exif_mnote_data_olympus_save (ExifMnoteData *ne,
		unsigned char **buf, unsigned int *buf_size)
{
	ExifMnoteDataOlympus *n = (ExifMnoteDataOlympus *) ne;
	size_t i, o, s, doff, base = 0, o2 = 6 + 2;
	size_t datao = 0;
	unsigned char *t;
	size_t ts;

	if (!n || !buf || !buf_size) return;

	/*
	 * Allocate enough memory for all entries and the number of entries.
	 */
	*buf_size = 6 + 2 + 2 + n->count * 12;
	switch (n->version) {
	case olympusV1:
	case sanyoV1:
	case epsonV1:
		*buf = exif_mem_alloc (ne->mem, *buf_size);
		if (!*buf) {
			EXIF_LOG_NO_MEMORY(ne->log, "ExifMnoteDataOlympus", *buf_size);
			return;
		}

		/* Write the header and the number of entries. */
		strcpy ((char *)*buf, n->version==sanyoV1?"SANYO":
					(n->version==epsonV1?"EPSON":"OLYMP"));
		exif_set_short (*buf + 6, n->order, (ExifShort) 1);
		datao = n->offset;
		break;

	case olympusV2:
		*buf_size += 8-6 + 4;
		*buf = exif_mem_alloc (ne->mem, *buf_size);
		if (!*buf) {
			EXIF_LOG_NO_MEMORY(ne->log, "ExifMnoteDataOlympus", *buf_size);
			return;
		}

		/* Write the header and the number of entries. */
		strcpy ((char *)*buf, "OLYMPUS");
		exif_set_short (*buf + 8, n->order, (ExifShort) (
			(n->order == EXIF_BYTE_ORDER_INTEL) ?
			('I' << 8) | 'I' :
			('M' << 8) | 'M'));
		exif_set_short (*buf + 10, n->order, (ExifShort) 3);
		o2 += 4;
		break;

	case nikonV1: 
		base = MNOTE_NIKON1_TAG_BASE;

		/* v1 has offsets based to main IFD, not makernote IFD */
		datao += n->offset + 10;
		/* subtract the size here, so the increment in the next case will not harm us */
		*buf_size -= 8 + 2;
	/* Fall through to nikonV2 handler */
	case nikonV2: 
	/* Write out V0 files in V2 format */
	case nikonV0: 
		*buf_size += 8 + 2;
		*buf_size += 4; /* Next IFD pointer */
		*buf = exif_mem_alloc (ne->mem, *buf_size);
		if (!*buf) {
			EXIF_LOG_NO_MEMORY(ne->log, "ExifMnoteDataOlympus", *buf_size);
			return;
		}

		/* Write the header and the number of entries. */
		strcpy ((char *)*buf, "Nikon");
		(*buf)[6] = n->version;

		if (n->version != nikonV1) {
			exif_set_short (*buf + 10, n->order, (ExifShort) (
				(n->order == EXIF_BYTE_ORDER_INTEL) ?
				('I' << 8) | 'I' :
				('M' << 8) | 'M'));
			exif_set_short (*buf + 12, n->order, (ExifShort) 0x2A);
			exif_set_long (*buf + 14, n->order, (ExifShort) 8);
			o2 += 2 + 8;
		}
		datao -= 10;
		/* Reset next IFD pointer */
		exif_set_long (*buf + o2 + 2 + n->count * 12, n->order, 0);
		break;

	default:
		return;
	}

	exif_set_short (*buf + o2, n->order, (ExifShort) n->count);
	o2 += 2;

	/* Save each entry */
	for (i = 0; i < n->count; i++) {
		o = o2 + i * 12;
		exif_set_short (*buf + o + 0, n->order,
				(ExifShort) (n->entries[i].tag - base));
		exif_set_short (*buf + o + 2, n->order,
				(ExifShort) n->entries[i].format);
		exif_set_long  (*buf + o + 4, n->order,
				n->entries[i].components);
		o += 8;
		s = exif_format_get_size (n->entries[i].format) *
						n->entries[i].components;
		if (s > 65536) {
			/* Corrupt data: EXIF data size is limited to the
			 * maximum size of a JPEG segment (64 kb).
			 */
			continue;
		}
		if (s > 4) {
			doff = *buf_size;
			ts = *buf_size + s;
			t = exif_mem_realloc (ne->mem, *buf,
						 sizeof (char) * ts);
			if (!t) {
				EXIF_LOG_NO_MEMORY(ne->log, "ExifMnoteDataOlympus", ts);
				return;
			}
			*buf = t;
			*buf_size = ts;
			exif_set_long (*buf + o, n->order, datao + doff);
		} else
			doff = o;

		/* Write the data. */
		if (n->entries[i].data) {
			memcpy (*buf + doff, n->entries[i].data, s);
		} else {
			/* Most certainly damaged input file */
			memset (*buf + doff, 0, s);
		}
	}
}