Kabushiki Kaisha Toshiba

Time Warner Entertainment Company, L.p.

Other

Greg B Thagard

Hideki Mimura

Hiroaki Unno

Christopher J Cookson

Tetsuya Kitamura

Andrew Drusin Rosen

Jay Yogeshwar

Sheau-Bao Ng

Faramarz Azadegan

Mikhail Tsinberg

Tomoo Yamakage

Toshinori Odaka

Teiichi Ichikawa

David Lehmann

Masaru Sakurai

Shin-ichiro Koto

Shin-Ichiro Koto

A method and system in which a section of a previously encoded digital bit stream is replaced with another section of encoded video. In order to remove a section of encoded video, it is necessary to determine the beginning and ending points of the encoded video in the digitally encoded bit stream. The addresses of the beginning and ending points of the encoded data cannot be simply looked up but are calculated by summing the bits consumed by each picture, the number of bits of the sequence header of each picture, the number of bits of each Group of Pictures (GOP) header, and all stuff bits. In order to encode the video which is to be inserted in place of the removed video, a process is performed which prevents decoding artifacts from appearing. This is accomplished by determining the last P-picture before the edit point and using it as a reference frame for frames after the edit point. Additionally, a short period of the original video encoded using its original quantizer values is included at the end of the video to be substituted. Alternatively, the encoder may be run so that an earlier encoded reference picture is not used. However, this requires extra bits to maintain picture quality because initial bidirectional frames of the substitute video will use only one reference frame instead of two.

Method and system to replace sections of an encoded video bitstream

An audiovisual encoding system using a multipass video encoder and a plurality of one-pass audio encoders. The number of audio encoders used by the system is equal to the number of audio tracks to be encoded divided by the number of passes required for the video encoding rounded up to the nearest integer, if necessary. The system allows the video encoder and audio encoders to be used at the same time so that the encoding of the video is completed at the same time as the encoding of all audio tracks is completed, using the minimum number of audio encoders.

Audiovisual encoding system with a reduced number of audio encoders

A method and system in which a user manually changes the quality of portions of video frames after the frames have been previously encoded. Regions of one or more frames of video are selected to have an increased quality, a decreased quality, or a quality which should not be altered. After the regions are defined by a user, the frame of video is digitally re-encoded and inserted into the digitally encoded data stream in place of the previously encoded data. In order to easily remove a previously encoded frame from the data steam and replace it with a newly encoded frame having regions of quality defined by the user, it is preferable to have the newly encoded frame consume the same number of bits as the previously encoded frame. Accordingly, if the user desires a region of a frame to have an increased quality, the extra bits necessary to provide the increased quality must be taken from other areas of the frame. This is accomplished by an automatic process which is transparent to the user. Additionally, if the user wants to change the quality of an object for a series of video frames, the user can mark a region in a first frame and a corresponding region in a last frame and the system will automatically adjust the quality of the region as the region moves through the series of video frames.

Method and system for a user to manually alter the quality of previously

A method and system in which a user manually changes the quality of specific time periods of encoded video. After the automatic encoding of video into a compressed digital format, a person editing the encoded video reviews the quality of the video and manually indicates that the quality of specific time periods of the video is to be altered. As the digital storage medium such as an optical disc which stores the encoded video has a finite storage capacity, the total number of bits for the encoded video and the quality of the video is limited. Consequently, in order to increase the quality for one time period, bits must be taken from other time periods. After the editor assigns the qualities to different time periods, a percentage of bits is removed from the time sequences and placed into a bit pool. The new number of bits for the various time periods are calculated using an exponential function and the bits in the bit pool are proportionally distributed to the video frames. The frames must then be checked and possibly adjusted to assure that underflow of the video buffer will not occur. After the underflow checking procedure, the video is re-encoded with an adjusted quantization in accordance with a quantizer model which will result in a picture having the calculated number of bits and a quality in accordance with the user's selection.

Method and system for a user to manually alter the quality of a

A method and system for re-encoding frames of a digital video stream in which selected areas are designated to have increased or reduced image quality, i.e., decreased or increased quantization levels, respectively, as compared to a previously run automatic encoding process, but without changing the previously calculated bit length of the stream. A set of macroblocks at a time are re-encoded, the number of resulting bits is calculated and the deviation from an estimated number of bits is calculated, either set-by-set or cumulatively. Based on the accuracy of the estimate and the remaining number of sets of macroblocks to re-encode, a correction factor for the quantization level of the next set of macroblocks is chosen from a lookup table. The correction factor is added to the quantization level of the next set of macroblocks and the results stored as the new quantization level of the set. This sequential process is done for all sets of macroblocks in the digital stream which are to be recoded according to changed image qualities.

Rate-controlled digital video editing method and system which controls

Growing community of inventors

Redondo Beach, CA, United States of America

Greg B Thagard