A disk player including a control module, a navigator, a de-multiplexer, a decoder, a text recognition module and a data comparing module is provided. The navigator reads an audio and video (AV) data according to a display control signal outputted by the control module. An audio decoding signal, a video decoding signal, a caption image and a display time information corresponding to the caption image are decoded by the decoder according to an audio data, a video data, and a sub-picture unit (SPU), respectively, divided from the AV data by the de-multiplexer. The text recognition module recognizes the caption image as a first text data. The data comparing module receives a second text data provided by a user or from a database and compares the first text data with the second text data to export an analysis result or another display time information corresponding to the second text data.