Grammars VS Kaitai Struct

I contributed a number of file formats a few years ago (and attempted numerous others) but ran into a number of problems with certain file formats:

1. It's not possible to read from the file until a multiple byte termination sequence is detected. [1]

2. You can't read sections of a file where the termination condition is the presence of a sequence of bytes denoting the next unrelated section of the file (and you don't want to consume/read these bytes) [2]

3. The WebIDE at the time couldn't handle very large file format specifications such as Photoshop (PSD) [3]

4. Files containing compressed or encrypted sections require a compression/encryption algorithm to be hardcoded into Kaitai struct libraries for each programming language it can output to.

The WebIDE I particularly liked as it makes it easy to get started and share results. I also liked how Kaitai Struct allows easy definition of constraints (simple ones at least) into the file format specification so that you can say "this section of the file shall have a size not exceeding header.length * 2 bytes".

Some alternative binary file format specification attempts for those interested in seeing alternatives, each with their own set of problems/pros/cons:

1. 010 Editor [4]

2. Synalysis [5]

3. hachoir [6]

4. DFDL [7]

[1] https://github.com/kaitai-io/kaitai_struct/issues/158

[2] https://github.com/kaitai-io/kaitai_struct/issues/156

[3] https://raw.githubusercontent.com/davidhicks/kaitai_struct_f...

[4] https://www.sweetscape.com/010editor/repository/templates/

[5] https://github.com/synalysis/Grammars

[6] https://github.com/vstinner/hachoir/tree/main/hachoir/parser

[7] https://github.com/DFDLSchemas/

- ImHex [2], which has a pattern language [3] which allows parsing, and it seems more powerful than what Kaitai offers. I stumbled upon some limitations with it but it was still useful.

[1]: https://kaitai.io/

Beautiful. Didn't know something like this exists. Reminds me of Katai[0]

[0]. https://kaitai.io/

An EDID override like this would be helpful for macOS as well, where the monitors swapping around after standby is a real annoyance [0] [1]

EDID rewrites are 99% of the time blocked by the monitor firmware: https://notes.alinpanaitiu.com/Decoding-monitor-EDID-on-macO...

By the way, one helpful tool that helped me navigate the EDID dump was Kaitai Struct [2]. It shows a side by side view with the hex view and the EDID structure, and it highlights the hex values in real time as you navigate the structure. Unfortunately [3] it doesn't support the extension blocks that the author needs.

[0] https://notes.alinpanaitiu.com/Weird-monitor-bugs

[1] https://forums.macrumors.com/threads/external-displays-swapp...

[2] https://kaitai.io/

[3] https://github.com/kaitai-io/edid.ksy

Kaitai Struct might be a good choice for that: https://kaitai.io/

For binary log format, there's the excellent Kaitai Struct frameworks, that make it very easy to generate parsers from a declarative schema

kaitai

https://kaitai.io/

Worth a look if you are writing binary parsers.