python: Add PLC interface for the python wrapper
diff --git a/python/lc3.py b/python/lc3.py
index 8c4ae71..eda76fa 100644
--- a/python/lc3.py
+++ b/python/lc3.py
@@ -472,14 +472,14 @@
@typing.overload
def decode(
- self, data: bytes | bytearray | memoryview, bit_depth: None = None
+ self, data: bytes | bytearray | memoryview | None, bit_depth: None = None
) -> array.array[float]: ...
@typing.overload
- def decode(self, data: bytes | bytearray | memoryview, bit_depth: int) -> bytes: ...
+ def decode(self, data: bytes | bytearray | memoryview | None, bit_depth: int) -> bytes: ...
def decode(
- self, data: bytes | bytearray | memoryview, bit_depth: int | None = None
+ self, data: bytes | bytearray | memoryview | None, bit_depth: int | None = None
) -> bytes | array.array[float]:
"""
Decodes an LC3 frame.
@@ -487,6 +487,8 @@
The input `data` is the channels concatenation of LC3 frames in a
byte-like object. Interleaved PCM samples are returned according to
the `bit_depth` indication.
+ Setting `data` to `None` enables PLC (Packet Loss Concealment)
+ reconstruction for the block of LC3 frames.
When no `bit_depth` is defined, it's a vector of floating point values
from -1 to 1, coding the sample levels. When `bit_depth` is defined,
it returns a byte array, each sample coded on `bit_depth` bits.
@@ -500,22 +502,28 @@
pcm_len = num_channels * self.get_frame_samples()
pcm_buffer = (pcm_t * pcm_len)()
- data_buffer = bytearray(data)
- data_offset = 0
+ if data is not None:
+ data_buffer = bytearray(data)
+ data_offset = 0
for ich, decoder in enumerate(self.__decoders):
pcm_offset = ich * ctypes.sizeof(pcm_t)
pcm = (pcm_t * (pcm_len - ich)).from_buffer(pcm_buffer, pcm_offset)
- data_size = len(data_buffer) // num_channels + int(
- ich < len(data_buffer) % num_channels
- )
- buf = (c_byte * data_size).from_buffer(data_buffer, data_offset)
- data_offset += data_size
+ if data is None:
+ ret = self.lib.lc3_decode(
+ decoder, None, 0, pcm_fmt, pcm, self.num_channels
+ )
+ else:
+ data_size = len(data_buffer) // num_channels + int(
+ ich < len(data_buffer) % num_channels
+ )
+ buf = (c_byte * data_size).from_buffer(data_buffer, data_offset)
+ data_offset += data_size
+ ret = self.lib.lc3_decode(
+ decoder, buf, len(buf), pcm_fmt, pcm, self.num_channels
+ )
- ret = self.lib.lc3_decode(
- decoder, buf, len(buf), pcm_fmt, pcm, self.num_channels
- )
if ret < 0:
raise InvalidArgumentError("Bad parameters")
