From 3e3e4de5e9d819658e9d9b39556f38d42b65208d Mon Sep 17 00:00:00 2001
From: Grant Sanderson <grant@3blue1brown.com>
Date: Wed, 8 Feb 2023 20:09:33 -0800
Subject: [PATCH] Add option for gamma correction to SceneFileWriter

---
 manimlib/scene/scene_file_writer.py | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/manimlib/scene/scene_file_writer.py b/manimlib/scene/scene_file_writer.py
index 3b5a32bc..53bbb589 100644
--- a/manimlib/scene/scene_file_writer.py
+++ b/manimlib/scene/scene_file_writer.py
@@ -49,7 +49,8 @@ class SceneFileWriter(object):
         progress_description_len: int = 40,
         video_codec: str = "libx264",
         pixel_format: str = "yuv420p",
-        saturation: float = 1.7
+        saturation: float = 1.7,
+        gamma: float = 1.2,
     ):
         self.scene: Scene = scene
         self.write_to_movie = write_to_movie
@@ -69,6 +70,7 @@ class SceneFileWriter(object):
         self.video_codec = video_codec
         self.pixel_format = pixel_format
         self.saturation = saturation
+        self.gamma = gamma
 
         # State during file writing
         self.writing_process: sp.Popen | None = None
@@ -264,7 +266,7 @@ class SceneFileWriter(object):
             '-pix_fmt', 'rgba',
             '-r', str(fps),  # frames per second
             '-i', '-',  # The input comes from a pipe
-            '-vf', f'eq=saturation={self.saturation},vflip',
+            '-vf', f'vflip,eq=saturation={self.saturation}:gamma={self.gamma}',
             '-an',  # Tells FFMPEG not to expect any audio
             '-loglevel', 'error',
         ]