diff --git a/src/data.c b/src/data.c
index 516e808..8b3ef4c 100644
--- a/src/data.c
+++ b/src/data.c
@@ -77,17 +77,22 @@ int ptp_parse_data_u32(void *d, int type, int *out) {
 }
 
 int ptp_parse_prop_value(struct PtpRuntime *r) {
-	uint8_t *d = ptp_get_payload(r);
+	int type;
 	switch (ptp_get_payload_length(r)) {
 	case 1:
-		return (int)(d[0]);
+		type = PTP_TC_UINT8; break;
 	case 2:
-		return (int)(d[0]);
+		type = PTP_TC_UINT16; break;
 	case 4:
-		return (int)(d[0]);
+		type = PTP_TC_UINT32; break;
+	default:
+		ptp_panic("ptp_parse_prop_value: unknown data type");
 	}
 
-	return -1;
+	int out;
+	ptp_parse_data_u32(ptp_get_payload(r), type, &out);
+
+	return out;
 }
 
 int parse_data_data_or_u32(uint8_t *d, int type, uint32_t *u32, void **data) {
diff --git a/src/packet.c b/src/packet.c
index 373835d..b550623 100644
--- a/src/packet.c
+++ b/src/packet.c
@@ -9,41 +9,6 @@
 #include <ptp.h>
 #include <camlib.h>
 
-static uint8_t ptp_read_uint8(void *dat) {
-	uint8_t **p = (uint8_t **)dat;
-	uint8_t x = (**p);
-	(*p)++;
-	return x;
-}
-
-static uint16_t ptp_read_uint16(void *dat) {
-	uint16_t **p = (uint16_t **)dat;
-	uint16_t x = (**p);
-	(*p)++;
-	return x;
-}
-
-static uint32_t ptp_read_uint32(void *dat) {
-	uint32_t **p = (uint32_t **)dat;
-	uint32_t x = (**p);
-	(*p)++;
-	return x;
-}
-
-static void ptp_write_uint8(void *dat, uint8_t b) {
-	uint8_t **ptr = (uint8_t **)dat;
-	(**ptr) = b;
-	(*ptr)++;
-}
-
-static int ptp_write_uint32(void *dat, uint32_t b) {
-	uint32_t **ptr = (uint32_t **)dat;
-	(**ptr) = b;
-	(*ptr)++;
-
-	return 4;
-}
-
 // Read standard UTF16 string
 int ptp_read_string(uint8_t *d, char *string, int max) {
 	int of = 0;
@@ -66,44 +31,39 @@ int ptp_read_string(uint8_t *d, char *string, int max) {
 	return of;
 }
 
-static int ptp_read_uint16_array_(void *dat, uint16_t *buf, int max) {
-	int n = ptp_read_uint32(dat);
+int ptp_read_uint16_array(uint8_t *dat, uint16_t *buf, int max, int *length) {
+	int of = 0;
 
-	for (int i = 0; i < n; i++) {
+	uint32_t n;
+	of += ptp_read_u32(dat + of, &n);
+
+	for (uint32_t i = 0; i < n; i++) {
 		if (i >= max) {
-			(void)ptp_read_uint16(dat);
+			ptp_panic("ptp_read_uint16_array overflow\n");
 		} else {
-			buf[i] = ptp_read_uint16(dat);
+			of += ptp_read_u16(buf + of, &buf[i]);
 		}
 	}
 
-	return n;
+	return of;
 }
 
-int ptp_read_uint16_array(uint8_t *dat, uint16_t *buf, int max, int *length) {
-	uint8_t *two = dat;
-	(*length) = ptp_read_uint16_array_(&two, buf, max);
-	return two - dat;
-}
+// Write standard PTP wchar string
+int ptp_write_string(uint8_t *dat, char *string) {
+	int of = 0;
 
-static int ptp_write_string_(void *dat, char *string) {
-	int length = strlen(string);
-	ptp_write_uint8(dat, length);
+	uint32_t length = strlen(string);
+	of += ptp_write_u8(dat + of, length);
 
 	for (int i = 0; i < length; i++) {
-		ptp_write_uint8(dat, string[i]);
-		ptp_write_uint8(dat, '\0');
+		of += ptp_write_u8(dat + of, string[i]);
+		of += ptp_write_u8(dat + of, '\0');
 	}
 
-	ptp_write_uint8(dat, '\0');
-
-	return (length * 2) + 2;
-}
-
-int ptp_write_string(uint8_t *dat, char *string) {
-	return ptp_write_string_(&dat, string);
+	return of;
 }
 
+// Write normal UTF-8 string
 int ptp_write_utf8_string(void *dat, char *string) {
 	char *o = (char *)dat;
 	int x = 0;
@@ -128,7 +88,7 @@ int ptp_write_unicode_string(char *dat, char *string) {
 	return i;
 }
 
-// Reaed null-terminated UTF16 string
+// Read null-terminated UTF16 string
 int ptp_read_unicode_string(char *buffer, char *dat, int max) {
 	int i;
 	for (i = 0; dat[i] != '\0'; i += 2) {
diff --git a/test/test.c b/test/test.c
index b71434b..61db80e 100644
--- a/test/test.c
+++ b/test/test.c
@@ -144,6 +144,11 @@ int test_props() {
 	int rc = test_setup_usb(&r);
 	if (rc) return rc;
 
+	rc = ptp_get_prop_value(&r, PTP_PC_BatteryLevel);
+	if (rc) return rc;
+	printf("Test parse: %d\n", ptp_parse_prop_value(&r));
+	assert(ptp_parse_prop_value(&r) == 50);
+
 	struct PtpPropDesc pd;
 	rc = ptp_get_prop_desc(&r, PTP_PC_BatteryLevel, &pd);
 	if (rc) return rc;