Patent Application
20060101486
This invention relates to the field of broadcast television and devices that locate and remove advertisements from digital television bitstreams.
It is a problem in the field of broadcast television to prevent subscribers from employing devices that locate and remove advertisements from digital television bitstreams. Digital television bitstreams in the MPEG-2 and other data formats contain audio-visual programming that includes advertisements. The location of these advertisements in the bitstream can be determined based on a number of factors, including: the time-wise predictability of advertisements, anomalies in the bitstream caused by the advertisement insertion process such as changes in bitrate or resolution, and differences in the characteristics of advertisements versus the digital media content.
There are existing systems that consumers use to monitor the digital television bitstream and search for the above-noted factors which identify the presence of an advertisement in the digital television bitstream. Once the advertisement is detected, it is excised from the digital television bitstream. This process is commonly used in systems that are used to record the program content contained in the digital television bitstream. Elimination of advertisements reduces the amount of memory required to store the digital television bitstream and also provides uninterrupted program content in the recorded program. However, the expunging of advertisements from the digital television bitstream reduces the advertisement value of the digital television bitstream to the advertiser, since the audience reached by the advertisements is reduced in size.
Thus, there is a need for a system that blocks the devices that locate and remove advertisements from digital television bitstreams.
The above-described problems are solved and a technical advance achieved by the present system for preventing advertising removal from digital television bitstreams. This system detects the various advertising-specific factors, including: the time-wise predictability of advertisements, anomalies in the bitstream caused by the advertisement insertion process such as changes in bitrate or resolution, and differences in the characteristics of advertisements versus the digital media content, then eliminates these characteristics from the digital media content bitstream. By eliminating the advertising-specific characteristics, there are no identifiable discontinuities in the digital media content bitstream that can be used to locate advertisements and therefore enable their removal from the digital media content bitstream.
Digital television bitstreams in the MPEG-2 and other data formats contain audio-visual programming that includes advertisements. Typically, digital audiovisual content is created separately from the digital advertisements. These two separate bitstreams are merged before transmission. Standards such as ANSI/SCTE 35 and ANSI/SCTE 30 define specific data indicators in the original bitstream to indicate where the advertisements can be inserted. These indicators can be used to identify the location of the advertisement and facilitate the removal of the advertisement from the bitstream. Removal of these indicators after the two bitstreams have been merged prevents this technique from being effective.
For example, ANSI/SCTE 35 defines Splice Points in an MPEG-2 transport stream as a means of providing opportunities to switch elementary streams from one source to another. The Splice Points indicate a place to switch elementary streams or a place in the bit stream where such a switch can be made. Transport streams are created by multiplexing packet identifier (PID) streams, which are all of the packets having the same packet identifier (PID) within a transport stream. The ANSI/SCTE 35 standard defines two types of Splice Points for PID streams: Out Points and In Points. In Points are places in the bit stream where it is acceptable to enter from a splicing standpoint. Out Points are places where it is acceptable to exit the bit stream. Out Points and In Points are imaginary points in the bitstream that are located between two elementary stream presentation units. Out Points and In Points may apply to program streams as well as elementary streams.
Architecture of an Advertising Insertion System
The location of advertisement insertion is typically managed by program advertising staff, which identifies the advertisement as well as the advertisement insertion points in the digital media content bitstream, pursuant to the standards articulated in the above-noted ANSI/SCTE 35 and ANSI/SCTE 30 standards.
In operation, the Advertisement Insertion Server 103 transmits an Insertion Multiplex Signal 102 consisting of advertisements to the Splicer 105, where the Insertion Multiplex Signal 102 is merged with the Primary Multiplex Signal 101. A network channel 104 is used to interconnect the Splicer 105 to the Advertisement Insertion Server 103 to enable control signals to be exchanged there between. The control signals identify the advertisement insertion points and are coordinated with the presence of the advertisement in the associated Insertion Multiplex Signal 102.
The Splicer 105 responds to the control signals by switching the elementary streams that are routed to the output of the Splicer 105. The output from the Splicer 105 is a single transport stream 106 comprising the combination of the two multiplex streams that are input to the Splicer 105. Logically, a splice involves two input channels 101, 102 and one output channel 106. The Splicer 105 is responsible for joining the various elementary streams (audio, video, and data) together. Typically, the communication between the Advertisement Insertion Server 103 and the Splicer 105 is conducted over one TCP/IP socket connection per output channel. The input channels 101, 102 and 103 may be communicated over TCP/IP as well.
Operation of the System for Preventing Advertising Removal
As part of the content splicing process, inserting advertisements into content bitstreams introduces any of a number of factors, including: the time-wise predictability of advertisements, anomalies in the bitstream caused by the advertisement insertion process, such as changes in bitrate or resolution, and differences in the characteristics of advertisements versus the digital media content. The present system for preventing advertising removal from digital television bitstreams detects the various advertising-specific factors, then eliminates these characteristics from the digital media content bitstream. By eliminating the advertising-specific characteristics, there are no identifiable discontinuities in the digital media content bitstream that can be used to locate advertisements and therefore enable their removal from the digital media content bitstream.
At step 221, the system for preventing advertising removal from digital television bitstreams detects a difference in the characteristics of advertisements versus the digital media content. One such difference is that the audio level changes during advertisements, such as the advertisement being louder than that of the digital program content. If the system for preventing advertising removal from digital television bitstreams detects a difference, then the audio level of the advertisements is matched to the content using digital technology at step 222.
At step 231, the system for preventing advertising removal from digital television bitstreams detects the time-wise predictability of advertisements which represents a major advertisement identifier, since advertisements and non-program content information is typically present in a predictable manner at the hour and half hour, with additional insertions typically happening at predetermined times between these benchmark times, at ten or fifteen minute intervals. To overcome this predictability, at step 232, the advertisements are placed at irregular intervals within a program to make it more difficult to locate them. In addition, at step 233, advertisements can be made of irregular duration, rather than the present consistent and uniform duration.
The present system for preventing advertising removal from digital television bitstreams detects the various advertising-specific factors, including: the time-wise predictability of advertisements, anomalies in the bitstream caused by the advertisement insertion process, and differences in the characteristics of advertisements versus the digital media content, then eliminates these characteristics from the digital media content bitstream.
