 With B-frames in the video stream, adjacent frames have to be encoded and decoded out-of-order (re-ordered frames).DTS is quite similar to PTS, but instead of just handling sequential frames, it contains the proper time-stamps to tell the decoder when to decode and display the next B-frame (types of frames explained below), ahead of its anchor (P- or I-) frame.Without B-frames in the video, PTS and DTS values are identical.