Updated readme

README.md

+This module add support for embedding HTML5 videos into your website using Video Embed Field
+
+## Installation
+
+To install this module, do the following:
+
+1. Download the Video Embed HTML5 module and follow the instruction for
+      [installing contributed modules](https://www.drupal.org/docs/8/extending-drupal-8/installing-contributed-modules-find-import-enable-configure-drupal-8).
+
+## Usage
+
+ 1. Install module
+ 2. Add video embed field and enable "HTML5" provider
+ 3. Add link that ends with mp4/ogg/webm
+ 
+## Generating thumbnails
+ * If you want to use the Thumbnail formatter, you have to install the [php_ffmpeg module](https://www.drupal.org/project/php_ffmpeg) 
+ * Configure it properly (install dependent binaries)
\ No newline at end of file

src/Plugin/video_embed_field/Provider/Html5.php

@@ -21,6 +21,7 @@ class Html5 extends ProviderPluginBase {
 
   /** @var FFMpeg $phpFFMpeg */
   protected $phpFFMpeg;
+  protected $filename;
 
   /**
    * Html5 constructor.
@@ -38,6 +39,10 @@ class Html5 extends ProviderPluginBase {
     if ($module_handler->moduleExists('php_ffmpeg')) {
       $this->phpFFMpeg = \Drupal::service('php_ffmpeg');
     }
+
+    // Set filename for thumbnail.
+    list($video_url, $video_type) = $this->getVideoId();
+    $this->filename = md5($video_url);
   }
 
   /**
@@ -75,13 +80,11 @@ class Html5 extends ProviderPluginBase {
       if (!file_exists($local_uri)) {
         file_prepare_directory($this->thumbsDirectory, FILE_CREATE_DIRECTORY);
         try {
-          // Thumb does not exist yet. Generate it.
           list($video_url, $video_type) = $this->getVideoId();
+          // Thumb does not exist yet. Generate it.
           $video = $this->phpFFMpeg->open($video_url);
-
-          $filename = md5($video_url);
           $video->frame(TimeCode::fromSeconds(1))
-            ->save(drupal_realpath($this->thumbsDirectory) . '/' . $filename . '.jpg');
+            ->save(drupal_realpath($this->thumbsDirectory) . '/' . $this->filename . '.jpg');
         } catch (\Exception $e) {
         }
       }
@@ -98,9 +101,7 @@ class Html5 extends ProviderPluginBase {
    * {@inheritdoc}
    */
   public function getLocalThumbnailUri() {
-    list($video_url, $video_type) = $this->getVideoId();
-    $filename = md5($video_url);
-    return $this->thumbsDirectory . '/' . $filename . '.jpg';
+    return $this->thumbsDirectory . '/' . $this->filename . '.jpg';
   }
 
   /**

video_embed_html5.module

 <?php
 
+use Drupal\Core\Routing\RouteMatchInterface;
+
+/**
+ * Implements hook_help().
+ */
+function video_embed_html5_help($route_name, RouteMatchInterface $route_match) {
+  switch ($route_name) {
+    case 'help.page.video_embed_html5':
+      $output = file_get_contents(drupal_get_path('module', 'video_embed_html5') . '/README.md');
+      return '<pre>' . $output . '</pre>';
+      break;
+    default:
+  }
+}
+
 /**
  * Implements hook_theme().
  */