Apple Wins Patents Relating to Advanced Video & Notebooks

On November 13, the US Patent & Trademark Office published two of Apple’s newly granted patents. The first is titled Determining the Number of Unidirectional and Bidirectional Motion Compensated Frames to be Encoded for a Video Sequence and Detecting Scene Cuts in the Video Sequence which relates to advanced video used in television broadcasting, internet streaming and teleconferencing in real or post-time. The second patent is titled Self aligning foot assembly which relates to Apple notebooks.

Patent: Determining the Number of Unidirectional and Bidirectional Motion Compensated Frames to be Encoded for a Video Sequence and Detecting Scene Cuts in the Video Sequence

Apple’s invention addresses methods for determining the number of unidirectional and bidirectional frames to be encoded for a video sequence and a method for detecting scene cuts in the video sequence.

Some embodiments described in Apple’s patent relate to video frames in YUV format. One of ordinary skill in the art, however, will realize that these embodiments may also relate to a variety of formats other than YUV. In addition, other video frame formats (such as RGB) can easily be transformed into the YUV format. Furthermore, embodiments of the present invention may relate to various video encoding applications (e.g., DVD, digital storage media, television broadcasting, internet streaming, communication, teleconferencing, etc.) in real-time or post-time. Embodiments of the present invention may also be used with video sequences having different encoding standards such as H.263 and H.264 (also known as MPEG-4/Part 10).

Apple’s Summary: The present invention provides methods for encoding frames of a video sequence where the sequence is processed in two passes. During the first pass, motion vectors are computed for pixelblocks of each frame in a set of successive frames with reference to other specific frame or frames. In some embodiments, motion compensation errors (MCEs) for pixelblocks of each frame are also computed. A motion cost value for each frame is then determined, the motion cost value being related to the number of bits required to encode the motion vectors and/or the value of the MCEs of the pixelblocks of the frame. A derived cost value is then computed based on the motion cost value of at least one frame (e.g., the derived cost value can be the motion cost value of one frame, the average motion cost value of two or more frames, or the ratio of the motion cost value of a first frame and the motion cost value of a second frame).

In addition, in the first pass, the derived cost value is used to determine the number (N.sub.B) of B-frames to be encoded in the set of successive frames. The number (N.sub.B) of B-frames to be encoded increases as long as the derived cost value is below a predetermined threshold value. In the second pass, frame N.sub.B+1 in the set of successive frames is encoded as a P-frame and frames 1 through N.sub.B are encoded as B-frames where some or all motion vectors computed in the first pass are re-used in the encoding process of the second pass.

Apple’s patent FIG. 9 is a graphical illustration of a set of successive frames that are processed in two passes with full re-use of motion vectors computed in the first pass.

In some embodiments, during the first pass, motion vectors are computed for each pixelblock and for each frame in a set of successive frames with reference to an immediately preceding frame. In these embodiments, some of the motion vectors computed in the first pass are re-used in the encoding process of the second pass. In further embodiments, during the first pass, motion vectors are computed for each frame in a set of successive frames with reference to a same preceding frame (frame 0 in the set of successive frames). In these embodiments, all of the motion vectors computed in the first pass are re-used in the encoding process of the second pass.

In some embodiments, the derived cost value is the average motion cost of a series of successive frames. In other embodiments, the derived cost value is the motion cost of a single frame. In further embodiments, the derived cost value is a ratio between the motion cost of a first frame and the motion cost of a second frame that immediately precedes the first frame. In these further embodiments, the ratio of motion costs is used to detect an impulse-like increase in the motion costs between two successive frames which typically indicates a scene cut between the two successive frames. As such, these further embodiments provide a scene cut detection method that is used in conjunction with the two pass encoding method of the present invention. In additional embodiments, the scene cut detection method is used independent from the two pass encoding method.
Apple lists Barin Geoffrey Haskell (Mountain View, CA), Adriana Dumitras (Sunnyvale, CA) and Atul Puri (Cupertino, CA) as the inventors of this patent which was originally filed in September 2003. For full details, see patent 7,295,612.

Patent: Self Aligning Foot Assembly

Apple’s Abstract: A foot assembly includes a foot including a snap and a first alignment feature, the snap and the alignment feature are coupled to a base, and the first alignment feature extending a greater distance from the base than an engagement of the snap. The assembly also includes a foot socket coupled to the foot, the socket including an undercut and a second alignment feature. In one aspect, the second alignment feature interfaces with the first alignment feature. In another aspect, the socket is coupled to an enclosure of a portable computing device.

Apple’s patent FIG. 2A shown above, illustrates an exploded view of an embodiment of a self aligning foot assembly 200.

Apple lists Banko; Joshua David Banko (Sunnyvale, CA) as the sole inventor of this patent which was originally filed in July 2006. For full details, see patent 7,293,749.

NOTICE: MacNN presents only a brief summary of patents with associated graphic(s) for journalistic news purposes as each such patent application and/or grant is revealed by the U.S. Patent & Trade Office. Readers are cautioned that the full text of any patent applications and/or grants should be read in its entirety for further details.

Written and researched by Neo.