Problems with codec map

Hi, lately I'm testing the new codec map capability that was recently added in the PliExtraInfo converter and also used in the ServiceInfo screen.
However, I see there are some problems with the mapping

codec_data = {
-1: "N/A",
0: "MPEG2",
1: "AVC",
2: "H263",
3: "VC1",
4: "MPEG4-VC",
5: "VC1-SM",
6: "MPEG1",
7: "HEVC",
8: "VB8",
9: "VB9",
10: "XVID",
11: "N/A 11",
12: "N/A 12",
13: "DIVX 3.11",
14: "DIVX 4",
15: "DIVX 5",
16: "AVC",
17: "N/A 17",
18: "VB6",
19: "N/A 19",
20: "N/A 20",
21: "SPARK",
}
More specifically:
- H.265 is reported as MPEG1
- VB6/8/9 are not named correctly they should be VP6/8/9. These codecs are recognized even though they are reported as N/A
- Chinese AVS (CAVS) is absent from the list, my HD51 can decode it (OpenATV recognizes the codec).

why AVC is mapped twice, in both 1 and 16?
How is the mapping determined? Is there any command that returns the number instead of the codec name, so I can test further?