TODO

x get current frame as bitmap
  - in OpenGL via glReadPixels:
    http://stackoverflow.com/questions/3310990/taking-screenshot-of-android-opengl
    https://github.com/google/grafika/blob/master/src/com/android/grafika/ReadPixelsActivity.java
    https://github.com/google/grafika/blob/master/src/com/android/grafika/gles/EglSurfaceBase.java

x video playlist as datasource abstraction that can chain videos
  Had it already implemented but removed it because playlist handling can be implemented in an
  application when needed, it's outside the scope of this library.

x MPEG-DASH MPD parser

x DASH playlist (MPD parser + playlist)
  Not using the public playlist approach, but the DashMediaExtractor internally takes care of the segments.

x DASH stream adaptation