added frame rate functionality

tkvideo/tkvideo.py

@@ -10,6 +10,7 @@ try:
 except ImportError:
     import tkinter as tk  # for Python3
 import threading
+from time import perf_counter, sleep
 import imageio
 from PIL import Image, ImageTk
 
@@ -28,15 +29,19 @@ class tkvideo():
         :param size:
             Changes the video's dimensions (2-tuple, 
             default is 640x360) 
+        :param hz:
+            Sets the video's frame rate (float, 
+            default 0 is unchecked) 
     
     """
-    def __init__(self, path, label, loop = 0, size = (640,360)):
+    def __init__(self, path, label, loop = 0, size = (640,360), hz = 0):
         self.path = path
         self.label = label
         self.loop = loop
         self.size = size
+        self.hz = hz
     
-    def load(self, path, label, loop):
+    def load(self, path, label, loop, hz):
         """
             Loads the video's frames recursively onto the selected label widget's image parameter.
             Loop parameter controls whether the function will run in an infinite loop
@@ -44,23 +49,44 @@ class tkvideo():
         """
         frame_data = imageio.get_reader(path)
 
+        if hz > 0:
+            frame_duration = float(1 / hz)
+        else:
+            frame_duration = float(0)
+
         if loop == 1:
             while True:
+                before = perf_counter()
                 for image in frame_data.iter_data():
                     frame_image = ImageTk.PhotoImage(Image.fromarray(image).resize(self.size))
                     label.config(image=frame_image)
                     label.image = frame_image
+
+                    diff = frame_duration + before
+                    after = perf_counter()
+                    diff = diff - after 
+                    if diff > 0:
+                        sleep(diff)
+                    before = perf_counter()
         else:
+            before = perf_counter()
             for image in frame_data.iter_data():
                     frame_image = ImageTk.PhotoImage(Image.fromarray(image).resize(self.size))
                     label.config(image=frame_image)
                     label.image = frame_image
 
+                    diff = frame_duration + before
+                    after = perf_counter()
+                    diff = diff - after 
+                    if diff > 0:
+                        sleep(diff)
+                    before = perf_counter()
+
     def play(self):
         """
             Creates and starts a thread as a daemon that plays the video by rapidly going through
             the video's frames.
         """
-        thread = threading.Thread(target=self.load, args=(self.path, self.label, self.loop))
+        thread = threading.Thread(target=self.load, args=(self.path, self.label, self.loop, self.hz))
         thread.daemon = 1
         thread.start()