WordPress上传图片自动添加webp格式文件-WP新手学园

webp格式的图片有点我就不说了，不明白的可以看看下面的描述：

WebP，是一种同时提供了有损压缩与无损压缩的图片文件格式，派生自视频编码格式 VP8。WebP 最初在2010年发布，目标是减少文件大小，但达到和 JEPG 格式相同的图片质量，希望能够减少图片档在网络上的发送时间。2011年11月8日，Google 开始让 WebP 支持无损压缩和透明色的功能。

现在很多站点已经开始使用这个格式的图片作为主力，但是我个人还是比较推荐保留两种格式，毕竟不是所有人都喜欢webp格式的文件，同时存在源文件格式和webp格式文件才是最优解，毕竟现在的硬盘空间已经不值钱了。

看了上面的所有说明，你没有顾虑，可以看看下面的代码：

<?php
/**
* Plugin Name: GD WebP Converter
* Plugin URI: https://stackoverflow.com/a/67234000
* Description: After uploading an image it will be converted to WebP format using the GD image engine. <a target="_blank" href="https://developer.wordpress.org/reference/classes/wp_image_editor_gd/" rel="noopener">WP GD Image Engine</a> If the file is deleted form the Media Library the created WebP conversions will also be deleted.
* Version: 1.0.0
* Requires at least: 5.5
* Requires PHP: 7.2
* Author: lowtechsun
* Author URI: https://stackoverflow.com/users/1010918/lowtechsun
* License: GPL v2 or later
* License URI: https://www.gnu.org/licenses/gpl-2.0.html
*/

//=================================================
// Security: Abort if this file is called directly
//=================================================
if ( ! defined( 'ABSPATH' ) ) {
    die;
}

function debug( $info ) {
    $message = null;

    if ( is_string( $info ) || is_int( $info ) || is_float( $info ) ) {
        $message = $info;
    } else {
        $message = var_export( $info, true );
    }

    if ( $fh = fopen( ABSPATH . '/gdwebpconvert.log', 'a' ) ) {
        fputs( $fh, date( 'Y-m-d H:i:s' ) . " $message\n" );
        fclose( $fh );
    }
}

add_filter( 'wp_generate_attachment_metadata', 'gd_webp_converter', 10, 2 );

function gd_webp_converter( $metadata, $attachment_id ) {

    $gd_webp_converter = new GDWebPConverter( $attachment_id );
    $gd_webp_converter->check_file_exists( $attachment_id );
    $gd_webp_converter->check_mime_type();
    $gd_webp_converter->create_array_of_sizes_to_be_converted( $metadata );
    $gd_webp_converter->convert_array_of_sizes();

    return $metadata;
}

class GDWebPConverter {

    private $file_path;
    private $file_dirname;
    private $file_ext;
    private $file_name_no_ext;

    private $array_of_sizes_to_be_converted = array();
    private $array_of_sizes_to_be_deleted   = array();

    public function __construct( $attachment_id ) {

        $this->file_path = get_attached_file( $attachment_id );
        debug( $this->file_path );

        // https://stackoverflow.com/questions/2183486/php-get-file-name-without-file-extension/19040276
        $this->file_dirname = pathinfo( $this->file_path, PATHINFO_DIRNAME );
        debug( $this->file_dirname );

        $this->file_ext = strtolower( pathinfo( $this->file_path, PATHINFO_EXTENSION ) );
        debug( $this->file_ext );

        $this->file_name_no_ext = pathinfo( $this->file_path, PATHINFO_FILENAME );
        debug( $this->file_name_no_ext );
    }

    public function check_file_exists( $attachment_id ) {

        $file = get_attached_file( $attachment_id );

        if ( ! file_exists( $file ) ) {
            $message = 'The uploaded file does not exist on the server. Encoding not possible.';
            debug( $message );
            throw new Exception( 'The uploaded file does exist on the server. Encoding not possible.', 1 );
        }

    }

    public function check_mime_type() {

        // https://www.php.net/manual/en/function.finfo-file.php
        $finfo = finfo_open( FILEINFO_MIME_TYPE );

        $this->file_mime_type = finfo_file( $finfo, $this->file_path );

        finfo_close( $finfo );
        // debug( $this->file_mime_type );

        // https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/MIME_types/Common_types
        $this->allowed_mime_type = array( 'image/jpeg', 'image/png' );

        if ( ! in_array( $this->file_mime_type, $this->allowed_mime_type, true ) ) {

            $message = 'MIME type of file not supported';
            // debug( $message );
            throw new Exception( 'MIME type of file not supported', 1 );

        }
    }

    public function create_array_of_sizes_to_be_converted( $metadata ) {

        // push original file to the array
        array_push( $this->array_of_sizes_to_be_converted, $this->file_path );
        // debug( $this->array_of_sizes_to_be_converted );

        // push all created sizes of the file to the array
        foreach ( $metadata['sizes'] as $value ) {
            // debug( $value['file'] );
            array_push( $this->array_of_sizes_to_be_converted, $this->file_dirname . '/' . $value['file'] );
        }
        // // debug( $this->array_of_sizes_to_be_converted );
    }

    public function convert_array_of_sizes() {

        debug( $this->array_of_sizes_to_be_converted );

        switch ( $this->file_ext ) {
            case 'jpeg':
            case 'jpg':
                foreach ( $this->array_of_sizes_to_be_converted as $key => $value ) {

                    $image = imagecreatefromjpeg( $value );

                    if ( 0 === $key ) {

                        imagewebp( $image, $this->file_dirname . '/' . $this->file_name_no_ext . '.webp', 80 );

                    } else {

                        $current_size = getimagesize( $value );
                        // debug( $current_size );
                        imagewebp( $image, $this->file_dirname . '/' . $this->file_name_no_ext . '-' . $current_size[0] . 'x' . $current_size[1] . '.webp', 80 );

                    }

                    imagedestroy( $image );
                }
                break;

            case 'png':
                foreach ( $this->array_of_sizes_to_be_converted as $key => $value ) {

                    $image = imagecreatefrompng( $value );
                    imagepalettetotruecolor( $image );
                    imagealphablending( $image, true );
                    imagesavealpha( $image, true );

                    if ( 0 === $key ) {

                        imagewebp( $image, $this->file_dirname . '/' . $this->file_name_no_ext . '.webp', 80 );

                    } else {

                        $current_size = getimagesize( $value );
                        // debug( $current_size );
                        imagewebp( $image, $this->file_dirname . '/' . $this->file_name_no_ext . '-' . $current_size[0] . 'x' . $current_size[1] . '.webp', 80 );

                    }

                    imagedestroy( $image );

                }
                break;

            // animated GIF to WebP not supported by GD - imagecreatefromgif
            // case 'gif':
            //  foreach ( $this->array_of_sizes_to_be_converted as $key => $value ) {

            //      $image = imagecreatefromgif( $value );

            //      if ( 0 === $key ) {

            //          imagewebp( $image, $this->file_dirname . '/' . $this->file_name_no_ext . '.webp', 80 );

            //      } else {

            //          $current_size = getimagesize( $value );
            //          // debug( $current_size );
            //          imagewebp( $image, $this->file_dirname . '/' . $this->file_name_no_ext . '-' . $current_size[0] . 'x' . $current_size[1] . '.webp', 80 );

            //      }

            //      imagedestroy( $image );

            //  }
            //  break;

            default:
                return false;
        }

    }

    public function create_array_of_sizes_to_be_deleted( $attachment_id ) {

        // debug( $attachment_id );

        $this->attachment_metadata_of_file_to_be_deleted = wp_get_attachment_metadata( $attachment_id );
        // debug( $this->attachment_metadata_of_file_to_be_deleted );

        // push original file to the array
        array_push( $this->array_of_sizes_to_be_deleted, $this->file_dirname . '/' . $this->file_name_no_ext . '.webp' );
        // debug( $this->array_of_sizes_to_be_converted );

        // push all created sizes of the file to the array
        foreach ( $this->attachment_metadata_of_file_to_be_deleted['sizes'] as $value ) {

            // debug( $value );

            $this->value_file_name_no_ext = pathinfo( $value['file'], PATHINFO_FILENAME );
            // debug( $this->value_file_name_no_ext );

            array_push( $this->array_of_sizes_to_be_deleted, $this->file_dirname . '/' . $this->value_file_name_no_ext . '.webp' );
        }
        // debug( $this->array_of_sizes_to_be_deleted );
    }

    public function delete_array_of_sizes() {

        debug( $this->array_of_sizes_to_be_deleted );

        foreach ( $this->array_of_sizes_to_be_deleted as $key => $value ) {

            // debug( $value );
            unlink( $value );

        }
    }

}

add_action( 'delete_attachment', 'delete_webp_conversions', 10 );

function delete_webp_conversions( $attachment_id ) {

    $delete_webp_conversions = new GDWebPConverter( $attachment_id );
    $delete_webp_conversions->create_array_of_sizes_to_be_deleted( $attachment_id );
    $delete_webp_conversions->delete_array_of_sizes();

}

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<?php

/**

* Plugin Name: GD WebP Converter

* Plugin URI: https://stackoverflow.com/a/67234000

* Description: After uploading an image it will be converted to WebP format using the GD image engine. <a target="_blank" href="https://developer.wordpress.org/reference/classes/wp_image_editor_gd/" rel="noopener">WP GD Image Engine</a> If the file is deleted form the Media Library the created WebP conversions will also be deleted.

* Version: 1.0.0

* Requires at least: 5.5

* Requires PHP: 7.2

* Author: lowtechsun

* Author URI: https://stackoverflow.com/users/1010918/lowtechsun

* License: GPL v2 or later

* License URI: https://www.gnu.org/licenses/gpl-2.0.html

//=================================================

// Security: Abort if this file is called directly

//=================================================

if ( ! defined( 'ABSPATH' ) ) {

die;

}

function debug( $info ) {

$message = null;

if ( is_string( $info ) || is_int( $info ) || is_float( $info ) ) {

$message = $info;

} else {

$message = var_export( $info, true );

}

if ( $fh = fopen( ABSPATH . '/gdwebpconvert.log', 'a' ) ) {

fputs( $fh, date( 'Y-m-d H:i:s' ) . " $message\n" );

fclose( $fh );

}

add_filter( 'wp_generate_attachment_metadata', 'gd_webp_converter', 10, 2 );

function gd_webp_converter( $metadata, $attachment_id ) {

$gd_webp_converter = new GDWebPConverter( $attachment_id );

$gd_webp_converter->check_file_exists( $attachment_id );

$gd_webp_converter->check_mime_type();

$gd_webp_converter->create_array_of_sizes_to_be_converted( $metadata );

$gd_webp_converter->convert_array_of_sizes();

return $metadata;

}

class GDWebPConverter {

private $file_path;

private $file_dirname;

private $file_ext;

private $file_name_no_ext;

private $array_of_sizes_to_be_converted = array();

private $array_of_sizes_to_be_deleted = array();

public function __construct( $attachment_id ) {

$this->file_path = get_attached_file( $attachment_id );

debug( $this->file_path );

// https://stackoverflow.com/questions/2183486/php-get-file-name-without-file-extension/19040276

$this->file_dirname = pathinfo( $this->file_path, PATHINFO_DIRNAME );

debug( $this->file_dirname );

$this->file_ext = strtolower( pathinfo( $this->file_path, PATHINFO_EXTENSION ) );

debug( $this->file_ext );

$this->file_name_no_ext = pathinfo( $this->file_path, PATHINFO_FILENAME );

debug( $this->file_name_no_ext );

}

public function check_file_exists( $attachment_id ) {

$file = get_attached_file( $attachment_id );

if ( ! file_exists( $file ) ) {

$message = 'The uploaded file does not exist on the server. Encoding not possible.';

debug( $message );

throw new Exception( 'The uploaded file does exist on the server. Encoding not possible.', 1 );

}

public function check_mime_type() {

// https://www.php.net/manual/en/function.finfo-file.php

$finfo = finfo_open( FILEINFO_MIME_TYPE );

$this->file_mime_type = finfo_file( $finfo, $this->file_path );

finfo_close( $finfo );

// debug( $this->file_mime_type );

// https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/MIME_types/Common_types

$this->allowed_mime_type = array( 'image/jpeg', 'image/png' );

if ( ! in_array( $this->file_mime_type, $this->allowed_mime_type, true ) ) {

$message = 'MIME type of file not supported';

// debug( $message );

throw new Exception( 'MIME type of file not supported', 1 );

}

public function create_array_of_sizes_to_be_converted( $metadata ) {

// push original file to the array

array_push( $this->array_of_sizes_to_be_converted, $this->file_path );

// debug( $this->array_of_sizes_to_be_converted );

// push all created sizes of the file to the array

foreach ( $metadata['sizes'] as $value ) {

// debug( $value['file'] );

array_push( $this->array_of_sizes_to_be_converted, $this->file_dirname . '/' . $value['file'] );

}

// // debug( $this->array_of_sizes_to_be_converted );

}

public function convert_array_of_sizes() {

debug( $this->array_of_sizes_to_be_converted );

switch ( $this->file_ext ) {

case 'jpeg':

case 'jpg':

foreach ( $this->array_of_sizes_to_be_converted as $key => $value ) {

$image = imagecreatefromjpeg( $value );

if ( 0 === $key ) {

imagewebp( $image, $this->file_dirname . '/' . $this->file_name_no_ext . '.webp', 80 );

} else {

$current_size = getimagesize( $value );

// debug( $current_size );

imagewebp( $image, $this->file_dirname . '/' . $this->file_name_no_ext . '-' . $current_size[0] . 'x' . $current_size[1] . '.webp', 80 );

}

imagedestroy( $image );

}

break;

case 'png':

foreach ( $this->array_of_sizes_to_be_converted as $key => $value ) {

$image = imagecreatefrompng( $value );

imagepalettetotruecolor( $image );

imagealphablending( $image, true );

imagesavealpha( $image, true );

if ( 0 === $key ) {

imagewebp( $image, $this->file_dirname . '/' . $this->file_name_no_ext . '.webp', 80 );

} else {

$current_size = getimagesize( $value );

// debug( $current_size );

imagewebp( $image, $this->file_dirname . '/' . $this->file_name_no_ext . '-' . $current_size[0] . 'x' . $current_size[1] . '.webp', 80 );

}

imagedestroy( $image );

}

break;

// animated GIF to WebP not supported by GD - imagecreatefromgif

// case 'gif':

// foreach ( $this->array_of_sizes_to_be_converted as $key => $value ) {

// $image = imagecreatefromgif( $value );

// if ( 0 === $key ) {

// imagewebp( $image, $this->file_dirname . '/' . $this->file_name_no_ext . '.webp', 80 );

// } else {

// $current_size = getimagesize( $value );

// // debug( $current_size );

// imagewebp( $image, $this->file_dirname . '/' . $this->file_name_no_ext . '-' . $current_size[0] . 'x' . $current_size[1] . '.webp', 80 );

// }

// imagedestroy( $image );

// }

// break;

default:

return false;

}

public function create_array_of_sizes_to_be_deleted( $attachment_id ) {

// debug( $attachment_id );

$this->attachment_metadata_of_file_to_be_deleted = wp_get_attachment_metadata( $attachment_id );

// debug( $this->attachment_metadata_of_file_to_be_deleted );

// push original file to the array

array_push( $this->array_of_sizes_to_be_deleted, $this->file_dirname . '/' . $this->file_name_no_ext . '.webp' );

// debug( $this->array_of_sizes_to_be_converted );

// push all created sizes of the file to the array

foreach ( $this->attachment_metadata_of_file_to_be_deleted['sizes'] as $value ) {

// debug( $value );

$this->value_file_name_no_ext = pathinfo( $value['file'], PATHINFO_FILENAME );

// debug( $this->value_file_name_no_ext );

array_push( $this->array_of_sizes_to_be_deleted, $this->file_dirname . '/' . $this->value_file_name_no_ext . '.webp' );

}

// debug( $this->array_of_sizes_to_be_deleted );

}

public function delete_array_of_sizes() {

debug( $this->array_of_sizes_to_be_deleted );

foreach ( $this->array_of_sizes_to_be_deleted as $key => $value ) {

// debug( $value );

unlink( $value );

}

add_action( 'delete_attachment', 'delete_webp_conversions', 10 );

function delete_webp_conversions( $attachment_id ) {

$delete_webp_conversions = new GDWebPConverter( $attachment_id );

$delete_webp_conversions->create_array_of_sizes_to_be_deleted( $attachment_id );

$delete_webp_conversions->delete_array_of_sizes();

}

代码方面来自： https://stackoverflow.com/questions/67183333/wordpress-convert-image-to-webp-format-programmatically-with-gd-image-engine

经过测试之后，上传图片确实是可以在后台生成对应的webp图片，效果截图如下：

同样的，你可以尝试一下，上方的图片修改后缀为webp同样可以看到图片。

上面的代码直接保存为一个php文件之后，在function文件中通过include导入即可完成该功能。

经过尝试，这里需要注意的就是PHP方面需要开启fileinfo扩展，否则会报错，报错内容大概为：Call to undefined function finfo_open()