Yi T Tse

US Patent:

6611624, Aug 26, 2003

Filed:

Oct 15, 1998

Appl. No.:

09/173708

Inventors:

Ji Zhang - San Jose CA
Yi Tong Tse - San Jose CA

Assignee:

Cisco Systems, Inc. - San Jose CA

International Classification:

G06K 936

US Classification:

382232, 37524026, 370498

Abstract:

A system for performing frame accurate bitstream splicing includes a first pre-buffer, a second pre-buffer, a seamless splicer, and a post-buffer. The system also includes a time stamp extractor, a time stamp adjuster, and a time stamp replacer for timing correction. The first and second pre-buffers are input buffers to the seamless splicer, and the post-buffer is coupled to the output of the seamless splicer. The seamless splicer receives the two streams via the first and second pre-buffers and produces a single spliced bitstream at its output in response to the cue tone signal. The seamless splicer provides the first bitstream, then re-encodes portions of the first and second bit streams proximate the splicing points (both the exit point and the entry point), and then switches to providing a second bitstream. The seamless splicer also performs rate conversion on the second stream as necessary to ensure decoder buffer compliance for the spliced bitstream. The present invention also includes a method for performing bitstream splicing comprising the steps of: determining a splicing point switching between a first bitstream and a second bitstream, determining whether the second bitstream has the same bit rate as the first bitstream, converting the rate of the second bitstream if it is not the same as the bit rate of the first bitstream, and re-encoding picture proximate the splicing point.

US Patent:

7054362, May 30, 2006

Filed:

May 29, 2001

Appl. No.:

09/867967

Inventors:

Ke Shen - Sunnyvale CA, US
Yi Tong Tse - San Jose CA, US

Assignee:

Cisco Technology, Inc. - San Jose CA

International Classification:

H04B 1/66
H04B 11/02
H04B 11/04
H04B 7/12

US Classification:

37524002

Abstract:

According to the present invention, methods and apparatus for updating reduction ratios are provided. An input bit sequence can be altered to provide modified output bit sequence. The input bit sequence may represent information in a portion of data such as a video sequence, a picture, or an audio stream. In one example, the bit sequence is an MPEG-2 video sequence. The input bit sequence is altered using a reduction ratio to provide a modified output bit sequence. The reduction ratio can be continually updated using rate control information to achieve a target reduction ratio for the input bit sequence.

US Patent:

7162097, Jan 9, 2007

Filed:

May 29, 2001

Appl. No.:

09/867966

Inventors:

Fang Wu - San Jose CA, US
Ke Shen - Sunnyvale CA, US
Yi Tong Tse - San Jose CA, US
Sangeeta Ramakrishnan - San Jose CA, US

Assignee:

Cisco Technology, Inc. - San Jose CA

International Classification:

G06K 9/46

US Classification:

382250

Abstract:

According to the present invention, methods and apparatus for filtering transform coefficients are provided. Transform coefficients associated with an input bit sequence can be zeroed to provide modified transform coefficients associated with an output bit sequence. The transform coefficients may represent information in a portion of data such as a video frame, a picture, or an audio stream. In one example, the transform coefficients are DCT coefficients of an MPEG-2 video sequence. The transform coefficients are filtered to provide modified transform coefficients associated with an output bit sequence. The output bit sequence is a rescaled version of the input bit sequence.

US Patent:

7289680, Oct 30, 2007

Filed:

Jul 23, 2003

Appl. No.:

10/626485

Inventors:

Yi Tong Tse - San Jose CA, US
Bipin Todur - Santa Clara CA, US

Assignee:

Cisco Technology, Inc. - San Jose CA

International Classification:

G06K 9/36

US Classification:

382251, 382248, 382250

Abstract:

According to the present invention, methods and apparatus for performing error minimizing requantization are provided. Quantized coefficients associated with a bitstream are received. It is determined whether the quantized coefficients are associated with an inter macroblock or an intra macroblock. Inter macroblock and intra macroblock formulas minimizing requantization error are applied to determine requantized coefficients.

US Patent:

7321698, Jan 22, 2008

Filed:

Aug 30, 2006

Appl. No.:

11/514122

Inventors:

Fang Wu - San Jose CA, US
Ke Shen - Sunnyvale CA, US
Yi Tong Tse - San Jose CA, US
Sangeeta Ramakrishnan - San Jose CA, US

Assignee:

Cisco Technology Inc. - San Jose CA

International Classification:

G06K 9/46

US Classification:

382250

Abstract:

According to the present invention, methods and apparatus for filtering transform coefficients are provided. Transform coefficients associated with an input bit sequence can be zeroed to provide modified transform coefficients associated with an output bit sequence. The transform coefficients may represent information in a portion of data such as a video frame, a picture, or an audio stream. In one example, the transform coefficients are DCT coefficients of an MPEG-2 video sequence. The transform coefficients are filtered to provide modified transform coefficients associated with an output bit sequence. The output bit sequence is a rescaled version of the input bit sequence.

US Patent:

7477688, Jan 13, 2009

Filed:

Jan 18, 2001

Appl. No.:

09/766020

Inventors:

Ji Zhang - San Jose CA, US
Yi Tong Tse - San Jose CA, US

Assignee:

Cisco Technology, Inc. - San Jose CA

International Classification:

H04B 1/66

US Classification:

375240, 37524003, 37524025, 37524026, 37524012, 382251, 382235, 382233, 382238

Abstract:

The present invention relates to systems and methods for efficient bit rate alteration of a bitstream to match an available channel capacity. The efficient bit rate alteration includes selective re-quantization of the compressed bitstream. Selective re-quantization according to the present invention applies multiple re-quantization schemes to different portions of a bitstream. In one embodiment, the multiple re-quantization schemes each have a different computational load. By selectively choosing which type of re-quantization is performed on each portion, efficient bandwidth scaling and data transmission may be achieved both when computational capacity is limited and when video data integrity is important.

US Patent:

7542617, Jun 2, 2009

Filed:

Sep 24, 2007

Appl. No.:

11/860462

Inventors:

Yi Tong Tse - San Jose CA, US
Bipin Todur - Santa Clara CA, US

Assignee:

Cisco Technology, Inc. - San Jose CA

International Classification:

G06K 9/00

US Classification:

382251, 382252, 382248

Abstract:

Techniques and mechanisms for performing error minimizing requantization are provided. Quantized coefficients associated with a bitstream are received. It is determined whether the quantized coefficients are associated with an inter macroblock or an intra macroblock. Inter macroblock and intra macroblock formulas minimizing requantization error are applied to determine requantized coefficients.

US Patent:

7778173, Aug 17, 2010

Filed:

Jan 4, 2005

Appl. No.:

11/029972

Inventors:

Yi Tong Tse - San Jose CA, US

Assignee:

Cisco Technology, Inc. - San Jose CA

International Classification:

H04J 1/16
H04L 12/26

US Classification:

3702301

Abstract:

A method and apparatus for clock recovery for constant bit rate MPEG-2 compliant single program transport stream and multiple program transport stream delivered over UDP/IP is disclosed. Clock recovery utilizes a dejittering filter to remove arrival time jitter from received packets and a phase lock loop is used to recover a PCR clock rate up to a range allowed by the MPEG-2 System specification. An MPEG-2 compliant output stream is produced, even when the input PCR does not meet the timing requirement specified by the MPEG-2 System specification.