feat: remove letterboxing from videos

3 files changed, 43 insertions, 0 deletions

diff --git a/lib/file.php b/lib/file.php
index 0b250ca..ebfc009 100644
--- a/lib/file.php
+++ b/lib/file.php
@@ -129,4 +129,25 @@ function strip_exif(string $file_path)
     $file_path = escapeshellarg($file_path);
     $output = shell_exec("exiftool -q -EXIF= $file_path $file_path");
     return empty($output);
+}
+
+function remove_video_letterbox(string $input_path, string $output_path)
+{
+    $input_path = escapeshellarg($input_path);
+    $output_path = escapeshellarg($output_path);
+    $output = shell_exec("ffmpeg -nostdin -i $input_path -vf cropdetect=24:16:0 -f null - 2>&1");
+
+    if (preg_match_all('/crop=\d+:\d+:\d+:\d+/', $output, $matches)) {
+        $area = end($matches);
+        $area = end($area);
+    } else {
+        throw new RuntimeException('Could not detect crop parameters. Try upload the video without "Remove letterbox" option.');
+    }
+
+    $area = escapeshellarg($area);
+
+    $output = [];
+    exec("ffmpeg -nostdin -i $input_path -vf $area -c:a copy $output_path 2>&1", $output, $code);
+
+    return $code == 0;
 }
\ No newline at end of file
diff --git a/public/index.php b/public/index.php
index 735f49d..a55199c 100644
--- a/public/index.php
+++ b/public/index.php
@@ -446,6 +446,14 @@ $privacy_exists = is_file($_SERVER['DOCUMENT_ROOT'] . '/static/PRIVACY.txt');
                                         <td><input type="checkbox" name="strip_exif_data" value="1" checked></td>
                                     </tr>
                                 <?php endif; ?>
+                                <?php if (FILE_REMOVE_LETTERBOXES): ?>
+                                    <tr>
+                                        <th>Remove letterboxing<span class="help"
+                                                title="Removes black bars from the video, may be inaccurate, and only applies to videos">[?]</span>:
+                                        </th>
+                                        <td><input type="checkbox" name="remove_letterbox" value="1"></td>
+                                    </tr>
+                                <?php endif; ?>
                             </table>
                             <button type="submit" class="fancy">Upload</button>
                     </form>
diff --git a/public/upload.php b/public/upload.php
index 123c30a..bfa1990 100644
--- a/public/upload.php
+++ b/public/upload.php
@@ -200,6 +200,20 @@ try {
         throw new RuntimeException('This file is not allowed for upload.' . (isset($row['reason']) ? ' Reason: ' . $row['reason'] : ''));
     }
 
+    // remove letterbox
+    $remove_letterbox = FILE_REMOVE_LETTERBOXES && boolval($_POST['remove_letterbox'] ?? '0');
+    if ($remove_letterbox && str_starts_with($file_data['mime'], 'video/')) {
+        $output_path = $file_path;
+        $input_path = FILE_UPLOAD_DIRECTORY . sprintf('/%s.temporary.%s', $file_id, $file_data['extension']);
+        rename($output_path, $input_path);
+        if (!remove_video_letterbox($input_path, $output_path)) {
+            rename($input_path, $output_path);
+            delete_file($file_id, $file_data['extension']);
+            throw new RuntimeException('Failed to remove letterbox from the video');
+        }
+        unlink($input_path);
+    }
+
     $file_data['size'] = filesize($file_path);
 
     if (FILE_THUMBNAILS && !is_dir(FILE_THUMBNAIL_DIRECTORY) && !mkdir(FILE_THUMBNAIL_DIRECTORY, 0777, true)) {