Apparatus and method of seamless switching between a live dtv decoding and a pvr playback

Abstract

Methods and apparatus for switching between a live video decoding and a recorded playback in a digital video and recording system. A received video data stream is transmitted to a first-in first-out video decoder buffer without first looping the video data stream through a playback buffer. The video data stream is transmitted from the video decoder buffer to a video decoder. If a “pause” command is received, the video data stream is transmitted to a first-in first-out playback buffer, while continuing to transmit the video data stream to the video decoder buffer. Transmission of the video data stream to the video decoder buffer is halted when the video decoder buffer fills up. The last byte of the video data stream that was transmitted to the video decoder buffer is marked. If a “play” command is received, the video data stored in the video decoder buffer is transmitted to the video decoder. The video data stored in the playback buffer is transmitted to the video decoder buffer starting at a point immediately after the data element that was marked previously.

1 . A method of switching between a live video decoding and a recorded playback in a digital video and recording system, comprising: 
 (a) receiving a stream of digital video data;    (b) transmitting the received video data stream to a video decoder without first looping the video data stream through a playback buffer;    (c) decoding the video data with the video decoder;    (d) if a command is received that requires the video data stream to be looped through a playback buffer prior to decoding, performing steps of: 
 (e) transmitting the video data stream to a first-in first-out playback buffer and storing the video data in the buffer;  
 (f) marking a data element of the video data stream that was last transmitted to the video decoder;  
 (g) if a command requiring decoding of the video data stream to resume is received, performing steps of: 
 (h) transmitting the video data stored in the playback buffer to the video decoder; and  
 (i) decoding the video data received from the playback buffer starting at one of the data element marked in marking step (f) and a point immediately after the data element marked in marking step (f).  
 
   
   
   
       2 . The method of  claim 1  further comprising: if a command that requires the video data stream to be looped through a playback buffer prior to further decoding is received pursuant to step (d), performing a step (j) of halting transmission of the received video data stream to the video decoder.  
   
   
       3 . The method of  claim 2  wherein halting step (j) comprises immediately halting transmission of the received video data stream to the video decoder.  
   
   
       4 . The method of  claim 2  wherein halting step (j) comprises halting transmission of the received video data stream to the video decoder at a next transport packet boundary.  
   
   
       5 . The method of  claim 1  wherein marking step (f) comprises saving an address that points to a data byte of the video data stream that was last transmitted to the video decoder.  
   
   
       6 . The method of  claim 1  wherein marking step (f) comprises marking a transport record offset of a data element of the video data stream that was last transmitted to the video decoder.  
   
   
       7 . The method of  claim 6  wherein marking step (f) comprises marking a transport record offset of a data byte of the video data stream that was last transmitted to the video decoder.  
   
   
       8 . The method of  claim 6  wherein marking step (f) comprises storing the transport record offset in an offset data register.  
   
   
       9 . The method of  claim 1  wherein the command that requires the video data stream to be looped through a playback buffer prior to further decoding is one of a pause command, a slow motion command, a record command and a normal-playback command.  
   
   
       10 . The method of  claim 1  wherein once a command requiring decoding of the video stream to resume is received pursuant to step (g), and transmitting step (h) and decoding step (i) are initiated, subsequent decoding of the video data stream is accomplished by sending the video data stream through the playback buffer before sending the video data stream to the video decoder.  
   
   
       11 . The method of  claim 10  wherein the digital video and recording system comprises a digital television system and wherein the method further comprises: 
 (j) if a channel-change command is received, repeating steps (a)-(i) for the video data stream of the new channel.    
   
   
       12 . The method of  claim 1  further comprising a step (j), performed after transmitting step (h) and prior to decoding step (i), of updating a system time clock using a timing reference element embedded in the video data stream.  
   
   
       13 . A method of switching between a live video decoding and a recorded playback in a digital video and recording system, comprising: 
 (a) receiving a digital video data stream in a first data path;    (b) decoding the video data received in the first data path;    (c) receiving a first PVR command;    (d) receiving the video data stream in a second data path;    (e) marking a data element of the video data stream in the first data path when the first PVR command is received;    (f) comparing the marked data element in the first data path with data elements in the second data path; and    (g) if a data element in the second data path matches the marked data element in the first data path, decoding the video data received in the second data path starting at the matching data element.    
   
   
       14 . The method of  claim 13  wherein the first PVR command is one of at least a pause, a record, and a slow motion.  
   
   
       15 . The method of  claim 13  further comprising receiving a second PVR command.  
   
   
       16 . The method of  claim 15  wherein the second PVR command is a play command.  
   
   
       17 . The method of  claim 13  further comprising halting receipt of the video data stream in the first data path after at least one of the first PVR command and the second PVR command is received.  
   
   
       18 . The method of  claim 13  wherein marking step (e) comprises saving an address that points to a data byte of the video data stream in the first data path that was last transmitted to a video decoder.  
   
   
       19 . The method of  claim 13  wherein marking step (e) comprises marking a transport record offset of a data element of the video data stream in the first data path that was last transmitted to a video decoder.  
   
   
       20 . The method of  claim 13  wherein marking step (e) comprises marking a transport record offset of a data byte of the video data stream in the first data path that was last transmitted to a video decoder.  
   
   
       21 . The method of  claim 19  wherein marking step (e) comprises storing the transport record offset in an offset data register.  
   
   
       22 . The method of  claim 13  wherein the second data path comprises at least one playback buffer.  
   
   
       23 . The method of  claim 13  further comprising steps of: 
 (h) receiving a channel-change command; and    (i) decoding the video data received in the first data path after the change-channel command is received.