## 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
pass
class Decoder(srd.Decoder):
- api_version = 2
+ api_version = 3
id = 'spdif'
name = 'S/PDIF'
longname = 'Sony/Philips Digital Interface Format'
def putx(self, ss, es, data):
self.put(ss, es, self.out_ann, data)
- def __init__(self, **kwargs):
- self.state = 0
- self.olddata = None
+ def puty(self, data):
+ self.put(self.ss_edge, self.samplenum, self.out_ann, data)
+
+ def __init__(self):
+ self.state = 'GET FIRST PULSE WIDTH'
self.ss_edge = None
self.first_edge = True
+ self.samplenum_prev_edge = 0
self.pulse_width = 0
self.clocks = []
def start(self):
self.out_ann = self.register(srd.OUTPUT_ANN)
+ # Assume that the initial pin state is logic 0.
+ self.initial_pins = [0]
+
def metadata(self, key, value):
if key == srd.SRD_CONF_SAMPLERATE:
self.samplerate = value
- def get_pulse_type(self, pulse):
+ def get_pulse_type(self):
if self.range1 == 0 or self.range2 == 0:
return -1
- if pulse >= self.range2:
+ if self.pulse_width >= self.range2:
return 2
- elif pulse >= self.range1:
+ elif self.pulse_width >= self.range1:
return 0
else:
return 1
def find_first_pulse_width(self):
if self.pulse_width != 0:
self.clocks.append(self.pulse_width)
- self.state = 1
+ self.state = 'GET SECOND PULSE WIDTH'
def find_second_pulse_width(self):
if self.pulse_width > (self.clocks[0] * 1.3) or \
self.pulse_width < (self.clocks[0] * 0.7):
self.clocks.append(self.pulse_width)
- self.state = 2
+ self.state = 'GET THIRD PULSE WIDTH'
def find_third_pulse_width(self):
if not ((self.pulse_width > (self.clocks[0] * 1.3) or \
spdif_bitrate = int(self.samplerate / (self.clocks[2] / 1.5))
self.ss_edge = 0
- self.putx(self.ss_edge, self.samplenum, [0, \
- ['Signal Bitrate: %d Mbit/s (=> %d kHz)' % \
- (spdif_bitrate, (spdif_bitrate/ (2 * 32)))]])
+ self.puty([0, ['Signal Bitrate: %d Mbit/s (=> %d kHz)' % \
+ (spdif_bitrate, (spdif_bitrate/ (2 * 32)))]])
clock_period_nsec = 1000000000 / spdif_bitrate
self.last_preamble = self.samplenum
# We are done recovering the clock, now let's decode the data stream.
- self.state = 3
+ self.state = 'DECODE STREAM'
def decode_stream(self):
- pulse = self.get_pulse_type(self.pulse_width)
+ pulse = self.get_pulse_type()
if not self.seen_preamble:
# This is probably the start of a preamble, decode it.
if pulse == 2:
- self.preamble.append(self.get_pulse_type(self.pulse_width))
- self.state = 4 # Decode a preamble.
+ self.preamble.append(self.get_pulse_type())
+ self.state = 'DECODE PREAMBLE'
self.ss_edge = self.samplenum - self.pulse_width - 1
return
self.seen_preamble = False
self.bitcount = 0
- def handle_preamble(self):
+ def decode_preamble(self):
if self.preamble_state == 0:
- self.preamble.append(self.get_pulse_type(self.pulse_width))
+ self.preamble.append(self.get_pulse_type())
self.preamble_state = 1
elif self.preamble_state == 1:
- self.preamble.append(self.get_pulse_type(self.pulse_width))
+ self.preamble.append(self.get_pulse_type())
self.preamble_state = 2
elif self.preamble_state == 2:
- self.preamble.append(self.get_pulse_type(self.pulse_width))
+ self.preamble.append(self.get_pulse_type())
self.preamble_state = 0
- self.state = 3
+ self.state = 'DECODE STREAM'
if self.preamble == [2, 0, 1, 0]:
- self.putx(self.ss_edge, self.samplenum, [1, ['Preamble W', 'W']])
+ self.puty([1, ['Preamble W', 'W']])
elif self.preamble == [2, 2, 1, 1]:
- self.putx(self.ss_edge, self.samplenum, [1, ['Preamble M', 'M']])
+ self.puty([1, ['Preamble M', 'M']])
elif self.preamble == [2, 1, 1, 2]:
- self.putx(self.ss_edge, self.samplenum, [1, ['Preamble B', 'B']])
+ self.puty([1, ['Preamble B', 'B']])
else:
- self.putx(self.ss_edge, self.samplenum, [1, ['Unknown Preamble', 'Unkown Prea.', 'U']])
+ self.puty([1, ['Unknown Preamble', 'Unknown Prea.', 'U']])
self.preamble = []
self.seen_preamble = True
self.bitcount = 0
self.last_preamble = self.samplenum
- def decode(self, ss, es, data):
+ def decode(self):
if not self.samplerate:
raise SamplerateError('Cannot decode without samplerate.')
- for (self.samplenum, pins) in data:
- data = pins[0]
-
- # Initialize self.olddata with the first sample value.
- if self.olddata == None:
- self.olddata = data
- continue
-
- # First we need to recover the clock.
- if self.olddata == data:
- self.pulse_width += 1
- continue
-
- # Found rising or falling edge.
- if self.first_edge:
- # Throw away first detected edge as it might be mangled data.
- self.first_edge = False
- self.pulse_width = 0
- else:
- if self.state == 0:
- self.find_first_pulse_width()
- elif self.state == 1:
- self.find_second_pulse_width()
- elif self.state == 2:
- self.find_third_pulse_width()
- elif self.state == 3:
- self.decode_stream()
- elif self.state == 4:
- self.handle_preamble()
-
- self.pulse_width = 0
-
- self.olddata = data
+ # Throw away first detected edge as it might be mangled data.
+ self.wait({0: 'e'})
+
+ while True:
+ # Wait for any edge (rising or falling).
+ (data,) = self.wait({0: 'e'})
+ self.pulse_width = self.samplenum - self.samplenum_prev_edge - 1
+ self.samplenum_prev_edge = self.samplenum
+
+ if self.state == 'GET FIRST PULSE WIDTH':
+ self.find_first_pulse_width()
+ elif self.state == 'GET SECOND PULSE WIDTH':
+ self.find_second_pulse_width()
+ elif self.state == 'GET THIRD PULSE WIDTH':
+ self.find_third_pulse_width()
+ elif self.state == 'DECODE STREAM':
+ self.decode_stream()
+ elif self.state == 'DECODE PREAMBLE':
+ self.decode_preamble()
projects / libsigrokdecode.git / blobdiff