Add error handling if block can't be downloaded

Copyright, Original, Private, CRC protected, Padding

src/Mp3FileLocal.php

@@ -0,0 +1,83 @@
+<?php
+
+namespace wapmorgan\Mp3Info;
+
+class Mp3FileLocal
+{
+    public string $fileName;
+
+    protected int $fileSize;
+
+    private $_filePtr;
+
+    /**
+     * Creates a new local file object.
+     *
+     * @param string $fileName URL to open
+     */
+    public function __construct(string $fileName)
+    {
+        $this->fileName = $fileName;
+        $this->_filePtr = fopen($this->fileName, 'rb');
+        $this->fileSize = filesize($this->fileName);
+    }
+
+    /**
+     * Returns the file size
+     *
+     * @return int File size
+     */
+    public function getFileSize(): int
+    {
+        return $this->fileSize;
+    }
+
+    /**
+     * Returns the given amount of Bytes from the current file position.
+     *
+     * @param int $numBytes Bytes to read
+     *
+     * @return string Read Bytes
+     */
+    public function getBytes(int $numBytes): string
+    {
+        return fread($this->_filePtr, $numBytes);
+    }
+
+    /**
+     * Returns the current file position
+     *
+     * @return int File position
+     */
+    public function getFilePos(): int
+    {
+        return ftell($this->_filePtr);
+    }
+
+    /**
+     * Sets the file point to the given position.
+     *
+     * @param int $posBytes Position to jump to
+     *
+     * @return bool TRUE if successful
+     */
+    public function seekTo(int $posBytes): bool
+    {
+        $result = fseek($this->_filePtr, $posBytes);
+        return ($result == 0);
+    }
+
+    /**
+     * Advances the file pointer the given amount.
+     *
+     * @param int $posBytes Bytes to advance
+     *
+     * @return bool TRUE if successful
+     */
+    public function seekForward(int $posBytes): bool
+    {
+        $newPos = $this->getFilePos() + $posBytes;
+        return $this->seekTo($newPos);
+    }
+
+}

src/Mp3FileRemote.php

@@ -0,0 +1,189 @@
+<?php
+
+namespace wapmorgan\Mp3Info;
+
+use \Exception;
+
+class Mp3FileRemote
+{
+    public string $fileName;
+    public int $blockSize;
+
+    protected $buffer;
+    protected int $filePos;
+    protected $fileSize;
+
+    /**
+     * Creates a new remote file object.
+     *
+     * @param string $fileName  URL to open
+     * @param int    $blockSize Size of the blocks to query from the server (default: 4096)
+     */
+    public function __construct(string $fileName, int $blockSize = 4096)
+    {
+        $this->fileName = $fileName;
+        $this->blockSize = $blockSize;
+        $this->buffer = [];
+        $this->filePos = 0;
+        $this->fileSize = $this->_readFileSize();
+    }
+
+    /**
+     * Returns the file size
+     *
+     * @return int File size
+     */
+    public function getFileSize(): int
+    {
+        return $this->fileSize;
+    }
+
+    /**
+     * Makes a HEAD request to get the file size
+     *
+     * @return int Content-Length header
+     */
+    private function _readFileSize(): int
+    {
+        // make HTTP HEAD request to get Content-Length
+        $context = stream_context_create([
+            'http' => [
+                'method' => 'HEAD',
+            ],
+        ]);
+        $result = get_headers($this->fileName, true, $context);
+        return $result['Content-Length'];
+    }
+
+    /**
+     * Returns the given amount of Bytes from the current file position.
+     *
+     * @param int $numBytes Bytes to read
+     *
+     * @return string Read Bytes
+     */
+    public function getBytes(int $numBytes): string
+    {
+        $blockId = intdiv($this->filePos, $this->blockSize);
+        $blockPos = $this->filePos % $this->blockSize;
+        
+        $output = [];
+        
+        do {
+            // make sure we have this block
+            if (!$this->downloadBlock($blockId)) {
+                throw new Exception('Error downloading block ' . $blockId . ' (starting at pos. ' . ($blockId * $this->blockSize) . ')!');
+            }   
+            if ($blockPos + $numBytes >= $this->blockSize) {
+                // length of request is more than this block has, truncate to block len
+                $subLen = $this->blockSize - $blockPos;
+            } else {
+                // requested length fits inside this block
+                $subLen = $numBytes;
+            }
+            // $subLen = ($blockPos + $numBytes >= $this->blockSize) ? ($this->blockSize - $blockPos) : $numBytes;
+            $output[] = substr($this->buffer[$blockId], $blockPos, $subLen);
+            $this->filePos += $subLen;
+            $numBytes -= $subLen;
+            // advance to next block
+            $blockPos = 0;
+            $blockId++;
+        } while ($numBytes > 0);
+        
+        return implode('', $output);
+    }
+
+    /**
+     * Returns the current file position
+     *
+     * @return int File position
+     */
+    public function getFilePos(): int
+    {
+        return $this->filePos;
+    }
+
+    /**
+     * Sets the file pointer to the given position.
+     *
+     * @param int $posBytes Position to jump to
+     *
+     * @return bool TRUE if successful
+     */
+    public function seekTo(int $posBytes): bool
+    {
+        if ($posBytes < 0 || $posBytes > $this->fileSize) {
+            return false;
+        }
+        $this->filePos = $posBytes;
+        return true;
+    }
+
+    /**
+     * Advances the file pointer the given amount.
+     *
+     * @param int $posBytes Bytes to advance
+     *
+     * @return bool TRUE if successful
+     */
+    public function seekForward(int $posBytes): bool
+    {
+        $newPos = $this->filePos + $posBytes;
+        return $this->seekTo($newPos);
+    }
+
+    /**
+     * Downloads the given block if needed
+     *
+     * @param int $blockNo Block to download
+     *
+     * @return bool TRUE if successful
+     */
+    protected function downloadBlock(int $blockNo): bool
+    {
+        if (array_key_exists($blockNo, $this->buffer)) {
+            // already downloaded
+            return true;
+        }
+        $bytesFrom = $blockNo * $this->blockSize;
+        $bytesTo   = $bytesFrom + $this->blockSize - 1;
+        // https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Range
+        $context = stream_context_create([
+            'http' => [
+                'method' => 'GET',
+                'header' => [
+                    'Range: bytes=' . $bytesFrom . '-' . $bytesTo,
+                ],
+            ],
+        ]);
+        $filePtr = fopen($this->fileName, 'rb', false, $context);
+        if ($filePtr === false) {
+            return false;
+        }
+        $this->buffer[$blockNo] = fread($filePtr, $this->blockSize);
+        $status = stream_get_meta_data($filePtr);
+        $httpStatus = explode(' ', $status['wrapper_data'][0])[1];
+        if ($httpStatus != '206') {
+            if ($httpStatus != '200') {
+                echo 'Download error!' . PHP_EOL;
+                var_dump($status);
+                return false;
+            }
+            echo 'Server doesn\'t support partial content!' . PHP_EOL;
+            // Content received is whole file from start
+            if ($blockNo != 0) {
+                // move block to start if needed
+                $this->buffer[0] =& $this->buffer[$blockNo];
+                unset($this->buffer[$blockNo]);
+                $blockNo = 0;
+            }
+            // receive remaining parts while we're at it
+            while (!feof($filePtr)) {
+                $blockNo++;
+                $this->buffer[$blockNo] = fread($filePtr, $this->blockSize);
+            }
+        }
+        fclose($filePtr);
+        return true;
+    }
+}

src/Mp3Info.php

@@ -1,8 +1,14 @@
 <?php
+
 namespace wapmorgan\Mp3Info;
 
-use Exception;
-use RuntimeException;
+require __DIR__ . '/Mp3FileLocal.php';
+require __DIR__ . '/Mp3FileRemote.php';
+
+use \wapmorgan\Mp3Info\Mp3FileLocal;
+use \wapmorgan\Mp3Info\Mp3FileRemote;
+use \Exception;
+use \RuntimeException;
 
 /**
  * This class extracts information about an mpeg audio. (supported mpeg versions: MPEG-1, MPEG-2)
@@ -23,7 +29,8 @@ use RuntimeException;
  * * {@link https://multimedia.cx/mp3extensions.txt Descripion of VBR header "Xing"}
  * * {@link http://gabriel.mp3-tech.org/mp3infotag.html Xing, Info and Lame tags specifications}
  */
-class Mp3Info {
+class Mp3Info
+{
     const TAG1_SYNC = 'TAG';
     const TAG2_SYNC = 'ID3';
     const VBR_SYNC = 'Xing';
@@ -79,6 +86,11 @@ class Mp3Info {
 
     public static $framesCountRead = 2;
 
+    /**
+     * @var Mp3File File object for I/O handling
+     */
+    protected $fileObj;
+
     /**
      * @var int MPEG codec version (1 or 2 or 2.5 or undefined)
      */
@@ -109,6 +121,31 @@ class Mp3Info {
      */
     public $sampleRate;
 
+    /**
+     * @var bool Header protection by 16 bit CRC
+     */
+    public $isProtected;
+
+    /**
+     * @var bool Frame data is padded with one slot
+     */
+    public $isPadded;
+
+    /**
+     * @var bool Private bit (only informative)
+     */
+    public $isPrivate;
+
+    /**
+     * @var bool Copyright bit (only informative)
+     */
+    public $isCopyright;
+
+    /**
+     * @var bool Original bit (only informative)
+     */
+    public $isOriginal;
+
     /**
      * @var boolean Contains true if audio has variable bit rate
      */
@@ -154,11 +191,13 @@ class Mp3Info {
      * @var int Major version of id3v2 tag (if id3v2  present) (2 or 3 or 4)
      */
     public $id3v2MajorVersion;
+    public $id3v2Version;
 
     /**
      * @var int Minor version of id3v2 tag (if id3v2 present)
      */
     public $id3v2MinorVersion;
+    public $id3v2Revision;
 
     /**
      * @var array List of id3v2 header flags (if id3v2 present)
@@ -208,29 +247,23 @@ class Mp3Info {
      *
      * @throws \Exception
      */
-    public function __construct($filename, $parseTags = false) {
+    public function __construct(string $filename, bool $parseTags = false)
+    {
         if (self::$_bitRateTable === null)
-            self::$_bitRateTable = require dirname(__FILE__).'/../data/bitRateTable.php';
+            self::$_bitRateTable = require __DIR__.'/../data/bitRateTable.php';
         if (self::$_sampleRateTable === null)
-            self::$_sampleRateTable = require dirname(__FILE__).'/../data/sampleRateTable.php';
+            self::$_sampleRateTable = require __DIR__.'/../data/sampleRateTable.php';
 
         $this->_fileName = $filename;
-        $isLocal = (strpos($filename, '://') === false);
-        if (!$isLocal) {
-            $this->_fileSize = static::getUrlContentLength($filename);
+        if (str_contains($filename, '://')) {
+            $this->fileObj = new Mp3FileRemote($filename);
         } else {
-            if (!file_exists($filename)) {
-                throw new \Exception('File ' . $filename . ' is not present!');
-            }
-            $this->_fileSize = filesize($filename);
-        }
-
-        if ($isLocal and !static::isValidAudio($filename)) {
-            throw new \Exception('File ' . $filename . ' is not mpeg/audio!');
+            $this->fileObj = new Mp3FileLocal($filename);
         }
+        $this->_fileSize = $this->fileObj->getFileSize();
 
         $mode = $parseTags ? self::META | self::TAGS : self::META;
-        $this->audioSize = $this->parseAudio($this->_fileName, $this->_fileSize, $mode);
+        $this->audioSize = $this->parseAudio($mode);
     }
     
 
@@ -243,79 +276,74 @@ class Mp3Info {
             return null;
         }
 
-        $fp = fopen($this->_fileName, 'rb');
-        if ($fp === false) {
-            return false;
-        }
-        fseek($fp, $this->coverProperties['offset']);
-        $data = fread($fp, $this->coverProperties['size']);
-        fclose($fp);
+        $curPos = $this->fileObj->getFilePos();
+        $this->fileObj->seekTo($this->coverProperties['offset']);
+        $data = $this->fileObj->getBytes($this->coverProperties['size']);
+        $this->fileObj->seekTo($curPos);
         return $data;
     }
 
+    protected function getSynchsafeSize(string $rawBytes): int
+    {
+        $sizeBytes = unpack('C4', $rawBytes);
+        $size = $sizeBytes[1] << 21 | $sizeBytes[2] << 14 | $sizeBytes[3] << 7 | $sizeBytes[4];
+        return $size;
+    }
+
     /**
      * Reads audio file in binary mode.
      * mpeg audio file structure:
      * ID3V2 TAG - provides a lot of meta data. [optional]
      * MPEG AUDIO FRAMES - contains audio data. A frame consists of a frame header and a frame data. The first frame may contain extra information about mp3 (marked with "Xing" or "Info" string). Rest of frames can contain only audio data.
      * ID3V1 TAG - provides a few of meta data. [optional]
-     * @param string $filename
-     * @param int $fileSize
      * @param int $mode
      * @return float|int
      * @throws \Exception
      */
-    private function parseAudio($filename, $fileSize, $mode) {
+    private function parseAudio($mode)
+    {
         $time = microtime(true);
 
-        // create temp storage for media
-        if (strpos($filename, '://') !== false) {
-            $fp = fopen('php://memory', 'rwb');
-            fwrite($fp, file_get_contents($filename));
-            rewind($fp);
-        } else {
-            $fp = fopen($filename, 'rb');
-        }
-
         /** @var int Size of audio data (exclude tags size) */
-        $audioSize = $fileSize;
+        $audioSize = $this->fileObj->getFileSize();
 
         // parse tags
-        if (fread($fp, 3) == self::TAG2_SYNC) {
-            if ($mode & self::TAGS) $audioSize -= ($this->_id3Size = $this->readId3v2Body($fp));
-            else {
-                fseek($fp, 2, SEEK_CUR); // 2 bytes of tag version
-                fseek($fp, 1, SEEK_CUR); // 1 byte of tag flags
-                $sizeBytes = $this->readBytes($fp, 4);
-                array_walk($sizeBytes, function (&$value) {
-                    $value = substr(str_pad(base_convert($value, 10, 2), 8, 0, STR_PAD_LEFT), 1);
-                });
-                $size = bindec(implode($sizeBytes)) + 10;
+        if ($this->fileObj->getBytes(3) == self::TAG2_SYNC) {
+            if ($mode & self::TAGS) {
+                $audioSize -= ($this->_id3Size = $this->readId3v2Body());
+            } else {
+                $this->fileObj->seekForward(2); // 2 bytes of tag version
+                $this->fileObj->seekForward(1); // 1 byte of tag flags
+                $size = $this->getSynchsafeSize($this->fileObj->getBytes(4));
+                $size += 10;   // add header size
                 $audioSize -= ($this->_id3Size = $size);
             }
         }
 
-        fseek($fp, $fileSize - 128);
-        if (fread($fp, 3) == self::TAG1_SYNC) {
-            if ($mode & self::TAGS) $audioSize -= $this->readId3v1Body($fp);
-            else $audioSize -= 128;
+        $this->fileObj->seekTo($this->fileObj->getFileSize() - 128);
+        if ($this->fileObj->getBytes(3) == self::TAG1_SYNC) {
+            if ($mode & self::TAGS) {
+                $audioSize -= $this->_readId3v1();
+            } else {
+                $audioSize -= 128;
+            }
         }
 
         if ($mode & self::TAGS) {
             $this->fillTags();
         }
 
-        fseek($fp, 0);
+        $this->fileObj->seekTo(0);
         // audio meta
         if ($mode & self::META) {
-            if ($this->_id3Size !== null) fseek($fp, $this->_id3Size);
+            if ($this->_id3Size !== null) $this->fileObj->seekTo($this->_id3Size);
             /**
              * First frame can lie. Need to fix in the future.
              * @link https://github.com/wapmorgan/Mp3Info/issues/13#issuecomment-447470813
              * Read first N frames
              */
             for ($i = 0; $i < self::$framesCountRead; $i++) {
-                $framesCount = $this->readMpegFrame($fp);
+                $framesCount = $this->_readMpegFrame();
             }
 
             $this->_framesCount = $framesCount !== null
@@ -338,128 +366,124 @@ class Mp3Info {
             // Calculate total number of audio samples (framesCount * sampleInFrameCount) / samplesInSecondCount
             $this->duration = ($this->_framesCount - 1) * $samples_in_second / $this->sampleRate;
         }
-        fclose($fp);
 
         $this->_parsingTime = microtime(true) - $time;
         return $audioSize;
     }
 
+    private function _findNextMpegFrame(int $headerSeekLimit): ?string
+    {
+        // find frame sync
+        $headerSeekMax = $this->fileObj->getFilePos() + $headerSeekLimit;
+        $headerBytes = $this->fileObj->getBytes(3);   // preload with 3 Bytes
+        do {
+            $headerBytes .= $this->fileObj->getBytes(1);   // load next Byte
+            $headerBytes = substr($headerBytes, -4);   // limit to 4 Bytes
+
+            if ((unpack('n', $headerBytes)[1] & self::FRAME_SYNC) === self::FRAME_SYNC) {
+                return $headerBytes;
+            }
+        } while ($this->fileObj->getFilePos() <= $headerSeekMax);
+ 
+        return null;
+    }
+
     /**
      * Read first frame information.
-     * @param resource $fp
+     *
+     * @link   https://www.codeproject.com/Articles/8295/MPEG-Audio-Frame-Header
      * @return int Number of frames (if present if first frame of VBR-file)
      * @throws \Exception
      */
-    private function readMpegFrame($fp) {
-        $header_seek_pos = ftell($fp) + self::$headerSeekLimit;
-        do {
-            $pos = ftell($fp);
-            $first_header_byte = $this->readBytes($fp, 1);
-            if ($first_header_byte[0] === 0xFF) {
-                $second_header_byte = $this->readBytes($fp, 1);
-                if ((($second_header_byte[0] >> 5) & 0b111) == 0b111) {
-                    fseek($fp, $pos);
-                    $header_bytes = $this->readBytes($fp, 4);
-                    break;
-                }
-            }
-            fseek($fp, 1, SEEK_CUR);
-        } while (ftell($fp) <= $header_seek_pos);
-
-        if (!isset($header_bytes) || $header_bytes[0] !== 0xFF || (($header_bytes[1] >> 5) & 0b111) != 0b111) {
-            throw new \Exception('At '.$pos
-                .'(0x'.dechex($pos).') should be a frame header!');
+    private function _readMpegFrame()
+    {
+        $headerBytes = $this->_findNextMpegFrame(self::$headerSeekLimit);
+        $pos = $this->fileObj->getFilePos() - 4;
+        if (is_null($headerBytes)) {
+            throw new Exception('No Mpeg frame header found up until pos ' . $pos . '(0x' . dechex($pos) . ')!');
         }
 
-        switch ($header_bytes[1] >> 3 & 0b11) {
-            case 0b00: $this->codecVersion = self::MPEG_25; break;
-            case 0b01: $this->codecVersion = self::CODEC_UNDEFINED; break;
-            case 0b10: $this->codecVersion = self::MPEG_2; break;
-            case 0b11: $this->codecVersion = self::MPEG_1; break;
-        }
+        // 2nd Byte: (rest of frame sync), Version, Layer, Protection
+        $this->codecVersion = [self::MPEG_25, null, self::MPEG_2, self::MPEG_1][ord($headerBytes[1]) >> 3 & 0b11];
+        $this->layerVersion = [null, self::LAYER_3, self::LAYER_2, self::LAYER_1][ord($headerBytes[1]) >> 1 & 0b11];
+        $this->isProtected = !((ord($headerBytes[1]) & 0b1) == 0b1);   // inverted as 0=protected, 1=not protected
 
-        switch ($header_bytes[1] >> 1 & 0b11) {
-            case 0b01: $this->layerVersion = self::LAYER_3; break;
-            case 0b10: $this->layerVersion = self::LAYER_2; break;
-            case 0b11: $this->layerVersion = self::LAYER_1; break;
+        // 3rd Byte: Bitrate, Sampling rate, Padding, Private
+        $this->bitRate = self::$_bitRateTable[$this->codecVersion][$this->layerVersion][ord($headerBytes[2]) >> 4];
+        $this->sampleRate = self::$_sampleRateTable[$this->codecVersion][(ord($headerBytes[2]) >> 2) & 0b11];
+        if ($this->sampleRate === false) {
+            return null;
         }
+        $this->isPadded = ((ord($headerBytes[2]) & 0b10) == 0b10);
+        $this->isPrivate = ((ord($headerBytes[2]) & 0b1) == 0b1);
 
-        $this->bitRate = self::$_bitRateTable[$this->codecVersion][$this->layerVersion][$header_bytes[2] >> 4];
-        $this->sampleRate = self::$_sampleRateTable[$this->codecVersion][($header_bytes[2] >> 2) & 0b11];
-
-        switch ($header_bytes[3] >> 6) {
-            case 0b00: $this->channel = self::STEREO; break;
-            case 0b01: $this->channel = self::JOINT_STEREO; break;
-            case 0b10: $this->channel = self::DUAL_MONO; break;
-            case 0b11: $this->channel = self::MONO; break;
-        }
+        // 4th Byte: Channels, Mode extension, Copyright, Original, Emphasis
+        $this->channel = [self::STEREO, self::JOINT_STEREO, self::DUAL_MONO, self::MONO][ord($headerBytes[3]) >> 6];
+        // TODO: Mode extension (2 bits)
+        $this->isCopyright = ((ord($headerBytes[3]) & 0b1000) == 0b1000);
+        $this->isOriginal  = ((ord($headerBytes[3]) & 0b100) == 0b100);
+        // TODO: Emphasis (2 bits)
 
         $vbr_offset = self::$_vbrOffsets[$this->codecVersion][$this->channel == self::MONO ? 0 : 1];
 
         // check for VBR
-        fseek($fp, $pos + $vbr_offset);
-        if (fread($fp, 4) == self::VBR_SYNC) {
+        $this->fileObj->seekTo($pos + $vbr_offset);
+        if ($this->fileObj->getBytes(4) == self::VBR_SYNC) {
             $this->isVbr = true;
-            $flagsBytes = $this->readBytes($fp, 4);
+            $flagsBytes = $this->fileObj->getBytes(4);
 
             // VBR frames count presence
-            if (($flagsBytes[3] & 2)) {
-                $this->vbrProperties['frames'] = implode(unpack('N', fread($fp, 4)));
+            if ((ord($flagsBytes[3]) & 2)) {
+                $this->vbrProperties['frames'] = implode(unpack('N', $this->fileObj->getBytes(4)));
             }
             // VBR stream size presence
-            if ($flagsBytes[3] & 4) {
-                $this->vbrProperties['bytes'] = implode(unpack('N', fread($fp, 4)));
+            if (ord($flagsBytes[3]) & 4) {
+                $this->vbrProperties['bytes'] = implode(unpack('N', $this->fileObj->getBytes(4)));
             }
             // VBR TOC presence
-            if ($flagsBytes[3] & 1) {
-                fseek($fp, 100, SEEK_CUR);
+            if (ord($flagsBytes[3]) & 1) {
+                $this->fileObj->seekForward(100);
             }
             // VBR quality
-            if ($flagsBytes[3] & 8) {
-                $this->vbrProperties['quality'] = implode(unpack('N', fread($fp, 4)));
+            if (ord($flagsBytes[3]) & 8) {
+                $this->vbrProperties['quality'] = implode(unpack('N', $this->fileObj->getBytes(4)));
             }
         }
 
         // go to the end of frame
         if ($this->layerVersion == self::LAYER_1) {
-            $this->_cbrFrameSize = floor((12 * $this->bitRate / $this->sampleRate + ($header_bytes[2] >> 1 & 0b1)) * 4);
+            $this->_cbrFrameSize = floor((12 * $this->bitRate / $this->sampleRate + (ord($headerBytes[2]) >> 1 & 0b1)) * 4);
         } else {
-            $this->_cbrFrameSize = floor(144 * $this->bitRate / $this->sampleRate + ($header_bytes[2] >> 1 & 0b1));
+            $this->_cbrFrameSize = floor(144 * $this->bitRate / $this->sampleRate + (ord($headerBytes[2]) >> 1 & 0b1));
         }
 
-        fseek($fp, $pos + $this->_cbrFrameSize);
+        $this->fileObj->seekTo($pos + $this->_cbrFrameSize);
 
-        return isset($this->vbrProperties['frames']) ? $this->vbrProperties['frames'] : null;
-    }
-
-    /**
-     * @param $fp
-     * @param $n
-     *
-     * @return array
-     * @throws \Exception
-     */
-    private function readBytes($fp, $n) {
-        $raw = fread($fp, $n);
-        if (strlen($raw) !== $n) throw new \Exception('Unexpected end of file!');
-        $bytes = array();
-        for($i = 0; $i < $n; $i++) $bytes[$i] = ord($raw[$i]);
-        return $bytes;
+        return $this->vbrProperties['frames'] ?? null;
     }
 
     /**
      * Reads id3v1 tag.
+     *
+     * @link   https://id3.org/ID3v1
      * @return int Returns length of id3v1 tag.
      */
-    private function readId3v1Body($fp) {
-        $this->tags1['song'] = trim(fread($fp, 30));
-        $this->tags1['artist'] = trim(fread($fp, 30));
-        $this->tags1['album'] = trim(fread($fp, 30));
-        $this->tags1['year'] = trim(fread($fp, 4));
-        $this->tags1['comment'] = trim(fread($fp, 28));
-        fseek($fp, 1, SEEK_CUR);
-        $this->tags1['track'] = ord(fread($fp, 1));
-        $this->tags1['genre'] = ord(fread($fp, 1));
+    private function _readId3v1(): int
+    {
+        $this->tags1['song']   = trim($this->fileObj->getBytes(30));
+        $this->tags1['artist'] = trim($this->fileObj->getBytes(30));
+        $this->tags1['album']  = trim($this->fileObj->getBytes(30));
+        $this->tags1['year']   = trim($this->fileObj->getBytes(4));
+        $comment = $this->fileObj->getBytes(30);
+        if ($comment[28] == "\x00" && $comment[29] != "\x00") {
+            // id3v1.1 - last Byte of comment is trackNo
+            $this->tags1['track']   = ord($comment[29]);
+            $this->tags1['comment'] = trim(substr($comment, 0, 28));
+        } else {
+            // id3v1.0
+            $this->tags1['comment'] = trim($comment);
+        }
+        $this->tags1['genre'] = '(' . ord($this->fileObj->getBytes(1)) . ')';
         return 128;
     }
 
@@ -512,60 +536,59 @@ class Mp3Info {
      * @return int Returns length of id3v2 tag.
      * @throws \Exception
      */
-    private function readId3v2Body($fp)
+    private function readId3v2Body()
     {
         // read the rest of the id3v2 header
-        $raw = fread($fp, 7);
-        $data = unpack('cmajor_version/cminor_version/H*', $raw);
-        $this->id3v2MajorVersion = $data['major_version'];
-        $this->id3v2MinorVersion = $data['minor_version'];
-        $data = str_pad(base_convert($data[1], 16, 2), 40, 0, STR_PAD_LEFT);
-        $flags = substr($data, 0, 8);
-        if ($this->id3v2MajorVersion == 2) { // parse id3v2.2.0 header flags
-            $this->id3v2Flags = array(
-                'unsynchronisation' => (bool)substr($flags, 0, 1),
-                'compression' => (bool)substr($flags, 1, 1),
-            );
-        } else if ($this->id3v2MajorVersion == 3) { // parse id3v2.3.0 header flags
-            $this->id3v2Flags = array(
-                'unsynchronisation' => (bool)substr($flags, 0, 1),
-                'extended_header' => (bool)substr($flags, 1, 1),
-                'experimental_indicator' => (bool)substr($flags, 2, 1),
-            );
-            if ($this->id3v2Flags['extended_header'])
-                throw new \Exception('NEED TO PARSE EXTENDED HEADER!');
-        } else if ($this->id3v2MajorVersion == 4) { // parse id3v2.4.0 header flags
-            $this->id3v2Flags = array(
-                'unsynchronisation' => (bool)substr($flags, 0, 1),
-                'extended_header' => (bool)substr($flags, 1, 1),
-                'experimental_indicator' => (bool)substr($flags, 2, 1),
-                'footer_present' => (bool)substr($flags, 3, 1),
-            );
-            if ($this->id3v2Flags['extended_header'])
-                throw new \Exception('NEED TO PARSE EXTENDED HEADER!');
-            if ($this->id3v2Flags['footer_present'])
-                throw new \Exception('NEED TO PARSE id3v2.4 FOOTER!');
+        $raw = $this->fileObj->getBytes(3);
+        $data = unpack('Cversion/Crevision/Cflags', $raw);
+        $this->id3v2Version = $data['version'];
+        $this->id3v2Revision = $data['revision'];
+        // backwards compatibility:
+        $this->id3v2MajorVersion = $data['version'];
+        $this->id3v2MinorVersion = $data['revision'];
+
+        $this->id3v2Flags = array();
+
+        if ($this->id3v2Version >= 2) {
+            // parse id3v2.2.0 header flags
+            $this->id3v2Flags['unsynchronisation'] = ($data['flags'] & 128 == 128);
+            $this->id3v2Flags['compression'] = ($data['flags'] & 64 == 64);
         }
-        $size = substr($data, 8, 32);
+        
+        if ($this->id3v2Version >= 3) {
+            // id3v2.3 changes second bit from compression to extended_header
+            $this->id3v2Flags['extended_header'] = &$this->id3v2Flags['compression'];
+            unset($this->id3v2Flags['compression']);
+            // parse additional id3v2.3.0 header flags
+            $this->id3v2Flags['experimental_indicator'] = ($data['flags'] & 32 == 32);
 
-        // some fucking shit
-        // getting only 7 of 8 bits of size bytes
-        $sizes = str_split($size, 8);
-        array_walk($sizes, function (&$value) {
-            $value = substr($value, 1);
-        });
-        $size = implode($sizes);
-        $size = bindec($size);
+            if ($this->id3v2Flags['extended_header']) {
+                throw new Exception('NEED TO PARSE EXTENDED HEADER!');
+            }
+        }
 
-        if ($this->id3v2MajorVersion == 2) {
+        if ($this->id3v2Version >= 4) {
+            // parse additional id3v2.4.0 header flags
+            $this->id3v2Flags['footer_present'] = ($data['flags'] & 16 == 16);
+
+            if ($this->id3v2Flags['footer_present']) {
+                // footer is a copy of header - so can be ignored
+                // (10 Bytes not included in $size)
+                //throw new Exception('NEED TO PARSE id3v2.4 FOOTER!');
+            }
+        }
+
+        $size = $this->getSynchsafeSize($this->fileObj->getBytes(4));
+
+        if ($this->id3v2Version == 2) {
             // parse id3v2.2.0 body
             /*throw new \Exception('NEED TO PARSE id3v2.2.0 flags!');*/
-        } else if ($this->id3v2MajorVersion == 3) {
+        } elseif ($this->id3v2Version == 3) {
             // parse id3v2.3.0 body
-            $this->parseId3v23Body($fp, 10 + $size);
-        } else if ($this->id3v2MajorVersion == 4)  {
+            $this->parseId3v23Body(10 + $size);
+        } elseif ($this->id3v2Version == 4) {
             // parse id3v2.4.0 body
-            $this->parseId3v24Body($fp, 10 + $size);
+            $this->parseId3v24Body(10 + $size);
         }
 
         return 10 + $size; // 10 bytes - header, rest - body
@@ -575,13 +598,14 @@ class Mp3Info {
      * Parses id3v2.3.0 tag body.
      * @todo Complete.
      */
-    protected function parseId3v23Body($fp, $lastByte) {
-        while (ftell($fp) < $lastByte) {
-            $raw = fread($fp, 10);
+    protected function parseId3v23Body($lastByte)
+    {
+        while ($this->fileObj->getFilePos() < $lastByte) {
+            $raw = $this->fileObj->getBytes(10);
             $frame_id = substr($raw, 0, 4);
 
             if ($frame_id == str_repeat(chr(0), 4)) {
-                fseek($fp, $lastByte);
+                $this->fileObj->seekTo($lastByte);
                 break;
             }
 
@@ -589,6 +613,7 @@ class Mp3Info {
             $frame_size = $data['frame_size'];
             $flags = base_convert($data['flags'], 16, 2);
             $this->id3v2TagsFlags[$frame_id] = array(
+                'payload_size' => $frame_size,
                 'flags' => array(
                     'tag_alter_preservation' => (bool)substr($flags, 0, 1),
                     'file_alter_preservation' => (bool)substr($flags, 1, 1),
@@ -643,7 +668,7 @@ class Mp3Info {
                 case 'TSIZ':    # Size
                 case 'TSRC':    # ISRC (international standard recording code)
                 case 'TSSE':    # Software/Hardware and settings used for encoding
-                    $this->tags2[$frame_id] = $this->handleTextFrame($frame_size, fread($fp, $frame_size));
+                    $this->tags2[$frame_id] = $this->handleTextFrame($frame_size, $this->fileObj->getBytes($frame_size));
                     break;
                 ################# Text information frames
 
@@ -683,15 +708,15 @@ class Mp3Info {
                 // case 'SYLT':    # Synchronized lyric/text
                 //     break;
                 case 'COMM':    # Comments
-                    $dataEnd = ftell($fp) + $frame_size;
-                    $raw = fread($fp, 4);
+                    $dataEnd = $this->fileObj->getFilePos() + $frame_size;
+                    $raw = $this->fileObj->getBytes(4);
                     $data = unpack('C1encoding/A3language', $raw);
                     // read until \null character
                     $short_description = '';
                     $last_null = false;
                     $actual_text = false;
-                    while (ftell($fp) < $dataEnd) {
-                        $char = fgetc($fp);
+                    while ($this->fileObj->getFilePos() < $dataEnd) {
+                        $char = $this->fileObj->getBytes(1);
                         if ($char == "\00" && $actual_text === false) {
                             if ($data['encoding'] == 0x1) { # two null-bytes for utf-16
                                 if ($last_null)
@@ -721,20 +746,20 @@ class Mp3Info {
                 //     break;
                  case 'APIC':    # Attached picture
                      $this->hasCover = true;
-                     $last_byte = ftell($fp) + $frame_size;
-                     $this->coverProperties = ['text_encoding' => ord(fread($fp, 1))];
+                     $dataEnd = $this->fileObj->getFilePos() + $frame_size;
+                     $this->coverProperties = ['text_encoding' => ord($this->fileObj->getBytes(1))];
 //                     fseek($fp, $frame_size - 4, SEEK_CUR);
-                     $this->coverProperties['mime_type'] = $this->readTextUntilNull($fp, $last_byte);
-                     $this->coverProperties['picture_type'] = ord(fread($fp, 1));
-                     $this->coverProperties['description'] = $this->readTextUntilNull($fp, $last_byte);
-                     $this->coverProperties['offset'] = ftell($fp);
-                     $this->coverProperties['size'] = $last_byte - ftell($fp);
-                     fseek($fp, $last_byte);
+                     $this->coverProperties['mime_type'] = $this->readTextUntilNull($dataEnd);
+                     $this->coverProperties['picture_type'] = ord($this->fileObj->getBytes(1));
+                     $this->coverProperties['description'] = $this->readTextUntilNull($dataEnd);
+                     $this->coverProperties['offset'] = $this->fileObj->getFilePos();
+                     $this->coverProperties['size'] = $dataEnd - $this->fileObj->getFilePos();
+                     $this->fileObj->seekTo($dataEnd);
                      break;
                 // case 'GEOB':    # General encapsulated object
                 //     break;
                 case 'PCNT':    # Play counter
-                    $data = unpack('L', fread($fp, $frame_size));
+                    $data = unpack('L', $this->fileObj->getBytes($frame_size));
                     $this->tags2[$frame_id] = $data[1];
                     break;
                 // case 'POPM':    # Popularimeter
@@ -760,7 +785,7 @@ class Mp3Info {
                 // case 'PRIV':    # Private frame
                 //     break;
                 default:
-                    fseek($fp, $frame_size, SEEK_CUR);
+                    $this->fileObj->seekForward($frame_size);
                     break;
             }
         }
@@ -768,24 +793,25 @@ class Mp3Info {
 
     /**
      * Parses id3v2.4.0 tag body.
-     * @param $fp
+     *
      * @param $lastByte
      */
-    protected function parseId3v24Body($fp, $lastByte)
+    protected function parseId3v24Body($lastByte)
     {
-        while (ftell($fp) < $lastByte) {
-            $raw = fread($fp, 10);
-            $frame_id = substr($raw, 0, 4);
+        while ($this->fileObj->getFilePos() < $lastByte) {
+            $frame_id = $this->fileObj->getBytes(4);
 
             if ($frame_id == str_repeat(chr(0), 4)) {
-                fseek($fp, $lastByte);
+                $this->fileObj->seekTo($lastByte);
                 break;
             }
 
-            $data = unpack('Nframe_size/H2flags', substr($raw, 4));
-            $frame_size = $data['frame_size'];
+            $frame_size = $this->getSynchsafeSize($this->fileObj->getBytes(4));
+
+            $data = unpack('H2flags', $this->fileObj->getBytes(2));
             $flags = base_convert($data['flags'], 16, 2);
             $this->id3v2TagsFlags[$frame_id] = array(
+                'payload_size' => $frame_size,
                 'flags' => array(
                     'tag_alter_preservation' => (bool)substr($flags, 1, 1),
                     'file_alter_preservation' => (bool)substr($flags, 2, 1),
@@ -806,7 +832,6 @@ class Mp3Info {
                 case 'TALB':    # Album/Movie/Show title
                 case 'TCON':    # Content type
                 case 'TYER':    # Year
-                case 'TXXX':    # User defined text information frame
                 case 'TRCK':    # Track number/Position in set
                 case 'TIT2':    # Title/songname/content description
                 case 'TPE1':    # Lead performer(s)/Soloist(s)
@@ -814,6 +839,7 @@ class Mp3Info {
                 case 'TCOM':    # Composer
                 case 'TCOP':    # Copyright message
                 case 'TDAT':    # Date
+                case 'TDRC':    # Recording time
                 case 'TDLY':    # Playlist delay
                 case 'TENC':    # Encoded by
                 case 'TEXT':    # Lyricist/Text writer
@@ -842,7 +868,25 @@ class Mp3Info {
                 case 'TSIZ':    # Size
                 case 'TSRC':    # ISRC (international standard recording code)
                 case 'TSSE':    # Software/Hardware and settings used for encoding
-                    $this->tags2[$frame_id] = $this->handleTextFrame($frame_size, fread($fp, $frame_size));
+                    $this->tags2[$frame_id] = $this->handleTextFrame($frame_size, $this->fileObj->getBytes($frame_size));
+                    break;
+
+                case 'TXXX':    # User defined text information frame
+                    $dataEnd = $this->fileObj->getFilePos() + $frame_size;
+                    $encoding = ord($this->fileObj->getBytes(1));
+                    $description_raw = $this->readTextUntilNull($dataEnd);
+                    $description = $this->_getUtf8Text($encoding, $description_raw);
+                    $value = $this->fileObj->getBytes($dataEnd - $this->fileObj->getFilePos());
+                    $tagName = $frame_id . ':' . $description;
+                    if (key_exists($tagName, $this->tags2)) {
+                        // this should never happen! TXXX-description must be unique.
+                        if (!is_array($this->tags2[$tagName])) {
+                            $this->tags2[$tagName] = array($this->tags2[$tagName]);
+                        }
+                        $this->tags2[$tagName][] = $value;
+                    } else {
+                        $this->tags2[$tagName] = $value;
+                    }
                     break;
 
                 ################# Text information frames
@@ -883,34 +927,17 @@ class Mp3Info {
                 // case 'SYLT':    # Synchronized lyric/text
                 //     break;
                 case 'COMM':    # Comments
-                    $dataEnd = ftell($fp) + $frame_size;
-                    $raw = fread($fp, 4);
-                    $data = unpack('C1encoding/A3language', $raw);
-                    // read until \null character
-                    $short_description = null;
-                    $last_null = false;
-                    $actual_text = false;
-                    while (ftell($fp) < $dataEnd) {
-                        $char = fgetc($fp);
-                        if ($char == "\00" && $actual_text === false) {
-                            if ($data['encoding'] == 0x1) { # two null-bytes for utf-16
-                                if ($last_null)
-                                    $actual_text = null;
-                                else
-                                    $last_null = true;
-                            } else # no condition for iso-8859-1
-                                $actual_text = null;
+                    $dataEnd = $this->fileObj->getFilePos() + $frame_size;
+                    $encoding = unpack('C', $this->fileObj->getBytes(1))[1];
+                    $language = $this->fileObj->getBytes(3);
+                    $allText_raw = $this->fileObj->getBytes($dataEnd - $this->fileObj->getFilePos());
+                    $allText = $this->_getUtf8Text($encoding, $allText_raw);
 
-                        }
-                        else if ($actual_text !== false) $actual_text .= $char;
-                        else $short_description .= $char;
-                    }
-                    if ($actual_text === false) $actual_text = $short_description;
-                    // list($short_description, $actual_text) = sscanf("s".chr(0)."s", $data['texts']);
-                    // list($short_description, $actual_text) = explode(chr(0), $data['texts']);
-                    $this->tags2[$frame_id][$data['language']] = array(
-                        'short' => (bool)($data['encoding'] == 0x00) ? mb_convert_encoding($short_description, 'utf-8', 'iso-8859-1') : mb_convert_encoding($short_description, 'utf-8', 'utf-16'),
-                        'actual' => (bool)($data['encoding'] == 0x00) ? mb_convert_encoding($actual_text, 'utf-8', 'iso-8859-1') : mb_convert_encoding($actual_text, 'utf-8', 'utf-16'),
+                    list($short_description, $actual_text) = explode("\0", $allText, 2);
+
+                    $this->tags2[$frame_id][$language] = array(
+                        'short' => $short_description,
+                        'actual' => $actual_text,
                     );
                     break;
                 // case 'RVAD':    # Relative volume adjustment
@@ -921,20 +948,20 @@ class Mp3Info {
                 //     break;
                 case 'APIC':    # Attached picture
                     $this->hasCover = true;
-                    $last_byte = ftell($fp) + $frame_size;
-                    $this->coverProperties = ['text_encoding' => ord(fread($fp, 1))];
-//                     fseek($fp, $frame_size - 4, SEEK_CUR);
-                    $this->coverProperties['mime_type'] = $this->readTextUntilNull($fp, $last_byte);
-                    $this->coverProperties['picture_type'] = ord(fread($fp, 1));
-                    $this->coverProperties['description'] = $this->readTextUntilNull($fp, $last_byte);
-                    $this->coverProperties['offset'] = ftell($fp);
-                    $this->coverProperties['size'] = $last_byte - ftell($fp);
-                    fseek($fp, $last_byte);
+                    $dataEnd = $this->fileObj->getFilePos() + $frame_size;
+                    $this->coverProperties = ['text_encoding' => ord($this->fileObj->getBytes(1))];
+//                     $this->fileObj->seekForward($frame_size - 4);
+                    $this->coverProperties['mime_type'] = $this->readTextUntilNull($dataEnd);
+                    $this->coverProperties['picture_type'] = ord($this->fileObj->getBytes(1));
+                    $this->coverProperties['description'] = $this->readTextUntilNull($dataEnd);
+                    $this->coverProperties['offset'] = $this->fileObj->getFilePos();
+                    $this->coverProperties['size'] = $dataEnd - $this->fileObj->getFilePos();
+                    $this->fileObj->seekTo($dataEnd);
                     break;
                 // case 'GEOB':    # General encapsulated object
                 //     break;
                 case 'PCNT':    # Play counter
-                    $data = unpack('L', fread($fp, $frame_size));
+                    $data = unpack('L', $this->fileObj->getBytes($frame_size));
                     $this->tags2[$frame_id] = $data[1];
                     break;
                 // case 'POPM':    # Popularimeter
@@ -960,12 +987,44 @@ class Mp3Info {
                 // case 'PRIV':    # Private frame
                 //     break;
                 default:
-                    fseek($fp, $frame_size, SEEK_CUR);
+                    $this->fileObj->seekForward($frame_size);
                     break;
             }
         }
     }
 
+    /**
+     * Converts text encoding according to ID3 indicator
+     *
+     * @param int    $encoding Encoding ID from ID3 frame
+     * @param string $rawText  Raw text from ID3 frame
+     *
+     * @return string
+     */
+    private function _getUtf8Text(int $encoding, ?string $rawText): string
+    {
+        if (is_null($rawText)) {
+            $rawText = '';
+        }
+        
+        switch ($encoding) {
+            case 0x00:   // ISO-8859-1
+                return mb_convert_encoding($rawText, 'utf-8', 'iso-8859-1');
+
+            case 0x01:   // UTF-16 with BOM
+                return mb_convert_encoding($rawText . "\00", 'utf-8', 'utf-16');
+
+            // Following is for id3v2.4.x only
+            case 0x02:   // UTF-16 without BOM
+                return mb_convert_encoding($rawText . "\00", 'utf-8', 'utf-16');
+            case 0x03:   // UTF-8
+                return $rawText;
+
+            default:
+                throw new RuntimeException('Unknown text encoding type: ' . $encoding);
+        }
+    }
+
     /**
      * @param $frameSize
      * @param $raw
@@ -975,22 +1034,7 @@ class Mp3Info {
     private function handleTextFrame($frameSize, $raw)
     {
         $data = unpack('C1encoding/A' . ($frameSize - 1) . 'information', $raw);
-
-        switch($data['encoding']) {
-            case 0x00: # ISO-8859-1
-                return mb_convert_encoding($data['information'], 'utf-8', 'iso-8859-1');
-            case 0x01: # utf-16 with BOM
-                return mb_convert_encoding($data['information'] . "\00", 'utf-8', 'utf-16');
-
-            # Following is for id3v2.4.x only
-            case 0x02: # utf-16 without BOM
-                return mb_convert_encoding($data['information'] . "\00", 'utf-8', 'utf-16');
-            case 0x03: # utf-8
-                return $data['information'];
-
-            default:
-                throw new RuntimeException('Unknown text encoding type: '.$data['encoding']);
-        }
+        return $this->_getUtf8Text($data['encoding'], $data['information']);
     }
 
     /**
@@ -998,11 +1042,11 @@ class Mp3Info {
      * @param int $dataEnd
      * @return string|null
      */
-    private function readTextUntilNull($fp, $dataEnd)
+    private function readTextUntilNull($dataEnd)
     {
         $text = null;
-        while (ftell($fp) < $dataEnd) {
-            $char = fgetc($fp);
+        while ($this->fileObj->getFilePos() < $dataEnd) {
+            $char = $this->fileObj->getBytes(1);
             if ($char === "\00") {
                 return $text;
             }
@@ -1044,38 +1088,35 @@ class Mp3Info {
      * @return boolean True if file looks that correct mpeg audio, False otherwise.
      * @throws \Exception
      */
-    public static function isValidAudio($filename) {
-        if (!file_exists($filename) && strpos($filename, '://') == false) {
-            throw new Exception('File ' . $filename . ' is not present!');
+    public static function isValidAudio($filename)
+    {
+        if (str_contains($filename, '://')) {
+            $fileObj = new Mp3FileRemote($filename);
+        } else {
+            if (!file_exists($filename)) {
+                throw new Exception('File ' . $filename . ' is not present!');
+            }
+            $fileObj = new Mp3FileLocal($filename);
         }
 
-        $filesize = file_exists($filename) ? filesize($filename) : static::getUrlContentLength($filename);
+        $filesize = $fileObj->getFileSize();
 
-        $raw = file_get_contents($filename, false, null, 0, 3);
-        return $raw === self::TAG2_SYNC // id3v2 tag
-            || (self::FRAME_SYNC === (unpack('n*', $raw)[1] & self::FRAME_SYNC)) // mpeg header tag
-            || (
-                $filesize > 128
-                && file_get_contents($filename, false, null, -128, 3) === self::TAG1_SYNC
-            )  // id3v1 tag
-            ;
-    }
-
-    /**
-     * @param string $url
-     * @return int|mixed|string
-     */
-    public static function getUrlContentLength($url) {
-        $context = stream_context_create(['http' => ['method' => 'HEAD']]);
-        $head = array_change_key_case(get_headers($url, true, $context));
-        // content-length of download (in bytes), read from Content-Length: field
-        $clen = isset($head['content-length']) ? $head['content-length'] : 0;
-
-        // cannot retrieve file size, return "-1"
-        if (!$clen) {
-            return -1;
+        $raw = $fileObj->getBytes(3);
+        if ($raw === self::TAG2_SYNC) {
+            // id3v2 tag
+            return true;
         }
-
-        return $clen; // return size in bytes
+        if ((unpack('n', $raw)[1] & self::FRAME_SYNC) === self::FRAME_SYNC) {
+            // mpeg header tag
+            return true;
+        }
+        if ($filesize > 128) {
+            $fileObj->seekTo($filesize - 128);
+            if ($fileObj->getBytes(3) === self::TAG1_SYNC) {
+                // id3v1 tag
+                return true;
+            }
+        }
+        return false;
     }
-}
+}