2013年02月19日
The ATSC standard
Digital television in the United States will be using the standard ATSC ( Advanced Television System Committee Advanced Television Systems Committee ), ATSC digital TV standard consists of four separate layers, with clear interface between levels. The highest as the image layer, determine the form of images, including pixel array, amplitude ratio and frame rate. Then the image compression layer, using MPEG-2 compression standard. Then system multiplexing layer, specific data can be incorporated into different compression package, using MPEG-2 compression standard. The last is the transport layer, determine the modulation and channel coding scheme of data transmission. For terrestrial broadcasting system, using the 8-VSB transport model developed by zenith, in 6mhz terrestrial broadcasting channel can realize the transmission rate of 19.3mb/s. This standard also contains is suitable for CATV system with high data rate 16-vsb transmission mode, can realize the transmission rate of 38.6mb/s in 6mhz cable TV channel.
The following two layers to share common data transmission. The above two layers determine the specific configuration operation based on common data transmission, such as HDTV or SDTV.
The above two layer also determine the specific image format supported by the ATSC standard, a total of 18 formats ( HDTV6, SDTV12 ), 14 of which employ progressive scanning.
A.HDTV, 1920 pixels ( H ) X1080 ( V ), pixel aspect ratio of 16:9, frame 60HZ/ interlaced, progressive scan frame 30Hz/, frame 24Hz/ line-by-line scanning system;
B.HDTV, 1280 pixels ( H ) X720 ( V ), pixel aspect ratio of 16:9, 60Hz and 30Hz frame rate, 24Hz/ line-by-line scanning system;
C.SDTV, 704 pixels ( H ) x480 ( V ), pixel aspect ratio of 16:9 or 4:3, a 60Hz/ interlaced scanning system, frame rate 60Hz and 30Hz, 24Hz/ line-by-line scanning system;
D.SDTV, 640 pixels ( H ) x480 ( V ), pixel aspect ratio of 4:3, a 60Hz/ interlaced scanning system, frame rate 60Hz, 30Hz, 24Hz/ line-by-line scanning system .
In addition, ATSC also develops through the frame rate of 50Hz countries use the prior standard. The pixel array HDTV the same, but the frame for the vertical resolution of the 25Hz and 50HzoSDTV format as 576 rows of horizontal resolution is different; also contains 352x288 format, necessary to adapt to the window settings. Based on the 50Hz version of the ATSCDTV standard to make the frame rate of 50Hz countries are more easy to use.
The following two layers to share common data transmission. The above two layers determine the specific configuration operation based on common data transmission, such as HDTV or SDTV.
The above two layer also determine the specific image format supported by the ATSC standard, a total of 18 formats ( HDTV6, SDTV12 ), 14 of which employ progressive scanning.
A.HDTV, 1920 pixels ( H ) X1080 ( V ), pixel aspect ratio of 16:9, frame 60HZ/ interlaced, progressive scan frame 30Hz/, frame 24Hz/ line-by-line scanning system;
B.HDTV, 1280 pixels ( H ) X720 ( V ), pixel aspect ratio of 16:9, 60Hz and 30Hz frame rate, 24Hz/ line-by-line scanning system;
C.SDTV, 704 pixels ( H ) x480 ( V ), pixel aspect ratio of 16:9 or 4:3, a 60Hz/ interlaced scanning system, frame rate 60Hz and 30Hz, 24Hz/ line-by-line scanning system;
D.SDTV, 640 pixels ( H ) x480 ( V ), pixel aspect ratio of 4:3, a 60Hz/ interlaced scanning system, frame rate 60Hz, 30Hz, 24Hz/ line-by-line scanning system .
In addition, ATSC also develops through the frame rate of 50Hz countries use the prior standard. The pixel array HDTV the same, but the frame for the vertical resolution of the 25Hz and 50HzoSDTV format as 576 rows of horizontal resolution is different; also contains 352x288 format, necessary to adapt to the window settings. Based on the 50Hz version of the ATSCDTV standard to make the frame rate of 50Hz countries are more easy to use.
Posted by cc at 18:19
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