42 lines
1.0 KiB
Markdown
42 lines
1.0 KiB
Markdown
# Region File (version 2)
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File format BNF (RFC 5234):
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```bnf
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file = header (*chunk) offsets complete file
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header = magic %x02 %x00 magic number, version and reserved
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zero byte
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magic = %x2E %x56 %x4F %x58 '.VOXREG\0'
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%x52 %x45 %x47 %x00
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chunk = int32 (*byte) byte array with size prefix
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offsets = (1024*int32) offsets table
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int32 = 4byte signed big-endian 32 bit integer
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byte = %x00-FF 8 bit unsigned integer
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```
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C struct visualization:
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```c
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typedef unsigned char byte;
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struct file {
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// 10 bytes
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struct {
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char magic[8] = ".VOXREG";
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byte version = 2;
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byte reserved = 0;
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} header;
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struct {
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int32_t size; // byteorder: big-endian
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byte* data;
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} chunks[1024]; // file does not contain zero sizes for missing chunks
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int32_t offsets[1024]; // byteorder: big-endian
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};
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```
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Offsets table contains chunks positions in file. 0 means that chunk is not present in the file. Minimal valid offset is 10 (header size).
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