Waveform [Class]: Support audio file waveform generation.

resources/classes/waveform.php

@@ -0,0 +1,301 @@
+<?php
+/**
+ *
+ *
+ * @author MaximAL
+ * @since 2019-02-13 Added `$onePhase` parameters to get only positive waveform data and image
+ * @since 2018-10-22 Added `getWaveformData()` method and `$soxCommand` configuration
+ * @since 2016-11-21
+ * @date 2016-11-21
+ * @time 19:08
+ * @link http://maximals.ru
+ * @link http://sijeko.ru
+ * @link https://github.com/maximal/audio-waveform-php
+ * @copyright © MaximAL, Sijeko 2016-2019
+ *
+ * @modified fusionate
+ * @since 2024-02-07 Added option to return image in base64 format by setting $filename to 'base64'
+ * @since 2024-02-08 Added `$singleAxis` parameter to combine channels (if stereo) into single axis
+ * @since 2024-02-08 Added `$colorA` and `$colorB` parameters to allow different colors for each channel
+ * @since 2024-02-08 Rename `$onePhase` parameter to `$singlePhase` and change to public static variable for class
+ * @since 2024-02-08 Modified singleAxis so channel 2 would display as negative waveform data when singlePhase enabled
+ *
+ *
+ */
+
+namespace maximal\audio;
+
+/**
+ * Waveform class allows you to get waveform data and images from audio files
+ * @package maximal\audio
+ */
+class Waveform
+{
+	protected $filename;
+	protected $info;
+	protected $channels;
+	protected $samples;
+	protected $sampleRate;
+	protected $duration;
+
+	public static $linesPerPixel = 8;
+	public static $samplesPerLine = 512;
+	public static $singlePhase; // set `true` to get positive waveform phase only, `false` to get both positive and negative waveform phases
+	public static $singleAxis; // combine double or single phases to use same axis
+
+	// Colors in CSS `rgba(red, green, blue, opacity)` format
+	public static $color = [95, 95, 95, 0.5];
+	public static $colorA; // color of left channel (1)
+	public static $colorB; // color of right channel (2)
+	public static $backgroundColor = [245, 245, 245, 1];
+	public static $axisColor = [0, 0, 0, 0.1];
+
+	// SoX command: 'sox', '/usr/local/bin/sox' etc
+	public static $soxCommand = 'sox';
+
+
+	public function __construct($filename)
+	{
+		$this->filename = $filename;
+	}
+
+	public function getInfo()
+	{
+		$out = null;
+		$ret = null;
+		exec(self::$soxCommand . ' --i ' . escapeshellarg($this->filename) . ' 2>&1', $out, $ret);
+		$str = implode('|', $out);
+
+		$match = null;
+		if (preg_match('/Channels?\s*\:\s*(\d+)/ui', $str, $match)) {
+			$this->channels = intval($match[1]);
+		}
+
+		$match = null;
+		if (preg_match('/Sample\s*Rate\s*\:\s*(\d+)/ui', $str, $match)) {
+			$this->sampleRate = intval($match[1]);
+		}
+
+		$match = null;
+		if (preg_match('/Duration.*[^\d](\d+)\s*samples?/ui', $str, $match)) {
+			$this->samples = intval($match[1]);
+		}
+
+		if ($this->samples && $this->sampleRate) {
+			$this->duration = 1.0 * $this->samples / $this->sampleRate;
+		}
+
+		if ($ret !== 0) {
+			throw new \Exception('Failed to get audio info.' . PHP_EOL . 'Error: ' . implode(PHP_EOL, $out) . PHP_EOL);
+		}
+	}
+
+	public function getSampleRate()
+	{
+		if (!$this->sampleRate) {
+			$this->getInfo();
+		}
+		return $this->sampleRate;
+	}
+
+	public function getChannels()
+	{
+		if (!$this->channels) {
+			$this->getInfo();
+		}
+		return $this->channels;
+	}
+
+	public function getSamples()
+	{
+		if (!$this->samples) {
+			$this->getInfo();
+		}
+		return $this->samples;
+	}
+
+	public function getDuration()
+	{
+		if (!$this->duration) {
+			$this->getInfo();
+		}
+		return $this->duration;
+	}
+
+	/**
+	 * Get waveform from the audio file.
+	 * @param string $filename Image file name
+	 * @param int $width Width of the image file in pixels
+	 * @param int $height Height of the image file in pixels
+	 * @return bool Returns `true` on success or `false` on failure, when generating an image file, or a base64 string.
+	 * @throws \Exception
+	 */
+	public function getWaveform($filename, $width, $height)
+	{
+		// Calculating parameters
+		$needChannels = $this->getChannels() > 1 ? 2 : 1;
+		$data = $this->getWaveformData($width, self::$singlePhase ?? false);
+		$lines1 = $data['lines1'];
+		$lines2 = $data['lines2'];
+
+		// Creating image
+		$img = imagecreatetruecolor($width, $height);
+		imagesavealpha($img, true);
+		//if (function_exists('imageantialias')) {
+		//	imageantialias($img, true);
+		//}
+
+		// Colors
+		$back = self::rgbaToColor($img, self::$backgroundColor);
+		$color = self::rgbaToColor($img, self::$color);
+		$colorA = self::$colorA ? self::rgbaToColor($img, self::$colorA) : null;
+		$colorB = self::$colorB ? self::rgbaToColor($img, self::$colorB) : null;
+		$axis = self::rgbaToColor($img, self::$axisColor);
+		$singleAxis = self::$singleAxis ?? false;
+		imagefill($img, 0, 0, $back);
+
+		// Center Ys
+		if ($singleAxis) {
+			$center1 = $center2 = $height / 2;
+		} else {
+			if (self::$singlePhase ?? false) {
+				$center1 = $needChannels === 2 ? $height / 2 - 1: $height - 1;
+				$center2 = $needChannels === 2 ? $height - 1 : null;
+			} else {
+				$center1 = $needChannels === 2 ? ($height / 2 - 1) / 2 : $height / 2;
+				$center2 = $needChannels === 2 ? $height - $center1 : null;
+			}
+		}
+
+		// Drawing channel 1
+		for ($i = 0; $i < count($lines1); $i += 2) {
+			$x = $i / 2 / self::$linesPerPixel;
+			if (self::$singlePhase ?? false) {
+				$max = max($lines1[$i], $lines1[$i + 1]);
+				imageline($img, $x, $center1, $x, $center1 - $max * $center1, $colorA ?? $color);
+			} else {
+				$min = $lines1[$i];
+				$max = $lines1[$i + 1];
+				imageline($img, $x, $center1 - $min * $center1, $x, $center1 - $max * $center1, $colorA ?? $color);
+			}
+		}
+		// Drawing channel 2
+		for ($i = 0; $i < count($lines2); $i += 2) {
+			$x = $i / 2 / self::$linesPerPixel;
+			if (self::$singlePhase ?? false) {
+				$max = max($lines2[$i], $lines2[$i + 1]);
+				if ($singleAxis) {
+					imageline($img, $x, $center1, $x, $center1 + $max * $center2, $colorB ?? $color);
+				} else {
+					imageline($img, $x, $center2, $x, $center2 - $max * $center1, $colorB ?? $color);
+				}
+			} else {
+				if ($singleAxis) {
+					$min = $lines2[$i];
+					$max = $lines2[$i + 1];
+					imageline($img, $x, $center1 - $min * $center1, $x, $center1 - $max * $center1, $colorB ?? $color);
+				} else {
+					$min = $lines2[$i];
+					$max = $lines2[$i + 1];
+					imageline($img, $x, $center2 - $min * $center1, $x, $center2 - $max * $center1, $colorB ?? $color);
+				}
+			}
+		}
+
+		// Axis
+		imageline($img, 0, $center1, $width - 1, $center1, $axis);
+		if ($center2 !== null) {
+			imageline($img, 0, $center2, $width - 1, $center2, $axis);
+		}
+
+		if ($filename == 'base64') {
+			ob_start();
+			imagepng($img);
+			$image_data = ob_get_clean();
+			return base64_encode($image_data);
+		} else {
+			return imagepng($img, $filename);
+		}
+	}
+
+	/**
+	 * Get waveform data from the audio file.
+	 * @param int $width Desired width of the image file in pixels
+	 * @return array
+	 * @throws \Exception
+	 */
+	public function getWaveformData($width)
+	{
+		// Calculating parameters
+		$needChannels = $this->getChannels() > 1 ? 2 : 1;
+		$samplesPerPixel = self::$samplesPerLine * self::$linesPerPixel;
+		$needRate = 1.0 * $width * $samplesPerPixel * $this->getSampleRate() / $this->getSamples();
+
+		//if ($needRate > 4000) {
+		//	$needRate = 4000;
+		//}
+
+		// Command text
+		$command = self::$soxCommand . ' ' . escapeshellarg($this->filename) .
+			' -c ' . $needChannels .
+			' -r ' . $needRate . ' -e floating-point -t raw -';
+
+		//var_dump($command);
+
+		$outputs = [
+			1 => ['pipe', 'w'],  // stdout
+			2 => ['pipe', 'w'],  // stderr
+		];
+		$pipes = null;
+		$proc = proc_open($command, $outputs, $pipes);
+		if (!$proc) {
+			throw new \Exception('Failed to run `sox` command');
+		}
+
+		$lines1 = [];
+		$lines2 = [];
+		while ($chunk = fread($pipes[1], 4 * $needChannels * self::$samplesPerLine)) {
+			$data = unpack('f*', $chunk);
+			$channel1 = [];
+			$channel2 = [];
+			foreach ($data as $index => $sample) {
+				if ($needChannels === 2 && $index % 2 === 0) {
+					$channel2 []= $sample;
+				} else {
+					$channel1 []= $sample;
+				}
+			}
+			if (self::$singlePhase ?? false) {
+				// Rectifying to get positive values only
+				$lines1 []= abs(min($channel1));
+				$lines1 []= abs(max($channel1));
+				if ($needChannels === 2) {
+					$lines2 []= abs(min($channel2));
+					$lines2 []= abs(max($channel2));
+				}
+			} else {
+				// Two phases
+				$lines1 []= min($channel1);
+				$lines1 []= max($channel1);
+				if ($needChannels === 2) {
+					$lines2 []= min($channel2);
+					$lines2 []= max($channel2);
+				}
+			}
+		}
+
+		$err = stream_get_contents($pipes[2]);
+		$ret = proc_close($proc);
+
+		if ($ret !== 0) {
+			throw new \Exception('Failed to run `sox` command. Error:' . PHP_EOL . $err);
+		}
+
+		return ['lines1' => $lines1, 'lines2' => $lines2];
+	}
+
+	public static function rgbaToColor($img, $rgba)
+	{
+		return imagecolorallocatealpha($img, $rgba[0], $rgba[1], $rgba[2], round((1 - $rgba[3]) * 127));
+	}
+}