I used the song Chua biet ro.kfn available from the and stored it as 1.kfn Knowing what to expect, we get the first KFN file.

the information of all the files is stored together) or decentralized (each file is prefixed by its own directory) The directory can be either centralized (i.e. It can also contain more fields, such as checksum, flags (whether the file is packed/encrypted and which way), file create/modification timestamps, name and so on. At minimum it contains two fields, the offset in the container file and the length. The container directory, which lists the files stored in the container.Typically it is located at the beginning of the file. The container file header which identifies the things such as the container type, version, creation/update date and so on.Now, in every container file there are at least three pieces of information: Therefore it is a container file type, like an archive. We know this file contains Karaoke, and this means it contains at least the music and lyrics. Therefore if you’re using Windows, you might have to install Cygwin and find out a few tools, notably hexdump.Įven before we see our first KaraFun file, we already have some information about it. I also wrote some Java code to speed the things up. Hopefully this article would be useful for the people who would like to support KaraFun files in their projects, or just curious about how the reverse engineering of file formats is done.Ī side note: since I use Linux, the whole reverse-engineering process happens by using the command-line tools. The whole format, including the encryption, was reverse-engineered by just looking at the file content. I didn’t even download any KaraFun software, and there was no need to use the editor. Then I decided to document those efforts for the readers to better understand how the reverse engineers work as there seem to be a lot of misunderstanding about the process. All I ultimately needed was a few KaraFun karaoke files.

Fortunately I have the relevant experience, and it was not a very difficult task. Therefore to support this file format I had to reverse-engineer it. There is no free open-source software supporting this format either.

The main issue we had to overcome was lack of any documentation on Internet about this popular format. Therefore we decided to add support for this format. Even the KaraFun Android application does not play those files which is unfortunate. This format seem to be very popular in some countries, and unfortunately there seem to be no player on Android capable of playing those files. Several of our users have expressed disappointment that our Ulduzsoft Karaoke Player for Android does not support the popular KaraFun Karaoke format.

Format lagu karafun