摘要:
A method of operating a multi-processor video encoder by determining a target size corresponding to a preferred number of bits to be used when creating an encoded version of a picture in a group of sequential pictures making up a video sequence. The method includes the steps of calculating a first degree of fullness of a coded picture buffer at a first time, operating on the first degree of fullness to return an estimated second degree of fullness of the coded picture buffer at a second time, and operating on the second degree of fullness to return an initial target sized for the picture. The first time corresponds to the most recent time an accurate degree of fullness of the coded picture buffer can be calculated and the second time occurs after the first time.
摘要:
Information needed to generate an encoded version of a matrix of j transform coefficients c0 . . . cj−1 representing a block of digital video data is determined by forming a numerical signature σ of the matrix and looking up a value for the information needed in an array employing the signature σ as an index to the array.
摘要:
A transparent routing device disposed within an access network configured in accordance with one or more lower-layer protocols is disclosed herein. The device includes a set of subscriber-side ports. Each of the subscriber-side ports is associated with a plurality of virtual subscriber-side interfaces disposed to effectively terminate a corresponding plurality of subscriber-side connections with subscriber host devices served by the access network. The device further includes at least one network-side port through which communication occurs with an external network in accordance with a higher-layer protocol. A routing table is configured to establish a correspondence between network addresses of the subscriber host devices and the plurality of virtual subscriber-side interfaces. During operation of the device, packets received through the at least one network-side port are forwarded to corresponding ones of the virtual subscriber-side interfaces based upon network addresses of the packets.
摘要:
A method of rate control using a picture-based lookahead sliding window in a dual-pass transcoder/encoder compressed video architecture extracts statistics from an input video signal according to a simple compression standard, the input video signal being a compressed video signal for transcoding or an uncompressed video signal for encoding. A trans-factor is calculated for a current picture based on previous pictures in a sliding window to predict the complexity of the current picture, the trans-factor being a ratio of global complexity measures for the simple compression standard versus a sophisticated compression standard. Bits for the current picture are then allocated based on the complexity of future pictures in the sliding window. After encoding the current picture according to the sophisticated compression standard, the target bits of and the picture complexity in the sliding window, as well as the trans-factor, are updated as the window is moved by one picture. The extraction of the statistics is achieved in a transcoder by using a simple compression standard decoder to produce the statistics from the compressed video signal as the input video signal, and in an encoder by using a simple compression encoder to generate the statistics from the uncompressed video signal as the input video signal.
摘要:
A method of automatically determining a peak level of a signal propagated on a carrier medium, such as for example POTS wiring, includes detecting a traversal of a noise threshold level by a data signal. The noise threshold level is determined relative to a noise floor. A determination is then made as to whether the data signal traverses a peak level within a predetermined time interval after the detection of the traversal of the noise threshold level. The peak level is then varied in accordance with the determination of whether the data signal traversed the peak level within the predetermined time interval. For example, should the data signal not traversed the peak level within the predetermined time interval, the peak level may be lowered. Alternatively, should the data signal traversed the peak level within the predetermined time interval, the peak level may be raised.
摘要:
A video conferencing terminal includes an encoder that receives a baseband audio signal and a baseband video signal and creates compressed audio packets and compressed audio-video packets. A network interface driver receives the compressed audio packets and the compressed audio-video packets, IP encapsulates the compressed audio packets and the compressed audio-video packets, transmits the IP packets onto an IGMP network. The network interface driver also requests audio packets and audio-video packets from the network and recovers compressed audio packets and compressed audio-video packets from the IP packets received from the network. A decoder receives compressed audio packets and compressed audio-video packets from the network interface driver and generates a baseband video signal and multiple baseband audio signals.
摘要:
Variation in delay in transmission of data from a transmitting station to a receiving station is measured by encapsulating a portion of the data and an outgoing time stamp in a packet, the outgoing time stamp substantially representing the degree of progression of a periodic process at the time of including the outgoing time stamp in the packet. The packet is transmitted from the transmitting station and is received at the receiving station. At the receiving station, an incoming time stamp is added to the packet. The incoming time stamp substantially represents the degree of progression of a periodic process at the time of adding the incoming time stamp to the packet. The incoming time stamp is compared to the outgoing time stamp.
摘要:
A method for connecting together two twisted pair lines in a LAN so as to avoid common mode current. The invention recognizes that the impedance to ground is different for each wire in the twisted pair line. Moreover, this impedance is different from spool-to-spool for lines having the same purported impedance. A balun is placed at the connection between the lines.
摘要:
A LAN which uses flat telephone cable having at least four conductors. The inner conductors are joined together and the outer conductors are joined together at each node thereby making reversals of the inner and outer conductors, which may occur at connectors, impossible. Each node uses two baluns to provide an unbalanced zone between the baluns for connecting to the DTE.
摘要:
An apparatus for monitoring and testing a twisted pair, particularly useful for an Ethernet network. First and second DC currents alternated with one another are applied to both ends of the line, asynchronously. By monitoring the potential on the line, a determination is made as to the condition of the line. For example, shorted, crossed, improperly terminated or open conditions can be detected. A visual indication of the condition of the line is provided and additionally, the visual indication provides an indication of the traffic level in the network.