mtmd : add C public API (#13184)

* init

* wip

* working version

* add mtmd::bitmaps

* add test target

* rm redundant define

* test: mtmd_input_chunks_free

* rm outdated comment

* fix merging issue

* explicitly create mtmd::input_chunks

* mtmd_input_chunk_copy

* add clone()

* add const to various places

* add warning about breaking changes

* helper: use mtmd_image_tokens_get_n_pos

tests/CMakeLists.txt

@@ -165,6 +165,10 @@ if (NOT GGML_BACKEND_DL)
     llama_build_and_test(test-rope.cpp)
 endif()
 
+# libmtmd
+set(LLAMA_TEST_NAME test-mtmd-c-api)
+llama_build_and_test(test-mtmd-c-api.c)
+target_link_libraries(${LLAMA_TEST_NAME} PRIVATE mtmd)
 
 # dummy executable - not installed
 get_filename_component(TEST_TARGET test-c.c NAME_WE)

tests/test-mtmd-c-api.c

@@ -0,0 +1,63 @@
+#include <stdio.h>
+#include <assert.h>
+
+#include "mtmd.h"
+
+int main(void) {
+    printf("\n\nTesting libmtmd C API...\n");
+    printf("--------\n\n");
+
+    struct mtmd_context_params params = mtmd_context_params_default();
+    printf("Default image marker: %s\n", params.image_marker);
+
+    mtmd_input_chunks * chunks = mtmd_test_create_input_chunks();
+
+    if (!chunks) {
+        fprintf(stderr, "Failed to create input chunks\n");
+        return 1;
+    }
+
+    size_t n_chunks = mtmd_input_chunks_size(chunks);
+    printf("Number of chunks: %zu\n", n_chunks);
+    assert(n_chunks > 0);
+
+    for (size_t i = 0; i < n_chunks; i++) {
+        const mtmd_input_chunk * chunk = mtmd_input_chunks_get(chunks, i);
+        assert(chunk != NULL);
+        enum mtmd_input_chunk_type type = mtmd_input_chunk_get_type(chunk);
+        printf("Chunk %zu type: %d\n", i, type);
+
+        if (type == MTMD_INPUT_CHUNK_TYPE_TEXT) {
+            size_t n_tokens;
+            const llama_token * tokens = mtmd_input_chunk_get_tokens_text(chunk, &n_tokens);
+            printf("    Text chunk with %zu tokens\n", n_tokens);
+            assert(tokens != NULL);
+            assert(n_tokens > 0);
+            for (size_t j = 0; j < n_tokens; j++) {
+                assert(tokens[j] >= 0);
+                printf("    > Token %zu: %d\n", j, tokens[j]);
+            }
+
+        } else if (type == MTMD_INPUT_CHUNK_TYPE_IMAGE) {
+            const mtmd_image_tokens * image_tokens = mtmd_input_chunk_get_tokens_image(chunk);
+            size_t n_tokens = mtmd_image_tokens_get_n_tokens(image_tokens);
+            size_t nx = mtmd_image_tokens_get_nx(image_tokens);
+            size_t ny = mtmd_image_tokens_get_ny(image_tokens);
+            const char * id = mtmd_image_tokens_get_id(image_tokens);
+            assert(n_tokens > 0);
+            assert(nx > 0);
+            assert(ny > 0);
+            assert(id != NULL);
+            printf("    Image chunk with %zu tokens\n", n_tokens);
+            printf("    Image size: %zu x %zu\n", nx, ny);
+            printf("    Image ID: %s\n", id);
+        }
+    }
+
+    // Free the chunks
+    mtmd_input_chunks_free(chunks);
+
+    printf("\n\nDONE: test libmtmd C API...\n");
+
+    return 0;
+}