The invention is directed toward the field of monitoring a digital signal, and more particularly to the field of monitoring a stream of packets, and more particularly toward how the monitored stream of packets is depicted on a display device, and more particularly to such a depiction of a digital television transport stream multiplex of packets.
A digital television (DTV) signal (a transport stream multiplex of packets) is formed of multiple packets, some of which represent video data, some which represent audio data and some of which represent metadata. The metadata is used by a DTV receiver to reconstruct the packetized DTV signal for a given virtual channel. A terrestrial DTV broadcaster's bandwidth, or physical channel, can contain multiple virtual channels, where each channel can contain a program or some other content.
A DTV signal can conform to the Moving Picture Experts Group (MPEG) 2 standard. An MPEG2 Transport Stream is defined as a number of fixed-length packets. Each packet has a four-byte header that contains a synchronization byte, a packet identification number, a continuity count and several control bits.
The transport stream multiplex is a complex arrangement of separate, mostly-independent information. An MPEG2 transport stream multiplex can include up to 8192 different packet identifiers (PIDs). Typically, though, perhaps a dozen PIDs are used in a transport stream multiplex.
Analyzing or visualizing the contents of such a stream is difficult because the volume of data is large and the complexity of the data is relatively high. For example, a high definition television (HDTV) broadcast that complies with the American Television Standards Committee (ATSC), i.e., an ATSC-compliant HDTV broadcast, will minimally contain data that includes at least 10 separate packet identifiers (PIDs), and packets will be sent at a rate of approximately 2.4 million bytes of data, or 12.9 thousand packets, per second. And this merely represents a relatively simple transport stream. Streams with multiple standard digital television (SDTV) programs and full electronic program guide (EPG) support (another type of metadata) can include dozens of PIDs.
Understanding and visualizing such a great amount of data at even low rates can be very confusing.
The known monitoring systems provide a means of selecting specific packets based on PID and a pre-existing knowledge of packet location in the stream (packet occurrence). The display of these packets is done by providing a dump of the actual digital contents of a single packet along with some formatting to identify particular portions of the packet.
Some of the systems allow packets to be grouped and traversed based on the type of the packet as indicated by the PID. For example, the AT953-ATSC STREAM STATION model of monitoring and analyzing system available from SENCORE ELECTRONICS can do the following. Once a packet of a given type has been identified and its contents displayed, a user can click on a back button or a forward button to view the contents of the previous or next packet of the same type. But at any one instance, only the contents of a simple packet are displayed.
The known monitoring devices only characterize a packet by displaying its contents. That is, they fail to give a visual impression or characterization of the each packet in the transport stream multiplex independently of a display of its contents, especially as this relates to visually differentiating amongst the variety, and emphasizing the relative sequential arrangement, of different packets contained in the transport multiplex during a display of a portion of the multiplex. In addition, the user of the known monitoring devices must have extensive knowledge of the make-up of an MPEG2 stream in order to be able to select a packet whose contents are to be examined in more detail. For example, the user of the known monitoring/analysis systems can discover that the PID 49 is video by viewing the PAT, finding the associated PMT and then determining the type of PID 49 by looking at the detailed contents of the PMT.
In the computer industry, it is known to use a grid of color-coded boxes to depict the progress of a disk defragmenting operation. But such visual representations have never been applied to a transport stream multiplex. In more detail, as shown in
The invention, in part, provides a technology to monitor a packetized signal, e.g., at least a portion of a transport stream multiplex, by presenting a visual image of the signal to a user that conveys a visual impression of the contents of the transport stream multiplex without displaying the actual contents, especially as it relates to the variety of different packets contained in the transport multiplex and the relative sequential arrangement of the packets therein. Such technology does not require the user/viewer to have knowledge of the make-up of an MPEG2 stream in order to be able to select a packet whose contents she wishes to examine in more detail.
The invention, also in part, provides an integrated digital television (DTV) diagnostic instrument (and the method and software embodied therein) comprising: a video display device (VDD); a controller to receive a DTV signal in the form of a stream of packets and to generate a graphical depiction on said VDD of a plurality of individual packets representing said stream. Such technology is operable to drill down into (select finer detail about) the contents of individual packets in the stream and to generate a display of such contents.
Such a graphical depiction on the VDD for the stream of packets can take the form of a matrix of geometric shapes, e.g., a square, each geometric shape representing a packet. Each geometric shape can have an appearance that is indicative of what type the corresponding packet is. Colors can be assigned to the geometric shapes to denote the types of the corresponding packets, respectively. Such technology can also generate a graphical depiction on the VDD of a legend explaining color and packet type relations. Each color in the legend can be depicted in the form of the geometric shape, and each geometric shape can be operable as a pointing-device-clickable button so that, in response to a user clicking on one of the geometric shapes, an interface can be generated by which the color assigned to the geometric shape can be changed by the user.
Such technology can accommodate a stream of packets representing a DTV signal containing multiple video programs. In that situation, different shades of a color representing a type of packet are assigned to denote which one of the multiple video programs corresponds to the geometric shape.
Advantages of the present invention will become more apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
The patent or application file contains at least one drawing excuted in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the office upon request and payment of the necessary fees.
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus do not limit the present invention.
And
An integrated digital television (DTV) diagnostic instrument (and the method and software embodied therein) according to the invention uses known hardware programmed according to the invention. Such hardware is depicted in FIG. 4. The system 400 of
The DTV receiver 412 can be DTVCARD A1000 model of circuit board manufactured and sold by TRIVENI DIGITAL INC. The processor 406 can be of the PENTIUM family of processors sold by INTEL INC., e.g., a 450 MHz PENTIUM III processor, preferably running a WINDOWS 98 operating system manufactured and sold by the MICROSOFT CORPORATION in the case where the DTV A1000 card is employed as the DTV receiver 412. Examples of portable computers with expansions slots to accommodate the DTV A1000 card (among others) are the PAC series of rugged portable computers, e.g., the FLEXPAC and the LPAC, manufactured by DOLCH COMPUTER SYSTEMS, INC.
Alternatively, the DTV receiver 412 and/or the processor 406 can be configured to received alternative formats of the stream of packets. Such alternate formats can include the DvB ASI format and the Society of Motion Picture and Television Engineers (SMPTE) 310M-1998 format.
Upon receiving a stream of packets representing a DTV transport stream multiplex, the controller 402 is operable to generate a graphical depiction on the VDD 416 of the transport stream multiplex.
Such a graphical depiction on the VDD 416 for the stream of packets can take the form of a grid/matrix of geometric shapes each geometric shape representing a packet, as in the transport stream packet map display of FIG. 1.
In
It is to be noted that the color coding of
Similarly, buttons in
The controller 402 can generate the grid in real time as the DTV signal is received via an antenna or coaxial cable 414 or can operate upon a recorded portion of a DTV signal obtained via the disk storage device 418 or the network 420. As a practical matter, for at least the short term, the grid will most likely be generated based upon a recorded DTV signal because commercially available processors that are reasonable in cost do not have the processing power to generate the grid in real time. And if they did, the grid would scroll so fast as to be unintelligible to the typical user/viewer.
The effect is that the viewer sees the transport stream multiplex in slow motion with each button colored to indicate the contents or type of its associated packet. The general animation along with the packet map color-coding and arrangement give the viewer an impression as to the contents of the stream without actually displaying the contents of a packet unless the user desires to see such contents.
Colors can be assigned to the geometric shapes to denote the types of the corresponding packets, respectively. The processor 406 can also generate a graphical depiction on the VDD 416 of a legend explaining the relations between color and the contents or type of the associated packet such as in the packet map key of FIG. 2.
In
Each color in the legend or packet map key of
Also, each geometric shape in the packet map display is operable as a pointing-device-clickable button. When selected (e.g., clicked on) with a pointing device, the processor 406 is operable to respond with a detailed diagram of the actual packet contents or contained therein information, i.e., drill down into the contents of the packet, as in the example of FIG. 3. There, the depicted contents of the packet include the true false states of the following parameters: transport_error_indicator; payload_unit_start_indicator; transport_priority; transport_scrambling_control;
Such drill down capability, along with the ability to quickly find packet types in the display because of the visual differentiation (due to whatever particular combination of colors and patterning is chosen), allows the user to easily identify the packet of a given type or content, select the packet of interest and view it in detail.
The controller 402 generates the grid of geometric shapes representing the packets in the transport stream multiplex according to how the processor 406 is programmed. A first embodiment of such software uses the known JAVA button for each of the geometric shapes. A known JAVA button has a significant amount of standard functionality. While effective at generating the grid, it was determined that most of the standard functionality is not being used, thus representing a squandering of the processing power consumed to make it available. So a second embodiment was developed.
The second embodiment achieves the functionality for the buttons as was used in the first embodiment without all of the unused functionality of the true JAVA button.
The result is a quasi button or faux button. Instead of using JAVA buttons, the second embodiment is an adaptation of known technology for (1) recognizing cursor positions over images such as maps and (2) performing one or more actions particular to the cursor location in response to the click of a pointing device.
In the second embodiment, the processor 406 builds the entire packet map display in advance before operating upon a DTV signal. It fills the available area with squares such as those in FIG. 5.
The square 500 in
Initially, the processor sets the regions 502, 504 and 506 of each square 500 to all be the same background color so that each square 500 does not appear to be present on the display. As the processor 406 extracts data about the packets, it causes the squares 500 to repaint according to a predetermined color and pattern scheme.
An advantage of the second embodiment is the ease with which the faux buttons, i.e., the squares 500, can be made to repaint themselves, especially as compared to the standard JAVA button.
The following is example pseudocode (in the JAVA language) for generating faux buttons according to the second embodiment. Comments within the pseudocode are preceded by two asterisks (**)
The particular example of color and pattern combinations in
It is to be noted that an ATSC-compliant transport stream may have a number of different types of transport packets: audio, video, data, PSIP, null, and unknown. Packets of unknown type can indicate one or more problems with the PAT, PMT and PSIP tables, since the tables should allow the DTV receiver 412 to identify the type of every packet that appears in the broadcast stream. However, almost all packets are “unknown” to the DTV receiver 412 until the program association table (PAT), program map tables (PMTs) and PSIP master guide table (MGT) are encountered in the DTV packet transport multiplex, so it is normal to encounter a large block of packets of the unknown type at the initial stage of analysis.
In addition to color information, there are also patterns superimposed on the button colors that indicate other additional information aside from simply the type of the associated packet. A button for which half is black indicates that the corresponding packet has a program clock reference (PCR). Each vertical or horizontal line through a button represents a flag in the packet header. More particularly, a button having a superimposed vertical line indicates that the corresponding packet is the start of a payload. And a button having a superimposed horizontal line indicates that that the corresponding packet is a packet with adaptation. A button having superimposed diagonal intersecting lines indicates that the corresponding packet has a transport error. And a button for which half is pink indicates that the corresponding packet has a packet adaptation data error.
Experienced operators can easily determine where such things as payload start indicators and adaptation headers occur by quickly looking at the display. If errors occur, these are marked with certain graphical symbols to easily allow the operator to determine where the error occurred.
The large white row of
The large white row is also formed of the squares 500, except that the background region 502, the main region 504 and the shading region 506 are all set to the color of the large row, namely white.
The invention is especially well suited to operating upon terrestrial digital television signals, but it is equally applicable to any packetized signal.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
This application claims priority under 35. U.S.C. § 120 upon provisional U.S. patent application Ser. No. 60/197,663, filed Apr. 17, 2000, the entirety of which is hereby incorporated by reference.
Number | Name | Date | Kind |
---|---|---|---|
4630266 | Deparis et al. | Dec 1986 | A |
5640388 | Woodhead et al. | Jun 1997 | A |
6057882 | van den Branden Lambrecht et al. | May 2000 | A |
6188674 | Chen et al. | Feb 2001 | B1 |
6366314 | Goudezeune et al. | Apr 2002 | B1 |
6421805 | McAuliffe | Jul 2002 | B1 |
6456605 | Laakso et al. | Sep 2002 | B1 |
6484143 | Swildens et al. | Nov 2002 | B1 |
Number | Date | Country |
---|---|---|
10042258 | Feb 1998 | JP |
Number | Date | Country | |
---|---|---|---|
20020008781 A1 | Jan 2002 | US |
Number | Date | Country | |
---|---|---|---|
60197663 | Apr 2000 | US |