ripcd: Read disc ID from TOC

When the verbose level of `icedax` contains `catalog`, the disc ID is printed
to stdout. This is a faster and simpler method compared to parsing the CD
index XML document.

ripcd.py

@@ -37,6 +37,12 @@ class TocProtocol(asyncio.SubprocessProtocol):
                 values = m.groupdict()
                 self.toc.album = values.get('album')
                 self.toc.artist = values.get('artist')
+            elif line.startswith('CDINDEX'):
+                try:
+                    discid = line.split(':', 1)[1].strip()
+                except ValueError:
+                    continue
+                self.toc.discid = discid
             elif line.startswith('Track'):
                 try:
                     title = line.split(':', 1)[1].strip().strip("'")
@@ -55,6 +61,7 @@ class TableOfContents(object):
     )
 
     def __init__(self):
+        self.discid = None
         self.artist = None
         self.album = None
         self.tracks = []
@@ -68,7 +75,7 @@ class TableOfContents(object):
         cmd.extend((
             '--info-only',
             '--no-infofile',
-            '--verbose-level', 'titles',
+            '--verbose-level', 'catalog,titles',
             '--quiet',
             '--silent-scsi',
         ))
@@ -162,19 +169,8 @@ class Track(object):
 
 
 @asyncio.coroutine
-def fetch_album_art():
+def fetch_album_art(discid):
     loop = asyncio.get_event_loop()
-    try:
-        with open('audio.cdindex') as f:
-            tree = yield from loop.run_in_executor(None, etree.parse, f)
-    except OSError as e:
-        sys.stderr.write('Could not read CD index: {}\n'.format(e))
-        return
-    try:
-        discid = tree.xpath('//DiskId/Id')[0].text
-    except IndexError:
-        sys.stderr.write('Missing disc ID in CD index\n')
-        return
 
     headers = {
         'Accept': 'application/json',
@@ -269,10 +265,11 @@ def rip_cd(args):
     toc = yield from TableOfContents.from_device(args.device)
     print('Found CD: {} by {}'.format(toc.album, toc.artist))
     yield from rip_info(args.device)
-    tasks = [
-        loop.create_task(fetch_album_art()),
-        loop.create_task(rip_tracks(args.device, args.num_encoders)),
-    ]
+    tasks = []
+    if toc.discid:
+        tasks.append(loop.create_task(fetch_album_art(toc.discid)))
+    tasks.append(loop.create_task(rip_tracks(args.device, args.codec,
+                                             args.num_encoders)))
     yield from asyncio.wait(tasks)
     if args.cleanup:
         cleanup()