Video decoding method

Abstract

Video decoding methods are disclosed. The video decoding method comprises providing a historical syntax element of a previous video frame, receiving a current video frame to determine a current syntax element therein, determining whether a high-level syntax error is present in the current syntax element, wherein upon detection of the high-level syntax error, determining a replacement syntax element according to the historical syntax element to replace the current syntax element, decoding the replaced current video frame to detect whether there is a missing video frame or undecodable video frame, and upon detection of the missing video frame or undecodable video frame, generating a replacement video frame to substitute for the missing or the undecodable video frame.

1 . A video decoding method, comprising:
 providing a historical syntax element of a previous video frame;   receiving a current video frame to determine a current syntax element therein;   determining whether a high-level syntax error is present in the current syntax element; and   upon detection of the high-level syntax error, determining a replacement syntax element according to the historical syntax element to replace the current syntax element,   wherein the high-level syntax error is a syntax error above a Macroblock layer.   
   
   
       2 . The video decoding method of  claim 1 , wherein the high-level syntax error is a picture-layer syntax error. 
   
   
       3 . The video decoding method of  claim 1 , wherein the previous video frame is in terms of the video decoding order. 
   
   
       4 . The video decoding method of  claim 1 , wherein the determination of the replacement syntax element comprises using the historical syntax element to estimate the correct syntax element and assigning the estimated result to be the replacement syntax element. 
   
   
       5 . The video decoding method of  claim 1 , further comprising:
 decoding the current video frame to detect whether there is a missing video frame or undecodable video frame; and   upon detection of the missing video frame or undecodable video frame, generating a replacement video frame to substitute for the missing or the undecodable video frame.   
   
   
       6 . The video decoding method of  claim 5 , wherein the generation of the replacement video frame comprises assigning a closest decodable video frame in a display order to be the replacement video frame. 
   
   
       7 . The video decoding method of  claim 5 , wherein the generation of the replacement video frame comprises generating a replacement video frame according to motion vectors of a decodable video frame and a temporal distance between the current video frame and the decodable video frame. 
   
   
       8 . A video decoding method capable of detecting a missing video frame, comprising:
 a demultiplexer receiving a Transport Stream to recover video Packetized Elementary Stream (PES) to determine a presentation time stamp (PTS) and a decoding time stamp (DTS) in a PES header of the PES;   a decoder retrieving a video frame from the video PES to determine temporal reference of the video frame; and   a controller receiving the PTS, the DTS, and the temporal reference to determine whether there is a missing video frame.   
   
   
       9 . The method of  claim 8 , further comprising:
 upon detection of the missing video frame, generating a replacement video frame to substitute for the missing video frame.   
   
   
       10 . The method of  claim 9 , wherein the generation of the replacement video frame comprises assigning a closest decodable video frame in a display order to be the replacement video frame. 
   
   
       11 . The method of  claim 9 , wherein the generation of the replacement video frame comprises generating a replacement video frame according to motion vectors of a decodable video frame and a temporal distance between the current video frame and the decodable video frame. 
   
   
       12 . A video decoding method, comprising:
 decoding a current video frame to detect a missing video frame or an undecodable video frame; and   in response to detecting the missing video frame or undecodable video frame, replacing the missing video frame or undecodable video frame with a closest decodable video frame in display order.   
   
   
       13 . The video decoding method of  claim 12 , further comprising:
 providing a historical syntax element of a previous video frame;   receiving the current video frame to determine a current syntax element therein;   determining whether a high-level syntax error is present in the current syntax element; and   upon detection of the high-level syntax error, determining a replaced syntax element according to the historical syntax element to replace the current syntax element,   wherein the high-level syntax error is a syntax error above a Macroblock layer.   
   
   
       14 . The video decoding method of  claim 12 , further comprising:
 a demultiplexer receiving a Transport Stream to recover video Packetized Elementary Stream (PES) to determine a presentation time stamp (PTS) and a decoding time stamp (DTS) in a PES header of the PES;   a decoder retrieving the current video frame from the video PES to determine temporal reference of the video frame; and   a controller receiving the PTS, the DTS, and the temporal reference to determine whether there is a missed video frame.   
   
   
       15 . A video decoding method, comprising:
 decoding a current video frame to detect a missing video frame or an undecodable video frame;   upon detection of the missing video frame or undecodable video frame, generating a replacement video frame according to motion vectors of a decodable video frame and a temporal distance between the current video frame and the decodable video frame; and   in response to detecting the missing video frame or undecodable video frame, replacing the missing video frame or undecodable video frame with the replacement video frame.   
   
   
       16 . The video decoding method of  claim 15 , wherein when the missing video frame or undecodable video frame is a reference frame with a dependent B-frame, the replacement video frame comprises only forward motion vectors, the decodable video frame is a preceding non-reference frame in display order, and the generation comprises extrapolating motion vectors of the preceding non-reference frame and another preceding video frame according to the temporal distance to generate the forward motion vectors of the replacement video frame. 
   
   
       17 . The video decoding method of  claim 15 , wherein when the missing video frame or undecodable video frame is a reference frame with reference to a decodable reference frame, the replacement video frame comprises only forward motion vectors, the decodable video frame is a preceding decodable reference frame in display order, and the generation comprises extrapolating motion vectors of the preceding decodable reference frame according to the temporal distance to generate the forward motion vectors of the replacement video frames. 
   
   
       18 . The video decoding method of  claim 15 , wherein when the missing video frame or undecodable video frame is a non-reference frame with a decodable reference frame, the replacement video frame comprises forward and backward motion vectors, and the generation comprises proportionating motion vectors of backward decodable reference frame of the missing video frame or undecodable non-reference frame according to the temporal distances between the preceding decodable reference frame and the undecodable video frame and between the succeeding decodable reference frame and the undecodable video frame, to generate the forward and backward motion vectors of the replacement video frame. 
   
   
       19 . The video decoding method of  claim 15 , further comprising:
 providing a historical syntax element of a previous video frame;   receiving the current video frame to determine a current syntax element therein;   determining whether a high-level syntax error is present in the current syntax element; and   upon detection of the high-level syntax error, determining a replaced syntax element according to the historical syntax element to replace the current syntax element,   wherein the high-level syntax error is a syntax error above a Macroblock layer.   
   
   
       20 . The video decoding method of  claim 15 , further comprising:
 a demultiplexer receiving a Transport Stream to recover video Packetized Elementary Stream (PES) to determine a presentation time stamp (PTS) and a decoding time stamp (DTS) in a PES header of the PES;   a decoder retrieving the current video frame from the video PES to determine temporal reference of the video frame; and   a controller receiving the PTS, the DTS, and the temporal reference to determine whether there is a missed video frame.