Add documentation

README.md

@@ -0,0 +1,32 @@
+# ffmpeg-python: Powerfully simple A/V routing with Python
+
+FFmpeg is extremely powerful, but its command-line interface gets really complicated really quickly - especially when working with signal graphs and doing anything more than trivial.
+
+Take for example a signal graph that looks like this:
+![Signal graph](https://raw.githubusercontent.com/kkroening/ffmpeg-python/master/doc/graph1.png)
+
+The corresponding command-line arguments are pretty gnarly:
+```
+ffmpeg -i input.mp4 -filter_complex "[0]trim=start_frame=10:end_frame=20,setpts=PTS-STARTPTS[v0];[0]trim=start_frame=30:end_frame=40,setpts=PTS-STARTPTS[v1];[0]trim=start_frame=50:end_frame=60,setpts=PTS-STARTPTS[v2];[v0][v1][v2]concat=n=3[v3]" -map [v3] output.mp4
+```
+
+Maybe this looks great to you, but if you haven't worked with FFmpeg before, this probably looks pretty alien.
+
+If you're like me and find Python to be powerful and readable, it's easy with `ffmpeg-python`:
+```
+import ffmpeg
+
+in_file = ffmpeg.file_input('input.mp4')
+joined = ffmpeg.concat(
+    ffmpeg.trim(in_file, start_frame=10, end_frame=20),
+    ffmpeg.trim(in_file, start_frame=30, end_frame=40),
+    ffmpeg.trim(in_file, start_frame=50, end_frame=60)
+)
+out = ffmpeg.file_output(joined, 'output.mp4')
+out.run()
+```
+
+`ffmpeg-python` takes care of running `ffmpeg` with the command-line arguments that correspond to the above filter diagram, and it's easy to what's going on and make changes as needed.
+
+Real-world signal graphs can get a heck of a lot more complex, and `ffmpeg-python` doesn't care.
+

ffmpeg.py

@@ -5,6 +5,7 @@ import hashlib
 import json
 import operator
 import subprocess
+import sys
 
 
 def _create_root_node(node_class, *args, **kwargs):
@@ -27,13 +28,13 @@ class _Node(object):
 
     @classmethod
     def _add_operator(cls, node_class):
-        if getattr(node_class, 'STATIC', False):
+        if not getattr(node_class, 'STATIC', False):
+            def func(self, *args, **kwargs):
+                return _create_child_node(node_class, self, *args, **kwargs)
+        else:
             @classmethod
             def func(cls2, *args, **kwargs):
                 return _create_root_node(node_class, *args, **kwargs)
-        else:
-            def func(self, *args, **kwargs):
-                return _create_child_node(node_class, self, *args, **kwargs)
         setattr(cls, node_class.NAME, func)
 
     @classmethod
@@ -233,13 +234,14 @@ NODE_CLASSES = [
 
 _Node._add_operators(NODE_CLASSES)
 
-
-for node_class in NODE_CLASSES:
-    if getattr(node_class, 'STATIC', False):
+_module = sys.modules[__name__]
+for _node_class in NODE_CLASSES:
+    if getattr(_node_class, 'STATIC', False):
         func = _create_root_node
     else:
         func = _create_child_node
-    globals()[node_class.NAME] = partial(func, node_class)
+    func = partial(func, _node_class)
+    setattr(_module, _node_class.NAME, func)
 
 
 def get_args(node):