System and method for trick play of highly compressed video data
View Patent ↗A system for providing trickplay functionality—such as pause, instant replay, rewind, fast forward, etc—for very highly compressed video/audio data stream. Depending on the trickplay functionality, the system configures the duration of playback before a jump, the decoding speed required, the number of pictures to display per second, and the distance between jumps. The system may comprise a decoder, a picture rate controller and a display.
1. A method of displaying a video bitstream comprising the steps of:
receiving a compressed video bitstream wherein the video bitstream includes a plurality of frames;
decoding the plurality of frames to provide uncompressed frames;
selecting a trickplay video display mode;
selecting a first sequence of uncompressed frames to be displayed prior to displaying a second sequence of uncompressed frames depending on the trickplay video display mode, wherein an interval between a last frame of the first sequence and a first frame of the second sequence is greater than an interval between any two consecutive frames in the first sequence; and
displaying the selected sequence of uncompressed frames in the trickplay video display mode.
2. The method of claim 1 , wherein the step of selecting a first sequence of uncompressed frames further comprises the step of determining a rate of frames to be displayed.
3. The method of claim 2 , wherein the rate of frames to be displayed depends on the trickplay mode.
4. The method of claim 1 , wherein the step of selecting a first sequence of uncompressed frames further comprises the steps of determining a duration of play before jumping to the second sequence of uncompressed frames; and determining a length between jumps within the video bitstream.
5. The method of claim 4 , wherein the duration of play and the length between jumps depend on the trickplay mode.
6. The method of claim 4 , wherein the length between jumps is between about one to about thirty seconds.
7. The method of claim 1 , wherein the video bitstream is in Advanced Video Coding or H.264 or MPEG4 Part 10 compressed video format.
8. The method of claim 1 further comprising jumping to the subsequent set of frames.
9. The method of claim 1 , wherein the plurality of frames is decoded two to four times a normal play time.
10. The method of claim 1 , wherein the group of frames includes intra frames, predicted frames, and bidirectionally predicted frames.
11. The method of claim 1 , wherein the trickplay mode comprises displaying the uncompressed frames of the video bitstream at a rate accelerated above the normal play rate.
12. The method of claim 1 , wherein the trickplay mode comprises displaying the frames of the video stream so that the video appears to be in reverse.
13. The method of claim 12 , further comprising jumping to a previous frame and displaying subsequent frames.
14. A system of displaying a video bitstream, comprising:
a decoder to receive compressed frames and to decode the compressed frames;
a trickplay controller connected to the decoder to select a first sequence of decoded frames to be displayed prior to displaying a second sequence of decoded frames depending on a trickplay mode, wherein an interval between a last frame of the first sequence and a first frame of the second sequence is greater than an interval between any two consecutive frames in the first sequence; and
a display connected to the trickplay controller to display the selected sequence of decoded frames in the trickplay mode.
15. The system of claim 14 , the trickplay controller determines a rate of frames to be displayed.
16. The system of claim 15 , wherein the rate of frames to be displayed depends on the trickplay mode.
17. The system of claim 14 , wherein the trickplay controller determines (i) a duration of play before jumping to the second sequence of decoded frames, and (ii) a length between jumps within the video bitstream.
18. The system of claim 17 , wherein the duration of play and the length between jumps depend on the trickplay mode.
19. The system of claim 17 , wherein the length between jumps depends on spacing between intra frames.
20. The system of claim 17 , wherein the length between jumps is between about one to about thirty seconds.