Add support for 24-bit and 32-bit WAV files

stego_lsb/WavSteg.py

@@ -51,8 +51,8 @@ def hide_data(sound_path: str, file_path: str, output_path: str, num_lsb: int) -
             required_lsb = math.ceil(file_size * 8 / num_samples)
             raise ValueError(f"Input file too large to hide, requires {required_lsb} LSBs, using {num_lsb}")
 
-        if sample_width != 1 and sample_width != 2:
-            # Python's wave module doesn't support higher sample widths
+        if sample_width < 1 or sample_width > 4:
+            # WavSteg doesn't support higher sample widths, see setsampwidth() in cpython/Libwave.py
             raise ValueError("File has an unsupported bit-depth")
 
         start = time()
@@ -83,8 +83,8 @@ def recover_data(sound_path: str, output_path: str, num_lsb: int, bytes_to_recov
         sound_frames = sound.readframes(num_frames)
         log.debug(f"{'Files read':<30} in {time() - start:.2f}s")
 
-        if sample_width != 1 and sample_width != 2:
-            # Python's wave module doesn't support higher sample widths
+        if sample_width < 1 or sample_width > 4:
+            # WavSteg doesn't support higher sample widths, see setsampwidth() in cpython/Libwave.py
             raise ValueError("File has an unsupported bit-depth")
 
         start = time()

tests/test_wavsteg.py

@@ -11,8 +11,8 @@
 class TestWavSteg(unittest.TestCase):
     def write_random_wav(self, filename: str, num_channels: int, sample_width: int, framerate: int,
                          num_frames: int) -> None:
-        if sample_width != 1 and sample_width != 2:
-            # WavSteg doesn't support higher sample widths
+        if sample_width < 1 or sample_width > 4:
+            # WavSteg doesn't support higher sample widths, see setsampwidth() in cpython/Libwave.py
             raise ValueError("File has an unsupported bit-depth")
 
         with wave.open(filename, "w") as file:
@@ -23,8 +23,10 @@ def write_random_wav(self, filename: str, num_channels: int, sample_width: int,
             dtype: Type[np.unsignedinteger[Any]]
             if sample_width == 1:
                 dtype = np.uint8
-            else:
+            elif sample_width == 2:
                 dtype = np.uint16
+            else:
+                dtype = np.uint32
 
             data = np.random.randint(0, 2 ** (8 * sample_width), dtype=dtype, size=num_frames * num_channels)
             # note: typing does not recognize that "writeframes() accepts any bytes-like object" (see documentation)
@@ -75,6 +77,12 @@ def test_consistency_8bit(self) -> None:
     def test_consistency_16bit(self) -> None:
         self.check_random_interleaving(byte_depth=2)
 
+    def test_consistency_24bit(self) -> None:
+        self.check_random_interleaving(byte_depth=3)
+
+    def test_consistency_32bit(self) -> None:
+        self.check_random_interleaving(byte_depth=4)
+
 
 if __name__ == "__main__":
     unittest.main()