TS streams are also composed of one or more PES. They can have the same time benchmark or different. The basic reuse idea is to reuse programs for multiple pes with the same time benchmark, and transmit and reuse each PS with an independent time benchmark, finally, ts is generated. The TS packet consists of two parts: the packet header and the packet data. The packet header can also include an extended self-applicable zone. The Header Length occupies 4 bytes, and the self-use zone and packet data occupy 184 bytes. The length of the entire ts package is equivalent to the length of 4 ATM packets. The header of the TS packet consists of the Synchronization Byte, transmission error code indicator, start indicator of the payload unit, transmission priority, and packet identification (PID-packet identification) as shown in the excerpt) transmission and Disturbance Control, adaptive Zone Control, and continuous counter.
It can be used to synchronize the automatic characteristics of the byte string, detect packet restrictions in the data stream, and establish packet synchronization. When the transmission error code indicator is available, the error correction decoder can represent 1 bit codes, but cannot be corrected. The start indicator of the payload Unit indicates whether a specified start information exists in the data packet, the priority is assigned to the TS package. The PID value is determined by the user. The Decoder uses the PID to differentiate the TS packages from different es to reconstruct the original es; transmission Disturbance Control, which indicates whether the data packet content is disturbed, but the packet header and the adaptive area are never disturbed. Adaptive zone control uses 2 bits to indicate whether there is an adaptive zone, that is, (01) indicates that useful information has no adaptive zone, (10) indicates that no useful information has an adaptive zone, (11) indicates that useful information has an adaptive zone, and (00) indicates that no adaptive zone is defined; the continuous counter can count the transfer sequence of the PID package. According to the counter reading, the receiving end can determine whether there are packet loss and packet transfer sequence errors. Apparently, Baotou has synchronization, identification, error checking, and encryption functions for TS packets. The adaptive area of the TS package consists of four parts: Adaptive Area chief, various sign indicators, information related to the inserted sign, and filled data. The marker consists of eight parts: intermittent indicator, random access indicator, es optimized indicator, PCR sign, contact sign, transmission specific data mark, original PCR sign, and adaptive area extension sign.. It is important to mark part of the PCR field, which can provide synchronization data for the 27mhz clock of the decoder for synchronization. The process is to use the PLL to compare the local PCR phase with the input instantaneous PCR phase lock during decoding to determine whether the decoding process is synchronized. If not, then the instantaneous PCR is used to adjust the clock frequency. Because digital images use complex and different compression encoding algorithms, resulting in different data of each image, making it impossible to obtain clock information directly from the beginning of the compressed image data. Therefore, some (rather than all) Self-Adaptive regions of TS packets are selected to transmit the scheduled information. Therefore, the adaptive area of the selected TS packet can be used to determine the control bit and important control information of the packet information. The adaptive area does not need to be sent along with each packet. the maximum number of messages sent is determined by the specific time-scale parameter of the selected TS packet. The random access indicator and contact sign in the sign. When the program changes, it provides a random entry point for the data stream that randomly enters the I-frame compression, and also facilitates the insertion of local programs. The padding data in the adaptive area is because the PES package length cannot be exactly an integer multiple of the TS package. The last ts package retains a small part of the useful capacity, which is filled by padding bytes, this prevents the buffer overflow and keeps the total bit rate unchanged. (To be continued) part of the content from <MPEG-2 compression coding Principles and Applications>
