According to examples, an apparatus may include a processor and a non-transitory computer-readable medium on which may be stored instructions that when executed by the processor, may cause the processor to access a data file. In some examples, the data file may include a frame rate of a video and information regarding driver functions associated with driver threads executing during playback of the video. In some examples, the processor may determine whether the frame rate is less than a predefined frame rate. When frame rate is determined to be less than the predefined frame rate, the processor may determine whether an execution time of a first driver function exceeds a first predefined length of time. In some examples, the processor may output a first error message that includes information associated with the first driver function.