The Serato Markers_ tag stores information about the first 5 Cues and 9
Loops. This is redunant with some of the information from the Serato Markers2 tag. Serato will prefer information from Serato Markers_ if it's present.
The tag data consists of a header followed by 14 entries and 4 footer bytes.
Every entry is apparently 22 (= 0x16) bytes long.
$ tail -c +7 data/id3/hotcue-positions-00m00s0-03m38s4-01m00s0-00m00s1-00m01s0/Serato\ Markers_.octet-stream | hexdump -v -e '"%08.8_ax " 22/1 "%02x " "\n"'
00000000 00 00 00 00 00 7f 7f 7f 7f 7f 00 7f 7f 7f 7f 7f 06 30 00 00 01 00
00000016 00 00 0d 2a 58 7f 7f 7f 7f 7f 00 7f 7f 7f 7f 7f 06 32 10 00 01 00
0000002c 00 00 03 54 64 7f 7f 7f 7f 7f 00 7f 7f 7f 7f 7f 00 00 01 4c 01 00
00000042 00 00 00 00 6c 7f 7f 7f 7f 7f 00 7f 7f 7f 7f 7f 06 33 18 00 01 00
00000058 00 00 00 07 77 7f 7f 7f 7f 7f 00 7f 7f 7f 7f 7f 00 03 18 00 01 00
0000006e 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 00 7f 7f 7f 7f 7f 00 00 00 00 03 00
00000084 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 00 7f 7f 7f 7f 7f 00 00 00 00 03 00
0000009a 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 00 7f 7f 7f 7f 7f 00 00 00 00 03 00
000000b0 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 00 7f 7f 7f 7f 7f 00 00 00 00 03 00
000000c6 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 00 7f 7f 7f 7f 7f 00 00 00 00 03 00
000000dc 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 00 7f 7f 7f 7f 7f 00 00 00 00 03 00
000000f2 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 00 7f 7f 7f 7f 7f 00 00 00 00 03 00
00000108 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 00 7f 7f 7f 7f 7f 00 00 00 00 03 00
0000011e 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 00 7f 7f 7f 7f 7f 00 00 00 00 03 00
00000134 07 7f 7f 7f
| Offset | Length | Raw Value | Decoded Value | Type | Description |
|---|---|---|---|---|---|
00 |
02 |
02 05 |
? (2 bytes) | ||
02 |
04 |
00 00 00 0e |
14 | uint32_t |
Number of Markers |
Each entry has the same format. Labels for Cues and Loops are not supported and are loaded from Serato Markers2 instead.
| Offset | Length | Raw Value | Decoded Value | Type | Description |
|---|---|---|---|---|---|
00 |
01 |
00 |
True | uint8_t (00 is True, 7f is False) |
Start Position set |
01 |
04 |
00 00 00 00 |
0 | uint24_t (serato32-encoded) (7f 7f 7f 7f if not set) |
Start Position in milliseconds |
05 |
01 |
7f |
False | uint8_t (00 is True, 7f is False) |
End Position set |
06 |
04 |
7f 7f 7f 7f |
None | uint24_t (serato32-encoded) (7f 7f 7f 7f if not set) |
End Position in milliseconds |
0a |
06 |
00 7f 7f 7f 7f 7f |
|||
10 |
04 |
06 30 00 00 |
#cc0000 |
3-byte RGB (serato32-encoded) |
Color |
14 |
01 |
01 |
Cue | uint8_t |
Type |
15 |
01 |
00 |
False | bool |
Locked |
| ID | Type |
|---|---|
| 1 | Cue |
| 3 | Loop |
The values that Serato uses in the Serato Markers_ entries are encoded in a
weird 4-byte binary format that I called serato32 in the tables above.
Apparently they thought it was best to do sprinkle some unused bits into
the 3-byte value. Hence, the resulting data becomes 4 bytes long:
Serato32 | Byte1 | Byte2 | Byte3 | Byte4 |
| Nibb1 | Nibb2 | Nibb3 | Nibb4 | Nibb5 | Nibb6 | Nibb7 | Nibb8 |
Bits |A A A A B B B B C C C C D D D D E E E E F F F F G G G G H H H H|
Ignored Bits |^ ^ ^ ^ ^ ^ ^ ^ |
Plaintext ||||||||||| Byte1 | Byte2 | Byte3 |
||||||||||| Nibb1 | Nibb2 | Nibb3 | Nibb4 | Nibb5 | Nibb6 |
Conversion is possible by doing some bitwise operations:
# Converting 3-byte plaintext into 4-byte Serato32 value
z = c & 0x7F
y = ((c >> 7) | (b << 1)) & 0x7F
x = ((b >> 6) | (a << 2)) & 0x7F
w = (a >> 5)
color = (w << 24) | (x << 16) | (y << 8) | z
# Converting 4-byte Serato color into 3-byte RGB
c = (z & 0x7F) | ((y & 0x01) << 7)
b = ((y & 0x7F) >> 1) | ((x & 0x03) << 6)
a = ((x & 0x7F) >> 2) | ((w & 0x07) << 5)
color = (a << 16) | (b << 8) | c
This data format is used to encode the 3-byte RGB color values (track color, cue colors) and the cue positions.
The footer consists of 4 bytes that indicate the track color.
| Offset | Length | Raw Value | Decoded Value | Type | Description |
|---|---|---|---|---|---|
00 |
04 |
07 7f 7f 7f |
#FFFFFF | 4-byte color value (see above) | Track Color |