1. A method for reducing blurriness of video data, the method comprising: receiving video data at a decoder; decoding a picture unit derived from the video data, the decoded picture unit corresponding to a picture unit stored in a display buffer; determining, at a filter operatively coupled to the decoder, whether to update a display buffer operatively coupled to the decoder and a display device, based, at least in part, on a comparison of a quantization step size of the decoded picture unit with a quantization step size of its corresponding picture unit; and updating, by the filter, the display buffer with the decoded picture unit when the size of the quantization step of the decoded picture unit is smaller than or equal to the size of the quantization step of the corresponding picture unit stored in the display buffer.