FritzAB2Matrix/libs/message/conversion/__init__.py

86 lines
2.8 KiB
Python

import wave, ctypes
### Convert fb speex format to wav ###
######################################
"""
This piece of code is just copied & pasted from https://git.savannah.nongnu.org/cgit/fbvbconv-py.git/tree/fbvbconv.py
which has kindly managed to convert the messages of the answering machine of fritzboxes from a specially configured Speex format to a wave file. All appreciation to the author(s).
"""
speexlib = ctypes.cdll.LoadLibrary("libspeex.so.1")
SPEEX_SET_SAMPLING_RATE = 24
SPEEX_GET_FRAME_SIZE = 3
class SpeexMode(ctypes.c_void_p):
pass
class Speex(ctypes.c_void_p):
pass
class SpeexBits(ctypes.Structure):
_fields_ = [
('chars', ctypes.c_char_p),
('nbBits', ctypes.c_int),
('charPtr', ctypes.c_int),
('bitPtr', ctypes.c_int),
('owner', ctypes.c_int),
('overflow', ctypes.c_int),
('but_size', ctypes.c_int),
('reserved1', ctypes.c_int),
('reserved2', ctypes.c_void_p)
]
speex_lib_get_mode = speexlib.speex_lib_get_mode
speex_lib_get_mode.restype = SpeexMode
speex_decoder_init = speexlib.speex_decoder_init
speex_decoder_init.restype = Speex
speex_decoder_ctl = speexlib.speex_decoder_ctl
speex_bits_init = speexlib.speex_bits_init
speex_bits_read_from = speexlib.speex_bits_read_from
speex_decode_int = speexlib.speex_decode_int
speex_bits_remaining = speexlib.speex_bits_remaining
speex_bits_destroy = speexlib.speex_bits_destroy
def speex_convert(inp, outp):
# rec = open(inp, 'rb').read()
rec = inp.read()
wav = wave.open(outp, 'wb')
wav.setnchannels(1)
wav.setsampwidth(2)
wav.setframerate(8000)
mode = speex_lib_get_mode(0)
speex = speex_decoder_init(mode)
speex_decoder_ctl(speex, SPEEX_SET_SAMPLING_RATE, ctypes.byref(ctypes.c_int(8000)))
bits = SpeexBits()
speex_bits_init(ctypes.byref(bits))
frame_size = ctypes.c_int()
speex_decoder_ctl(speex, SPEEX_GET_FRAME_SIZE, ctypes.byref(frame_size))
output = ctypes.create_string_buffer(2000)
offs = 0
while offs < len(rec):
nbytes = rec[offs]
offs += 1
if nbytes != 0x26:
continue
buf = ctypes.create_string_buffer(rec[offs:offs + nbytes])
offs += nbytes
speex_bits_read_from(ctypes.byref(bits), buf, ctypes.c_int(nbytes))
# this loop looks strange, but its like in roger router and seems to work
for i in range(2):
rc = speex_decode_int(speex, ctypes.byref(bits), output)
if rc == -1:
break
elif rc == -2:
print("Decoding error: corrupted stream?");
break
if speex_bits_remaining(ctypes.byref(bits)) < 0:
print("Decoding overflow: corrupted stream?");
break
wav.writeframes(output[0:2 * frame_size.value])
wav.close()
speex_bits_destroy(ctypes.byref(bits))