Fixes #17 by adding configuration parameter for fingerprinting seconds, preserves this in FileRecognizer, and documents this in the README

README.md

@@ -70,6 +70,36 @@ You'll have a lot of fingerprints once it completes a large folder of mp3s:
 
 Also, any subsequent calls to `fingerprint_file` or `fingerprint_directory` will fingerprint and add those songs to the database as well. It's meant to simulate a system where as new songs are released, they are fingerprinted and added to the database seemlessly without stopping the system. 
 
+## Configuration options
+
+The configuration object to the Dejavu constructor must be a dictionary. 
+
+The following keys are mandatory:
+
+* `database`, with a value as a dictionary with keys that the database you are using will accept. For example with MySQL, the keys must can be anything that the [`MySQLdb.connect()`](http://mysql-python.sourceforge.net/MySQLdb.html) function will accept. 
+
+The following keys are optional:
+
+* `fingerprint_limit`: allows you to control how many seconds of each audio file to fingerprint. Leaving out this key, or alternatively using `-1` and `None` will cause Dejavu to fingerprint the entire audio file. Default value is `None`.
+* `database_type`: as of now, only `mysql` (the default value) is supported. If you'd like to subclass `Database` and add another, please fork and send a pull request!
+
+An example configuration is as follows:
+
+```python
+>>> from dejavu import Dejavu
+>>> config = {
+...     "database": {
+...         "host": "127.0.0.1",
+...         "user": "root",
+...         "passwd": "Password123", 
+...         "db": "dejavu_db",
+...     },
+...     "database_type" : "mysql",
+...     "fingerprint_limit" : 10
+... }
+>>> djv = Dejavu(config)
+```
+
 ## Recognizing
 
 There are two ways to recognize audio using Dejavu. You can use Dejavu interactively through the terminal. Assuming you've already instantiated a Dejavu object, you can match audio through your computer's microphone:

dejavu/__init__.py

@@ -17,6 +17,12 @@ class Dejavu(object):
         self.db = db_cls(**config.get("database", {}))
         self.db.setup()
         
+        # if we should limit seconds fingerprinted, 
+        # None|-1 means use entire track
+        self.limit = self.config.get("fingerprint_limit", None)
+        if self.limit == -1: # for JSON compatibility
+            self.limit = None
+
         # get songs previously indexed
         # TODO: should probably use a checksum of the file instead of filename
         self.songs = self.db.get_songs()
@@ -46,7 +52,7 @@ class Dejavu(object):
                 continue
 
             result = pool.apply_async(_fingerprint_worker,
-                                      (filename, self.db))
+                                      (filename, self.db, self.limit))
             results.append(result)
 
         while len(results):
@@ -134,10 +140,10 @@ class Dejavu(object):
         return r.recognize(*options, **kwoptions)
 
 
-def _fingerprint_worker(filename, db):
+def _fingerprint_worker(filename, db, limit):
     song_name, extension = os.path.splitext(os.path.basename(filename))
 
-    channels, Fs = decoder.read(filename)
+    channels, Fs = decoder.read(filename, limit)
 
     # insert song into database
     sid = db.insert_song(song_name)

dejavu/recognize.py

@@ -26,7 +26,7 @@ class FileRecognizer(BaseRecognizer):
         super(FileRecognizer, self).__init__(dejavu)
 
     def recognize_file(self, filename):
-        frames, self.Fs = decoder.read(filename)
+        frames, self.Fs = decoder.read(filename, self.dejavu.limit)
 
         t = time.time()
         match = self._recognize(*frames)

go.py

@@ -10,7 +10,7 @@ with open("dejavu.cnf") as f:
 # create a Dejavu instance
 djv = Dejavu(config)
 # Fingerprint all the mp3's in the directory we give it
-djv.fingerprint_directory("va_us_top_40/mp3", [".mp3"])
+djv.fingerprint_directory("mp3", [".mp3"])
 
 # Recognize audio from a file
 from dejavu.recognize import FileRecognizer
@@ -23,4 +23,4 @@ song = djv.recognize(MicrophoneRecognizer, seconds=2)
 # Or use a recognizer without the shortcut, in anyway you would like
 from dejavu.recognize import FileRecognizer
 recognizer = FileRecognizer(djv)
-song = recognizer.recognize_file("va_us_top_40/wav/17_-_#Beautiful_-_Mariah_Carey_ft.wav")
+song = recognizer.recognize_file("mp3/sail.mp3")