Neil Harvey

Hey, I've had a look at what happens to an Excel file when you password protect it, it looks as though it's being wrapped as a compound file binary. In...

Excel xlsx format is actually a zip file, you can actually decompress it and it will be a directory structure containing several xml files. This isn't specific to Linux though,...

Docker would have been my first attempt too, I've no idea why it would fail on a Linux server but work on Docker. Current suspects are that either the entries...

I've tested this on a Ubuntu 20.04 LTS VM and it seems to work as expected: ``` user@vm-ubunutu:~/OfficeFileProbe$ dotnet run ~/OfficeFileProbe/Test.xlsx FileSignatures detected format as: xlsx [application/vnd.openxmlformats-officedocument.spreadsheetml.sheet] Zip contains 10...

Okay, yes that would explain why it's not being detected as an xlsx file. Internally we [use the ZipArchive class](https://github.com/neilharvey/FileSignatures/blob/684cb5fe0aefe3cd770eb0500e8d10232466ee2b/src/FileSignatures/Formats/OfficeOpenXml.cs#L51) to read the zip entries and look for the item...

I've created a Debian 11 VM in Azure and re-run the test, and it succeeds: ``` azureuser@vm-debian:~/OfficeFileProbe$ dotnet run Test.xlsx FileSignatures detected format as: xlsx [application/vnd.openxmlformats-officedocument.spreadsheetml.sheet] ``` Perhaps I can...

Hey, what you need to do is create a new format which inherits from the `FileFormat` class and has the header/extension for mp3/mp4 files. **mp3** has a signature of `49...

@tiesont From what I've read, the first four bytes in the sig mean it's a Quicktime format, then the next four are the subtype, e.g. `66 74 79 70 4D...

Hey, this should have been fixed in #38 - does it work if you upgrade to v4.1?

I'm happy to accept a pull request if it adds some useful formats, I'd always intended this to be written in such a way that the formats could be added...