HDTV Bandwidth Management

Many people, especially with receivers of satellite television, have heard of MPEG. MPEG is a standard to reduce the size of the video signal, so they are more easily spread. This is called "compression of signals known." Compressed Digital Video (CDV) is similar to MP3 files for music. Thus the file smaller without damaging it, so that less time to download (less bandwidth), and more songs can be stored on the hard drive.

CDV reduces the signal bandwidth Requirements for a TV signal to allow its transmission over the Internet, DVD, cable or satellite. This is necessary because an uncompressed video signal is very large. HD files are much larger than the standard definition files.

A standard definition DVD-Video file size is approximately 3 GB / hour.
An uncompressed 1280 X 720 (HDTV) video file size is over 150 GB / hour.
An uncompressed 1920 X 1080 (HDTV) video file size is over 350 GB / hour.
An MPEG-2 (CDV)> Resize HDTV video is about 9 GB / hour.
An MPEG-4 (VCT), the size of the HDTV movie file is about 5 GB / hour.

The early use of VCT (for programming in standard definition) was created by the companies of satellite television, DirecTV and Dish Network to life.

VCT is the process of rejection of data for information that would be invisible to the viewer. However, VCT significantly distort the result. The higher the level of VCT, more data is eliminated.Jeter, too, and the distortion is very noticeable.

CDV is a compromise between file size and image quality. VCT is working on neighborhoods of pixels called macroblock. VCT records only the changes in these blocks. This works well when the video mostly static images like text.

In a game of basketball, Kobe, when he takes to the basket, more pixels change from one image to another. To work in this case, the video compression algorithm harder. Image qualityafter compression depends on the complexity and predictability of the image.

The common standards CDV is written by the Moving Picture Experts Group (MPEG). Applying CDV video of the computer is an intensive cooperation, but relief (undo VCT) data into MPEG video is much less difficult. A C-Cube real-time MPEG-1 video encoder with 8 specifically for video processor chips sold for $ 120,000.

The MPEG standards are not heard by anyone. Various companies and researchersMPEG patents, but said not to pay a license fee for the use of MPEG technology.

DVD and Blu-ray have mastered CDV during the process (Blu-ray disc used has a capacity is not sufficient that the CDV is aggressive, however) leads to significant distortions. Algorithms broadband video with little CDV exist for video post-production, but it always creates a very large file, and therefore only rarely for video distribution.

There are different MPEG standards areused, but only three are typically used for video distribution industries:

MPEG-1

MPEG-1 was the first widespread video (and audio) VCT standard. MP3 stands for MPEG-1 Audio Layer 3. "MPEG-1 supports a video resolution of 352 x 240 at 30 fps (frames per second). It is the norm for VCD moving images (and audio). This standard has its roots (in video applications, CD-ROM and is popular for video available on the Internet. MpgFiles).

MPEG-2

MPEG-2 video resolutions to 720 x 480 1280 x 720 at 60 frames / sec. MPEG-2 is both for standard-definition TV and high-definition-capable. The MPEG-2 standard is also used to store data on DVD. This is the algorithm used by DirecTV and Dish Network.

MPEG-2 is the digital TV standard to which the decoders and DVD-based CDV. This last is based on the MPEG-1, but also for broadcast digital television. Various algorithms have beendeveloped and were integrated into the standard. MPEG-2 is well suited to HDTV resolution and bit rate. With this technique, CDV can compress the video data 25 to 15 times while providing image quality is generally considered high quality.

MPEG-4

This standard is the future VCT-standard, are of use almost certainly by most services, create HDTV. These include AT & T, DirecTV and Dish Network. A number of cable operatorsalso begun to MPEG-4 tests. This standard was originally designed for the Internet. The individual objects within a scene will be recorded separately. This is very effective.

The transition to MPEG-4 by the satellite companies is not designed to improve image quality, but because this algorithm is much more effective. An MPEG-2 HDTV channels with the bandwidth of six television channels in standard definition, MPEG-4 HDTV channels consume bandwidth three standard-definitionChannels Television. MPEG-4 half the bandwidth of MPEG-2 used, and if you'll be by your service provider able to offer twice the number of channels.

OpenCable Application Platform (OCAP)

Consumers are now able to buy their own cable box / DVR combos with electronics retailing. OCAP is a way for cable operators and other service providers to deploy interactive services, such as a PC. In this way you can your American Idol voters with their remote control to voteTv.

Consumers want their HDTVs, and service providers, the programming can be achieved, a success. MPEG-4 is the best and least expensive for cable operators and other service provider is.

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