def scan_fast(path, _read_id3_hook=None):
"""Quickly produce an AudioFile object for the file at 'path'.
This function avoids expensive calculations by assuming that the
file is fully and correctly tagged. It never sets the 'payload'
field. The 'duration_ms' field will be set based on the TLEN tag,
if present. The 'frame_count' and 'frame_size' will be set based
on the CHIRP-specific TXXX tags, if present.
Args:
path: The path to an MP3 file.
_read_id3_hook: An optional callable that takes a path and
returns mutagen ID3 data. Passing in None (the default) uses
a default implementation. This argument should only be used
for testing.
Returns:
An AudioFile object describing the file at 'path', or None if it does
not appear to be a valid MPEG file.
"""
au_file = AudioFile()
au_file.path = path
au_file.mutagen_id3 = (_read_id3_hook or _get_mp3)(path)
if au_file.mutagen_id3 is None:
return None
this_ufid = au_file.mutagen_id3.get(constants.MUTAGEN_UFID_KEY)
if this_ufid:
try:
au_file.volume, au_file.import_timestamp, au_file.fingerprint = (
ufid.parse(this_ufid.data))
except ValueError:
pass
# Note we use the fact that mutagen_id3 is actually a mutagen.MP3 object.
au_file.mp3_header = mp3_header.from_mutagen(au_file.mutagen_id3)
# We assume that TLEN is accurate. Note that it would make sense to
# use au_file.mutagen_id3.info.length for this, but mutagen's length
# computation is not reliable.
au_file.duration_ms = _tag_to_int(au_file, "TLEN")
# Try to get the frame_size and frame_count from the tags. Again,
# we assume these are accurate.
au_file.frame_count = _tag_to_int(au_file, constants.TXXX_FRAME_COUNT_KEY)
au_file.frame_size = _tag_to_int(au_file, constants.TXXX_FRAME_SIZE_KEY)
# Try to pull the album ID out of a a tag.
au_file.album_id = _tag_to_int(au_file, constants.TXXX_ALBUM_ID_KEY)
return au_file
def scan_fast(path, _read_id3_hook=None):
"""Quickly produce an AudioFile object for the file at 'path'.
This function avoids expensive calculations by assuming that the
file is fully and correctly tagged. It never sets the 'payload'
field. The 'duration_ms' field will be set based on the TLEN tag,
if present. The 'frame_count' and 'frame_size' will be set based
on the CHIRP-specific TXXX tags, if present.
Args:
path: The path to an MP3 file.
_read_id3_hook: An optional callable that takes a path and
returns mutagen ID3 data. Passing in None (the default) uses
a default implementation. This argument should only be used
for testing.
Returns:
An AudioFile object describing the file at 'path', or None if it does
not appear to be a valid MPEG file.
"""
au_file = AudioFile()
au_file.path = path
au_file.mutagen_id3 = (_read_id3_hook or _get_mp3)(path)
if au_file.mutagen_id3 is None:
return None
this_ufid = au_file.mutagen_id3.get(constants.MUTAGEN_UFID_KEY)
if this_ufid:
try:
au_file.volume, au_file.import_timestamp, au_file.fingerprint = (
ufid.parse(this_ufid.data))
except ValueError:
pass
# Note we use the fact that mutagen_id3 is actually a mutagen.MP3 object.
au_file.mp3_header = mp3_header.from_mutagen(au_file.mutagen_id3)
# We assume that TLEN is accurate. Note that it would make sense to
# use au_file.mutagen_id3.info.length for this, but mutagen's length
# computation is not reliable.
au_file.duration_ms = _tag_to_int(au_file, "TLEN")
# Try to get the frame_size and frame_count from the tags. Again,
# we assume these are accurate.
au_file.frame_count = _tag_to_int(au_file, constants.TXXX_FRAME_COUNT_KEY)
au_file.frame_size = _tag_to_int(au_file, constants.TXXX_FRAME_SIZE_KEY)
# Try to pull the album ID out of a a tag.
au_file.album_id = _tag_to_int(au_file, constants.TXXX_ALBUM_ID_KEY)
return au_file
def test_from_mutagen(self):
mp3 = mutagen.mp3.MP3()
class MockInfo(mutagen.mp3.MPEGInfo):
def __init__(self):
pass
mp3.info = MockInfo()
mp3.info.sample_rate = 12345
mp3.info.bitrate = 123456
mp3.info.mode = mp3_header.STEREO
hdr = mp3_header.from_mutagen(mp3)
self.assertEqual(12345, hdr.sampling_rate_hz)
self.assertEqual(123.456, hdr.bit_rate_kbps)
self.assertEqual(mp3_header.STEREO, hdr.channels)
self.assertEqual("stereo", hdr.channels_str)
self.assertEqual(None, hdr.protected)
self.assertEqual(None, hdr.padding)
