Before the Beijing Olympic Games, terrestrial digital TV was launched, using DMB-H scheme, MPEG-2 and H.264 for video coding and ACC and MP3 for audio coding, all of which are international common standards. And from the beginning, the mode of encrypted charging was adopted. This scheme introduces HD mode for home TV (only in a few cities such as Beijing) and CMMB mode for mobile devices respectively. Due to the cost and patents, it has not been widely promoted nationwide. Only CMMB has formed a certain market because it is used for rural household registration.
Shortly thereafter, China began to formulate its own terrestrial digital TV standard DTMB. Video coding adopts AVS+ (AVS is incompatible in the early stage), and audio coding adopts DRA, which is played by Liu Qing for free. It has become a new national standard for terrestrial digital TV, and has been listed as one of the four global standards by ITU.
DTMB terrestrial digital TV has been piloted in Hunan since 20 13. In 20 14, it is required that the newly listed TV sets of 40 inches and above must directly support the reception and decoding of this standard, that is to say, ordinary terrestrial wave antennas can watch directly without set-top boxes. However, there are still a large number of TV sets on the market that do not support the audio and video decoding of the new national standard and need external ground wave set-top boxes.
Knowledge expansion:
Installation method:
1. Connect the wired white signal line to the RF input port on the back of the set-top box. Note that there is a loop output next to the RF input port that does not need to be connected, and the instructions will generally be connected to you.
2. Connect the set-top box to the AV signal line of the TV, that is, the red, white and yellow lotus heads, and there will be this interface on the back of the TV. Some very old TVs don't. You must have it. Some TVs have multiple sets of AV interfaces behind them. If AV 1 is connected, you need to switch to AV 1 with the TV remote control after turning on the TV. So is AV2.
3. Insert the distributed smart card into the set-top box, and pay attention to the insertion direction and the positive and negative directions. There are samples in the manual.
4. Connect the power supply of the set-top box and turn it on, then turn on the TV and switch to the corresponding AV state.