add code to read cue files

morituri/image/cue.py

@@ -0,0 +1,183 @@
+# -*- Mode: Python; test-case-name: morituri.test.test_image_cue -*-
+# vi:si:et:sw=4:sts=4:ts=4
+
+# Morituri - for those about to RIP
+
+# Copyright (C) 2009 Thomas Vander Stichele
+
+# This file is part of morituri.
+# 
+# morituri is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+# 
+# morituri is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License
+# along with morituri.  If not, see <http://www.gnu.org/licenses/>.
+
+"""
+Reading .cue files
+
+See http://digitalx.org/cuesheetsyntax.php
+"""
+
+import re
+
+_REM_RE = re.compile("^REM\s(\w+)\s(.*)$")
+_PERFORMER_RE = re.compile("^PERFORMER\s(.*)$")
+_TITLE_RE = re.compile("^TITLE\s(.*)$")
+
+_FILE_RE = re.compile(r"""
+    ^FILE       # FILE
+    \s+"(.*)"   # 'file name' in quotes
+    \s+(\w+)$   # format (WAVE/MP3/AIFF/...)
+""", re.VERBOSE)
+
+_TRACK_RE = re.compile(r"""
+    ^\s+TRACK   # TRACK
+    \s+(\d\d)   # two-digit track number
+    \s+(\w+)$   # mode (AUDIO/...)
+""", re.VERBOSE)
+
+_INDEX_RE = re.compile(r"""
+    ^\s+INDEX   # INDEX
+    \s+(\d\d)   # two-digit index number
+    \s+(\d\d)   # minutes
+    :(\d\d)     # seconds
+    :(\d\d)$    # frames
+""", re.VERBOSE)
+
+
+class Cue:
+    def __init__(self, path):
+        self._path = path
+        self._rems = {}
+        self._messages = []
+        self._tracks = []
+
+    def parse(self):
+        state = 'HEADER'
+        currentFile = None
+        currentTrack = None
+
+        handle = open(self._path, 'r')
+
+        for number, line in enumerate(handle.readlines()):
+            line = line.rstrip()
+
+            m = _REM_RE.search(line)
+            if m:
+                tag = m.expand('\\1')
+                value = m.expand('\\2')
+                if state != 'HEADER':
+                    self.message(number, 'REM %s outside of header' % tag)
+                else:
+                    self._rems[tag] = value
+                continue
+
+            # look for FILE lines
+            m = _FILE_RE.search(line)
+            if m:
+                filePath = m.expand('\\1')
+                fileFormat = m.expand('\\2')
+                currentFile = File(filePath, fileFormat)
+
+            # look for TRACK lines
+            m = _TRACK_RE.search(line)
+            if m:
+                if not currentFile:
+                    self.message(number, 'TRACK without preceding FILE')
+                    continue
+
+                state = 'TRACK'
+
+                trackNumber = int(m.expand('\\1'))
+                trackMode = m.expand('\\2')
+
+                currentTrack = Track(trackNumber)
+                self._tracks.append(currentTrack)
+                continue
+
+            # look for INDEX lines
+            m = _INDEX_RE.search(line)
+            if m:
+                if not currentTrack:
+                    self.message(number, 'INDEX without preceding TRACK')
+                    print 'ouch'
+                    continue
+
+                indexNumber = int(m.expand('\\1'))
+                minutes = int(m.expand('\\2'))
+                seconds = int(m.expand('\\3'))
+                frames = int(m.expand('\\4'))
+
+                totalFrames = frames + seconds * 75 + minutes * 75 * 60
+                currentTrack.index(indexNumber, totalFrames, currentFile)
+                print 'index %d, offset %d of track %r' % (indexNumber, totalFrames, currentTrack)
+                continue
+
+            
+
+    def message(self, number, message):
+        """
+        Add a message about a given line in the cue file.
+
+        @param number: line number, counting from 0.
+        """
+        self._messages.append((number + 1, message))
+
+class File:
+    """
+    I represent a FILE line in a cue file.
+    """
+    def __init__(self, path, format):
+        self.path = path
+        self.format = format
+
+    def __repr__(self):
+        return '<File "%s" of format %s>' % (self.path, self.format)
+
+
+# FIXME: add type ? separate AUDIO from others
+class Track:
+    """
+    I represent a track in a cue file.
+    I have index points.
+    Each index point is linked to an audio file.
+
+    @ivar number: track number
+    @type number: int
+    """
+
+    def __init__(self, number):
+        if number < 1 or number > 99:
+            raise IndexError, "Track number must be from 1 to 99"
+
+        self.number = number
+        self._indexes = {} # index number -> (sector, path)
+
+        self.title = None
+        self.performer = None
+
+    def __repr__(self):
+        return '<Track %02d with %d indexes>' % (self.number,
+            len(self._indexes.keys()))
+
+    def index(self, number, sector, file):
+        """
+        Add the given index to the current track.
+
+        @type file: L{File}
+        """
+        if number in self._indexes.keys():
+            raise KeyError, "index %d already in track" % number
+        if number < 0 or number > 99:
+            raise IndexError, "Index number must be from 0 to 99"
+
+        self._indexes[number] = (sector, file)
+