Abstract:
A system enables the user to monitor a number of channels to determine the degree of action occurring on each of those channels which are not currently tuned for reception. The system may develop a count of the number of packets received over a given period of time for a plurality of channels selected by the user and may advise the user when those channels exceed a preset level. Thus, the user may be advised when the action level on another channel exceeds a desired level allowing the user to tune to that channel if desired.

Description:
BACKGROUND 
     This invention relates generally to digital video display systems and in particular embodiments to systems adapted to display video television programs. 
     The convergence of the television receiver and the personal computer has accelerated recently with the advent of the set top computer systems. These systems, sometimes called set top boxes, use a conventional analog television receiver as a display for computer systems. In some cases, the set top box sits on top of the television receiver. By combining the capabilities of a computer system and a television, the system may provide advanced television programming features, such as an electronic programming guide, without requiring the user to incur any unnecessary costs for an additional monitor. 
     Digital format television broadcasts will be available soon. Currently, high definition television (HDTV) systems receive both digital and analog television broadcasts. The digital broadcast may include one of the various formats of high definition television. 
     The taste of television viewers varies across the gamut of ages and personality types. Moreover, some television viewers prefer television programs with a lot of action. These programs may be sporting events such as football games, so-called action movies and other types of programs. Some users “surf” through television channels attempting to locate programs which meet their tastes. Those who surf for so-called action programs must change from channel to channel, watch a portion of the program to see if the program meets their interests, and then switch to other programs until a suitable program is located. 
     Thus, it would be desirable to have an automatic technique for identifying video transmissions with a high degree of action. 
     SUMMARY 
     In accordance with one aspect, a method of receiving a digital video transmission includes receiving video data. Indicia of the amount of video data received over a given time interval is developed. 
     Other aspects are set forth in the accompanying detailed description and claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front elevational view of one embodiment of the present invention; 
     FIG. 2 is a block diagram for one embodiment for implementing a portion of the device shown in FIG. 1; 
     FIG. 3 is a graph of channel versus bit rate in accordance with one embodiment of the present invention; 
     FIG. 4 is a block diagram for one embodiment of the system shown in FIG. 1; and 
     FIGS. 5 and 6 are flow charts showing software for one embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION 
     Referring to FIG. 1, a processor-based system  130 , illustrated as a set top computer system, includes a processor-based unit  110  which sits atop a television receiver  112 . The television receiver  112  and the processor-based unit  110  may be controlled by a remote control unit  114 . 
     The remote control unit  114  may communicate through its own transceiver  118  with a transceiver  134  on the processor-based unit  110  and a transceiver  128  on the television receiver  112 . The communications between the remote control unit  114  and the television receiver  112 /processor-based unit  110  may use any of a variety of airwave communications including infrared, ultrasonic or radiowave signaling. 
     While the present invention is illustrated in connection with a set top computer system, those skilled in the art will appreciate that the present invention is also applicable to any of a variety of other processor-based systems. Examples of other processor-based systems include desktop computers, laptop computers and a variety of processor-based appliances. 
     The remote control unit  114  may include a cursor control system  116  which operates essentially like a mouse. The RCU  114  may also include a mouse button  122  and a plurality of cursor direction control buttons  120 . Thus, the position of a cursor or highlighting on a screen  132  may be controlled by operating one of the four direction control buttons  120 . When the desired icon is indicated on the screen  132 , it may be selected by operating the button  122 . The remote control unit  114  may also include a numerical keypad  124 . 
     The processor-based unit  110  may include a tuner/capture card  162 , as shown in FIG.  2 . The card  162  may receive a multiplexed transport medium which provides a plurality of packets. A packet may include a header followed by a number of continuous bytes from an elementary data stream. An elementary data stream is a term for one of the coded video, coded audio or other coded bit streams. 
     A variety of standards for digital television broadcasts are available to designers. One such standard is the ATSC Digital Television Standard prepared by the Advanced Television Systems Committee dated Sep. 16, 1995. That standard describes a system for transmitting high quality compressed and multiplexed video and audio and ancillary data over a single six megahertz channel. A coded video source may have a resolution as high as five times that of conventional television. 
     Digital television systems may include source coding and compression, a service multiplex and transport and a radio frequency (RF)/transmission section. Source coding and compression refers to bit rate reduction methods, also known as data compression, appropriate for application to video, audio and ancillary digital data streams. The ancillary data may include control data and conditional access control data associated with the programmed audio and video services, such as closed captioning. The purpose of the source coding is to minimize the number of bits needed to represent the audio and video information. Digital television systems may employ the Moving Picture Experts Group ISO/IEL 13818-1 (MPEG-2 Systems) video streams syntax for coding of video and the ATSC A/52 Digital Audio Compression (AC-3) Standard (1995) for coding of audio. 
     Service multiplex and transport refers to a means of dividing the digital data stream into packets of information, the means of uniquely identifying each packet or packet type and appropriate methods of multiplexing video data stream packets, audio data stream packets, and ancillary data stream packets into a single data stream. Potential digital transport media include terrestrial broadcasting, cable distribution, satellite distribution, use of recording media and computer interfaces as examples. 
     RF/transmission refers to channel coding and modulation. The channel coder takes a bit stream and adds additional information that can be used by the receiver to reconstruct the data from the received signal which, due to transmission impairments, may not accurately represent the transmitted signal. The modulation uses the digital data stream information to modulate the transmitted signal. 
     Referring to FIG. 2, a packet filter  10 , receives the service multiplex and transport. The packet filter  10  separates out a tuned channel and further separates the video and audio data for that tuned channel. Thus, the output signal of the packet filter  10  includes a video data queue  14  and an audio data queue  16  for a channel. The video and audio data is decoded in an audio/visual decoder  18 . 
     The decoder  18  produces decompressed audio and video data which passes to an encoder  20  and an audio digital to analog converter  22 . As a result, the information may be converted into an analog audio format compatible with a conventional analog television receiver. If the television receiver is a digital television receiver, the output of the decoder  18  may be coupled directly to the television  112 . 
     The packet filter  10  may receive a list of channels of interest through an input device  12 . The channels of interest are channels which the user wishes to have the system monitor to determine the degree of action on those channels. For each of the channels which are not currently tuned in but which are channels of interest, the system outputs the packets by channel to a plurality of counters  24 ,  26  and  28 . Each counter  24 ,  26  and  28  counts the number of packets identified as video data. 
     The counters  24 ,  26  and  28  are coupled to a timer  30  so that a count of packets over a given time interval can be maintained for each selected channel. Each packet counter outputs a bit rate for a given channel. The bit rate is a rate at which the compressed bit stream is delivered from the channel to the input of the counter. 
     The filter  10  includes circuitry for parsing a packet identifier (PID) from the multiplexed transport stream of packets. The packet identifier is a unique integer value used to associate elementary streams of a program in a single or multi-program transport stream. Thus, the filter  10  filters the headers containing the packet identifiers. The filter  10  determines when a packet of interest has been encountered, for example, by scanning packet headers. The packet of interest may be the one to which the television receiver is currently tuned or any of the channels listed in the viewer&#39;s interest list. 
     Thus, the bit rate for each of the channels of interest may be provided to a display device  32  which may display the bit rates for the selected channels on the television  112  screen. For example, a variety of integrated circuit character generators are available to convert data into a display screen overlay. Alternatively, the display may be implemented using software. 
     Thus, referring to FIG. 3, the device  32  may produce a graph of bit rate versus channel, in accordance with one embodiment of the invention, so that the user can see the relative degree of action on each of the various channels which the user monitors. The user then may switch to another channel. For example, in one embodiment of the present invention, when the user cursor clicks on the graph for a given channel, such as a channel graphic  36  or  38 , the receiver may be automatically tune to that channel. Alternatively, if the bit rate exceeds a preset level, the user may be immediately notified, for example, by displaying the other channel in a picture-in-picture display associated with the system  130 . 
     The present invention is applicable to a variety of systems including digital systems using variable bit rates (VBRs). A variable bit rate is where the bit rate varies with time during the decoding of a compressed bit stream. In VBR streams, because slow moving scenes are easy to encode, they do not use as many bits as action packed scenes. The action packed scenes are hard to encode and use far more bits. Action scenes include fast moving action such as sports action. If the bit rate of all the channels or a select set of channels is monitored, then the user can be notified in real time of situations when the bit rate makes a significant increase. This may signify the beginning of an event that may be of the type the viewer wants to watch. 
     Referring next to FIG. 4, a hardware implementation for the embodiment shown in FIG. 1 includes a processor  150 . In one embodiment, the processor  150  may be coupled to an accelerated graphics port AGP (see Accelerated Graphics Port Interface Specification, Rev. 1.0, published Jul. 31, 1996 by Intel Corporation, Santa Clara, Calif.) chipset  152  for implementing an accelerated graphics port embodiment. The chipset  152  may communicate with the AGP port  154  and a graphics accelerator  156 . The television  112  may be coupled to the video output of the graphics accelerator  156 . The chipset  152  accommodates the system memory  158 . 
     The chipset  152  may also be coupled to bus  160 . The bus  160  couples a television tuner/capture card  162  which is coupled to an antenna  164  or other video input port, such as a cable input port, a satellite receiver/antenna or the like. The television tuner/capture card  162  selects a television channel and also performs a video capture function. 
     The bus  160  is also coupled to a bridge  166  which may couple a storage device such as a hard disk drive  168  or flash memory. The drive  168  may store the software  40  and  50  which may be responsible for providing the display illustrated in FIG.  3  and for implementing an automatic channel tuning embodiment. 
     The bridge  166  may also be coupled to another bus  170 . The bus  170  may in turn be coupled to a serial input/output (SIO) device  172 . The device  172  may be coupled to an infrared (IR) interface  134 . Also connected to the bus  170  is a basic input/output system (BIOS)  174 . 
     The IR interface  134  may communicate using infrared signals with an IR interface  118  on the RCU  114 . Any of a variety of protocols may be utilized for implementing IR communications. In addition, other forms of airwave communications may be utilized as well. 
     The IR interface  118  on the RCU  114  communicates with a controller  150   a  which may be a processor such as a digital signal processor. The processor  150   a  communicates with the keypad  116  on the RCU  114  and the memory  158   a . The memory  158   a  may conveniently be implemented by a flash memory. 
     Referring to FIG. 5, channel set-up software  40  may begin by prompting for channels to monitor (block  42 ). The user may input a plurality of channels which the system may monitor for action. The user input commands may be provided through the input device  12 , such as a keyboard, and provided to the packet filter  10 . The channels which are selected for monitoring are received and stored as indicated in block  44 . 
     The user may then be asked to provide a preset action level which serves as the floor for providing a user notification when an actual detected action level exceeds a preset level, as indicated in block  46 . The preset action level for each channel is then received and stored as indicated in block  48 . 
     Referring next to FIG. 6, the software  50  for indicating the level of action begins by receiving the action levels from the card  162 , as indicated in block  52 . Those levels may be compared to the preset level previously provided by the user, as indicated in block  54 . If the detected action level exceeds the preset level, as determined in diamond  56 , the monitored channel with a high level of action may be displayed within a picture-in-picture display, as indicated in block  58 , in one embodiment of the invention. 
     While the present invention has been described with respect to a limited number of embodiments, those skilled in the art will appreciate numerous modifications and variations therefrom. It is intended that the appended claims cover all such modifications and variations as fall within the true spirit and scope of this present invention.