Smooth scanning presenter
View Patent ↗Described herein is a technology for the presentation of digital video. One implementation, described herein, smoothly presents variable-speed scanning of a compressed digital video stream—for example, a MPEG video stream. One implementation, described herein, smooth scanning (e.g., fast-forward and fast-rewind) video is produced by selectively displaying certain types of frames of a Group-of-Pictures (GOP). The scope of the present invention is pointed out in the appending claims.
1. A computer-readable medium encoded with computer-executable instructions that, when executed by a computer, configure the computer to perform operations comprising:
dropping frames of a Group-of-Pictures (GOP) of a digital video, wherein the dropping includes:
dropping a first frame that is parent-way dependent such that a second frame is child-way dependent on the first frame;
dropping the second frame; and
dropping any other frames that are child-way dependent on the first frame; and
displaying remaining frames of the GOP.
2. The medium as recited in claim 1 , wherein the dropped frames are selected from a group consisting of B-frames and P-frames.
3. The medium as recited in claim 1 , wherein the method further comprises obtaining one or more GOPs of a MPEG digital video.
4. The medium as recited in claim 1 , the operations further comprising:
obtaining a variable scan-rate indicator; and
varying the dropping in response to the indicator.
5. The medium as recited in claim 1 , the operations further comprising:
obtaining a variable scan-rate indicator; and
determining a ratio of non-presentation frames to presentation frames relative to the variable scan-rate indicator, wherein the dropping of frames is based upon the ratio.
6. A presentation device comprising:
an audio/visual output; and
the medium as recited in claim 1 .
7. A computer-readable medium encoded with computer-executable instructions that, when executed by a computer, configure the computer to perform operations comprising:
selecting frames of a Group-of-Pictures (GOP) of a digital video for presentation and frames of the GOP for non-presentation, wherein the selecting frames for non-presentation includes:
first, selecting frames that are not capable of acting as parent way dependent frames; and
second, selecting a particular frame that is capable of acting as a parent way dependent frame but for which, during the first selecting, all child frames that depend on the particular frame were selected for non-presentation, such that the particular frame and any frames that depend from the particular frame are each selected for non-presentation; and
presenting the selected presentation frames of the GOP.
8. The medium as recited in claim 7 , wherein the selected presentation frames of the GOP comprise more than one frame.
9. The medium as recited in claim 7 , the operations further comprising obtaining one or more GOPs of a MPEG digital video.
10. The medium as recited in claim 7 , wherein the presenting comprises sending the selected presentation frames of the GOP over a communications medium.
11. The medium as recited in claim 7 , the operations further comprising:
obtaining a variable scan-rate indicator; and
varying the selecting in response to such the indicator.
12. The medium as recited in claim 7 , the operations further comprising:
obtaining a variable scan-rate indicator; and
determining a ratio of non-presentation frames to presentation frames relative to the variable scan-rate indicator, wherein the selecting of frames is based upon the ratio.
13. A presentation device comprising:
an audio/visual output; and
the medium as recited in claim 7 .
14. A method comprising:
selecting, by a video presentation device, frames of a Group-of-Pictures (GOP) of a digital video for presentation and frames of the GOP for non-presentation, wherein the selected non-presentation frames comprise a frame that is parent-way dependent, and wherein for each child-way dependent frame selected for presentation, also selecting for presentation each parent-way dependent frame from which the child-way dependent frames selected for presentation depend; and
presenting, by the video presentation device, the selected presentation frames of the GOP.
15. The method as recited in claim 14 further comprising obtaining one or more GOPs of a digital video.
16. The method as recited in claim 14 further comprising:
obtaining a variable scan-rate indicator; and
varying the selecting in response to the indicator.
17. The method as recited in claim 14 , further comprising:
obtaining a variable scan-rate indicator; and
determining a ratio of non-presentation frames to presentation frames relative to the variable scan-rate indicator, wherein the selecting frames is based upon such the ratio.
18. A presentation device configured to perform the method as recited in claim 14 .