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##
## This file is part of the libsigrokdecode project.
##
## Copyright (C) 2013 Uwe Hermann <uwe@hermann-uwe.de>
##
## This program is free software; you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
## the Free Software Foundation; either version 2 of the License, or
## (at your option) any later version.
##
## This program is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
## GNU General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with this program; if not, write to the Free Software
## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
##
import sigrokdecode as srd
import os
import sys
class Decoder(srd.Decoder):
api_version = 1
id = 'i2s_dump'
name = 'I2S dump'
longname = 'I2S dump'
desc = 'Output decoded I2S data to a file.'
license = 'gplv2+'
inputs = ['i2s']
outputs = []
probes = []
optional_probes = []
options = {
'format': ['File format for the output data', 'wav'],
'filename': ['File name for the output data', '-'],
}
annotations = []
def __init__(self, **kwargs):
self.wrote_header = False
self.f = None
def file_open(self, filename):
if filename == 'none':
return None
elif filename == '-':
return sys.stdout
else:
return open(filename, 'wb')
def start(self):
# A filename of 'none' is not allowed (has special meaning). A filename
# of '-' means 'stdout'.
self.f = self.file_open(self.options['filename'])
def report(self):
pass
# TODO: Lots of hard-coded fields in here.
def write_wav_header(self):
# Chunk descriptor
self.f.write(b'RIFF')
self.f.write(b'\x24\x80\x00\x00') # Chunk size (2084)
self.f.write(b'WAVE')
# Fmt subchunk
self.f.write(b'fmt ')
self.f.write(b'\x10\x00\x00\x00') # Subchunk size (16 bytes)
self.f.write(b'\x01\x00') # Audio format (0x0001 == PCM)
self.f.write(b'\x02\x00') # Number of channels (2)
self.f.write(b'\x80\x3e\x00\x00') # Samplerate (16000)
self.f.write(b'\x00\x7d\x00\x00') # Byterate (32000)
self.f.write(b'\x04\x00') # Blockalign (4)
self.f.write(b'\x10\x00') # Bits per sample (16)
# Data subchunk
self.f.write(b'data')
self.f.write(b'\xff\xff\x00\x00') # Subchunk size (65535 bytes) TODO
self.f.flush()
def decode(self, ss, es, data):
ptype, pdata = data
if ptype != 'DATA':
return
channel, sample = pdata
if self.wrote_header == False:
self.write_wav_header()
self.wrote_header = True
# Output the next sample to 'filename'.
# TODO: Data: first left channel, then right channel.
if self.f != None:
# TODO: This currently assumes U32 samples, and converts to S16.
s = sample >> 16
if s >= 0x8000:
s -= 0x10000
lo, hi = s & 0xff, (s >> 8) & 0xff
self.f.write(bytes([lo, hi]))
self.f.flush()
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