shimmie2/ext/handle_mp3/main.php

<?php declare(strict_types=1);

class MP3FileHandler extends DataHandlerExtension
{
    public function onMediaCheckProperties(MediaCheckPropertiesEvent $event)
    {
        switch ($event->ext) {
            case "mp3":
                $event->image->audio = true;
                $event->image->video = false;
                $event->image->lossless = false;
                $event->image->image = false;
                break;
        }
        // TODO: Buff out audio format support, length scanning
    }

    protected function create_thumb(string $hash, string $type): bool
    {
        copy("ext/handle_mp3/thumb.jpg", warehouse_path(Image::THUMBNAIL_DIR, $hash));
        return true;
    }

    protected function supported_ext(string $ext): bool
    {
        $exts = ["mp3"];
        return in_array(strtolower($ext), $exts);
    }

    protected function create_image_from_data(string $filename, array $metadata)
    {
        $image = new Image();

        //NOTE: No need to set width/height as we don't use it.
        $image->width  = 1;
        $image->height = 1;

        $image->filesize  = $metadata['size'];
        $image->hash      = $metadata['hash'];

        //Filename is renamed to "artist - title.mp3" when the user requests download by using the download attribute & jsmediatags.js
        $image->filename = $metadata['filename'];

        $image->ext       = $metadata['extension'];
        $image->tag_array = is_array($metadata['tags']) ? $metadata['tags'] : Tag::explode($metadata['tags']);
        $image->source    = $metadata['source'];


        return $image;
    }

    protected function check_contents(string $tmpname): bool
    {
        return getMimeType($tmpname) == 'audio/mpeg';
    }
}