FFmpeg support for WebMs. Fixes threads with large amounts of WebM's causing crashes for some users.

inc/lib/webm/README.md

@@ -20,6 +20,16 @@ Add these lines to inc/instance-config.php:
     $config['additional_javascript'][] = 'js/webm-settings.js';
     $config['additional_javascript'][] = 'js/expand-video.js';
 
+If you have an [FFmpeg](https://www.ffmpeg.org/) binary on your server and you wish to generate real thumbnails (the webm thumbnails created with the original implementation reportedly cause users' browsers to crash), add the following to inc/instance-config.php as well:
+
+    $config['webm']['use_ffmpeg'] = true;
+
+    // If your ffmpeg binary isn't in your path you need to set these options
+    // as well.
+
+    $config['webm']['ffmpeg_path'] = '/path/to/ffmeg';
+    $config['webm']['ffprobe_path'] = '/path/to/ffprobe';
+
 License
 -------
 

inc/lib/webm/ffmpeg.php

@@ -0,0 +1,58 @@
+<?php
+/*
+* ffmpeg.php
+* A barebones ffmpeg based webm implementation for vichan.
+*/
+
+function get_webm_info($filename) {
+  global $board, $config;
+
+  $filename = escapeshellarg($filename);
+  $ffprobe = $config['webm']['ffprobe_path'];
+  $ffprobe_out = array();
+  $webminfo = array();
+
+  exec("$ffprobe -v quiet -print_format json -show_format -show_streams $filename", $ffprobe_out);
+  $ffprobe_out = json_decode(implode("\n", $ffprobe_out), 1);
+  $webminfo['error'] = is_valid_webm($ffprobe_out);
+
+  if(empty($webminfo['error'])) {
+    $webminfo['width'] = $ffprobe_out['streams'][0]['width'];
+    $webminfo['height'] = $ffprobe_out['streams'][0]['height'];
+  }
+
+  return $webminfo;
+}
+
+function is_valid_webm($ffprobe_out) {
+  global $board, $config;
+
+  if (empty($ffprobe_out))
+    return array('code' => 1, 'msg' => $config['error']['genwebmerror']);
+
+  if ($ffprobe_out['format']['format_name'] != 'matroska,webm')
+    return array('code' => 2, 'msg' => $config['error']['invalidwebm']);
+
+  if ((count($ffprobe_out['streams']) > 1) && (!$config['webm']['allow_audio']))
+    return array('code' => 3, 'msg' => $config['error']['webmhasaudio']);
+
+  if ($ffprobe_out['streams'][0]['codec_name'] != 'vp8')
+    return array('code' => 2, 'msg' => $config['error']['invalidwebm']);
+
+  if (empty($ffprobe_out['streams'][0]['width']) || (empty($ffprobe_out['streams'][0]['height'])))
+    return array('code' => 2, 'msg' => $config['error']['invalidwebm']);
+
+  if ($ffprobe_out['format']['duration'] > $config['webm']['max_length'])
+    return array('code' => 4, 'msg' => $config['error']['webmtoolong']);
+}
+
+function make_webm_thumbnail($filename, $thumbnail, $width, $height) {
+  global $board, $config;
+
+  $ffmpeg = $config['webm']['ffmpeg_path'];
+  $ffmpeg_out = array();
+
+  exec("$ffmpeg -i $filename -v quiet -ss 00:00:00 -an -vframes 1 -f mjpeg -vf scale=$width:$height $thumbnail 2>&1");
+
+  return count($ffmpeg_out);
+}

inc/lib/webm/posthandler.php

@@ -6,6 +6,34 @@ function postHandler($post) {
     global $board, $config;
 
     if ($post->has_file) foreach ($post->files as &$file) if ($file->extension == 'webm') {
+      if ($config['webm']['use_ffmpeg']) {
+        require_once dirname(__FILE__) . '/ffmpeg.php';
+        $webminfo = get_webm_info($file->file_path);
+
+        if (empty($webminfo['error'])) {
+          $file->width = $webminfo['width'];
+          $file->height = $webminfo['height'];
+
+          if ($config['spoiler_images'] && isset($_POST['spoiler'])) {
+            $file = webm_set_spoiler($file);
+          }
+          else {
+            $file = set_thumbnail_dimensions($post, $file);
+            $tn_path = $board['dir'] . $config['dir']['thumb'] . $file->file_id . '.jpg';
+
+            if(empty(make_webm_thumbnail($file->file_path, $tn_path, $file->thumbwidth, $file->thumbheight))) {
+              $file->thumb = $file->file_id . '.jpg';
+            }
+            else {
+              $file->thumb = 'file';
+            }
+          }
+        }
+        else {
+          return $webminfo['error']['msg'];
+        }
+      }
+      else {
         require_once dirname(__FILE__) . '/videodata.php';
         $videoDetails = videoData($file->file_path);
         if (!isset($videoDetails['container']) || $videoDetails['container'] != 'webm') return "not a WebM file";
@@ -14,10 +42,7 @@ function postHandler($post) {
         $thumbName = $board['dir'] . $config['dir']['thumb'] . $file->file_id . '.webm';
         if ($config['spoiler_images'] && isset($_POST['spoiler'])) {
             // Use spoiler thumbnail
-            $file->thumb = 'spoiler';
-            $size = @getimagesize($config['spoiler_image']);
-            $file->thumbwidth = $size[0];
-            $file->thumbheight = $size[1];
+              $file = webm_set_spoiler($file);
         } elseif (isset($videoDetails['frame']) && $thumbFile = fopen($thumbName, 'wb')) {
             // Use single frame from video as pseudo-thumbnail
             fwrite($thumbFile, $videoDetails['frame']);
@@ -33,17 +58,40 @@ function postHandler($post) {
         if (isset($videoDetails['width']) && isset($videoDetails['height'])) {
             $file->width = $videoDetails['width'];
             $file->height = $videoDetails['height'];
+
             if ($file->thumb != 'file' && $file->thumb != 'spoiler') {
-                $thumbMaxWidth = $post->op ? $config['thumb_op_width'] : $config['thumb_width'];
-                $thumbMaxHeight = $post->op ? $config['thumb_op_height'] : $config['thumb_height'];
-                if ($videoDetails['width'] > $thumbMaxWidth || $videoDetails['height'] > $thumbMaxHeight) {
-                    $file->thumbwidth = min($thumbMaxWidth, intval(round($videoDetails['width'] * $thumbMaxHeight / $videoDetails['height'])));
-                    $file->thumbheight = min($thumbMaxHeight, intval(round($videoDetails['height'] * $thumbMaxWidth / $videoDetails['width'])));
-                } else {
-                    $file->thumbwidth = $videoDetails['width'];
-                    $file->thumbheight = $videoDetails['height'];
+                  $file = set_thumbnail_dimensions($post, $file);
                 }
             }
         }
     }
 }
+
+function set_thumbnail_dimensions($post,$file) {
+  global $board, $config;
+
+  $tn_dimensions = array();
+  $tn_maxw = $post->op ? $config['thumb_op_width'] : $config['thumb_width'];
+  $tn_maxh = $post->op ? $config['thumb_op_height'] : $config['thumb_height'];
+
+  if ($file->width > $tn_maxw || $file->height > $tn_maxh) {
+      $file->thumbwidth = min($tn_maxw, intval(round($file->width * $tn_maxh / $file->height)));
+      $file->thumbheight = min($tn_maxh, intval(round($file->height * $tn_maxw / $file->width)));
+  } else {
+      $file->thumbwidth = $file->width;
+      $file->thumbheight = $file->height;
+  }
+
+  return $file;
+}
+
+function webm_set_spoiler($file) {
+  global $board, $config;
+
+  $file->thumb = 'spoiler';
+  $size = @getimagesize($config['spoiler_image']);
+  $file->thumbwidth = $size[0];
+  $file->thumbheight = $size[1];
+
+  return $file;
+}