1 files changed, 62 insertions, 0 deletions
diff --git a/catapult/telemetry/telemetry/internal/image_processing/frame_generator.py b/catapult/telemetry/telemetry/internal/image_processing/frame_generator.py
new file mode 100644
index 00000000..b701418e
--- /dev/null
+++ b/catapult/telemetry/telemetry/internal/image_processing/frame_generator.py
@@ -0,0 +1,62 @@
+# Copyright 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import abc
+
+
+class FrameReadError(Exception):
+  pass
+
+
+class FrameGenerator(object):
+  """ Defines an interface for reading input frames.
+
+  Attributes:
+    _generator: A reference to the created generator.
+  """
+  __metaclass__ = abc.ABCMeta
+
+  def __init__(self):
+    """ Initializes the FrameGenerator object. """
+    self._generator = self._CreateGenerator()
+
+  @abc.abstractmethod
+  def _CreateGenerator(self):
+    """ Creates a new generator.
+
+    Implemented in derived classes.
+
+    Raises:
+      FrameReadError: A error occurred in reading the frame.
+    """
+    raise NotImplementedError
+
+  @property
+  def Generator(self):
+    """ Returns:
+          A reference to the created generator.
+    """
+    return self._generator
+
+  @abc.abstractproperty
+  def CurrentTimestamp(self):
+    """ Returns:
+          float, The timestamp of the current frame in milliseconds.
+    """
+    raise NotImplementedError
+
+  @abc.abstractproperty
+  def CurrentFrameNumber(self):
+    """ Returns:
+          int, The frame index of the current frame.
+    """
+    raise NotImplementedError
+
+  @abc.abstractproperty
+  def Dimensions(self):
+    """ Returns:
+          The dimensions of the frame sequence as a tuple int (width, height).
+          This value should be constant across frames.
+    """
+    raise NotImplementedError