Feature Request: Add C api for mtmd

[chinshou]

Prerequisites

• I am running the latest code. Mention the version if possible as well.
• I carefully followed the README.md.
• I searched using keywords relevant to my issue to make sure that I am creating a new issue that is not already open (or closed).
• I reviewed the Discussions, and have a new and useful enhancement to share.

Feature Description

mtmd api now is C++ api, for example mtmd_tokenize function parameters is C++ vector.

We also need the pure C api to use it from 3rd language bindings.

Motivation

for example: such c api interface will be helpful

MTMD_API int32_t mtmd_tokenize(mtmd_context * ctx,
mtmd_input_chunk** output,
const mtmd_input_text & text,
mtmd_bitmap* bitmaps);

Possible Implementation

No response

[ngxson]

We will definitely add a pure C API once the libmtmd become more stable. Adding it right now may risk giving you a lot of breaking change and headaches.

I think I will work on this once qwen2 / qwen2.5 is finally migrated to libmtmd

[chinshou]

Thank you very much. I will start to use the api to support vision