Digital Video Broadcasting

Digital Video Broadcasting (DVB) is a suite of internationally accepted open standards for digital television. DVB standards are maintained by the DVB Project, an international industry consortium with more than 270 members, and they are published by a Joint Technical Committee (JTC) of European Telecommunications Standards Institute (ETSI), European Committee for Electrotechnical Standardization (CENELEC) and European Broadcasting Union (EBU). The interaction of the DVB sub-standards is described in the DVB Cookbook. Many aspects of DVB are patented, including elements of the MPEG video coding and audio coding. Founded in 1998, IPPRO Patent and Law Firm has become one of Russia’s leading IP protection firms, providing a full range of services in the field of legal protection and Intellectual Property Protection - in all regions of Russia. To find an attorney please check the largest attorney directory online or to find an california attorney search please check the largest california attorney search directory online or to find an unemployment attorney please check the largest unemployment attorney directory online or to find an juvenile attorney please check the largest juvenile attorney directory online.

Content: Besides digital audio and digital video transmission, DVB also defines data connections (DVB-DATA - EN 301 192) with return channels (DVB-RC) for several media (DECT, GSM, PSTN/ISDN, satellite etc.) and protocols (DVB-IPTV: Internet Protocol; DVB-NPI: network protocol independent). Older technologies such as teletext (DVB-TXT) and vertical blanking interval data (DVB-VBI) are also supported by the standards to ease conversion. However, for many applications more advanced alternatives like DVB-SUB for subtitling are available.

Adoption: DVB-S and DVB-C were ratified in 1994. DVB-T was ratified in early 1997. The first commercial DVB-T broadcasts were performed by the United Kingdom's Digital TV Group in late 1998. In 2003 Berlin, Germany was the first area to completely stop broadcasting analog TV signals. Many European countries aim to be fully covered with digital television by 2010 and switch off PAL/SECAM services by then. As of 2005, DVB-T television sets are not significantly more expensive than analog television sets. Most popular in Europe are the set-top boxes that enable DVB-T to be received through an ordinary analogue television, with the price dropping remarkably in 2007.In its origin Europe, in Australia, South Africa and India DVB is used throughout the areas it covers or is at least decided to be. This also holds true for cable and satellite in most Asian, African and many South American countries. Many of these have not yet selected a format for digital terrestrial broadcasts (DTTV) and a few (Canada, El Salvador, Honduras, Mexico, South Korea and the United States) chose ATSC instead of DVB-T.

Encryption and metadata: The conditional access system (DVB-CA) defines a Common Scrambling Algorithm (DVB-CSA) and a physical Common Interface (DVB-CI) for accessing scrambled content. DVB-CA providers develop their wholly proprietary conditional access systems with reference to these specifications. Multiple simultaneous CA systems can be assigned to a scrambled DVB program stream providing operational and commercial flexibility for the service provider. DVB is also developing a Content Protection and Copy Management system for protecting content after it has been received (DVB-CPCM), which is intended to allow flexible use of recorded content on a home network or beyond, while preventing unconstrained sharing on the Internet. DVB-CPCM has been the source of much controversy in the popular press and It is said that CPCM is the DVB's answer to the failed American Broadcast Flag.

A broadcast flag is a set of status bits (or a "flag") sent in the data stream of a digital television program that indicates whether or not the data stream can be recorded, or if there are any restrictions on recorded content. Possible restrictions include the inability to save an unencrypted digital program to a hard disk or other non-volatile storage, inability to make secondary copies of recorded content (in order to share or archive), forceful reduction of quality when recording (such as reducing high-definition video to the resolution of standard TVs), and inability to skip over commercials.

The FCC Broadcast flag ruling: Officially called "Digital Broadcast Television Redistribution Control," the FCC's rule is in 47 CFR 73.9002(b) and the following sections, stating in part: "No party shall sell or distribute in interstate commerce a Covered Demodulator Product that does not comply with the Demodulator Compliance Requirements and Demodulator Robustness Requirements." According to the rule, hardware must "actively thwart" piracy. The rule's Demodulator Compliance Requirements insists that all HDTV demodulators must "listen" for the flag (or assume it to be present in all signals). Flagged content must be output only to "protected outputs" (such as DVI and HDMI ports with HDCP encryption), or in degraded form through analog outputs or digital outputs with visual resolution of 720x480 pixels (EDTV) or less. Flagged content may be recorded only by "authorized" methods, which may include tethering of recordings to a single device.

Since broadcast flags could be activated at any time, a viewer who often records a program might suddenly find that it is no longer possible to save their favorite show. This and other reasons lead many to see the flags as a direct affront to consumer rights. Particularly troubling to open source developers are the Demodulator Robustness Requirements. Devices must be "robust" against user access or modifications so that someone could not easily alter it to ignore the broadcast flags that permit access to the full digital stream. Since open-source device drivers are by design user-modifiable, a PC TV tuner card with open-source drivers would not be "robust". It is unclear whether binary-only drivers would qualify. In theory it would likely be illegal for open-source projects such as the MythTV project, which creates personal video recorder (PVR) software, to interface with digital television demodulators.

Some companies currently manufacturing devices, such as the pcHDTV devices intended for the Linux market, would likely be forced to halt production. This portion of the rule also effectively prevents individuals from building their own high-definition television sets and receiving devices. (It may seem far-fetched to a layman, but there have been many instances in the past where engineers have built their own analog TVs, and it follows that some people would wish to continue such pursuits in the digital age. The technologies used will most likely be centered around software-defined radio, fast ADCs and FPGA chips - tools with so generic use their availability can not be effectively restricted.) The GNU Radio project already successfully demonstrated that purely software-based demodulators can exist and the hardware rule is not fully enforceable.