In this new post to PHPMaster.com, Aurelio De Rosa covers an interesting use of PHP that could be handy in certain circumstances - extracting a section of a WAV audio file using the Audero Wav Extractor library.
Although PHP is well known for building web pages and applications, it can do more than that. I recently needed to extract a piece of audio from a WAV file on-the-fly and let the user download it through his browser. I tried to find a library that fit my needs but wasn't successful and had to write the code myself. It was a good opportunity to study in depth how a WAV file is made.
He starts off with an overview of what a WAV file is, how it's structured and how you can correctly figure out where in the binary data of the file the section you want is located. He then introduces the library and shows how to use it to extract "chunks" from the WAV file. He also includes an example of pulling out a chunk and saving it off to another file.