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
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
|
import re
from typing import Optional
def get_mime_type(content: bytes) -> str:
if not content:
return "application/octet-stream"
if content[0:3] in (b"CWS", b"FWS", b"ZWS"):
return "application/x-shockwave-flash"
if content[0:3] == b"\xFF\xD8\xFF":
return "image/jpeg"
if content[0:6] == b"\x89PNG\x0D\x0A":
return "image/png"
if content[0:6] in (b"GIF87a", b"GIF89a"):
return "image/gif"
if content[8:12] == b"WEBP":
return "image/webp"
if content[0:2] == b"BM":
return "image/bmp"
if content[4:12] in (b"ftypavif", b"ftypavis"):
return "image/avif"
if content[4:12] == b"ftypmif1":
return "image/heif"
if content[4:12] in (b"ftypheic", b"ftypheix"):
return "image/heic"
if content[0:4] == b"\x1A\x45\xDF\xA3":
return "video/webm"
if content[4:12] in (b"ftypisom", b"ftypiso5", b"ftypmp42", b"ftypM4V "):
return "video/mp4"
if content[4:12] == b"ftypqt ":
return "video/quicktime"
return "application/octet-stream"
def get_extension(mime_type: str) -> Optional[str]:
extension_map = {
"application/x-shockwave-flash": "swf",
"image/gif": "gif",
"image/jpeg": "jpg",
"image/png": "png",
"image/webp": "webp",
"image/bmp": "bmp",
"image/avif": "avif",
"image/heif": "heif",
"image/heic": "heic",
"video/mp4": "mp4",
"video/quicktime": "mov",
"video/webm": "webm",
"application/octet-stream": "dat",
}
return extension_map.get((mime_type or "").strip().lower(), None)
def is_flash(mime_type: str) -> bool:
return mime_type.lower() == "application/x-shockwave-flash"
def is_video(mime_type: str) -> bool:
return mime_type.lower() in (
"application/ogg",
"video/mp4",
"video/quicktime",
"video/webm",
)
def is_image(mime_type: str) -> bool:
return mime_type.lower() in (
"image/jpeg",
"image/png",
"image/gif",
"image/webp",
"image/bmp",
"image/avif",
"image/heif",
"image/heic",
)
def is_animated_gif(content: bytes) -> bool:
pattern = b"\x21\xF9\x04[\x00-\xFF]{4}\x00[\x2C\x21]"
return (
get_mime_type(content) == "image/gif"
and len(re.findall(pattern, content)) > 1
)
def is_heif(mime_type: str) -> bool:
return mime_type.lower() in (
"image/heif",
"image/heic",
"image/avif",
)
|
