, definition of control information in ddff files More...
Include dependency graph for ControlBlock.hxx:
Classes | |
| struct | dueca::ddff::ControlBlockRead |
| Object to decode a control block. More... | |
Functions | |
| void | dueca::ddff::control_block_write (DDFFMessageBuffer::ptr_type buffer, uint16_t stream_id, unsigned buffer_num) |
| Write a control block at the start of a message buffer. | |
Variables | |
| const size_t | dueca::ddff::control_block_size = 28 |
| Size of ddff control blocks. | |
Detailed Description
, definition of control information in ddff files
Each block has the following 28-byte header:
- 8 byte signed integer, big endian, with the offset of the next block in the sequence of blocks with this ID, or -1, for the last block. When this is 0 (impossible number), the location of this block is not yet known
- 2-byte unsigned integer crc checksum for the block; all bytes of the block's data area except the present are included in this checksum
- 2-byte unsigned integer, big endian, indicates the stream id
- 4-byte unsigned integer, big endian, indicates this block's size.
- 4-byte unsigned integer, big endian, indicates this block's fill level, i.e., number of data bytes, including the 28 control bytes.
- 4-byte unsigned integer, big endian, indicates the offset of this block's first started write. 0 if no write started in this block; for starting reading at any place
- 4-byte unsigned integer, big endian, indicates the block number