Melodia/archiver/song.py

151 lines
5.6 KiB
Python

from django.db import models
from Melodia import melodia_settings
import datetime
"""
The Song model
Each instance of a Song represents a single music file.
This database model is used for storing the metadata information about a song,
and helps in doing sorting etc.
"""
_default_string = "_UNAVAILABLE_"
_default_date = datetime.datetime.now
_default_int = -1
_default_rating = 0
_default_rating_bad = 1
_default_rating_ok = 2
_default_rating_decent = 3
_default_rating_good = 4
_default_rating_excellent = 5
_default_rating_choices = (
(_default_rating, 'Default'),
(_default_rating_bad, 'Bad'),
(_default_rating_ok, 'OK'),
(_default_rating_decent, 'Decent'),
(_default_rating_good, 'Good'),
(_default_rating_excellent, 'Excellent'),
)
class Song (models.Model):
"""
This class defines the fields and functions related to controlling
individual music files.
Note that the Playlist model depends on this model's PK being an int.
"""
#Standard song metadata
title = models.CharField(max_length = 64, default = _default_string)
artist = models.CharField(max_length = 64, default = _default_string)
album = models.CharField(max_length = 64, default = _default_string)
year = models.IntegerField(default = _default_string)
genre = models.CharField(max_length = 64, default = _default_string)
bpm = models.IntegerField(default = _default_int)
disc_number = models.IntegerField(default = _default_int)
disc_total = models.IntegerField(default = _default_int)
track_number = models.IntegerField(default = _default_int)
track_total = models.IntegerField(default = _default_int)
comment = models.CharField(default = _default_string, max_length=512)
#File metadata
bit_rate = models.IntegerField(default = _default_int)
duration = models.FloatField(default = _default_int)
add_date = models.DateField(default = _default_date)
echonest_song_id = models.CharField(max_length = 64, default = _default_string)
url = models.CharField(max_length = 255)
file_hash = melodia_settings.HASH_RESULT_DB_TYPE
file_size = models.IntegerField(default = _default_int)
#Melodia metadata
play_count = models.IntegerField(default = _default_int)
skip_count = models.IntegerField(default = _default_int)
rating = models.IntegerField(default = _default_int, choices = _default_rating_choices)
#Set a static reference to the rating options
RATING_DEFAULT = _default_rating
RATING_BAD = _default_rating_bad
RATING_OK = _default_rating_ok
RATING_DECENT = _default_rating_decent
RATING_GOOD = _default_rating_good
RATING_EXCELLENT = _default_rating_excellent
def _file_not_changed(self):
"Make sure the hash for this file is valid - return True if it has not changed."
#Overload the hash function with whatever Melodia as a whole is using
from Melodia.melodia_settings import HASH_FUNCTION as hash
#Check if there's a hash entry - if there is, the song may not have changed,
#and we can go ahead and return
if self.file_hash != None:
song_file = open(self.url, 'rb')
current_file_hash = hash(song_file.read())
if current_file_hash == self.file_hash:
#The song data hasn't changed at all, we don't need to do anything
return True
return False
def _grab_file_info(self):
"Populate file-based metadata about this song."
import os
#Overload the hash function with whatever Melodia as a whole is using
from Melodia.melodia_settings import HASH_FUNCTION as hash
file_handle = open(self.url, 'rb')
self.file_hash = hash(file_handle.read())
self.file_size = os.stat(self.url).st_size
def _grab_metadata_echonest(self):
"Populate this song's metadata using EchoNest"
pass
def _grab_metadata_local(self):
"Populate this song's metadata using what is locally available"
#Use mutagen to get the song metadata
import mutagen
try:
#Use mutagen to scan local metadata - don't update anything else (i.e. play_count)
track = mutagen.File(self.url)
track_easy = mutagen.File(self.url, easy=True)
self.title = track_easy['title'][0] or _default_string
self.artist = track_easy['artist'][0] or _default_string
self.album_artist = track_easy['albumartist'][0] or _default_string
self.album = track_easy['album'][0] or _default_string
self.year = int(track_easy['date'][0][0:4]) or _default_int
self.genre = track_easy["genre"][0] or _default_string
self.disc_number = int(track_easy['discnumber'][0].split('/')[0]) or _default_int
self.disc_total = int(track_easy['discnumber'][0].split('/')[-1]) or _default_int
self.track_number = int(track_easy['track_number'][0].split('/')[0]) or _default_int
self.track_total = int(track_easy['track_number'][0].split('/')[-1]) or _default_int
self.comment = track_easy['comment'][0] or _default_string
self.bit_rate = track.info.bitrate or _default_int
self.duration = track.info.length or _default_int
except:
#Couldn't grab the local data
return False
def populate_metadata(self, use_echonest = False):
"Populate the metadata of this song (only if file hash has changed), and save the result."
if self._file_not_changed():
return
#If we've gotten to here, we do actually need to fully update the metadata
if use_echonest:
self._grab_echonest()
else:
self._grab_metadata_local()
def convert(self, output_location, output_format, progress_func = lambda x, y: None):
"Convert a song to a new format."
pass #Need to get pydub code in place