, definition of control information in ddff files More...

Include dependency graph for ControlBlock.hxx:

Classes
struct	ControlBlockRead
	Object to decode a control block. More...

Functions
void	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.

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

Function Documentation

Write a control block at the start of a message buffer.

Parameters

buffer	Buffer where the block is written.
stream_id	Stream number.
buffer_num	Number of the buffer in the stream.