UespWebpHandler.php

<?php
/*
 * UespWebpHandler.php -- Dave Humphrey (dave@uesp.net), April 2020
 *
 * Very simple handler for WEBP images that supports resizing to WEBP format (instead of PNG) as well as basic
 * resizing of animated images. Note that resizing animated WEBPs can result in imperfect replicas.
 *
 * Uses the Google shell applications available in the webp-libtools package or at:
 * 		https://developers.google.com/speed/webp/download
 *
 * Specifically created for the UESP.net wiki but can be customized using the $wgUespWebpBinPath and
 * $wgUespWebpCustomConvert global variables.
 */


global $IP;
require_once "$IP/includes/media/WebP.php";

global $wgUespWebpBinPath;
$wgUespWebpBinPath = '/usr/bin';
$wgUespWebpBinPath = '/home/uesp/webp/bin';

global $wgUespWebpCustomConvert;
$wgUespWebpCustomConvert = 'cwebp -resize %w %h %s -o %d';


class UespWebpHandler extends WebPHandler
{
	public $ENABLE_ANIMATED_THUMBNAILS = false;


	public function canRender($file)
	{
		return true;
	}


	public function canAnimateThumbnail($file)
	{
		return true;
	}


	public function getThumbType($ext, $mime, $params = null)
	{
		return array('webp', 'image/webp');
	}


	protected function getScalerType($dstPath, $checkDstPath = true)
	{
		return 'custom';
	}


	protected function transformCustom($image, $params)
	{
		global $wgUespWebpCustomConvert;
		global $wgUespWebpBinPath;

		if ($this->isAnimatedImage($image)) return $this->transformCustomAnimated($image, $params);

		# Variables: %s %d %w %h
		$src = wfEscapeShellArg($params['srcPath']);
		$dst = wfEscapeShellArg($params['dstPath']);
		$cmd = $wgUespWebpBinPath . "/" . $wgUespWebpCustomConvert;
		$cmd = str_replace('%s', $src, str_replace('%d', $dst, $cmd)); # Filenames
		$cmd = str_replace(
			'%h',
			wfEscapeShellArg($params['physicalHeight']),
			str_replace('%w', wfEscapeShellArg($params['physicalWidth']), $cmd)
		); # Size
		wfDebug(__METHOD__ . ": Running custom convert command $cmd\n");
		$retval = 0;
		$err = wfShellExecWithStderr($cmd, $retval);

		if ($retval !== 0) {
			$this->logErrorForExternalProcess($retval, $err, $cmd);

			return $this->getMediaTransformError($params, $err);
		}

		return false; # No error
	}


	protected function transformCustomAnimated($image, $params)
	{
		global $wgUespWebpCustomConvert;
		global $wgUespWebpBinPath;

		//if (!$this->ENABLE_ANIMATED_THUMBNAILS) return transformCustomNonAnimated( $image, $params );

		$src       = wfEscapeShellArg($params['srcPath']);
		$dst       = wfEscapeShellArg($params['dstPath']);
		$width     = wfEscapeShellArg($params['physicalWidth']);
		$height    = wfEscapeShellArg($params['physicalHeight']);
		$srcWidth  = $params['srcWidth'];
		$srcHeight = $params['srcHeight'];
		$pctWidth  = floatval($params['physicalWidth']) / floatval($srcWidth);
		$pctHeight = floatval($params['physicalHeight']) / floatval($srcHeight);

		$cmd = "$wgUespWebpBinPath/webpmux -info $src";
		wfDebug(__METHOD__ . ": Running custom convert command $cmd\n");

		$retval = 0;
		$output = wfShellExecWithStderr($cmd, $retval);

		if ($retval !== 0) {
			$this->logErrorForExternalProcess($retval, $output, $cmd);
			return $this->getMediaTransformError($params, $output);
		}

		$outputLines = explode("\n", $output);
		$frames = array();

		if (count($outputLines) <= 2) {
			$this->logErrorForExternalProcess($retval, $output, $cmd);
			return $this->getMediaTransformError($params, $output);
		}

		foreach ($outputLines as $line) {
			$frame = array();

			$cols = preg_split("# #", $line, -1, PREG_SPLIT_NO_EMPTY);
			if (count($cols) < 10) continue;

			$frame['no'] = $cols[0];
			$frame['width'] = $cols[1];
			$frame['height'] = $cols[2];
			$frame['alpha'] = $cols[3];
			$frame['xoffset'] = $cols[4];
			$frame['yoffset'] = $cols[5];
			$frame['duration'] = $cols[6];
			$frame['dispose'] = $cols[7];
			$frame['blend'] = $cols[8];
			$frame['size'] = $cols[9];
			$frame['compression'] = $cols[10];

			$frames[] = $frame;
		}

		if (count($frames) <= 1) {
			$this->logErrorForExternalProcess($retval, $output, $cmd);
			return $this->getMediaTransformError($params, $output);
		}

		$createCmd = "";

		for ($i = 1; $i < count($frames); ++$i) {
			$frame = &$frames[$i];

			$tmpFile = TempFSFile::factory("anitransform_{$i}_", 'webp');
			$tmpFile->bind($frames[$i]);
			$frames[$i]['tmpfile'] = $tmpFile;
			$tmpName = $tmpFile->getPath();

			$cmd = "$wgUespWebpBinPath/webpmux -get frame $i $src -o '$tmpName'";
			wfDebug(__METHOD__ . ": Running custom convert command $cmd\n");

			$retval = 0;
			$output = wfShellExecWithStderr($cmd, $retval);

			if ($retval !== 0) {
				$this->logErrorForExternalProcess($retval, $output, $cmd);
				return $this->getMediaTransformError($params, $output);
			}

			$frameWidth  = round(floatval($frame['width']) * $pctWidth);
			$frameHeight = round(floatval($frame['height']) * $pctHeight);

			$cmd = "$wgUespWebpBinPath/cwebp -resize $frameWidth $frameHeight '$tmpName' -o '$tmpName'";
			wfDebug(__METHOD__ . ": Running custom convert command $cmd\n");

			$retval = 0;
			$output = wfShellExecWithStderr($cmd, $retval);

			if ($retval !== 0) {
				$this->logErrorForExternalProcess($retval, $output, $cmd);
				return $this->getMediaTransformError($params, $output);
			}

			$di = $frame['duration'];
			$xi = round(floatval($frame['xoffset']) * $pctWidth);
			$yi = round(floatval($frame['yoffset']) * $pctHeight);
			$mi = $frame['dispose'] == "none" ? "0" : "1";
			$bi = $frame['blend'] == 'yes' ? '+b' : '-b';

			$createCmd .= " -frame '$tmpName' +$di+$xi+$yi+$mi$bi";

			if (!$this->ENABLE_ANIMATED_THUMBNAILS) break;
		}

		$cmd = "$wgUespWebpBinPath/webpmux $createCmd -o $dst";
		wfDebug(__METHOD__ . ": Running custom convert command $cmd\n");

		$retval = 0;
		$output = wfShellExecWithStderr($cmd, $retval);

		if ($retval !== 0) {
			$this->logErrorForExternalProcess($retval, $output, $cmd);
			return $this->getMediaTransformError($params, $output);
		}

		return false;	# No error
	}
};