(* The celt-codec.org site only contains source code as far as I'm aware, so tracking down a commandline decoder binary might be tricky - it's not on rarewares.org, though I didn't check reallyrarewares)


Thank you very much for your help, I installed the foo_input_celt but unfortunately it did not work. I'm trying to rip sound files from a game called: "League of Legends". They used MP3 files for a while then they switched over to .celt files, making it a hell of a lot harder. This wasn't to try to deter people from ripping sounds, because they haven't told me it was against the rules to do so when I  asked them for help (PS they weren't much help but they pointed me to this site.) So I'm kinda of stuck as to what to do now. I can link one of the sound files if that would help any?

Here is one of the .celt files. (http://www.mediafire.com/?lb52acghscyyxi7)

What game?

League of Legends (http://na.leagueoflegends.com/)
Title: .celt files
Post by: pdq on 2012-09-28 17:48:13
Would this be a copyright violation?
Title: .celt files
Post by: Dynamic on 2012-09-28 18:07:09
It might be possible to compare it to a CELT file made by one version of the CELT encoder using a hex editor. Very quickly I took a look at it in Notepad, which often reveals if there's a text signature (like OPUSHEAD in an Ogg Opus file) and didn't see anything. Frankly I'm unmotivated to do any more. They needn't have stuck to regular CELT as it's open source and patent free, and could have modified it anyway. Their software will know how to decode it, regardless of whether it's well-formed for a regular CELT encoder. I note that Mumble uses CELT internally and is used for in-game communications between players and the like. It is upgrading to OPUS, but might still support CELT. It's quite possible a game would base its audio around CELT for that sort of reason - compatibility with low-delay real time chat and high quality stored audio too in a single format.

Maybe this gives you some more leads to try, depending how motivated you are to keep playing around, assuming you're allowed to do so.
Title: .celt files
Post by: ExUser on 2012-09-28 18:07:32
Would this be a copyright violation?
The game is freely-available.
Title: .celt files
Post by: saratoga on 2012-09-28 19:33:45
Probably just a raw CELT stream.  Its pretty common to skip using a container for embedded applications like this since theres usually no need for things like headers when all the files are identical format and don't need to work with any other software.
Title: .celt files
Post by: YouGoByeBye on 2012-09-30 09:24:24
It might be possible to compare it to a CELT file made by one version of the CELT encoder using a hex editor. Very quickly I took a look at it in Notepad, which often reveals if there's a text signature (like OPUSHEAD in an Ogg Opus file) and didn't see anything. Frankly I'm unmotivated to do any more. They needn't have stuck to regular CELT as it's open source and patent free, and could have modified it anyway. Their software will know how to decode it, regardless of whether it's well-formed for a regular CELT encoder. I note that Mumble uses CELT internally and is used for in-game communications between players and the like. It is upgrading to OPUS, but might still support CELT. It's quite possible a game would base its audio around CELT for that sort of reason - compatibility with low-delay real time chat and high quality stored audio too in a single format.

Maybe this gives you some more leads to try, depending how motivated you are to keep playing around, assuming you're allowed to do so.


I've honestly had a few to many headaches trying to figure this thing out. I just want a straight answer but it seems that is rather hard to do, Thanks for all your time. I hope I find some one who has some experience with Riot or LoL, doubtful though.