X-Git-Url: http://git.tuebingen.mpg.de/?a=blobdiff_plain;f=mp4.c;h=1ab200545180be77722b511afd6aaf1c86006faa;hb=142635c8ad8d98f00247cb1c477c036efdb8a088;hp=e2512db17de21c0fd20286860a0e6861f9542b2d;hpb=18ea2d87153bfcf386905b7c36b425d8e7bcc592;p=paraslash.git

diff --git a/mp4.c b/mp4.c
index e2512db1..1ab20054 100644
--- a/mp4.c
+++ b/mp4.c
@@ -137,95 +137,49 @@ static uint8_t read_int8(struct mp4 *f, uint8_t *result)
 	return ret;
 }
 
-static bool atom_compare(int8_t a1, int8_t b1, int8_t c1, int8_t d1,
-		int8_t a2, int8_t b2, int8_t c2, int8_t d2)
+#define ATOM_ITEMS \
+	ATOM_ITEM(MOOV, 'm', 'o', 'o', 'v') \
+	ATOM_ITEM(TRAK, 't', 'r', 'a', 'k') \
+	ATOM_ITEM(MDIA, 'm', 'd', 'i', 'a') \
+	ATOM_ITEM(MINF, 'm', 'i', 'n', 'f') \
+	ATOM_ITEM(STBL, 's', 't', 'b', 'l') \
+	ATOM_ITEM(UDTA, 'u', 'd', 't', 'a') \
+	ATOM_ITEM(ILST, 'i', 'l', 's', 't') /* iTunes Metadata list */ \
+	ATOM_ITEM(ARTIST, 0xa9, 'A', 'R', 'T') \
+	ATOM_ITEM(TITLE, 0xa9, 'n', 'a', 'm') \
+	ATOM_ITEM(ALBUM, 0xa9, 'a', 'l', 'b') \
+	ATOM_ITEM(DATE, 0xa9, 'd', 'a', 'y') \
+	ATOM_ITEM(COMMENT, 0xa9, 'c', 'm', 't') \
+	ATOM_ITEM(MDHD, 'm', 'd', 'h', 'd') /* track header */ \
+	ATOM_ITEM(STSD, 's', 't', 's', 'd') /* sample description box */ \
+	ATOM_ITEM(STTS, 's', 't', 't', 's') /* time to sample box */ \
+	ATOM_ITEM(STSZ, 's', 't', 's', 'z') /* sample size box */ \
+	ATOM_ITEM(STCO, 's', 't', 'c', 'o') /* chunk offset box */ \
+	ATOM_ITEM(STSC, 's', 't', 's', 'c') /* sample to chunk box */ \
+	ATOM_ITEM(MP4A, 'm', 'p', '4', 'a') \
+	ATOM_ITEM(META, 'm', 'e', 't', 'a') /* iTunes Metadata box */ \
+	ATOM_ITEM(DATA, 'd', 'a', 't', 'a') /* iTunes Metadata data box */ \
+
+#define ATOM_ITEM(_name, a, b, c, d) ATOM_ ## _name,
+enum atom {ATOM_ITEMS};
+#undef ATOM_ITEM
+
+static uint8_t atom_name_to_type(uint8_t *p)
 {
-	return a1 == a2 && b1 == b2 && c1 == c2 && d1 == d2;
-}
-
-enum atoms {
-	/* atoms with subatoms */
-	ATOM_MOOV,
-	ATOM_TRAK,
-	ATOM_MDIA,
-	ATOM_MINF,
-	ATOM_STBL,
-	ATOM_UDTA,
-	ATOM_ILST, /* iTunes Metadata list */
-	ATOM_TITLE,
-	ATOM_ARTIST,
-	ATOM_ALBUM,
-	ATOM_DATE,
-	ATOM_COMMENT,
-
-	SUBATOMIC = 128,
-
-	/* atoms without subatoms */
-	ATOM_MDHD, /* track header */
-	ATOM_STSD, /* sample description box */
-	ATOM_STTS, /* time to sample box */
-	ATOM_STSZ, /* sample size box */
-	ATOM_STCO, /* chunk offset box */
-	ATOM_STSC, /* sample to chunk box */
-	ATOM_MP4A,
-	ATOM_META, /* iTunes Metadata box */
-	ATOM_DATA, /* iTunes Metadata data box */
-	ATOM_UNKNOWN = 255
-};
-
-#define COPYRIGHT_SYMBOL ((int8_t)0xA9)
-
-static uint8_t atom_name_to_type(int8_t a, int8_t b, int8_t c, int8_t d)
-{
-	if (a == 'm') {
-		if (atom_compare(a, b, c, d, 'm', 'o', 'o', 'v'))
-			return ATOM_MOOV;
-		else if (atom_compare(a, b, c, d, 'm', 'i', 'n', 'f'))
-			return ATOM_MINF;
-		else if (atom_compare(a, b, c, d, 'm', 'd', 'i', 'a'))
-			return ATOM_MDIA;
-		else if (atom_compare(a, b, c, d, 'm', 'd', 'h', 'd'))
-			return ATOM_MDHD;
-		else if (atom_compare(a, b, c, d, 'm', 'p', '4', 'a'))
-			return ATOM_MP4A;
-		else if (atom_compare(a, b, c, d, 'm', 'e', 't', 'a'))
-			return ATOM_META;
-	} else if (a == 't') {
-		if (atom_compare(a, b, c, d, 't', 'r', 'a', 'k'))
-			return ATOM_TRAK;
-	} else if (a == 's') {
-		if (atom_compare(a, b, c, d, 's', 't', 'b', 'l'))
-			return ATOM_STBL;
-		else if (atom_compare(a, b, c, d, 's', 't', 's', 'd'))
-			return ATOM_STSD;
-		else if (atom_compare(a, b, c, d, 's', 't', 't', 's'))
-			return ATOM_STTS;
-		else if (atom_compare(a, b, c, d, 's', 't', 'c', 'o'))
-			return ATOM_STCO;
-		else if (atom_compare(a, b, c, d, 's', 't', 's', 'c'))
-			return ATOM_STSC;
-		else if (atom_compare(a, b, c, d, 's', 't', 's', 'z'))
-			return ATOM_STSZ;
-	} else if (a == COPYRIGHT_SYMBOL) {
-		if (atom_compare(a, b, c, d, COPYRIGHT_SYMBOL, 'n', 'a', 'm'))
-			return ATOM_TITLE;
-		else if (atom_compare(a, b, c, d, COPYRIGHT_SYMBOL, 'A', 'R', 'T'))
-			return ATOM_ARTIST;
-		else if (atom_compare(a, b, c, d, COPYRIGHT_SYMBOL, 'a', 'l', 'b'))
-			return ATOM_ALBUM;
-		else if (atom_compare(a, b, c, d, COPYRIGHT_SYMBOL, 'd', 'a', 'y'))
-			return ATOM_DATE;
-		else if (atom_compare(a, b, c, d, COPYRIGHT_SYMBOL, 'c', 'm', 't'))
-			return ATOM_COMMENT;
-	}
-	if (atom_compare(a, b, c, d, 'u', 'd', 't', 'a'))
-		return ATOM_UDTA;
-	else if (atom_compare(a, b, c, d, 'i', 'l', 's', 't'))
-		return ATOM_ILST;
-	else if (atom_compare(a, b, c, d, 'd', 'a', 't', 'a'))
-		return ATOM_DATA;
-	else
-		return ATOM_UNKNOWN;
+	#define ATOM_VALUE(a, b, c, d) ((a << 24) + (b << 16) + (c << 8) + d)
+	#define ATOM_ITEM(_name, a, b, c, d) \
+		{.name = # _name, .val = ATOM_VALUE(a, b, c, d)},
+	static const struct {
+		const char *name;
+		uint32_t val;
+	} atom_table[] = {ATOM_ITEMS};
+	#undef ATOM_ITEM
+	uint32_t val = read_u32_be(p);
+
+	for (uint8_t n = 0; n < ARRAY_SIZE(atom_table); n++)
+		if (val == atom_table[n].val)
+			return n;
+	return 255;
 }
 
 /* read atom header, atom size is returned with header included. */
@@ -234,7 +188,7 @@ static int atom_read_header(struct mp4 *f, uint8_t *atom_type,
 {
 	uint32_t size;
 	int ret;
-	int8_t atom_header[8];
+	uint8_t atom_header[8];
 
 	ret = read_data(f, atom_header, 8);
 	if (ret <= 0)
@@ -252,8 +206,7 @@ static int atom_read_header(struct mp4 *f, uint8_t *atom_type,
 		if (atom_size)
 			*atom_size = size;
 	}
-	*atom_type = atom_name_to_type(atom_header[4], atom_header[5],
-		atom_header[6], atom_header[7]);
+	*atom_type = atom_name_to_type(atom_header + 4);
 	return 1;
 }
 
@@ -657,29 +610,6 @@ static int32_t read_meta(struct mp4 *f, uint64_t size)
 	return 1;
 }
 
-static int parse_leaf_atom(struct mp4 *f, uint64_t size, uint8_t header_size,
-		uint8_t atom_type)
-{
-	uint64_t dest_position = get_position(f) + size - 8;
-	int ret = 1; /* return success for atoms we don't care about */
-
-	switch (atom_type) {
-	case ATOM_STSZ: ret = read_stsz(f); break;
-	case ATOM_STTS: ret = read_stts(f); break;
-	case ATOM_STSC: ret = read_stsc(f); break;
-	case ATOM_STCO: ret = read_stco(f); break;
-	case ATOM_STSD: ret = read_stsd(f); break;
-	case ATOM_MDHD: ret = read_mdhd(f); break;
-	case ATOM_META:
-		f->meta_offset = get_position(f) - header_size;
-		f->meta_size = size;
-		ret = read_meta(f, size);
-		break;
-	}
-	set_position(f, dest_position);
-	return ret;
-}
-
 static bool need_atom(uint8_t atom_type, bool meta_only)
 {
 	/* these are needed in any case */
@@ -712,18 +642,16 @@ static bool need_atom(uint8_t atom_type, bool meta_only)
 static int parse_sub_atoms(struct mp4 *f, uint64_t total_size, bool meta_only)
 {
 	int ret;
-	uint64_t size;
-	uint8_t atom_type = 0;
-	uint64_t counted_size = 0;
-	uint8_t header_size = 0;
+	uint64_t dest, size, end = get_position(f) + total_size;
 
-	while (counted_size < total_size) {
+	for (dest = get_position(f); dest < end; set_position(f, dest)) {
+		uint8_t header_size, atom_type;
 		ret = atom_read_header(f, &atom_type, &header_size, &size);
 		if (ret <= 0)
 			return ret;
 		if (size == 0)
 			return -1;
-		counted_size += size;
+		dest = get_position(f) + size - header_size;
 		if (atom_type == ATOM_TRAK) {
 			if (f->total_tracks >= MAX_TRACKS)
 				return -1;
@@ -734,14 +662,23 @@ static int parse_sub_atoms(struct mp4 *f, uint64_t total_size, bool meta_only)
 			f->udta_offset = get_position(f) - header_size;
 			f->udta_size = size;
 		}
-		if (!need_atom(atom_type, meta_only)) {
-			set_position(f, get_position(f) + size - header_size);
+		if (!need_atom(atom_type, meta_only))
 			continue;
-		}
-		if (atom_type < SUBATOMIC) /* atom contains subatoms */
+		switch (atom_type) {
+		case ATOM_STSZ: ret = read_stsz(f); break;
+		case ATOM_STTS: ret = read_stts(f); break;
+		case ATOM_STSC: ret = read_stsc(f); break;
+		case ATOM_STCO: ret = read_stco(f); break;
+		case ATOM_STSD: ret = read_stsd(f); break;
+		case ATOM_MDHD: ret = read_mdhd(f); break;
+		case ATOM_META:
+			f->meta_offset = get_position(f) - header_size;
+			f->meta_size = size;
+			ret = read_meta(f, size);
+			break;
+		default:
 			ret = parse_sub_atoms(f, size - header_size, meta_only);
-		else
-			ret = parse_leaf_atom(f, size, header_size, atom_type);
+		}
 		if (ret <= 0)
 			return ret;
 	}