generalise python wave writer

common/wavewriter.py

@@ -0,0 +1,95 @@
+import struct
+from abc import abstractmethod
+from enum import Enum
+from typing import BinaryIO, List
+from riffwriter import RiffFile, AbstractRiffChunk
+
+
+class WaveSampleFormat(Enum):
+	PCM        = 0x0001
+	IEEE_FLOAT = 0x0003
+	ALAW       = 0x0006
+	MULAW      = 0x0007
+	EXTENSIBLE = 0xFFFE
+
+
+class WaveAbstractFormatChunk(AbstractRiffChunk):
+	def fourcc(self) -> bytes: return b"fmt "
+
+	def size(self) -> int: return 16
+
+	@abstractmethod
+	def sampleformat(self) -> WaveSampleFormat: raise NotImplementedError
+
+	@abstractmethod
+	def channels(self) -> int: raise NotImplementedError
+
+	@abstractmethod
+	def samplerate(self) -> int: raise NotImplementedError
+
+	@abstractmethod
+	def byterate(self) -> int: raise NotImplementedError
+
+	@abstractmethod
+	def align(self) -> int: raise NotImplementedError
+
+	@abstractmethod
+	def bitdepth(self) -> int: raise NotImplementedError
+
+	def write(self, f: BinaryIO):
+		f.write(struct.pack("<HHIIHH",
+			self.sampleformat().value,
+				self.channels(),
+				self.samplerate(),
+				self.byterate(),
+				self.align(),
+				self.bitdepth()))
+
+
+class WavePcmFormatChunk(WaveAbstractFormatChunk):
+	def sampleformat(self) -> WaveSampleFormat: return WaveSampleFormat.PCM
+
+	def channels(self) -> int: return self._channels
+
+	def samplerate(self) -> int: return self._samplerate
+
+	def byterate(self) -> int: return self._samplerate * self._channels * self._bytedepth
+
+	def align(self) -> int: return self._channels * self._bytedepth
+
+	def bitdepth(self) -> int: return self._bytedepth * 8
+
+	def __init__(self, channels: int, samplerate: int, bitdepth: int):
+		if channels < 0 or channels >= 256: raise ValueError
+		if samplerate < 1 or samplerate > 0xFFFFFFFF: raise ValueError
+		if bitdepth not in [8, 16, 32]: raise ValueError
+		self._channels = channels
+		self._samplerate = samplerate
+		self._bytedepth = bitdepth // 8
+
+
+class WaveDataChunk(AbstractRiffChunk):
+	def fourcc(self) -> bytes: return b"data"
+
+	def size(self) -> int: return len(self._data)
+
+	def write(self, f: BinaryIO): f.write(self._data)
+
+	def __init__(self, data: bytes):
+		self._data = data
+
+
+class WaveCommentChunk(AbstractRiffChunk):
+	def fourcc(self) -> bytes: return b"clm "
+
+	def size(self) -> int: return len(self._comment)
+
+	def write(self, f: BinaryIO): f.write(self._comment)
+
+	def __init__(self, comment: bytes):
+		self._comment = comment
+
+
+class WaveFile(RiffFile):
+	def __init__(self, format: WaveAbstractFormatChunk, chunks: List[AbstractRiffChunk]):
+		super().__init__(b"WAVE", [format] + chunks)