#13 #24 Fix invalid duration due to difference in first N frames. Solution: read few frames and compute duration based on the last frame data.

Author: wapmorgan

README.md

@@ -115,6 +115,12 @@ php bin/scan ./
 - `Mp3Info::isValidAudio($filename)`
     Static method that checks if file `$filename` looks like a mp3-file. Returns `true` if file looks like a mp3, otherwise false.
 
+### Settings
+You can adjust some variables to reconfigure before instantiating of object:
+
+- `Mp3Info::$headerSeekLimit` - count of bytes to search for the first mpeg header in audio. Default: `2048` (bytes).
+- `Mp3Info::$framesCountRead` - count of mpeg frames to read before compute audio duration. Default: `2` (frames). 
+
 ## Technical information
 Supporting features:
 * id3v1

bin/mp3scan

@@ -97,7 +97,7 @@ class Mp3InfoConsoleRunner {
                 .':'.str_pad($time % 60, 2, 0, STR_PAD_LEFT);
         else
             return floor($time / 60)
-                .':'.str_pad($time % 60, 2, 0, STR_PAD_LEFT);
+                .':'.str_pad((int)$time % 60, 2, 0, STR_PAD_LEFT);
     }
 
     /**

src/Mp3Info.php

@@ -56,17 +56,17 @@ class Mp3Info {
     /**
      * @var array
      */
-    static private $_bitRateTable;
+    private static $_bitRateTable;
 
     /**
      * @var array
      */
-    static private $_sampleRateTable;
+    private static $_sampleRateTable;
 
     /**
      * @var array
      */
-    static private $_vbrOffsets = [
+    private static $_vbrOffsets = [
         self::MPEG_1 => [21, 36],
         self::MPEG_2 => [13, 21],
         self::MPEG_25 => [13, 21],
@@ -77,6 +77,8 @@ class Mp3Info {
      */
     public static $headerSeekLimit = 2048;
 
+    public static $framesCountRead = 2;
+
     /**
      * @var int MPEG codec version (1 or 2 or 2.5 or undefined)
      */
@@ -307,8 +309,11 @@ private function parseAudio($filename, $fileSize, $mode) {
             /**
              * First frame can lie. Need to fix in the future.
              * @link https://github.com/wapmorgan/Mp3Info/issues/13#issuecomment-447470813
+             * Read first N frames
              */
-            $framesCount = $this->readMpegFrame($fp);
+            for ($i = 0; $i < self::$framesCountRead; $i++) {
+                $framesCount = $this->readMpegFrame($fp);
+            }
 
             $this->_framesCount = $framesCount !== null
                 ? $framesCount