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
78
79
80
81
|
#!/usr/bin/lua
require "lspipat"
function uint(bytes, val) -- binary integer decoding
return Len(bytes) % function(bin)
bin = littleEndian and bin or bin:reverse()
local n = 0
local base = 1
for _, c in ipairs{bin:byte(1, bytes)} do
n = n + base * c
base = base * 256
end
val(n)
end
end
function _uint(bytes, name) return uint(bytes, function(n) _G[name] = n end) end
function _uint16(name) return _uint(2, name) end
function _uint32(name) return _uint(4, name) end
hnd = assert(io.open(arg[1]))
file = hnd:read("*a")
hnd:close()
-- WAVE file "grammar"
format = "fmt "
* _uint32 "FmtChunkSize"
* _Setcur "FmtStartPos"
* _uint16 "AudioFormat"
* _uint16 "NumChannels"
* _uint32 "SampleRate"
* _uint32 "ByteRate"
* _uint16 "BlockAlign"
* _uint16 "BitsPerSample"
* ( -function() return AudioFormat == 1 end
+ _uint16 "ExtraParamSize"
* _Len "ExtraParamSize" )
* Pos(function() return FmtStartPos + FmtChunkSize end)
* -function() return BitsPerSample % 8 == 0 and
BlockAlign == NumChannels * BitsPerSample/8 and
ByteRate == SampleRate * BlockAlign end
data = "data"
* _uint32 "DataChunkSize"
* _Len "DataChunkSize"
misc = Len(4)
* _uint32 "MiscChunkSize"
* _Len "MiscChunkSize"
wave = (topattern("RIFF") + "RIFX")
% function(id) littleEndian = id == "RIFF" end
* _uint32 "ChunkSize"
* _Setcur "StartPos"
* "WAVE"
* Arbno(format + data + misc)
* Pos(function() return StartPos + ChunkSize end)
* -function() return DataChunkSize % BlockAlign == 0 end
* RPos(0)
assert(file:smatch(wave, spipat.match_anchored),
arg[1].." is not a valid WAVE file!")
print(string.format(
"%s\
Format: %u\
Channels: %u\
Samplerate: %u Hz\
Byterate: %u Hz\
Bits/Sample: %u\
Samples: %u",
arg[1],
AudioFormat, NumChannels, SampleRate, ByteRate, BitsPerSample, DataChunkSize / BlockAlign))
print(os.date("Length:\t\t%T", DataChunkSize / ByteRate + 60*60*23))
|
