Trick mode using dummy bidirectional predictive pictures
View Patent ↗The invention concerns a method ( 200 ) or ( 300 ) and system ( 100 ) for performing a trick mode on a video signal containing a plurality of progressively scanned original pictures. The method ( 200 ) includes the steps of: selectively repeating ( 214 ) at least one of the original pictures to convert the video signal to a trick mode video signal in response to a trick mode command; and the step of selectively inserting ( 216 ) at least one dummy bidirectional predictive picture in the trick mode video signal. In addition, the method ( 300 ) can include the step of monitoring ( 316 ) the trick mode video signal so that the dummy bidirectional predictive picture is selectively inserted when the bit rate exceeds a predetermined threshold. Certain pictures in the trick mode video signal can also be modified ( 220 ) ( 328 ) to reflect an intended display order.
1. A method of performing a trick mode on a video signal containing a plurality of progressively scanned original pictures, characterized by the steps of:
in response to a trick mode command,
selectively inserting at least one dummy bidirectional predictive picture in the video signal to form a trick mode video signal;
monitoring the trick mode video signal; and
in response to a bit rate of the trick mode video signal exceeding a predetermined threshold, adjusting a number of said dummy bidirectional predictive pictures selectively inserted in the trick mode video signal to control the bit rate of the trick mode video signal.
2. The method according to claim 1 , wherein each of the plurality of original pictures contains a display indicator and the method further comprises the step of selectively modifying the display indicator of at least a portion of the plurality of original pictures to reflect an intended display order when an original picture is repeated or when a dummy bidirectional predictive picture is inserted in the trick mode video signal.
3. The method according to claim 2 , wherein the display indicator is a temporal reference field.
4. The method according to claim 3 , wherein each temporal reference field has an integer value and the step of selectively modifying the temporal reference field of at least a portion of the plurality of original pictures comprises the step of incrementally increasing by one the integer value of the temporal reference field each time an original picture is repeated and each time a dummy bidirectional predictive picture is inserted in the trick mode video signal.
5. The method according to claim 1 , wherein each dummy bidirectional predictive picture is predicted from a reference picture.
6. The method according to claim 1 , wherein each dummy bidirectional predictive picture is a one-directional predictive picture.
7. The method according to claim 5 , wherein the reference picture is an intra picture.
8. The method according to claim 5 , wherein the reference picture is a predictive picture.
9. The method according to claim 1 , wherein at least a portion of the trick mode video signal is decoded by a remote decoder.
10. In a remote decoder arrangement, a method of performing a trick mode on a video signal containing a plurality of progressively scanned original pictures, wherein each of the plurality of progressively scanned original pictures contains a display indicator, comprising the steps of:
in response to a trick mode command, selectively repeating at least one of the original pictures to convert the video signal to a trick mode video signal;
monitoring a bit rate of the trick mode video signal;
selectively inserting at least one dummy bidirectional predictive picture in the trick mode video signal if the bit rate exceeds a predetermined threshold; and
selectively modifying the display indicator of at least a portion of the plurality of original pictures to reflect an intended display order when an original picture is repeated or when a dummy bidirectional predictive picture is inserted in the trick mode video signal.
11. A system for performing a trick mode on a video signal containing a plurality of progressively scanned original pictures, comprising:
a controller for reading data from a storage medium and generating the video signal containing the plurality of original pictures; and
a processor, wherein the processor is programmed to:
in response to a trick mode command,
selectively insert at least one dummy bidirectional predictive picture in the trick mode video signal to form a trick mode video signal;
monitor the trick mode video signal; and
in response to a bit rate of the trick mode video signal exceeding a predetermined threshold, adjust a number of said dummy bidirectional predictive pictures selectively inserted in the trick mode video signal to control the bit rate of the trick mode video signal.
12. The system according to claim 11 , wherein each of the plurality of original pictures contains a display indicator and the video processor is further programmed to modify selectively the display indicator of at least a portion of the plurality of original pictures to reflect an intended display order when an original picture is repeated and when a dummy bidirectional predictive picture is inserted in the trick mode video signal.
13. The system according to claim 12 , wherein the display indicator is a temporal reference field.
14. The system according to claim 13 , wherein each temporal reference field has an integer value and the step of selectively modifying the temporal reference field of at least a portion of the plurality of original pictures comprises the step of incrementally increasing by one the integer value of the temporal reference field each time an original picture is repeated or when a dummy bidirectional predictive picture is inserted in the trick mode video signal.
15. The system according to claim 11 , wherein each dummy bidirectional predictive picture is predicted from a reference picture.
16. The system according to claim 11 , wherein each dummy bidirectional predictive picture is a one-directional predictive picture.
17. The system according to claim 15 , wherein the reference picture is an intra picture.
18. The system according to claim 15 , wherein the reference picture is a predictive picture.
19. The system according to claim 11 , further comprising a remote decoder for remotely decoding at least a portion of the trick mode video signal.
20. A remote decoder system for performing a trick mode on a video signal containing a plurality of progressively scanned original pictures, wherein each of the plurality of progressively scanned original pictures contains a display indicator, comprising:
a controller for reading data from a storage medium and generating the video signal containing the plurality of original pictures; and
a processor, wherein the processor is programmed to:
in response to a trick mode command, selectively repeat at least one of the original pictures to convert the video signal to a trick mode video signal;
monitor a bit rate of the trick mode video signal;
selectively insert at least one dummy bidirectional predictive picture in the trick mode video signal if the bit rate exceeds a predetermined threshold; and
selectively modify the display indicator of at least a portion of the plurality of original pictures to reflect an intended display order when an original picture is repeated or when a dummy bidirectional predictive picture is inserted in the trick mode video signal.
21. A system for performing a trick mode on a video signal containing a plurality of progressively scanned original pictures, comprising:
a controller for reading data from a storage medium and generating the video signal containing the plurality of original pictures; and
a video processor programmed to:
receive a trick mode command;
selectively insert at least one dummy bidirectional predictive picture in the video signal to form a trick mode video signal;
monitor the trick mode video signal; and
in response to a bit rate of the trick mode video signal exceeding a predetermined threshold, adjust a number of said dummy bidirectional predictive pictures selectively inserted in the trick mode video signal to control the bit rate of the trick mode video signal.
22. The system according to claim 21 , wherein each of the plurality of original pictures contains a display indicator and the processor is further programmed to selectively modify the display indicator of at least a portion of the plurality of original pictures to reflect an intended display order each time the processor performs the selectively inserting step.
23. The system according to claim 22 , wherein the display indicator is a temporal reference field.
24. The system according to claim 22 , wherein each temporal reference field has an integer value and the processor is further programmed to selectively modify the temporal reference field of at least a portion of the plurality of original pictures by incrementally increasing by one the integer value of the temporal reference field each time the processor performs the selectively inserting step.
25. The system according to claim 21 , wherein each dummy bidirectional predictive picture is a one-directional predictive picture.
26. The system according to claim 21 , further comprising a remote decoder, wherein the remote decoder decodes at least a portion of the trick mode video signal.