Incorrect output filename

Thank you for this module. Exactly what I needed. One problem - no documentation and I had to patch the code to make it work correctly, it kept giving me SOX file errors. After some investigation I found out that the module is not adding the directory path to the output file.

I also wanted the file extension to be changed from .wav or .WAV to .mp3 (currently the module just adds the .mp3 part to the current filename).

I changed the following in audiosoxfield.module line 125-135 from

function _convert_helper(&$job) {
  $videofile = escapeshellarg($job->filepath); // escape file name for safety
  $convfile = basename($job->filename . ".mp3");
  $converter = variable_get('sox_executable_path', '/usr/bin/sox');

To the following - please forgive my PHP - and could not get the correct pattern with preg_replace which is better than the str_replace I used.
The problem was with the $convfile variable - in the original code the path is lost.

function _convert_helper(&$job) {
  $videofile = escapeshellarg($job->filepath); // escape file name for safety
  $convfile = str_replace(array('.wav', '.WAV'), '.mp3', $videofile); // replace wav and WAV with mp3 in output file and retains path of original file
  $convfile = str_replace("'", '', $convfile); // had to add this for some reason it gives a SOX error if the ' is not removed in the output filepath
  $converter = variable_get('sox_executable_path', '/usr/bin/sox');

Hope this is of use.