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python: Add python library wrapper

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This commit is contained in:
Antoine Soulier
2024-01-04 14:12:54 -08:00
parent 10999c6c58
commit 8e0bd81fe4
9 changed files with 905 additions and 170 deletions
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81
test/decoder.py Executable file → Normal file
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@@ -1,4 +1,3 @@
#!/usr/bin/env python3
#
# Copyright 2022 Google LLC
#
@@ -27,8 +26,6 @@ import tables as T, appendix_c as C
import mdct, energy, bwdet, sns, tns, spec, ltpf
import bitstream
### ------------------------------------------------------------------------ ###
class Decoder:
def __init__(self, dt_ms, sr_hz):
@@ -96,8 +93,6 @@ class Decoder:
return x
### ------------------------------------------------------------------------ ###
def check_appendix_c(dt):
i0 = dt - T.DT_7M5
@@ -120,79 +115,3 @@ def check():
ok = ok and check_appendix_c(dt)
return ok
### ------------------------------------------------------------------------ ###
if __name__ == "__main__":
parser = argparse.ArgumentParser(description='LC3 Decoder Test Framework')
parser.add_argument('lc3_file',
help='Input bitstream file', type=argparse.FileType('r'))
parser.add_argument('--pyout',
help='Python output file', type=argparse.FileType('w'))
parser.add_argument('--cout',
help='C output file', type=argparse.FileType('w'))
args = parser.parse_args()
### File Header ###
f_lc3 = open(args.lc3_file.name, 'rb')
header = struct.unpack('=HHHHHHHI', f_lc3.read(18))
if header[0] != 0xcc1c:
raise ValueError('Invalid bitstream file')
if header[4] != 1:
raise ValueError('Unsupported number of channels')
sr_hz = header[2] * 100
bitrate = header[3] * 100
nchannels = header[4]
dt_ms = header[5] / 100
f_lc3.seek(header[1])
### Setup ###
dec = Decoder(dt_ms, sr_hz)
dec_c = lc3.setup_decoder(int(dt_ms * 1000), sr_hz)
pcm_c = np.empty(0).astype(np.int16)
pcm_py = np.empty(0).astype(np.int16)
### Decoding loop ###
nframes = 0
while True:
data = f_lc3.read(2)
if len(data) != 2:
break
(frame_nbytes,) = struct.unpack('=H', data)
print('Decoding frame %d' % nframes, end='\r')
data = f_lc3.read(frame_nbytes)
x = dec.run(data)
pcm_py = np.append(pcm_py,
np.clip(np.round(x), -32768, 32767).astype(np.int16))
x_c = lc3.decode(dec_c, data)
pcm_c = np.append(pcm_c, x_c)
nframes += 1
print('done ! %16s' % '')
### Terminate ###
if args.pyout:
wavfile.write(args.pyout.name, sr_hz, pcm_py)
if args.cout:
wavfile.write(args.cout.name, sr_hz, pcm_c)
### ------------------------------------------------------------------------ ###