## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
##
-# I2S protocol decoder
-
import sigrokdecode as srd
'''
-Protocol output format:
+OUTPUT_PYTHON format:
Packet:
[<ptype>, <pdata>]
'''
class Decoder(srd.Decoder):
- api_version = 1
+ api_version = 2
id = 'i2s'
- name = 'I2S'
+ name = 'I²S'
longname = 'Integrated Interchip Sound'
desc = 'Serial bus for connecting digital audio devices.'
license = 'gplv2+'
inputs = ['logic']
outputs = ['i2s']
- probes = [
+ channels = (
{'id': 'sck', 'name': 'SCK', 'desc': 'Bit clock line'},
{'id': 'ws', 'name': 'WS', 'desc': 'Word select line'},
{'id': 'sd', 'name': 'SD', 'desc': 'Serial data line'},
- ]
- optional_probes = []
- options = {}
- annotations = [
- ['left', 'Left channel'],
- ['right', 'Right channel'],
- ['warnings', 'Warnings'],
- ]
+ )
+ annotations = (
+ ('left', 'Left channel'),
+ ('right', 'Right channel'),
+ ('warnings', 'Warnings'),
+ )
+ binary = (
+ ('wav', 'WAV file'),
+ )
def __init__(self, **kwargs):
self.samplerate = None
self.first_sample = None
self.start_sample = None
self.wordlength = -1
+ self.wrote_wav_header = False
def start(self):
- self.out_proto = self.add(srd.OUTPUT_PYTHON, 'i2s')
- self.out_ann = self.add(srd.OUTPUT_ANN, 'i2s')
+ self.out_python = self.register(srd.OUTPUT_PYTHON)
+ self.out_bin = self.register(srd.OUTPUT_BINARY)
+ self.out_ann = self.register(srd.OUTPUT_ANN)
def metadata(self, key, value):
if key == srd.SRD_CONF_SAMPLERATE:
self.samplerate = value
def putpb(self, data):
- self.put(self.start_sample, self.samplenum, self.out_proto, data)
+ self.put(self.start_sample, self.samplenum, self.out_python, data)
+
+ def putbin(self, data):
+ self.put(self.start_sample, self.samplenum, self.out_bin, data)
def putb(self, data):
self.put(self.start_sample, self.samplenum, self.out_ann, data)
self.samplerate / (self.start_sample -
self.first_sample))
- return 'I2S: %d %d-bit samples received at %sHz' % \
+ return 'I²S: %d %d-bit samples received at %sHz' % \
(self.samplesreceived, self.wordlength, samplerate)
+ def wav_header(self):
+ # Chunk descriptor
+ h = b'RIFF'
+ h += b'\x24\x80\x00\x00' # Chunk size (2084)
+ h += b'WAVE'
+ # Fmt subchunk
+ h += b'fmt '
+ h += b'\x10\x00\x00\x00' # Subchunk size (16 bytes)
+ h += b'\x01\x00' # Audio format (0x0001 == PCM)
+ h += b'\x02\x00' # Number of channels (2)
+ h += b'\x80\x3e\x00\x00' # Samplerate (16000)
+ h += b'\x00\x7d\x00\x00' # Byterate (32000)
+ h += b'\x04\x00' # Blockalign (4)
+ h += b'\x10\x00' # Bits per sample (16)
+ # Data subchunk
+ h += b'data'
+ h += b'\xff\xff\x00\x00' # Subchunk size (65535 bytes) TODO
+ return h
+
+ def wav_sample(self, sample):
+ # 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
+ return bytes([lo, hi])
+
def decode(self, ss, es, data):
if self.samplerate is None:
raise Exception("Cannot decode without samplerate.")
# Only submit the sample, if we received the beginning of it.
if self.start_sample != None:
+
+ if not self.wrote_wav_header:
+ self.put(0, 0, self.out_bin, (0, self.wav_header()))
+ self.wrote_wav_header = True
+
self.samplesreceived += 1
idx = 0 if self.oldws else 1
self.putpb(['DATA', [c3, self.data]])
self.putb([idx, ['%s: %s' % (c1, v), '%s: %s' % (c2, v),
'%s: %s' % (c3, v), c3]])
+ self.putbin((0, self.wav_sample(self.data)))
# Check that the data word was the correct length.
if self.wordlength != -1 and self.wordlength != self.bitcount: