[#1928 - Make thumbnail generation more flexible for movies (graphics and movie helpers)]

- graphics helper: add movie_extract_frame event to generate function
(allows modules to add to the options sent to movie::extract_frame or to
generate the thumbnail on their own without movie::extract_frame)
- movie helper: add extra optional argument to movie::extract_frame
(can add ffmpeg arguments and/or change the frame extract time)
- gallery_installer: add movie_extract_time module variable, update to v53
- module.info: update to v53
- install.sql: update to v53

4 files changed, 56 insertions, 16 deletions

diff --git a/modules/gallery/helpers/gallery_installer.php b/modules/gallery/helpers/gallery_installer.php
index 1f190800..597771f3 100644
--- a/modules/gallery/helpers/gallery_installer.php
+++ b/modules/gallery/helpers/gallery_installer.php
@@ -313,8 +313,9 @@ class gallery_installer {
     module::set_var("gallery", "extra_binary_paths", "/usr/local/bin:/opt/local/bin:/opt/bin");
     module::set_var("gallery", "timezone", null);
     module::set_var("gallery", "lock_timeout", 1);
+    module::set_var("gallery", "movie_extract_frame_time", 3);
 
-    module::set_version("gallery", 52);
+    module::set_version("gallery", 53);
   }
 
   static function upgrade($version) {
@@ -735,6 +736,13 @@ class gallery_installer {
         ->execute();
       module::set_version("gallery", $version = 52);
     }
+    
+    if ($version == 52) {
+      // In v53, we added the ability to change the default time used when extracting frames from
+      // movies.  Previously we hard-coded this at 3 seconds, so we use that as the default.
+      module::set_var("gallery", "movie_extract_frame_time", 3);
+      module::set_version("gallery", $version = 53);
+    }
   }
 
   static function uninstall() {
diff --git a/modules/gallery/helpers/graphics.php b/modules/gallery/helpers/graphics.php
index c19fbe6d..c7f87403 100644
--- a/modules/gallery/helpers/graphics.php
+++ b/modules/gallery/helpers/graphics.php
@@ -155,13 +155,27 @@ class graphics_Core {
     try {
       foreach ($ops as $target => $output_file) {
         if ($input_item->is_movie()) {
-          // Convert the movie to a JPG first
+          // Convert the movie filename to a JPG first, delete anything that might already be there
           $output_file = legal_file::change_extension($output_file, "jpg");
-          try {
-            movie::extract_frame($input_file, $output_file);
-          } catch (Exception $e) {
-            // Assuming this is MISSING_FFMPEG for now
-            copy(MODPATH . "gallery/images/missing_movie.jpg", $output_file);
+          unlink($output_file);
+          // Run movie_extract_frame events, which can either:
+          //  - generate an output file, bypassing the ffmpeg-based movie::extract_frame
+          //  - add to the options sent to movie::extract_frame (e.g. change frame extract time,
+          //    add de-interlacing arguments to ffmpeg... see movie helper for more info)
+          // Note that the args are similar to those of the events in gallery_graphics
+          $movie_options_wrapper = new stdClass();
+          $movie_options_wrapper->movie_options = array();
+          module::event("movie_extract_frame", $input_file, $output_file,
+            $movie_options_wrapper, $input_item);
+          // If no output_file generated by events, run movie::extract_frame with movie_options
+          clearstatcache();
+          if (@filesize($output_file) == 0) {
+            try {
+              movie::extract_frame($input_file, $output_file, $movie_options_wrapper->movie_options);
+            } catch (Exception $e) {
+              // Didn't work, likely because of MISSING_FFMPEG - copy missing_movie instead
+              copy(MODPATH . "gallery/images/missing_movie.jpg", $output_file);
+            }
           }
           $working_file = $output_file;
         } else {
diff --git a/modules/gallery/helpers/movie.php b/modules/gallery/helpers/movie.php
index ddc513ea..6d70ab2d 100644
--- a/modules/gallery/helpers/movie.php
+++ b/modules/gallery/helpers/movie.php
@@ -57,7 +57,16 @@ class movie_Core {
     return $form;
   }
 
-  static function extract_frame($input_file, $output_file) {
+  /**
+   * Extract a frame from a movie file.  Valid movie_options are start_time (in seconds),
+   * input_args (extra ffmpeg input args) and output_args (extra ffmpeg output args).  Extra args
+   * are added at the end of the list, so they can override any prior args.
+   *
+   * @param string     $input_file
+   * @param string     $output_file
+   * @param array      $movie_options (optional)
+   */
+   static function extract_frame($input_file, $output_file, $movie_options=NULL) {
     $ffmpeg = movie::find_ffmpeg();
     if (empty($ffmpeg)) {
       throw new Exception("@todo MISSING_FFMPEG");
@@ -65,23 +74,32 @@ class movie_Core {
 
     list($width, $height, $mime_type, $extension, $duration) = movie::get_file_metadata($input_file);
 
-    // extract frame at 0:03, unless movie is shorter than 4 sec.
-    $start_time_arg = ($duration > 4) ? " -ss 00:00:03" : "";
-
-    $cmd = escapeshellcmd($ffmpeg) . " -i " . escapeshellarg($input_file) .
+    if (is_numeric($movie_options["start_time"])) {
+      $start_time = max(0, $movie_options["start_time"]); // ensure it's non-negative
+    } else {
+      $start_time = module::get_var("gallery", "movie_extract_frame_time", 3); // use default
+    }
+    // extract frame at start_time, unless movie is too short
+    $start_time_arg = ($duration >= $start_time + 0.1) ?
+      "-ss " . date("H:i:s", mktime(0,0,$start_time,0,0,0,0)) : "";
+      
+    $input_args = $movie_options["input_args"] ? $movie_options["input_args"] : "";
+    $output_args = $movie_options["output_args"] ? $movie_options["output_args"] : "";
+
+    $cmd = escapeshellcmd($ffmpeg) . " $input_args -i " . escapeshellarg($input_file) .
       " -an $start_time_arg -an -r 1 -vframes 1" .
       " -s {$width}x{$height}" .
-      " -y -f mjpeg " . escapeshellarg($output_file) . " 2>&1";
+      " -y -f mjpeg $output_args " . escapeshellarg($output_file) . " 2>&1";
     exec($cmd, $exec_output, $exec_return);
 
     clearstatcache();  // use $filename parameter when PHP_version is 5.3+
     if (filesize($output_file) == 0 || $exec_return) {
       // Maybe the movie needs the "-threads 1" argument added
       // (see http://sourceforge.net/apps/trac/gallery/ticket/1924)
-      $cmd = escapeshellcmd($ffmpeg) . " -threads 1 -i " . escapeshellarg($input_file) .
+      $cmd = escapeshellcmd($ffmpeg) . " -threads 1 $input_args -i " . escapeshellarg($input_file) .
         " -an $start_time_arg -an -r 1 -vframes 1" .
         " -s {$width}x{$height}" .
-        " -y -f mjpeg " . escapeshellarg($output_file) . " 2>&1";
+        " -y -f mjpeg $output_args " . escapeshellarg($output_file) . " 2>&1";
       exec($cmd, $exec_output, $exec_return);
 
       clearstatcache();
diff --git a/modules/gallery/module.info b/modules/gallery/module.info
index faefd663..64cad0a7 100644
--- a/modules/gallery/module.info
+++ b/modules/gallery/module.info
@@ -1,6 +1,6 @@
 name = "Gallery 3"
 description = "Gallery core application"
-version = 52
+version = 53
 author_name = "Gallery Team"
 author_url = "http://codex.gallery2.org/Gallery:Team"
 info_url = "http://codex.gallery2.org/Gallery3:Modules:gallery"