Coverage for pyguymer3/media/does_FLAC_have_padding.py: 90%

1#!/usr/bin/env python3 

2 

3# Define function ... 

4def does_FLAC_have_padding( 

5 fname, 

6 /, 

7): 

8 # NOTE: The following website has some very useful information on how to 

9 # parse FLAC files. 

10 # * https://xiph.org/flac/format.html 

11 

12 # Import standard modules ... 

13 import os 

14 

15 # List block types ... 

16 blocks = { 

17 0 : "STREAMINFO", 

18 1 : "PADDING", 

19 2 : "APPLICATION", 

20 3 : "SEEKTABLE", 

21 4 : "VORBIS_COMMENT", 

22 5 : "CUESHEET", 

23 6 : "PICTURE", 

24 127 : "INVALID", 

25 } 

26 

27 # Open FLAC read-only ... 

28 with open(fname, "rb") as fObj: 

29 # Create short-hand ... 

30 fsize = os.path.getsize(fname) # [B] 

31 

32 # Read magic marker and raise exception if it is not expected ... 

33 if fObj.read(4).decode("utf-8") != "fLaC": 

34 raise Exception(f"\"{fname}\" is not a FLAC") from None 

35 

36 # Initialize flag ... 

37 last = False 

38 

39 # Loop over entire contents of FLAC ... 

40 while fObj.tell() < fsize: 

41 # Attempt to read 1 byte as a big-endian un-signed integer ... 

42 name = int.from_bytes(fObj.read(1), byteorder = "big", signed = False) 

43 

44 # Check if this integer has the "last block" flag set and take it 

45 # off ... 

46 if name > 127: 

47 last = True 

48 name -= 128 

49 

50 # Attempt to read 3 bytes as a big-endian un-signed integer ... 

51 val = int.from_bytes(fObj.read(3), byteorder = "big", signed = False) # [B] 

52 

53 # Check if it is a PADDING block ... 

54 if blocks.get(name, "RESERVED") == "PADDING": 

55 return True 

56 

57 # Check if this is the last block before the frames ... 

58 if last: 

59 # Stop looping ... 

60 break 

61 

62 # Skip to the end of the block ... 

63 fObj.seek(val, os.SEEK_CUR) 

64 

65 # Return answer ... 

66 return False