[libsigrokdecode.git] / decoders / spdif / pd.py

##
## This file is part of the libsigrokdecode project.
##
## Copyright (C) 2014 Guenther Wenninger <robin@bitschubbser.org>
##
## 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

class SamplerateError(Exception):
    pass

class Decoder(srd.Decoder):
    api_version = 2
    id = 'spdif'
    name = 'S/PDIF'
    longname = 'Sony/Philips Digital Interface Format'
    desc = 'Serial bus for connecting digital audio devices.'
    license = 'gplv2+'
    inputs = ['logic']
    outputs = ['spdif']
    channels = (
        {'id': 'data', 'name': 'Data', 'desc': 'Data line'},
    )
    annotations = (
        ('bitrate', 'Bitrate / baudrate'),
        ('preamble', 'Preamble'),
        ('bits', 'Bits'),
        ('aux', 'Auxillary-audio-databits'),
        ('samples', 'Audio Samples'),
        ('validity', 'Data Valid'),
        ('subcode', 'Subcode data'),
        ('chan_stat', 'Channnel Status'),
        ('parity', 'Parity Bit'),
    )
    annotation_rows = (
        ('info', 'Info', (0, 1, 3, 5, 6, 7, 8)),
        ('bits', 'Bits', (2,)),
        ('samples', 'Samples', (4,)),
    )

    def putx(self, ss, es, data):
        self.put(ss, es, self.out_ann, data)

    def puty(self, data):
        self.put(self.ss_edge, self.samplenum, self.out_ann, data)

    def __init__(self, **kwargs):
        self.state  = 0
        self.olddata = None
        self.ss_edge = None
        self.first_edge = True
        self.pulse_width = 0

        self.clocks = []
        self.range1 = 0
        self.range2 = 0

        self.preamble_state = 0
        self.preamble = []
        self.seen_preamble = False
        self.last_preamble = 0

        self.first_one = True
        self.subframe = []

    def start(self):
        self.out_ann = self.register(srd.OUTPUT_ANN)

    def metadata(self, key, value):
        if key == srd.SRD_CONF_SAMPLERATE:
            self.samplerate = value

    def get_pulse_type(self, pulse):
        if self.range1 == 0 or self.range2 == 0:
            return -1
        if pulse >= self.range2:
            return 2
        elif pulse >= 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

    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

    def find_third_pulse_width(self):
        if not ((self.pulse_width > (self.clocks[0] * 1.3) or \
                self.pulse_width < (self.clocks[0] * 0.7)) \
                and (self.pulse_width > (self.clocks[1] * 1.3) or \
                self.pulse_width < (self.clocks[1] * 0.7))):
            return

        self.clocks.append(self.pulse_width)
        self.clocks.sort()
        self.range1 = (self.clocks[0] + self.clocks[1]) / 2
        self.range2 = (self.clocks[1] + self.clocks[2]) / 2
        spdif_bitrate = int(self.samplerate / (self.clocks[2] / 1.5))
        self.ss_edge = 0

        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

    def decode_stream(self):
        pulse = self.get_pulse_type(self.pulse_width)

        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.ss_edge = self.samplenum - self.pulse_width - 1
            return

        # We've seen a preamble.
        if pulse == 1 and self.first_one:
            self.first_one = False
            self.subframe.append([pulse, self.samplenum - \
                self.pulse_width - 1, self.samplenum])
        elif pulse == 1 and not self.first_one:
            self.subframe[-1][2] = self.samplenum
            self.putx(self.subframe[-1][1], self.samplenum, [2, ['1']])
            self.bitcount += 1
            self.first_one = True
        else:
            self.subframe.append([pulse, self.samplenum - \
                self.pulse_width - 1, self.samplenum])
            self.putx(self.samplenum - self.pulse_width - 1,
                      self.samplenum, [2, ['0']])
            self.bitcount += 1

        if self.bitcount == 28:
            aux_audio_data = self.subframe[0:4]
            sam, sam_rot = '', ''
            for a in aux_audio_data:
                sam = sam + str(a[0])
                sam_rot = str(a[0]) + sam_rot
            sample = self.subframe[4:24]
            for s in sample:
                sam = sam + str(s[0])
                sam_rot = str(s[0]) + sam_rot
            validity = self.subframe[24:25]
            subcode_data = self.subframe[25:26]
            channel_status = self.subframe[26:27]
            parity = self.subframe[27:28]

            self.putx(aux_audio_data[0][1], aux_audio_data[3][2], \
                      [3, ['Aux 0x%x' % int(sam, 2), '0x%x' % int(sam, 2)]])
            self.putx(sample[0][1], sample[19][2], \
                      [3, ['Sample 0x%x' % int(sam, 2), '0x%x' % int(sam, 2)]])
            self.putx(aux_audio_data[0][1], sample[19][2], \
                      [4, ['Audio 0x%x' % int(sam_rot, 2), '0x%x' % int(sam_rot, 2)]])
            if validity[0][0] == 0:
                self.putx(validity[0][1], validity[0][2], [5, ['V']])
            else:
                self.putx(validity[0][1], validity[0][2], [5, ['E']])
            self.putx(subcode_data[0][1], subcode_data[0][2],
                [6, ['S: %d' % subcode_data[0][0]]])
            self.putx(channel_status[0][1], channel_status[0][2],
                [7, ['C: %d' % channel_status[0][0]]])
            self.putx(parity[0][1], parity[0][2], [8, ['P: %d' % parity[0][0]]])

            self.subframe = []
            self.seen_preamble = False
            self.bitcount = 0

    def handle_preamble(self):
        if self.preamble_state == 0:
            self.preamble.append(self.get_pulse_type(self.pulse_width))
            self.preamble_state = 1
        elif self.preamble_state == 1:
            self.preamble.append(self.get_pulse_type(self.pulse_width))
            self.preamble_state = 2
        elif self.preamble_state == 2:
            self.preamble.append(self.get_pulse_type(self.pulse_width))
            self.preamble_state = 0
            self.state = 3
            if self.preamble == [2, 0, 1, 0]:
                self.puty([1, ['Preamble W', 'W']])
            elif self.preamble == [2, 2, 1, 1]:
                self.puty([1, ['Preamble M', 'M']])
            elif self.preamble == [2, 1, 1, 2]:
                self.puty([1, ['Preamble B', 'B']])
            else:
                self.puty([1, ['Unknown Preamble', 'Unkown Prea.', 'U']])
            self.preamble = []
            self.seen_preamble = True
            self.bitcount = 0
            self.first_one = True

        self.last_preamble = self.samplenum

    def decode(self, ss, es, data):
        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
Commit	Line	Data
cb6d4c6d GW	1	##
	2	## This file is part of the libsigrokdecode project.
	3	##
	4	## Copyright (C) 2014 Guenther Wenninger <robin@bitschubbser.org>
	5	##
	6	## This program is free software; you can redistribute it and/or modify
	7	## it under the terms of the GNU General Public License as published by
	8	## the Free Software Foundation; either version 2 of the License, or
	9	## (at your option) any later version.
	10	##
	11	## This program is distributed in the hope that it will be useful,
	12	## but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	## GNU General Public License for more details.
	15	##
	16	## You should have received a copy of the GNU General Public License
	17	## along with this program; if not, write to the Free Software
	18	## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	19	##
	20
	21	import sigrokdecode as srd
	22
	23	class SamplerateError(Exception):
	24	pass
	25
	26	class Decoder(srd.Decoder):
	27	api_version = 2
	28	id = 'spdif'
	29	name = 'S/PDIF'
	30	longname = 'Sony/Philips Digital Interface Format'
	31	desc = 'Serial bus for connecting digital audio devices.'
	32	license = 'gplv2+'
	33	inputs = ['logic']
	34	outputs = ['spdif']
	35	channels = (
	36	{'id': 'data', 'name': 'Data', 'desc': 'Data line'},
	37	)
	38	annotations = (
	39	('bitrate', 'Bitrate / baudrate'),
	40	('preamble', 'Preamble'),
	41	('bits', 'Bits'),
	42	('aux', 'Auxillary-audio-databits'),
	43	('samples', 'Audio Samples'),
	44	('validity', 'Data Valid'),
	45	('subcode', 'Subcode data'),
	46	('chan_stat', 'Channnel Status'),
	47	('parity', 'Parity Bit'),
	48	)
	49	annotation_rows = (
	50	('info', 'Info', (0, 1, 3, 5, 6, 7, 8)),
	51	('bits', 'Bits', (2,)),
	52	('samples', 'Samples', (4,)),
	53	)
	54
	55	def putx(self, ss, es, data):
	56	self.put(ss, es, self.out_ann, data)
	57
cc16130e UH	58	def puty(self, data):
	59	self.put(self.ss_edge, self.samplenum, self.out_ann, data)
	60
cb6d4c6d GW	61	def __init__(self, **kwargs):
	62	self.state = 0
	63	self.olddata = None
	64	self.ss_edge = None
	65	self.first_edge = True
	66	self.pulse_width = 0
	67
	68	self.clocks = []
	69	self.range1 = 0
	70	self.range2 = 0
	71
	72	self.preamble_state = 0
	73	self.preamble = []
	74	self.seen_preamble = False
	75	self.last_preamble = 0
	76
	77	self.first_one = True
	78	self.subframe = []
	79
	80	def start(self):
	81	self.out_ann = self.register(srd.OUTPUT_ANN)
	82
	83	def metadata(self, key, value):
	84	if key == srd.SRD_CONF_SAMPLERATE:
	85	self.samplerate = value
	86
	87	def get_pulse_type(self, pulse):
	88	if self.range1 == 0 or self.range2 == 0:
	89	return -1
	90	if pulse >= self.range2:
	91	return 2
	92	elif pulse >= self.range1:
	93	return 0
	94	else:
	95	return 1
	96
eb148e7a UH	97	def find_first_pulse_width(self):
	98	if self.pulse_width != 0:
	99	self.clocks.append(self.pulse_width)
	100	self.state = 1
	101
	102	def find_second_pulse_width(self):
	103	if self.pulse_width > (self.clocks[0] * 1.3) or \
	104	self.pulse_width < (self.clocks[0] * 0.7):
	105	self.clocks.append(self.pulse_width)
	106	self.state = 2
	107
	108	def find_third_pulse_width(self):
	109	if not ((self.pulse_width > (self.clocks[0] * 1.3) or \
	110	self.pulse_width < (self.clocks[0] * 0.7)) \
	111	and (self.pulse_width > (self.clocks[1] * 1.3) or \
	112	self.pulse_width < (self.clocks[1] * 0.7))):
	113	return
	114
	115	self.clocks.append(self.pulse_width)
	116	self.clocks.sort()
	117	self.range1 = (self.clocks[0] + self.clocks[1]) / 2
	118	self.range2 = (self.clocks[1] + self.clocks[2]) / 2
	119	spdif_bitrate = int(self.samplerate / (self.clocks[2] / 1.5))
	120	self.ss_edge = 0
	121
cc16130e UH	122	self.puty([0, ['Signal Bitrate: %d Mbit/s (=> %d kHz)' % \
cc16130e UH	123	(spdif_bitrate, (spdif_bitrate/ (2 * 32)))]])
eb148e7a UH	124
	125	clock_period_nsec = 1000000000 / spdif_bitrate
	126
	127	self.last_preamble = self.samplenum
	128
	129	# We are done recovering the clock, now let's decode the data stream.
	130	self.state = 3
	131
	132	def decode_stream(self):
	133	pulse = self.get_pulse_type(self.pulse_width)
	134
	135	if not self.seen_preamble:
	136	# This is probably the start of a preamble, decode it.
	137	if pulse == 2:
	138	self.preamble.append(self.get_pulse_type(self.pulse_width))
	139	self.state = 4 # Decode a preamble.
	140	self.ss_edge = self.samplenum - self.pulse_width - 1
	141	return
	142
	143	# We've seen a preamble.
	144	if pulse == 1 and self.first_one:
	145	self.first_one = False
	146	self.subframe.append([pulse, self.samplenum - \
	147	self.pulse_width - 1, self.samplenum])
	148	elif pulse == 1 and not self.first_one:
	149	self.subframe[-1][2] = self.samplenum
	150	self.putx(self.subframe[-1][1], self.samplenum, [2, ['1']])
	151	self.bitcount += 1
	152	self.first_one = True
	153	else:
	154	self.subframe.append([pulse, self.samplenum - \
	155	self.pulse_width - 1, self.samplenum])
	156	self.putx(self.samplenum - self.pulse_width - 1,
	157	self.samplenum, [2, ['0']])
	158	self.bitcount += 1
	159
	160	if self.bitcount == 28:
	161	aux_audio_data = self.subframe[0:4]
	162	sam, sam_rot = '', ''
	163	for a in aux_audio_data:
	164	sam = sam + str(a[0])
	165	sam_rot = str(a[0]) + sam_rot
	166	sample = self.subframe[4:24]
	167	for s in sample:
	168	sam = sam + str(s[0])
	169	sam_rot = str(s[0]) + sam_rot
	170	validity = self.subframe[24:25]
	171	subcode_data = self.subframe[25:26]
	172	channel_status = self.subframe[26:27]
	173	parity = self.subframe[27:28]
	174
	175	self.putx(aux_audio_data[0][1], aux_audio_data[3][2], \
	176	[3, ['Aux 0x%x' % int(sam, 2), '0x%x' % int(sam, 2)]])
	177	self.putx(sample[0][1], sample[19][2], \
	178	[3, ['Sample 0x%x' % int(sam, 2), '0x%x' % int(sam, 2)]])
	179	self.putx(aux_audio_data[0][1], sample[19][2], \
	180	[4, ['Audio 0x%x' % int(sam_rot, 2), '0x%x' % int(sam_rot, 2)]])
	181	if validity[0][0] == 0:
	182	self.putx(validity[0][1], validity[0][2], [5, ['V']])
	183	else:
	184	self.putx(validity[0][1], validity[0][2], [5, ['E']])
	185	self.putx(subcode_data[0][1], subcode_data[0][2],
	186	[6, ['S: %d' % subcode_data[0][0]]])
	187	self.putx(channel_status[0][1], channel_status[0][2],
188	[7, ['C: %d' % channel_status[0][0]]])
189	self.putx(parity[0][1], parity[0][2], [8, ['P: %d' % parity[0][0]]])
190
191	self.subframe = []
192	self.seen_preamble = False
193	self.bitcount = 0
194
195	def handle_preamble(self):
196	if self.preamble_state == 0:
197	self.preamble.append(self.get_pulse_type(self.pulse_width))
198	self.preamble_state = 1
199	elif self.preamble_state == 1:
200	self.preamble.append(self.get_pulse_type(self.pulse_width))
201	self.preamble_state = 2
202	elif self.preamble_state == 2:
203	self.preamble.append(self.get_pulse_type(self.pulse_width))
204	self.preamble_state = 0
205	self.state = 3
206	if self.preamble == [2, 0, 1, 0]:
cc16130e	207	self.puty([1, ['Preamble W', 'W']])
eb148e7a	208	elif self.preamble == [2, 2, 1, 1]:
cc16130e	209	self.puty([1, ['Preamble M', 'M']])
eb148e7a	210	elif self.preamble == [2, 1, 1, 2]:
cc16130e	211	self.puty([1, ['Preamble B', 'B']])
eb148e7a	212	else:
cc16130e	213	self.puty([1, ['Unknown Preamble', 'Unkown Prea.', 'U']])
eb148e7a UH	214	self.preamble = []
	215	self.seen_preamble = True
	216	self.bitcount = 0
	217	self.first_one = True
	218
	219	self.last_preamble = self.samplenum
	220
cb6d4c6d GW	221	def decode(self, ss, es, data):
	222	if not self.samplerate:
	223	raise SamplerateError('Cannot decode without samplerate.')
	224
	225	for (self.samplenum, pins) in data:
	226	data = pins[0]
	227
eb148e7a	228	# Initialize self.olddata with the first sample value.
cb6d4c6d GW	229	if self.olddata == None:
	230	self.olddata = data
	231	continue
	232
	233	# First we need to recover the clock.
	234	if self.olddata == data:
	235	self.pulse_width += 1
eb148e7a	236	continue
cb6d4c6d	237
eb148e7a UH	238	# Found rising or falling edge.
	239	if self.first_edge:
	240	# Throw away first detected edge as it might be mangled data.
	241	self.first_edge = False
cb6d4c6d	242	self.pulse_width = 0
eb148e7a UH	243	else:
	244	if self.state == 0:
	245	self.find_first_pulse_width()
	246	elif self.state == 1:
	247	self.find_second_pulse_width()
	248	elif self.state == 2:
	249	self.find_third_pulse_width()
	250	elif self.state == 3:
	251	self.decode_stream()
	252	elif self.state == 4:
	253	self.handle_preamble()
	254
	255	self.pulse_width = 0
cb6d4c6d GW	256
cb6d4c6d GW	257	self.olddata = data