Add new methods to encode and decode waveforms

This commit is contained in:
Lonami Exo 2019-06-04 21:36:38 +02:00
parent 065719c8d8
commit 770c2c504d

View File

@ -1141,6 +1141,72 @@ def get_appropriated_part_size(file_size):
raise ValueError('File size too large')
def encode_waveform(waveform):
"""
Encodes the input ``bytes`` into a 5-bit byte-string
to be used as a voice note's waveform. See `decode_waveform`
for the reverse operation.
Example
.. code-block:: python
chat = ...
file = 'my.ogg'
# Send 'my.ogg' with a ascending-triangle waveform
client.send_file(chat, file, attributes=[types.DocumentAttributeAudio(
duration=7,
voice=True,
waveform=utils.encode_waveform(bytes(range(2 ** 5)) # 2**5 because 5-bit
)]
# Send 'my.ogg' with a square waveform
client.send_file(chat, file, attributes=[types.DocumentAttributeAudio(
duration=7,
voice=True,
waveform=utils.encode_waveform(bytes((31, 31, 15, 15, 15, 15, 31, 31)) * 4)
)]
"""
bits_count = len(waveform) * 5
bytes_count = (bits_count + 7) // 8
result = bytearray(bytes_count + 1)
for i in range(len(waveform)):
byte_index, bit_shift = divmod(i * 5, 8)
value = (waveform[i] & 0b00011111) << bit_shift
or_what = struct.unpack('<H', (result[byte_index:byte_index + 2]))[0]
or_what |= value
result[byte_index:byte_index + 2] = struct.pack('<H', or_what)
return bytes(result[:bytes_count])
def decode_waveform(waveform):
"""
Inverse operation of `encode_waveform`.
"""
bit_count = len(waveform) * 8
value_count = bit_count // 5
if value_count == 0:
return b''
result = bytearray(value_count)
for i in range(value_count - 1):
byte_index, bit_shift = divmod(i * 5, 8)
value = struct.unpack('<H', waveform[byte_index:byte_index + 2])[0]
result[i] = (value >> bit_shift) & 0b00011111
byte_index, bit_shift = divmod(value_count - 1, 8)
if byte_index == len(waveform) - 1:
value = waveform[byte_index]
else:
value = struct.unpack('<H', waveform[byte_index:byte_index + 2])[0]
result[value_count - 1] = (value >> bit_shift) & 0b00011111
return bytes(result)
class AsyncClassWrapper:
def __init__(self, wrapped):
self.wrapped = wrapped