add configuration option to pass extra args to flac encode

whipper/command/cd.py

@@ -326,6 +326,11 @@ def add_arguments(self):
                                  help="continue ripping further tracks "
                                  "instead of giving up if a track "
                                  "can't be ripped")
+        self.parser.add_argument('--extra-flac-encode-args',
+                                 action="store", dest="extra_flac_encode_args",
+                                 help="extra arguments to pass to the flac "
+                                 "encode command",
+                                 default="")
 
     def handle_arguments(self):
         self.options.output_directory = os.path.expanduser(
@@ -471,10 +476,12 @@ def _ripIfNotRipped(number):
                             self.itable.tracks[number - 1].isrc is not None):
                         tag_list['ISRC'] = self.itable.tracks[number - 1].isrc
 
+                    extraFlacArgs = self.options.extra_flac_encode_args.split()
                     try:
                         self.program.ripTrack(self.runner, trackResult,
                                               offset=int(self.options.offset),
                                               device=self.device,
+                                              extraFlacArgs=extraFlacArgs,
                                               taglist=tag_list,
                                               overread=self.options.overread,
                                               what='track %d of %d%s' % (

whipper/common/encode.py

@@ -50,9 +50,11 @@ def _sox_peak(self):
 class FlacEncodeTask(task.Task):
     description = 'Encoding to FLAC'
 
-    def __init__(self, track_path, track_out_path, what="track"):
+    def __init__(self, track_path, track_out_path, extra_flac_args,
+                 what="track"):
         self.track_path = track_path
         self.track_out_path = track_out_path
+        self.extra_flac_args = extra_flac_args
         self.new_path = None
         self.description = 'Encoding %s to FLAC' % what
 
@@ -61,7 +63,7 @@ def start(self, runner):
         self.schedule(0.0, self._flac_encode)
 
     def _flac_encode(self):
-        flac.encode(self.track_path, self.track_out_path)
+        flac.encode(self.track_path, self.track_out_path, self.extra_flac_args)
         self.stop()
 
 

whipper/common/program.py

@@ -557,8 +557,8 @@ def verifyTrack(runner, trackResult):
                      'result %r', trackResult.testcrc, t.checksum, ret)
         return ret
 
-    def ripTrack(self, runner, trackResult, offset, device, taglist,
-                 overread, what=None, coverArtPath=None):
+    def ripTrack(self, runner, trackResult, offset, device, extraFlacArgs,
+                 taglist, overread, what=None, coverArtPath=None):
         """
         Rip and store a track of the disc.
 
@@ -573,6 +573,8 @@ def ripTrack(self, runner, trackResult, offset, device, taglist,
         :type offset: int
         :param device: path to the hardware disc drive
         :type device: str
+        :param extraFlacArgs: additional encoding args to pass to flac binary
+        :type extraFlacArgs: list
         :param taglist: dictionary of tags for the given track
         :type taglist: dict
         :param overread: whether to force overreading into the
@@ -600,6 +602,7 @@ def ripTrack(self, runner, trackResult, offset, device, taglist,
                                            stop, overread,
                                            offset=offset,
                                            device=device,
+                                           extraFlacArgs=extraFlacArgs,
                                            taglist=taglist,
                                            what=what,
                                            coverArtPath=coverArtPath)

whipper/program/cdparanoia.py

@@ -440,7 +440,8 @@ class ReadVerifyTrackTask(task.MultiSeparateTask):
     _tmppath = None
 
     def __init__(self, path, table, start, stop, overread, offset=0,
-                 device=None, taglist=None, what="track", coverArtPath=None):
+                 device=None, extraFlacArgs=None, taglist=None, what="track",
+                 coverArtPath=None):
         """
         Init ReadVerifyTrackTask.
 
@@ -456,6 +457,8 @@ def __init__(self, path, table, start, stop, overread, offset=0,
         :type offset: int
         :param device: the device to rip from
         :type device: str
+        :param extraFlacArgs: additional encoding args to pass to flac binary
+        :type extraFlacArgs: list
         :param taglist: a dict of tags
         :type taglist: dict
         """
@@ -499,7 +502,8 @@ def __init__(self, path, table, start, stop, overread, offset=0,
 
         from whipper.common import encode
 
-        self.tasks.append(encode.FlacEncodeTask(tmppath, tmpoutpath))
+        self.tasks.append(encode.FlacEncodeTask(tmppath, tmpoutpath,
+                                                extraFlacArgs))
 
         # MerlijnWajer: XXX: We run the CRC32Task on the wav file, because it's
         # in general stupid to run the CRC32 on the flac file since it already

whipper/program/flac.py

@@ -4,17 +4,22 @@
 logger = logging.getLogger(__name__)
 
 
-def encode(infile, outfile):
+def encode(infile, outfile, extraArgs=None):
     """
     Encode infile to outfile, with flac.
 
+    extraArgs is a list of additional arguments for the flac binary
+
     Uses ``-f`` because whipper already creates the file.
     """
+    cmd = ['flac', '--silent', '--verify' ]
+    cmd.extend(extraArgs or [])
+    cmd.extend(['-o', outfile, '-f', infile])
+    logger.debug("executing %r", cmd)
     try:
         # TODO: Replace with Popen so that we can catch stderr and write it to
         # logging
-        check_call(['flac', '--silent', '--verify', '-o', outfile,
-                    '-f', infile])
+        check_call(cmd)
     except CalledProcessError:
         logger.exception('flac failed')
         raise

whipper/test/test_program_flac.py

@@ -0,0 +1,45 @@
+# -*- Mode: Python; test-case-name: whipper.test.test_program_flac -*-
+
+import os
+import subprocess
+from tempfile import NamedTemporaryFile
+import wave
+
+from whipper.program import flac
+from whipper.test import common
+
+def read_flac(path):
+    with NamedTemporaryFile(suffix='.wav') as fp:
+        subprocess.check_call(['flac', '--silent', '-d', path, '-fo', fp.name])
+        wf = wave.open(fp.name)
+        return wf._data_chunk.read()
+
+class FlacTestCase(common.TestCase):
+    def setUp(self):
+        self.original_path = os.path.join(os.path.dirname(__file__),
+                                          'track.flac')
+
+    def testEncode(self):
+        with (NamedTemporaryFile(suffix='.wav') as decoded,
+              NamedTemporaryFile(suffix='.flac') as encoded_default,
+              NamedTemporaryFile(suffix='.flac') as encoded_optimum):
+            # Create a wav file
+            subprocess.check_call(['flac', '--silent', '-d', self.original_path,
+                                   '-fo', decoded.name])
+
+            # Encode it with different extraArgs
+            flac.encode(decoded.name, encoded_default.name)
+            flac.encode(decoded.name, encoded_optimum.name,
+                        ['--best', '-e'])
+
+            # Ensure the file with higher compression is smaller
+            size_default = os.path.getsize(encoded_default.name)
+            size_optimum = os.path.getsize(encoded_optimum.name)
+            self.assertLess(size_optimum, size_default)
+
+            # Make sure the the contents are identical
+            data_original = read_flac(self.original_path)
+            data_default = read_flac(encoded_default.name)
+            data_optimum = read_flac(encoded_optimum.name)
+            self.assertEqual(data_original, data_default)
+            self.assertEqual(data_original, data_optimum)