How to readfile() in PHP while file being created (mp3)

Question

I would like to set up a script that reads an mp3 file using the readfile function in PHP. Only problem is I do not want to wait for the mp3 file to be finished encoding before I start reading for the end user.

Answer 1

Assuming that you are spawning the encoder as a separate process from PHP, you should use popen to do so and instruct it to spew the encode at stdout. You can then easily use fread on the pipe that represents the encoder's standard output and forward whatever you read to the browser.

Something like this:

// Assuming that you have already sent the proper 
// HTTP headers to serve a download earlier

$handle = popen('encoder --param --output-to-stdout', 'r');
while (!$feof($handle)) {
    echo fread($handle, 2048); // or some other size, doesn't really matter
}
pclose($handle);