Fixed .gif related issues (#2494)

* fix-order of operations

* Use ffplay to preview gifs

* typo

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

manim/scene/scene_file_writer.py

@@ -144,7 +144,12 @@ def init_output_directories(self, scene_name):
             if is_gif_format():
                 self.gif_file_path = os.path.join(
                     movie_dir,
-                    add_extension_if_not_present(self.output_name, GIF_FILE_EXTENSION),
+                    add_version_before_extension(
+                        add_extension_if_not_present(
+                            self.output_name,
+                            GIF_FILE_EXTENSION,
+                        ),
+                    ),
                 )
 
             self.partial_movie_directory = guarantee_existence(
@@ -606,7 +611,7 @@ def combine_to_movie(self):
         # determine output path
         movie_file_path = self.movie_file_path
         if is_gif_format() and not config["output_file"]:
-            movie_file_path = str(add_version_before_extension(self.gif_file_path))
+            movie_file_path = self.gif_file_path
         logger.info("Combining to Movie file.")
         self.combine_files(
             partial_movie_files,

manim/utils/file_ops.py

@@ -178,7 +178,10 @@ def open_file(file_path, in_browser=False):
             commands = ["cygstart"]
             file_path = file_path if not in_browser else os.path.dirname(file_path)
         elif current_os == "Darwin":
-            commands = ["open"] if not in_browser else ["open", "-R"]
+            if is_gif_format():
+                commands = ["ffplay", "-loglevel", config["ffmpeg_loglevel"].lower()]
+            else:
+                commands = ["open"] if not in_browser else ["open", "-R"]
         else:
             raise OSError("Unable to identify your operating system...")
         commands.append(file_path)