Various data streams

First, ES flow:

Also called the basic Bitstream, which contains the continuous stream of video, audio, or data.

Second, PES flow:

Also called the basic code stream of packaging, is the basic stream es stream according to the need to divide the length of the packet, and add Baotou to form a packaged basic bitstream pes stream.

The original stream is divided into many PES groupings, keeping the serial order, and an PES grouping contains only the encoded data of a raw stream. The PES packet length is large and can be up to 64K bytes.
PES groupings are grouped into "header" and "Payload (payload)". "Payload" refers to the byte following the first byte. The first 4 bytes of the header form the starting code for the grouping, identifying the type and ID number of the original stream to which the grouping belongs.

Third, TS Flow:

Also known as the transport stream, is a fixed length of 188 bytes of the package, containing a separate time base of one or more programs, suitable for more error-free environment.

ts grouping is The data packets that are formed by the transport stream data. Each TS packet length is 188 bytes, including the "Packet Header" and "payload, the first 4 bytes is the packet header, which contains some information about this grouping." In some cases when more information is required, add the "Adjust field (adaption fields)" later.

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Four, GS flow

Due to the dvb-s in bandwidth utilization and modulation coding, the second generation of digital satellite broadcasting standards (the second generation of a digital video broadcasting.satellite, DVB? S2),

Using a more advanced modulation coding method, on the basis of compatible TS stream, a new stream is introduced, i.e. General Stream,gs. Under the same conditions, DVB. The S2 saves about 30% of the bandwidth compared to DVB.S.

Concept:

Protocol Unit (Protocol data UNIT,PDU)

Universal Flow Package (General stream en. capsulation,gse)

According to the base band frame:

Matype's first byte (matype.1) of the TS/GS domain, indicating that the transport stream format is a TS stream or GS stream,

The Sis/mis field indicates whether the input stream is a single or multiple input. The Sis/mis value is "L", which represents a single input stream,

The 2nd byte (matype.2) of the matype is equal to the input stream identifier (InputStream Identi.tier,isi) and is not "0";

The Sis/mis value is "0", which indicates a multiple input stream, MATYPE.2 is a reserved byte, and the value is generally "Ox00".
The UPL field represents the length of the user package, in bits. The UPL value is "0000 ... ", which indicates that the input stream is a continuous stream, and the UPL value is" 188x8. ", which indicates that the user package is an MPEG transport stream package with a length of 188 bytes.

The baseband frame header of the GS stream for IP data has the following characteristics:
(1) The TS/GS value of matype.1 is binary "01";
(2) when the Sis/mis value of Matype 11 is "1", the MATYPE-2 byte is not "0"; When the Sis/mis value is "0", Matype 12 Bytes is "0x00";
(3) The UPL value is "0x0000";
(4) The DFL value is divisible by 8, because the 1th byte of the DFL domain is a high byte, so the 2nd byte of the DFL domain, the low byte, is also divisible by 8:
(5) The crc.8 does not perform error checking on the first 9 bytes of the baseband frame header.

(1) The S field indicates the starting segment, and the E field is the end segment

(2) LT is label_type type:

The value is "XX", the label domain is 6 bytes, for addressing, equivalent to the MAC address in Ethernet;
The LT value is "11", which indicates that the previous GSE package used in the same baseband frame can be reused, and the GSE header no longer has a label field.
That is, for GSE packages with the same label transferred sequentially, the label field of the GSE header does not need to recur. Need to be aware of
Yes, the baseband frame 1th GSE Package of the LT value cannot be "11", that is, the base band frame of the 1th GSE package can not be the same as the PDU Middle segment of the GSE package.

(3) Gse_length: The GSE package size

(4) Total_length: Total length of the PDU

Various data streams