Support M3U playlists

Some videos are not MP4, but are instead M3Us. Or, rather, the MP4 is broken into hundreds of pieces, each in the M3U playlist. So here we identify such files and piece them together again.

bin/get_video.php

@@ -151,9 +151,20 @@ function delete($message)
 set_time_limit(0);
 
 /*
- * Retrieve the file and store it locally.
+ * Retrieve the file and store it locally. It may be a video or it may be just be a playlist in the
+ * M3U format.
  */
-$video->filename = $video->chamber . '-' . $video->type . '-' . $video->date . '.mp4';
+if (substr($video->url, -4) == '.mp4')
+{
+    $video->format = 'mp4';
+    $video->filename = $video->chamber . '-' . $video->type . '-' . $video->date . '.mp4';
+}
+elseif (substr($video->url, -5) == '.m3u8')
+{
+    $video->format = 'm3u';
+    $video->filename = $video->chamber . '-' . $video->type . '-' . $video->date . '.mp4';
+}
+
 $fp = fopen('../video/' . $video->filename, 'w+');
 $ch = curl_init($video->url);
 curl_setopt($ch, CURLOPT_FILE, $fp);
@@ -177,7 +188,7 @@ function delete($message)
 /*
  * If the file is less than 1 MB, we've gotten an HTML error page instead of video.
  */
-if (filesize('../video/' . $video->filename) < 1048576) {
+if ($video->format == 'mp4' && filesize('../video/' . $video->filename) < 1048576) {
     $log->put('The ' . $video->chamber . ' ' . $video->type . ' video for ' . $video->date
         . ', at ' . $video->url . ' is returning HTML instead of video. Requeuing for later '
         . 'retrieval and analysis.', 7);
@@ -186,6 +197,42 @@ function delete($message)
     exit(1);
 }
 
+/*
+ * If it's a playlist, combine all of its components into an MP4.
+ */
+if ($video->format = 'm3u') {
+    $log->put($video->filename . ' is a playlist, not a video. Converting to MP4.', 3);
+
+    $new_filename = str_replace('.m3u8', '.mp4', $video->filename);
+
+    // Modify the M3U file to prepend every segment with the full URL
+    $m3u = file_get_contents('../video/' . $video->filename);
+    $url_prefix = str_replace('playlist.m3u8', '', $video->url);
+    // Turn the segment paths into URLs
+    preg_replace('/^media_/', $url_prefix . 'media_', $m3u);
+    if (file_put_contents('../video/' . $video->filename, $m3u) === false)
+    {
+        $log->put('Error: Failed in rewriting contents of ' . $video->filename . ', with the '
+            .'full path of each chunk, because the file could not be saved.', 4);
+        exit(1);
+    }
+
+    $cmd = 'ffmpeg -protocol_whitelist file,http,https,tcp,tls,crypto -i "../video/'
+        . $video->filename .' -c copy -bsf:a aac_adtstoasc "' . $new_filename . '"';
+    exec($cmd, $output, $return_var);
+
+    if ($return_var != 0) {
+        $log->put('Error: Failed in M3U -> MP4 conversion of ' . $video->filename . ', with the '
+            .'following error: ' . implode(' ' , $output), 4);
+        exit(1);
+    }
+
+    /*
+     * Now make the MP4 the filename, rather than the playlist.
+     */
+    $video->filename = $new_filename;
+}
+
 /*
  * Connect to the database.
  */