## 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
+## along with this program; if not, see <http://www.gnu.org/licenses/>.
##
import sigrokdecode as srd
+import struct
'''
OUTPUT_PYTHON format:
<value>: integer
'''
+class SamplerateError(Exception):
+ pass
+
class Decoder(srd.Decoder):
- api_version = 1
+ api_version = 3
id = 'i2s'
name = 'I²S'
longname = 'Integrated Interchip Sound'
('wav', 'WAV file'),
)
- def __init__(self, **kwargs):
+ def __init__(self):
+ self.reset()
+
+ def reset(self):
self.samplerate = None
- self.oldsck = 1
self.oldws = 1
self.bitcount = 0
self.data = 0
self.samplesreceived = 0
self.first_sample = None
- self.start_sample = None
+ self.ss_block = None
self.wordlength = -1
self.wrote_wav_header = False
def start(self):
self.out_python = self.register(srd.OUTPUT_PYTHON)
- self.out_bin = self.register(srd.OUTPUT_BINARY)
+ self.out_binary = self.register(srd.OUTPUT_BINARY)
self.out_ann = self.register(srd.OUTPUT_ANN)
def metadata(self, key, value):
self.samplerate = value
def putpb(self, data):
- self.put(self.start_sample, self.samplenum, self.out_python, data)
+ self.put(self.ss_block, self.samplenum, self.out_python, data)
def putbin(self, data):
- self.put(self.start_sample, self.samplenum, self.out_bin, data)
+ self.put(self.ss_block, self.samplenum, self.out_binary, data)
def putb(self, data):
- self.put(self.start_sample, self.samplenum, self.out_ann, data)
+ self.put(self.ss_block, self.samplenum, self.out_ann, data)
def report(self):
# Calculate the sample rate.
samplerate = '?'
- if self.start_sample != None and \
- self.first_sample != None and \
- self.start_sample > self.first_sample:
+ if self.ss_block is not None and \
+ self.first_sample is not None and \
+ self.ss_block > self.first_sample:
samplerate = '%d' % (self.samplesreceived *
- self.samplerate / (self.start_sample -
+ self.samplerate / (self.ss_block -
self.first_sample))
return 'I²S: %d %d-bit samples received at %sHz' % \
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'\x00\xfa\x00\x00' # Byterate (64000)
h += b'\x04\x00' # Blockalign (4)
- h += b'\x10\x00' # Bits per sample (16)
+ h += b'\x20\x00' # Bits per sample (32)
# Data subchunk
h += b'data'
- h += b'\xff\xff\x00\x00' # Subchunk size (65535 bytes) TODO
+ h += b'\xff\xff\xff\xff' # Subchunk size (4G 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.")
- for self.samplenum, (sck, ws, sd) in data:
-
- # Ignore sample if the bit clock hasn't changed.
- if sck == self.oldsck:
- continue
+ return struct.pack('<I', self.data)
- self.oldsck = sck
- if sck == 0: # Ignore the falling clock edge.
- continue
+ def decode(self):
+ if not self.samplerate:
+ raise SamplerateError('Cannot decode without samplerate.')
+ while True:
+ # Wait for a rising edge on the SCK pin.
+ sck, ws, sd = self.wait({0: 'r'})
self.data = (self.data << 1) | sd
self.bitcount += 1
continue
# Only submit the sample, if we received the beginning of it.
- if self.start_sample != None:
+ if self.ss_block is not None:
if not self.wrote_wav_header:
- self.put(0, 0, self.out_bin, (0, self.wav_header()))
+ self.put(0, 0, self.out_binary, [0, self.wav_header()])
self.wrote_wav_header = True
self.samplesreceived += 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)))
+ 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:
# Reset decoder state.
self.data = 0
self.bitcount = 0
- self.start_sample = self.samplenum
+ self.ss_block = self.samplenum
# Save the first sample position.
- if self.first_sample == None:
+ if self.first_sample is None:
self.first_sample = self.samplenum
self.oldws = ws
-
projects / libsigrokdecode.git / blobdiff