Renambed wave_parser -> riff_parser

wavinfo/riff_parser.py

@@ -0,0 +1,59 @@
+
+import struct
+
+from collections import namedtuple
+
+class ListChunkDescriptor(namedtuple('ListChunkDescriptor' , 'signature children')):
+
+    def find(chunk_path):
+        if len(chunk_path) > 1:
+            for chunk in self.children:
+                if type(chunk) is ListChunkDescriptor and \
+                        chunk.signature is chunk_path[0]:
+                            return chunk.find(chunk_path[1:])
+        else:
+            for chunk in self.children:
+                if type(chunk) is ChunkDescriptor and \
+                        chunk.ident is chunk_path[0]:
+                            return chunk
+
+
+class ChunkDescriptor(namedtuple('ChunkDescriptor', 'ident start length') ):
+    def read_data(self, from_stream):
+        from_stream.seek(self.start)
+        return from_stream.read(self.length)
+
+def parse_list_chunk(stream, length):
+    start = stream.tell()
+
+    signature = stream.read(4)
+
+    children = []
+    while (stream.tell() - start) < length:
+        children.append(parse_chunk(stream))
+
+    return ListChunkDescriptor(signature=signature, children=children)
+
+def parse_chunk(stream):
+    ident = stream.read(4)
+    if len(ident) != 4:
+        return
+
+    sizeb = stream.read(4)
+    size  = struct.unpack('<I',sizeb)[0]
+
+    displacement = size
+    if displacement % 2 is not 0:
+        displacement = displacement + 1
+
+    if ident in [b'RIFF',b'LIST']:
+        return parse_list_chunk(stream=stream, length=size)
+    else:
+        start = stream.tell()
+        stream.seek(displacement,1)
+        return ChunkDescriptor(ident=ident, start=start, length=size)
+
+
+
+
+