At+t Corp.

At&t Intellectual Property I, L.p.

At&t Bell Laboratories

Bell Telephone Laboratories

American Telephone and Telegraph, Co.

James H Snyder

Schuyler Reynier Quackenbush

Mathias R Kretschmer

Peter Frank Driessen

John Blakeway Lacy

David R Fischell

Amy Ruth Reibman

David Hilton Shur

Robert L Wallace, Jr

John A Dispenza

Christopher D Stockbridge

Gihyun Cho

Tzu-Chieh Chang

Mathias R Kretchmer

Noel A Smith

A special rendering mode for the first few seconds of play out of multimedia data minimizes the delay caused by pre-buffering of data packets in multimedia streaming applications. Instead of pre-buffering all incoming data packets until a certain threshold is reached, the streaming application starts playing out some of the data packets immediately after the arrival of the first data packet. Immediate play out of the first data packet, for example, results in minimum delay between channel selection and perception, thereby allowing a user to quickly scan through all available channels to quickly get a notion of the content. The immediate play out is done at a reduced speed.

Method and apparatus for time stretching to hide data packet pre-buffering delays

A system and method for transmitting data over a channel, in which the data are categorized in at least two different categories. For example, the data are categorized according to the effect on perceived degradation on the data when error mitigation is performed on the data. Corrupted data of the first category are replaced using a first replacement method, such as retransmission and forward error correction. The corrupted data of the second category are replaced using a second replacement method different from the first replacement method, e.g., error mitigation or interpolation.

Systems and methods for transmitting data

System and methods for transmitting data

An apparatus for compressing media content is disclosed. The apparatus divides the media content into at least three predetermined portions, compresses each of the at least three portions using one of at least three different compression algorithms and makes the at least three compressed predetermined portions publicly available. Making the portions publicly available includes, for example, transmitting the portions over a computer network such as the Internet.

System and method for decompressing and making publically available received media content

Custom character-coding compression for encoding and watermarking media content

This invention provides methods and apparatus for protecting data transmitted using standard compression techniques such as Huffman coding. After input data is preprocessed (filtered, quantized, etc.), the data is encoded using a Huffman coder based on Huffman codes or code books which have been scrambled to change the order of the code books and/or codes from established standard Huffman code books and/or codes. When the transmitted information is received by a Huffman code receiver, the received data may be decoded using the scrambled Huffman code book/codes to obtain the data that was transmitted by the transmitter.

Scrambling a compression-coded signal

A method of compressing media content in which a first predetermined portion of a media content is compressed using a first data-based compression algorithm and inserted into a first portion of a data frame. A second predetermined portion of the media content is compressed using a second data-based compression algorithm and is inserted into a second portion of the data frame. The second predetermined portion of the media content is different from the first predetermined portion of the media content, and the second data-based compression algorithm is different from the first data-based compression algorithm. At least one of the first and second data-based compression algorithms is a private data-based compression algorithm. A plurality of data frames are generated and are made available for distribution, for example, by transmission over a computer network, such as the Internet.

A method and apparatus are described for inserting a watermark in the compressed domain. The watermark inserted does not require a reference. An overall watermarking system incorporating the invention combines cleartext, bitstream, and integrated watermarking. In a perceptual coder, the data enters a filterbank, where it is processed into multiple separate coefficients. A rate/distortion control module uses noise threshold information from a perceptual coder, together with bit-count information from a noiseless coder, to compute scale factors. The coefficients are multiplied by the scale factors and quantized, then noiseless coded and then output for further processing/transmission. The invention supports three embodiments for inserting a mark into the bitstream imperceptibly. It is assumed that some set of scale factor bands have been selected, into which mark data will be inserted. In one embodiment, a set of multipliers &lcub;x &equals;2 : i&egr;M&rcub; is chosen. Each triple is modified by dividing the scale factor by x, multiplying the quantized coefficients by &lcub;x &rcub;, and adding mark data to the non-zero modified quantized coefficients. In an alternate embodiment, watermark data is represented via two characteristics of the bitstream data. A Huffinan table is selected for encoding the Scale Factor Band receiving watermark data which is not the table that would normally be used. The watermark data bit is set according to any desired scheme, and the quantized coefficients are derived using the alternate Huffinan table. In another embodiment, watermarking is integrated with quantization. The watermark is therefore difficult to remove without perceptible effects. The fact that marking data is present is again indicated by characteristics of the bitstream data. The modification factors &lcub;x &rcub; are now all close to unity.

Electronic watermarking in the compressed domain utilizing perceptual coding

Growing community of inventors

North Plainfield, NJ, United States of America

James H Snyder