#!/usr/bin/php
<?php

/*******************************************************************************
* mp3v2c.php - Converts a variable bitrate MP3 file to one with a constant     *
*              bitrate of 320 kbps, while retaining/repairing the ID3 tags     *
********************************************************************************
* filename        mp3v2c.php                                                   *
* short for       MP3Variable2Constant                                         *
* author          Richard Vrijhof <R.J.Vrijhof@bigfoot.com>                    *
* version         0.1                                                          *
* date            November 23, 2005                                            *
* dependencies    -PHP 4.1.0                                                   *
*                 -getID3 library (http://www.getid3.org/)                     *
********************************************************************************
*                                                                              *
*                                ***************                               *
*                                * ERRORLEVELS *                               *
*                                ***************                               *
*                                                                              *
* 0   Everything fine                                                          *
* 1   No parameter given or more than one parameter                            *
* 2   File not found                                                           *
* 3   File is not an MP3 file                                                  *
* 4   File doesn't have a variable bitrate                                     *
* 5   Error decoding to wave file                                              *
* 6   Error re-encoding to 320 kbps CBR file                                   *
* 7   Error moving temporary file over original file                           *
*******************************************************************************/

// This lib does wonders... "Terrific!" in one word.
require_once("getid3.php");

echo basename($_SERVER[argv][0]) . " - Converts a variable bitrate MP3 file ";
echo "to one with a constant bitrate of 320 kbps,\nwhile retaining/repairing ";
echo "the ID3 tags\n\n";

// Check for parameter (only one allowed: the path to an MP3 file).
if ($_SERVER[argc] != 2) {
  echo "FATAL ERROR: no path to an MP3 file given! Exiting.\n";
  exit(1);
}

// Check whether file exists.
if (! file_exists($_SERVER[argv][1])) {
  echo "FATAL ERROR: file \"" . $_SERVER[argv][1] . "\" not found! Exiting.\n";
  exit(2);
}

$id3 = new getID3;

getid3_lib::IncludeDependency(GETID3_INCLUDEPATH.'write.php', __FILE__, true);

// Now, do your magic.
$info = $id3->analyze($_SERVER[argv][1]);

// Check for MP3 file.
if ($info[audio][dataformat] != "mp3") {
  echo "FATAL ERROR: \"" . $info[filename] . "\" is not an MP3 file! ";
  echo "Exiting.\n";
  exit(3);
}

getid3_lib::CopyTagsToComments($info);

/*
// Check for VBR.
if ($info[audio][bitrate_mode] != "vbr") {
  echo "FATAL ERROR: \"" . $info[filename] . "\" doesn't have a variable ";
  echo "bitrate! Exiting.\n";
  exit(4);
}
*/

// Decode to wave file.
exec(
  "lame -S --decode " . escapeshellarg($info[filename]) . " " .
  escapeshellarg(substr($info[filename], 0, -3) . "wav") ." 2>&1 >/dev/null",
  $output,
  $return_var
);

// Decoding has gone wrong. Clean up the mess and exit.
if ($return_var > 0) {
  echo "FATAL ERROR: decoding \"" . $info[filename] . "\" has failed! ";
  echo "Exiting.\n";
  // Clean up.
  if (file_exists(substr($info[filename], 0, -3) . "wav")) {
    unlink(substr($info[filename], 0, -3) . "wav");
  }
  exit(5);
}

$tmp = tempnam("~/tmp", "mp3v2c_");

// Re-encode to 320 kbps CBR file.
exec(
  "lame -S --cbr -b 320 -h -m s " . escapeshellarg(
    substr($info[filename], 0, -3) . "wav"
  ) . " " . $tmp . " 2>&1 >/dev/null",
  $output,
  $return_var
);

// Re-encoding has gone wrong. Clean up the mess and exit.
if ($return_var > 0) {
  echo "FATAL ERROR: re-encoding \"" . substr($info[filename], 0, -3) . "wav\ ";
  echo "has failed! Exiting.\n";
  // Clean up.
  if (file_exists(substr($info[filename], 0, -3) . "wav")) {
    unlink(substr($info[filename], 0, -3) . "wav");
  }
  if (file_exists($tmp)) {
    unlink($tmp);
  }
  exit(6);
}

// Clean up.
if (file_exists(substr($info[filename], 0, -3) . "wav")) {
  unlink(substr($info[filename], 0, -3) . "wav");
}

// (Re)write ID3 tags to temporary file.
if (
  $info[comments][artist][0] != "" ||
  $info[comments][title][0] != "" ||
  $info[comments][album][0] != "" ||
  $info[comments][year][0] != "" ||
  $info[comments][track][0] != "" ||
  $info[comments][genre][0] != "" ||
  $info[comments][totaltracks][0] != "" ||
  $info[comments][tracknum][0] != ""
) {
  $tagwriter = new getid3_writetags;
  $tagwriter->filename = $tmp;
  $tagwriter->tagformats = array("id3v1", "id3v2.4");
  $tagwriter->remove_other_tags = true;
  $tagdata = array(array());
  if ($info[comments][artist][0] != "") {
    echo "\$info[comments][artist][0] = \"" . $info[comments][artist][0] . "\"\n";
    $tagdata[ARTIST][0] = $info[comments][artist][0];
  }
  if ($info[comments][title][0] != "") {
    echo "\$info[comments][title][0] = \"" . $info[comments][title][0] . "\"\n";
    $tagdata[TITLE][0] = $info[comments][title][0];
  }
  if ($info[comments][album][0] != "") {
    echo "\$info[comments][album][0] = \"" . $info[comments][album][0] . "\"\n";
    $tagdata[ALBUM][0] = $info[comments][album][0];
  }
  if ($info[comments][year][0] != "") {
    echo "\$info[comments][year][0] = \"" . $info[comments][year][0] . "\"\n";
    $tagdata[YEAR][0] = $info[comments][year][0];
  }
  if ($info[comments][track][0] != "") {
    echo "\$info[comments][track][0] = \"" . $info[comments][track][0] . "\"\n";
    $tagdata[TRACK][0] = $info[comments][track][0];
  }
  if ($info[comments][genre][0] != "") {
    echo "\$info[comments][genre][0] = \"" . $info[comments][genre][0] . "\"\n";
    $tagdata[GENRE][0] = $info[comments][genre][0];
  }
  if ($info[comments][totaltracks][0] != "") {
    echo "\$info[comments][totaltracks][0] = \"" . $info[comments][totaltracks][0] . "\"\n";
    $tagdata[TOTALTRACKS][0] = $info[comments][totaltracks][0];
  }
  if ($info[comments][tracknum][0] != "") {
    echo "\$info[comments][tracknum][0] = \"" . $info[comments][tracknum][0] . "\"\n";
    $tagdata[TRACKNUMBER][0] = $info[comments][tracknum][0];
  }
  $tagwriter->tag_data = $tagdata;
  if ($tagwriter->WriteTags()) {
    if (! empty($tagwriter->warnings)) {
      echo "Some warnings have arisen while (re)writing the ID3 tags.\nThey ";
      echo "were:\n" . implode("\n", $tagwriter->warnings) . "\n";
    }
  } else {
    echo "Error (re)writing ID3 tags to the re-encoded MP3 file. Keeping ";
    echo "converted MP3\nthough.\n";
  }
}

// Move temporary file over the original file.
if (rename($tmp, $info[filename])) {
  echo "Successfully converted \"" . $info[filename] . "\" to a 320 kbps CBR ";
  echo "file.\n";
} else {
  echo "ERROR: there was an error moving the temporary file to \"";
  echo $info[filename] . "\"! The temporary file is retained as \"$tmp\".\n";
  exit(7);
}

?>