An endpoint device outputs frames of test media during a testing procedure. Each frame of test media includes a test pattern. A test module coupled to the endpoint device samples the test pattern and transmits sample data to a media test engine. The media test engine decodes a binary number from the test pattern and then converts the binary number to an integer value that is associated with the corresponding frame. The media test engine then analyzes sequences of these integer values to identify playback errors associated with the endpoint device.