summaryrefslogtreecommitdiffstats
path: root/3rdparty/openpgm-svn-r1085/pgm/fec.txt
blob: b83590ded33d46c30d2cfcc27436a8e9d52591ed (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
pkt:k=1

non-parity

rs eqn:

n = 255
k = 2t
255 = 2k
k = 128
=> 2t = 128

--------------------------------------------------------------------------------

1456, 1442

pkt:k=2 ( 2 data packets )

1 packet loss:

pkt:h=1
pkt:n=3

rs eqn: 

n = 255
# reed-solomon codes = tsdu / n
k =      2  4  6 ... 254
=> 2t =  1  2  3     127 (k/2)

255 = k + (k/2)
510 = 2k + k
510 = 3k
170 = k
=> 2t = 85

2 packet loss:

pkt:h=2 pkts
pkt:n=4 pkts

--------------------------------------------------------------------------------

pkt:k=4 ( 4 data packets )

1 packet loss:

255 = k + (k/4)
k = 51
2t = 13 (rounded up)

--------------------------------------------------------------------------------

pkt:k=8 ( 8 data packets )

1 packet loss:

255 = k + (k/8)
k = 29
2t = 4 (rounded up)

--------------------------------------------------------------------------------

pkt:k=16 ( 16 data packets )

1 packet loss:

255 = k + (k/16)
k = 15
2t = 1 (invalid?)

2 packet loss:

255 = k + (2k/16)
k = 29
2t = 4