Nec Corporation

Yasuhiko Okuhara

Hirotaka Nakano

Shiro Fujihara

Fumihiro Okazaki

A digital information processing system ensures illegal-copy protection of video and audio signals without changing the structure or format of a stream of multiplexed video, audio and data packets. A packet demultiplexer selects packets from a packet stream according to the packet identifiers (PID) of the packets. The packet demultiplexer has a first output port electrically connected to video and audio signal decoders, and a second output port for digital processing such as storage. When a selected packet is a video or audio packet, the packet demultiplexer outputs the selected packet through the first output port. When the selected packet is a data packet, and packet demultiplexer outputs the selected packet through the second output port.

Digital information processing system with copy protection subsystem

An encoder, which comprises a means,for embedding a specific electronic mark data in a characteristic part of an image converted to a spatial frequency area, a quantizing means,for quantizing the spatial frequency area data in which the electronic mark data is embedded and a variable length encoder,for variable length coding the quantizer output, outputs compression coded digital image data. A decoder comprises a variable length decoder,and reverse quantizer,for restoring compression encoded digital image data to spatial frequency area data, means,for detecting the electronic mark data from the restored data, and detection display means,for displaying the detection result.

Image data processor

In an output control device which controls an amplification factor of an amplifier in response to an input signal and a fade control signal to carry out a fade operation of an output signal, such as a fade-in or a fade-out operation, a level control signal is produced to widely control output levels of the output signal. A plurality of timing signals are produced from either the fade control signal or the level control signal and are selected in response to the level control signal and are selected in response to the level control signal to determine a combination of the timing signals. The amplification factor is controlled by the combination of the timing signals to change the output levels over a wide range by varying the combination of the timing signals from one to another.

Growing community of inventors

Tokyo, Japan

Yasuhiko Okuhara