Field type
Numbers:
- Bit: one bit (True/False) ;
- Bits: unsigned number with a size in bits ;
- Bytes: vector of know bytes (eg. file signature) ;
- UInt8, UInt16, UInt32, UInt64: unsigned number (size: 8, 16, 32, 64 bits) ;
- Int8, Int16, Int32, Int64: signed number (size: 8, 16, 32, 64 bits) ;
- Float32, Float64: 32/64 bits floatting point number (IEEE 754).
Text:
- Character: 8 bits ASCII character ;
- String: fixed length string ;
- CString: string ending with nul byte ("0") ;
- PascalString?8, PascalString?16, PascalString?32: string prefixed with length in a unsigned 8 / 16 / 32 bits integer (use parent endian).
Tools:
- Enum: generic class to associate a value to a description (encapsulate another field) ;
- PaddingBits: padding with a size in bits ;
- PaddingBytes: padding with a size in bytes ;
- FieldSet: a ordered list of fields (contains other fields).
If you didn't found documentation about a format, use "raw" types:
- RawBits: unsigned number with a size in bits ;
- RawBytes: vector with a size in bytes.
Stream
Input stream
- InputStream (generic) ;
- StringInputStream (from a string) ;
- FileInputStream (from a file).
Output stream
- OutputStream (generic) ;
- StringOutputStream (to a string) ;
- FileOutputStream (to a file).
Endian
"Endian" is the order of bytes in memory/file. Different sort of endian does exist:
| Endian | Hachoir name | String "ABCD" | Number 0x1A2B3C4D (1234) | CPU |
| Big endian | BIG_ENDIAN | ABCD | 0x1A 0x2B 0x3C 0x4D (1234) | PowerPC, Motorola 68000, System/370 |
| Little endian | LITTLE_ENDIAN | DCBA | 0x4D 0x3C 0x2B 0x1A (4321) | Intel x86, VAX |
| PDP endian | PDP_ENDIAN | CDAB | 0x3C 0x4D 0x1A 0x2B (3412) | PDP-11 |
| (other endian) | - | BADC | 0x2B 0x1A 0x4D 0x3D (2143) | Is it really used? |
Notes:
- PDP endian is also called "middle endian".
- PDP_ENDIAN is not supported in Hachoir yet
- NETWORK_ENDIAN is an alias for BIG_ENDIAN, it's the endian in network packets
See also:
Other Hachoir documentation
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