Add python wrapper for ffmpeg movie maker, and a diffraction pattern movie maker

cmeutils/structure.py

@@ -582,7 +582,17 @@ def diffraction_pattern(
         grid_size=grid_size, output_size=output_size
     )
     with gsd.hoomd.open(gsdfile) as trajectory:
-        for frame in trajectory[start:stop]:
+        if start != stop:
+            for frame in trajectory[start:stop]:
+                system = frame_to_freud_system(
+                    frame=frame, ref_length=ref_length
+                )
+                for view in views:
+                    dp.compute(
+                        system=system, view_orientation=view, reset=False
+                    )
+        else:
+            frame = trajectory[start]
             system = frame_to_freud_system(frame=frame, ref_length=ref_length)
             for view in views:
                 dp.compute(system=system, view_orientation=view, reset=False)

cmeutils/visualize.py

@@ -1,7 +1,14 @@
+import os
+import shutil
+
+import ffmpeg
 import fresnel
 import gsd.hoomd
+import matplotlib
 import numpy as np
 
+from cmeutils.structure import diffraction_pattern
+
 
 class FresnelGSD:
     def __init__(
@@ -434,3 +441,55 @@ def path_trace(self, width=300, height=300, samples=64, light_samples=1):
             samples=samples,
             light_samples=light_samples,
         )
+
+
+def diffraction_pattern_movie(
+    gsdfile,
+    start,
+    stop,
+    stride,
+    views,
+    ref_length,
+    grid_size,
+    output_size,
+    mov_file_name,
+    framerate,
+    clean_up=True,
+):
+    """"""
+    matplotlib.use("Agg")
+    img_path = os.path.join(os.getcwd(), "images/")
+    os.mkdir(img_path)
+    for idx, frame in enumerate(range(start, stop, stride)):
+        dp = diffraction_pattern(
+            gsdfile=gsdfile,
+            views=views,
+            start=frame,
+            stop=frame,
+            ref_length=ref_length,
+            grid_size=grid_size,
+            output_size=output_size,
+        )
+        dp.plot().figure.savefig(os.path.join(img_path, f"{idx}.png"))
+
+    movie_maker(
+        file_dir=img_path,
+        img_file_type="png",
+        mov_file_name=mov_file_name,
+        framerate=framerate,
+    )
+    # Remove dir and images
+    if clean_up:
+        shutil.rmtree(img_path)
+
+
+def movie_maker(
+    file_dir, img_file_type, mov_file_name, pattern_type="glob", framerate=25
+):
+    """"""
+    input_arg = f"{file_dir}*.{img_file_type}"
+    (
+        ffmpeg.input(input_arg, pattern_type=pattern_type, framerate=framerate)
+        .output(mov_file_name)
+        .run()
+    )