Method and apparatus for clipping video segments from an audiovisual file

• US 6,285,361 B1
• Filed: 10/09/1997
• Issued: 09/04/2001
• Est. Priority Date: 11/15/1996
• Status: Expired due to Term

• Current Assignee: OT IP SUB, LLC
• Original Assignee: FutureTel, Inc.
• Inventors: Brewer, Eric T., Palfreyman, Andrew, Gilley, Thomas S.
• Primary Examiner(s): Lee, Michael
• Application Number:
  US08/948,352
• Time in Patent Office: 1,426 Days
• Field of Search: G06/F.300, 348/441, 348/442, 348/443, 348/444, 348/445, 348/446, 348/448, 348/575, 348/384, 348/400, 348/401, 348/402, 348/409, 348/415, 348/394, 348/395, 345/328, 345/302, 345/440, 345/473, 707/10, 707/102, 707/104, 707/1, 386/109, 386/52, 386/111, 386/64, 386/112, 386/27
• US Class Current: 715/723
• CPC Class Codes: G11B 27/036 Insert-editing

Abstract

Disclosed is a method for clipping a segment from a video file having a multiplicity of video frames. Preferably, at least some of the frames in the video file are encoded as predicted frames. The method includes selecting a mark-in location in the video file that defines the beginning of the clipped segment. A mark-out location defining the end of the clipped segment is also selected in the video file. Once the mark-in and mark-out locations are selected, the method decodes a first frame associated with one of the mark-in location and the mark-out location. The first frame is preferably a predictive frame that has an associated first format. The first frame is then re-encoded into a second format and stored. The method then proceeds to create a clipped segment that includes the re-encoded first frame.

Claims

1. A method for clipping a segment from a video file having a multiplicity of video frames, wherein at least some of the frames are encoded as predicted frames, the method comprising the steps of:

selecting a mark-in location in the video file, the mark-in location defining the beginning of the clipped segment;

selecting a mark-out location in the video file, the mark-out location defining the end of the clipped segment;

decoding a first frame associated with one of the mark-in location and the mark-out location, the first frame being a predictive frame having an associated first format;

re-encoding the decoded first frame into a second format;

storing the re-encoded first frame; and

creating a clipped segment that includes the re-encoded first frame.

2. A method for clipping a segment from a video file as recited in claim 1, wherein the clipped segment has a size that corresponds to the number of frames from the mark-in location and extending to the mark-out location.

3. A method for clipping a segment from a video file as recited in claim 1, wherein the second format is an I-frame.

4. A method for clipping a segment from a video file as recited in claim 3, wherein the re-encoded first frame is stored as one of an in-glue and an out-glue files during a first pass of an editing engine.

5. A method for clipping a segment from a video file as recited in claim 4, further comprising a step of defining one or more frames in the clipped segment as middle-glue frames.

6. A method for clipping a segment from a video file as recited in claim 5, wherein the step of creating the clipped segment includes the substep of:

stitching glue files selected from the group consisting of the in-glue, the middle-glue and the out-glue together to create the clipped segment.

7. A method for clipping a segment from a video file as recited in claim 6, wherein the stitching is performed in a second pass by the editing engine, and an associated glue object is used for retrieving data from at least one of the in-glue, middle-glue, and out-glue files.

8. A method for clipping a segment from a video file as recited in claim 5, further comprises the steps of:

multiplexing the stitched glue files to generate multiplexed data; and

outputting the multiplexed data that is identified as the created clipped segment to an application.

9. A method for clipping a segment from a video file as recited in claim 6, wherein the step of stitching glue files further comprises the steps of:

opening one of the in-glue, middle-glue or out-glue files;

read glue file data in a time ordered sequence; and

close any open glue file.

10. A method for clipping a segment from a video file as recited in claim 9, wherein the step of reading glue file data further comprises the substeps of:

performing time re-stamping for the duration of the step of reading glue file data;

performing B-frame stripping when a particular B-frame is present in another glue file, and a reference frame for the particular B frame is absent.

11. A method for clipping a segment from a video file as recited in claim 1, wherein the step of decoding a first frame further comprises the step of:

decoding a most previous I frame to provide a decoder with sufficient context.

12. A method for clipping a segment from a video file as recited in claim 1, where the re-encoded first frame is stored in a storage medium selected from the group consisting a cache memory, a computer hard drive, a floppy disk, and a remotely networked storage medium.

13. A method for copying a segment from a video file having a multiplicity of video frames, wherein at least some of the frames are encoded as predicted frames, the method comprising the steps of:

selecting a mark-in location in the video file, the mark-in location defining the beginning of the copied segment;

decoding each of the frames positioned between the mark-in location and a final group frame associated with a group of frames that includes the mark-in location, each decoded frame having an associated first format;

re-encoding each of the decoded frames into an associated second format, wherein the re-encoded second format of at least one of the decoded frames is different than its associated first format;

storing the re-encoded frames; and

creating a copied segment that includes the re-encoded frames.

14. A method for copying a segment from a video file as recited in claim 13, wherein the group of frames further includes an initial group frame that is an I frame, and the final group frame is a frame before the next I frame in time.

15. A method for copying a segment from a video file as recited in claim 13, further comprising the step of selecting a mark-out location in the video file, the mark-out location defining the end of the copied segment.

16. A method for copying a segment from a video file as recited in claim 13, wherein the copying step is performed in response to a copy request in an edit list provided by an application requesting that a segment be copied from the video file.

17. A method for copying a segment from a video file as recited in claim 13, further comprising the step of:

creating a copy operator in response to a copy request; and

creating control objects configured to perform the decoding and re-encoding steps to generate the re-encoded frames.

18. A method for copying a segment from a video file as recited in claim 17, wherein the control objects are created by the copy operator.

19. A method for copying a segment from a video file as recited in claim 18, wherein the control objects include a decoder, an encoder, a seeking engine, and a streamer for streaming an un-processed middle-glue segment from the video file.

20. A method for copying a segment from a video file as recited in claim 19, wherein the seek engine is responsible for identifying a particular frame within the video file.

21. A method for copying a segment from a video file as recited in claim 20, wherein the streamer is responsible for retrieving an un-processed middle-glue segment from the video file.

22. A method for copying a segment from a video file as recited in claim 19, wherein the control objects further include a demultiplexer, and a glue object for managing the re-encoded frames.

23. A method for copying a segment from a video file as recited in claim 22, wherein the re-encoded frames are stored as one of an in-glue file and an out-glue file.

24. A method for copying a segment from a video file as recited in claim 23, wherein the in-glue file contains re-encoded frames beginning with the mark-in frame and extending to one frame before the next I frame from the mark-in frame.

25. A method for copying a segment from a video file as recited in claim 23, wherein the out-glue file contains re-encoded frames beginning with a next frame after the most previous I frame from a mark-out frame, and extending to the mark-out frame.

26. A method for copying a segment from a video file as recited in claim 13, further including a middle-in location beginning at a first I frame after the final group frame, the middle-in frame defining the first frame in a middle-glue segment that is un-processed.

27. A method for copying a segment from a video file as recited in claim 26, further including a middle-out location identified as one frame prior to a most previous I frame from the mark-out location, the frames beginning with the middle-in location and ending at the middle-out location defining a middle-glue segment.

28. A method for copying a segment from a video file as recited in claim 13, wherein the associated second format includes re-encoded frame sequences of I frames, I and P frames, and I, P and B frames.

29. An apparatus for copying a segment from a video file having a multiplicity of video frames, wherein at least some of the frames are encoded as predicted frames, the method comprising the steps of:

selecting means for selecting a mark-in location in the video file, the mark-in location defining the beginning of the copied segment;

decoding means for decoding each of the frames positioned between the mark-in location and a final group frame associated with a group of frames that includes the mark-in location, each decoded frame having an associated first format;

re-encoding means for re-encoding each of the decoded frames into an associated second format, wherein the re-encoded second format of at least one of the decoded frames is different than its associated first format;

a storage medium for storing the re-encoded frames; and

whereby a copied segment that includes the re-encoded frames is generated.

30. A computer readable media containing program instructions for clipping a segment from a video file having a multiplicity of video frames, wherein at least some of the frames are encoded as predicted frames, said computer readable media comprising:

program instructions for selecting a mark-in location in the video file, the markin location defining the beginning of the clipped segment;

program instructions for selecting a mark-out location in the video file, the mark-out location defining the end of the clipped segment;

program instructions for decoding a first frame associated with one of the mark-in location and the mark-out location, the first frame being a predictive frame having an associated first format;

program instructions for re-encoding the decoded first frame into a second format;

program instructions for storing the re-encoded first frame; and

program instructions for creating a clipped segment that includes the re-encoded first frame.