Decoder: Add a abstract base class for Decoders

diff --git a/timeside/decoder/core.py b/timeside/decoder/core.py
index 5a24530a56cc89ee702b3fbb225e0760984f770c..5b193c2201f5c433bec566345d37363ea31a2961 100644 (file)
--- a/timeside/decoder/core.py
+++ b/timeside/decoder/core.py
@@ -28,7 +28,7 @@
 
 from __future__ import division
 
-from timeside.core import Processor, implements, interfacedoc
+from timeside.core import Processor, implements, interfacedoc, abstract
 from timeside.api import IDecoder
 from timeside.tools import *
 
@@ -57,17 +57,78 @@ def stack(process_func):
     return wrapper
 
 
-class FileDecoder(Processor):
-    """ gstreamer-based decoder """
+class Decoder(Processor):
+    """General abstract base class for Decoder
+    """
     implements(IDecoder)
+    abstract()
 
     mimetype = ''
-    output_blocksize  = 8*1024
     output_samplerate = None
-    output_channels   = None
+    output_channels = None
+
+    def __init__(self, start=0, duration=None):
+        super(Decoder, self).__init__()
+
+        self.uri_start = float(start)
+        if duration:
+            self.uri_duration = float(duration)
+        else:
+            self.uri_duration = duration
+
+        if start == 0 and duration is None:
+            self.is_segment = False
+        else:
+            self.is_segment = True
+
+    @interfacedoc
+    def channels(self):
+        return self.output_channels
+
+    @interfacedoc
+    def samplerate(self):
+        return self.output_samplerate
+
+    @interfacedoc
+    def blocksize(self):
+        return self.output_blocksize
 
-    pipeline          = None
-    mainloopthread    = None
+    @interfacedoc
+    def totalframes(self):
+        return self.input_totalframes
+
+    @interfacedoc
+    def release(self):
+        pass
+
+    @interfacedoc
+    def mediainfo(self):
+        return dict(uri=self.uri,
+                    duration=self.uri_duration,
+                    start=self.uri_start,
+                    is_segment=self.is_segment,
+                    samplerate=self.input_samplerate)
+
+    def __del__(self):
+        self.release()
+
+    @interfacedoc
+    def encoding(self):
+        return self.format().split('/')[-1]
+
+    @interfacedoc
+    def resolution(self):
+        return self.input_width
+
+
+class FileDecoder(Decoder):
+    """ gstreamer-based decoder """
+    implements(IDecoder)
+
+    output_blocksize = 8*1024
+
+    pipeline = None
+    mainloopthread = None
 
     # IProcessor methods
 
@@ -92,25 +153,13 @@ class FileDecoder(Processor):
 
         """
 
-        super(FileDecoder, self).__init__()
+        super(FileDecoder, self).__init__(start=start, duration=duration)
 
         self.from_stack = False
         self.stack = stack
 
         self.uri = get_uri(uri)
 
-        self.uri_start = float(start)
-        if duration:
-            self.uri_duration = float(duration)
-        else:
-            self.uri_duration = duration
-
-        if start == 0 and duration is None:
-            self.is_segment = False
-        else:
-            self.is_segment = True
-
-
     def set_uri_default_duration(self):
         # Set the duration from the length of the file
         uri_total_duration = get_media_uri_info(self.uri)['duration']
@@ -314,18 +363,6 @@ class FileDecoder(Processor):
         frames, eod = buf
         return frames, eod
 
-    @interfacedoc
-    def channels(self):
-        return self.output_channels
-
-    @interfacedoc
-    def samplerate(self):
-        return self.output_samplerate
-
-    @interfacedoc
-    def blocksize(self):
-        return self.output_blocksize
-
     @interfacedoc
     def totalframes(self):
         if self.input_samplerate == self.output_samplerate:
@@ -341,17 +378,6 @@ class FileDecoder(Processor):
             self.from_stack = True
         pass
 
-    @interfacedoc
-    def mediainfo(self):
-        return dict(uri=self.uri,
-                    duration=self.uri_duration,
-                    start=self.uri_start,
-                    is_segment=self.is_segment,
-                    samplerate=self.input_samplerate)
-
-    def __del__(self):
-        self.release()
-
     ## IDecoder methods
 
     @interfacedoc
@@ -377,14 +403,11 @@ class FileDecoder(Processor):
         return self.tags
 
 
-class ArrayDecoder(Processor):
+class ArrayDecoder(Decoder):
     """ Decoder taking Numpy array as input"""
     implements(IDecoder)
 
-    mimetype = ''
     output_blocksize = 8*1024
-    output_samplerate = None
-    output_channels = None
 
     # IProcessor methods
 
@@ -407,7 +430,7 @@ class ArrayDecoder(Processor):
             duration : float
                 duration of the segment in seconds
         '''
-        super(ArrayDecoder, self).__init__()
+        super(ArrayDecoder, self).__init__(start=start, duration=duration)
 
         # Check array dimension
         if samples.ndim > 2:
@@ -423,17 +446,6 @@ class ArrayDecoder(Processor):
                             'x'.join([str(dim) for dim in samples.shape]),
                              samples.dtype.type.__name__])
 
-        self.uri_start = float(start)
-        if duration:
-            self.uri_duration = float(duration)
-        else:
-            self.uri_duration = duration
-
-        if start == 0 and duration is None:
-            self.is_segment = False
-        else:
-            self.is_segment = True
-
         self.frames = self.get_frames()
 
     def setup(self, channels=None, samplerate=None, blocksize=None):
@@ -485,41 +497,6 @@ class ArrayDecoder(Processor):
     def process(self):
         return self.frames.next()
 
-    @interfacedoc
-    def channels(self):
-        return self.output_channels
-
-    @interfacedoc
-    def samplerate(self):
-        return self.output_samplerate
-
-    @interfacedoc
-    def blocksize(self):
-        return self.output_blocksize
-
-    @interfacedoc
-    def totalframes(self):
-        if self.input_samplerate == self.output_samplerate:
-            return self.input_totalframes
-        else:
-            ratio = self.output_samplerate / self.input_samplerate
-            return int(self.input_totalframes * ratio)
-
-    @interfacedoc
-    def release(self):
-        pass
-
-    @interfacedoc
-    def mediainfo(self):
-        return dict(uri=self.uri,
-                    duration=self.uri_duration,
-                    start=self.uri_start,
-                    is_segment=self.is_segment,
-                    samplerate=self.input_samplerate)
-
-    def __del__(self):
-        self.release()
-
     ## IDecoder methods
     @interfacedoc
     def format(self):
@@ -527,14 +504,6 @@ class ArrayDecoder(Processor):
         base_type = re.search('^[a-z]*', self.samples.dtype.name).group(0)
         return 'audio/x-raw-'+base_type
 
-    @interfacedoc
-    def encoding(self):
-        return self.format().split('/')[-1]
-
-    @interfacedoc
-    def resolution(self):
-        return self.input_width
-
     @interfacedoc
     def metadata(self):
         return None