Abstract: A system for implementing an interactive broadcast program which includes a transmitter for transmitting a multiplexed data stream which includes a main program and a plurality of different commercials, and a receiver (e.g., a digital television receiver) configured to receive the multiplexed data stream. The receiver includes a display device (e.g., a television monitor) and, facilities responsive to a user action for causing the display device to display a selected one of the plurality of different commercials during a commercial interruption in the main program. Also disclosed is a system for implementing an interactive broadcast program which includes a transmitter for transmitting a multiplexed data stream which includes an interactive main program comprised of a plurality of main program segments including at least a first main program segment and a plurality of different second main program segments, and a receiver. The receiver (e.g.

Abstract: A method and system for high resolution formatting of video images and dynamically adjusting the transmission resolution of the high-resolution images is presented. The method first downscales the high-resolution images and encodes the downscaled images into base layer frames. Quality enhancement layer data is generated from the downscaled video images and the encoded data contained in corresponding base layer frames. The quality enhancement layer data is encoded into quality enhancement layer frames. The data contained in the base layer frames and corresponding quality layer frames are then upscaled and spatial scalability data is determined from the upscaled data and the original image. The spatial scalability data is then encoded into spatial scalability data. During transmission of the encoded video image, each available encoded frame is transmitted using different amounts or portions of the enhancement layers so as to occupy the available bandwidth.

Abstract: A method and system for producing decoding the transmission of high-resolution images transmitted as a low resolution spatially scalable FGS encoded base layer and at least one enhancement layer is presented. The low resolution received base layer is representative of a downscaled image of the original image. In this manner, a minimum resolution base layer is transmitted and higher resolutions may be obtained and utilized depending on the available bandwidth and the receiving system resolution capability. In one aspect of the invention, the base layer is decoded and a quality enhancement is next applied to the base layer. The combined base layer and quality layer video frames are then upscaled and the upscaled image is combined with a decoded spatial enhancement layer information. The spatial enhancement layer information fills in resolution lacking in the upscaled base layer/quality layer image. Thus, a high resolution image is formed.

Abstract: A system for implementing an interactive broadcast program which includes a transmitter for transmitting a multiplexed data stream which includes a main program and a plurality of different commercials, and a receiver (e.g., a digital television receiver) configured to receive the multiplexed data stream. The receiver includes a display device (e.g., a television monitor) and, facilities responsive to a user action for causing the display device to display a selected one of the plurality of different commercials during a commercial interruption in the main program. Also disclosed is a system for implementing an interactive broadcast program which includes a transmitter for transmitting a multiplexed data stream which includes an interactive main program comprised of a plurality of main program segments including at least a first main program segment and a plurality of different second main program segments, and a receiver. The receiver (e.g.

Abstract: A method of achieving seamless switching of digitally compressed signals. The method includes the steps of identifying the point in a video signal where splicing to a second video signal is desired, and thereafter, maintaining adherence to certain parameters in the encoder buffer to ensure that the input signal. is not being compressed at a rate that causes either underflow or overflow in the encoder buffer. The method also includes the steps of constraining the upper bound of the encoder buffer to ensure that data is not being outputted from the encoder buffer to the decoder buffer too slowly so as to cause an underflow of data in the decoder buffer. The method may also include the steps of constraining the lower bound of the encoder buffer to ensure that data is not being outputted from the encoder buffer to the decoder buffer too quickly so as to cause an overflow of data in the decoder buffer.

Abstract: A system extracts, from uncoded video data, coding parameters that correspond substantially to coding parameters used in a coding operation that was previously performed on the video data. The system generates a histogram for at least one AC frequency band in the uncoded video data and calculates a correlation function for the histogram. A maximum value of the correlation function is then identified, and a coding parameter for the at least one AC frequency band is determined using the maximum value of the correlation function.

Abstract: A method of encoding a digital video bit stream which includes a plurality of successively-encoded pictures. The method includes the steps of constructing a seamless In Point in accordance with a constraint expressed by the following equation (1):dd.sub.f.sbsb.--.sub.ip .ltoreq.minimum {DD.sub.thr.sbsb.--.sub.ip, (B.sub.d /r.sub.n.sbsb.--.sub.ip)}, (1)where dd.sub.f.sbsb.--.sub.ip represents an amount of time by which a first byte of the digital video bit stream after the seamless In Point must stay in a decoder buffer before it is decoded; B.sub.d is a size of the decoder buffer; r.sub.n.sbsb.--.sub.ip is a bit rate at which the digital video bit stream is normally encoded at the seamless In Point; and, DD.sub.thr.sbsb.--.sub.ip represents a prescribed minimum decoding delay threshold for seamless In Points, where DD.sub.thr.sbsb.--.sub.ip is defined by the following equation (2):DD.sub.thr.sbsb.--.sub.ip =((MSR/r.sub.n.sbsb.--.sub.ip)*SDD)+T.sub.p.sbsb.--.sub.i *(1-(MSR/r.sub.n.sbsb.--.sub.ip), (2)where T.

Abstract: A method of achieving seamless switching of digitally compressed signals. The method includes the steps of identifying the point in a video signal where splicing to a second video signal is desired, and thereafter, maintaining adherence to certain parameters in the encoder buffer to ensure that the input signal is not being compressed at a rate that causes either underflow or overflow in the encoder buffer. The method also includes the steps of constraining the upper bound of the encoder buffer to ensure that data is not being outputted from the encoder buffer to the decoder buffer too slowly so as to cause an underflow of data in the decoder buffer. The method may also include the steps of constraining the lower bound of the encoder buffer to ensure that data is not being outputted from the encoder buffer to the decoder buffer too quickly so as to cause an overflow of data in the decoder buffer.

Abstract: A method and apparatus for dynamically allocating the available bandwidth of a common transmission channel of a multiplexed system among multiple encoders in such a manner as to maximize and equalize the quality of the encoded data output by all of the encoders, while also preventing underflow or overflow of encoder or decoder buffers at each end of the common transmission channel, and moreover, while also ensuring compliance with (i.e., without violating) the data encoding and transmission protocol utilized by the system. Further, the bandwidth of the common transmission channel is preferably allocated using an algorithm that does not impose any constraints on the size of the encoder or decoder buffers, other than any constraints specified by the data transmission protocol employed in transmitting the encoded data over the common transmission channel.

Abstract: The effective (or logical) size of the encoder buffer in a video transmission system is varied with the transmission bit-rate. Also, a minimum fill level is maintained in the encoder buffer whenever the transmission rate is too high to assure otherwise that the decoder buffer will not overflow or underflow. The encoding rate is varied so as to maintain a fill level in the encoder buffer within limits. In the preferred embodiment, the logical encoder buffer has a size which is maintained at R.DELTA.T(1-m.sub.1)-M, where R is the average transmission bit-rate, which may vary, .DELTA.T is the fixed delay between the encoding and decoding processes for a transmitted video signal, R(1-m.sub.m) is the minimum instantaneous transmission rate that the communication system achieves at average rate R, and M is the maximum total buffer storage in the communication system. When the decoder buffer has a size less than R.DELTA.T(1+m.sub.2), where R(1+m.sub.