Abstract: A high-definition multimedia interface (HDMI) extender compatible with high-bandwidth digital content protection (HDCP) has a data receiver for receiving video/audio data and a data transmitter for transmitting the video/audio data to a display device. An Ethernet cable consisting of eight cores is connected between the data receiver and the data transmitter. When either the video/audio data or the display device complies with the HDCP, a voltage signal with level variation is transmitted between the data receiver and the data transmitter through the Ethernet cable to permit the display device to display the video/audio data.

Abstract: A digital surveillance camera includes a video capture component, a data converter coupled to the video capture component and a signal transmission unit coupled to an output terminal of the data converter. The data converter processes the video signal with high frequency components from the video capture component in digital domain to generate the video signal in a specific format to be further transmitted in the digital serial differential form. The signal transmission unit transmits the signal via either an optical fiber or a cable with characteristics of long-distance transmission and lowers the resulting signal loss to ensure the quality of the received video signal.

Abstract: A variable frequency decoding apparatus operable in a portable audio device that can improve the power management is disclosed. The above apparatus has a decoder and a clock generator that provides the system clock for the decoder. When a bit stream representing audio compressed data is received, the decoder simultaneously provides the audio information embedded in the audio compressed data such as the bit rate and the sampling frequency of the data frame to the clock generator, and then the clock generator adjusts the clock signals; which are used by the decoder to restore to the original PCM format, to match the audio information embedded in the data frame. This audio signal compression technique can prevent possible output delay and reduce power consumption as compared with the conventional way that used a fixed sys clock.

Abstract: A method of improving performance and power utilization of portable a CD player with an electronic anti-shock system (EASS) is disclosed. When PCM signals are received by the EASS, the audio signals are compressed with a high compression rate algorithm and saved in a temporary memory, and later when the audio data are read out from the temporary memory, the audio data are decoded with the same audio compression algorithm to restore to the original PCM format, thus a data buffering is created between the reading of data and the playback of sound. A high compression rate algorithm can increase the utilization of DRAM memory and lengthen the buffering time considerably. The present invention has incorporated an audio compression algorithm having high compression rate in the EASS to attain the most desirable balance point between audio performance, power management, and costs.

Abstract: A method of optimizing the compression rate in Adaptive Differential Pulse Code Modulation (ADPCM) is disclosed. The modified pulse code modulation technique employs a prognostic code converter to generate variable length codes on top of the ADPCM coding, based on the probability of occurrence of data bits in a data sample. This variable-length coding is able to further reduce the compressed data size by increasing the compression rate of the conventional ADPCM coding.