1 files changed, 43 insertions, 0 deletions
diff --git a/src/cnki_jbig2.c b/src/cnki_jbig2.c
new file mode 100644
index 0000000..69f4a5b
--- /dev/null
+++ b/src/cnki_jbig2.c
@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2022, yzrh <yzrh@noema.org>
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "cnki_jbig.h"
+#include "jbig2.h"
+
+int
+cnki_jbig2(char **bitmap, int *bitmap_size,
+	int *bitmap_width, int *bitmap_height,
+	const char * restrict jbig, int jbig_size)
+{
+	dib_t *dib = malloc(sizeof(dib_t));
+
+	if (dib == NULL)
+		return 1;
+
+	memcpy(dib, jbig, 40);
+
+	int width_padded = (dib->width * dib->depth + 7) / 8;
+
+	*bitmap_size = dib->height * width_padded;
+	*bitmap = malloc(*bitmap_size);
+
+	if (*bitmap == NULL) {
+		free(dib);
+		return 1;
+	}
+
+	strdec_jbig2(bitmap, jbig + 48, jbig_size - 48);
+
+	*bitmap_width = dib->width;
+	*bitmap_height = dib->height;
+
+	free(dib);
+
+	return 0;
+}