[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, see <http://www.gnu.org/licenses/>.
##

import sigrokdecode as srd

class SamplerateError(Exception):
    pass

class Decoder(srd.Decoder):
    api_version = 3
    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):
        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 = []
        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):
        if self.range1 == 0 or self.range2 == 0:
            return -1
        if self.pulse_width >= self.range2:
            return 2
        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 = '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 = 'GET THIRD PULSE WIDTH'

    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 = 'DECODE STREAM'

    def decode_stream(self):
        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.state = 'DECODE 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 decode_preamble(self):
        if self.preamble_state == 0:
            self.preamble.append(self.get_pulse_type())
            self.preamble_state = 1
        elif self.preamble_state == 1:
            self.preamble.append(self.get_pulse_type())
            self.preamble_state = 2
        elif self.preamble_state == 2:
            self.preamble.append(self.get_pulse_type())
            self.preamble_state = 0
            self.state = 'DECODE STREAM'
            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', 'Unknown Prea.', 'U']])
            self.preamble = []
            self.seen_preamble = True
            self.bitcount = 0
            self.first_one = True

        self.last_preamble = self.samplenum

    def decode(self):
        if not self.samplerate:
            raise SamplerateError('Cannot decode without samplerate.')

        # 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()
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
4539e9ca	17	## along with this program; if not, see <http://www.gnu.org/licenses/>.
cb6d4c6d GW	18	##
	19
	20	import sigrokdecode as srd
	21
	22	class SamplerateError(Exception):
	23	pass
	24
	25	class Decoder(srd.Decoder):
5e39fa54	26	api_version = 3
cb6d4c6d GW	27	id = 'spdif'
	28	name = 'S/PDIF'
	29	longname = 'Sony/Philips Digital Interface Format'
	30	desc = 'Serial bus for connecting digital audio devices.'
	31	license = 'gplv2+'
	32	inputs = ['logic']
	33	outputs = ['spdif']
	34	channels = (
	35	{'id': 'data', 'name': 'Data', 'desc': 'Data line'},
	36	)
	37	annotations = (
	38	('bitrate', 'Bitrate / baudrate'),
	39	('preamble', 'Preamble'),
	40	('bits', 'Bits'),
	41	('aux', 'Auxillary-audio-databits'),
	42	('samples', 'Audio Samples'),
	43	('validity', 'Data Valid'),
	44	('subcode', 'Subcode data'),
	45	('chan_stat', 'Channnel Status'),
	46	('parity', 'Parity Bit'),
	47	)
	48	annotation_rows = (
	49	('info', 'Info', (0, 1, 3, 5, 6, 7, 8)),
	50	('bits', 'Bits', (2,)),
	51	('samples', 'Samples', (4,)),
	52	)
	53
	54	def putx(self, ss, es, data):
	55	self.put(ss, es, self.out_ann, data)
	56
cc16130e UH	57	def puty(self, data):
	58	self.put(self.ss_edge, self.samplenum, self.out_ann, data)
	59
92b7b49f	60	def __init__(self):
5302d1e9	61	self.state = 'GET FIRST PULSE WIDTH'
cb6d4c6d GW	62	self.ss_edge = None
cb6d4c6d GW	63	self.first_edge = True
5e39fa54	64	self.samplenum_prev_edge = 0
cb6d4c6d GW	65	self.pulse_width = 0
	66
	67	self.clocks = []
	68	self.range1 = 0
	69	self.range2 = 0
	70
	71	self.preamble_state = 0
	72	self.preamble = []
	73	self.seen_preamble = False
	74	self.last_preamble = 0
	75
	76	self.first_one = True
	77	self.subframe = []
	78
	79	def start(self):
	80	self.out_ann = self.register(srd.OUTPUT_ANN)
	81
	82	def metadata(self, key, value):
	83	if key == srd.SRD_CONF_SAMPLERATE:
	84	self.samplerate = value
	85
58636105	86	def get_pulse_type(self):
cb6d4c6d GW	87	if self.range1 == 0 or self.range2 == 0:
cb6d4c6d GW	88	return -1
58636105	89	if self.pulse_width >= self.range2:
cb6d4c6d	90	return 2
58636105	91	elif self.pulse_width >= self.range1:
cb6d4c6d GW	92	return 0
	93	else:
	94	return 1
	95
eb148e7a UH	96	def find_first_pulse_width(self):
	97	if self.pulse_width != 0:
	98	self.clocks.append(self.pulse_width)
5302d1e9	99	self.state = 'GET SECOND PULSE WIDTH'
eb148e7a UH	100
	101	def find_second_pulse_width(self):
	102	if self.pulse_width > (self.clocks[0] * 1.3) or \
	103	self.pulse_width < (self.clocks[0] * 0.7):
	104	self.clocks.append(self.pulse_width)
5302d1e9	105	self.state = 'GET THIRD PULSE WIDTH'
eb148e7a UH	106
	107	def find_third_pulse_width(self):
	108	if not ((self.pulse_width > (self.clocks[0] * 1.3) or \
	109	self.pulse_width < (self.clocks[0] * 0.7)) \
	110	and (self.pulse_width > (self.clocks[1] * 1.3) or \
	111	self.pulse_width < (self.clocks[1] * 0.7))):
	112	return
	113
	114	self.clocks.append(self.pulse_width)
	115	self.clocks.sort()
	116	self.range1 = (self.clocks[0] + self.clocks[1]) / 2
	117	self.range2 = (self.clocks[1] + self.clocks[2]) / 2
	118	spdif_bitrate = int(self.samplerate / (self.clocks[2] / 1.5))
	119	self.ss_edge = 0
	120
cc16130e UH	121	self.puty([0, ['Signal Bitrate: %d Mbit/s (=> %d kHz)' % \
cc16130e UH	122	(spdif_bitrate, (spdif_bitrate/ (2 * 32)))]])
eb148e7a UH	123
	124	clock_period_nsec = 1000000000 / spdif_bitrate
	125
	126	self.last_preamble = self.samplenum
	127
	128	# We are done recovering the clock, now let's decode the data stream.
5302d1e9	129	self.state = 'DECODE STREAM'
eb148e7a UH	130
eb148e7a UH	131	def decode_stream(self):
58636105	132	pulse = self.get_pulse_type()
eb148e7a UH	133
	134	if not self.seen_preamble:
	135	# This is probably the start of a preamble, decode it.
	136	if pulse == 2:
58636105	137	self.preamble.append(self.get_pulse_type())
5302d1e9	138	self.state = 'DECODE PREAMBLE'
eb148e7a UH	139	self.ss_edge = self.samplenum - self.pulse_width - 1
	140	return
	141
	142	# We've seen a preamble.
	143	if pulse == 1 and self.first_one:
	144	self.first_one = False
	145	self.subframe.append([pulse, self.samplenum - \
	146	self.pulse_width - 1, self.samplenum])
	147	elif pulse == 1 and not self.first_one:
	148	self.subframe[-1][2] = self.samplenum
	149	self.putx(self.subframe[-1][1], self.samplenum, [2, ['1']])
	150	self.bitcount += 1
	151	self.first_one = True
	152	else:
	153	self.subframe.append([pulse, self.samplenum - \
	154	self.pulse_width - 1, self.samplenum])
	155	self.putx(self.samplenum - self.pulse_width - 1,
	156	self.samplenum, [2, ['0']])
	157	self.bitcount += 1
	158
	159	if self.bitcount == 28:
	160	aux_audio_data = self.subframe[0:4]
	161	sam, sam_rot = '', ''
	162	for a in aux_audio_data:
	163	sam = sam + str(a[0])
	164	sam_rot = str(a[0]) + sam_rot
	165	sample = self.subframe[4:24]
	166	for s in sample:
	167	sam = sam + str(s[0])
	168	sam_rot = str(s[0]) + sam_rot
	169	validity = self.subframe[24:25]
	170	subcode_data = self.subframe[25:26]
	171	channel_status = self.subframe[26:27]
	172	parity = self.subframe[27:28]
	173
	174	self.putx(aux_audio_data[0][1], aux_audio_data[3][2], \
	175	[3, ['Aux 0x%x' % int(sam, 2), '0x%x' % int(sam, 2)]])
	176	self.putx(sample[0][1], sample[19][2], \
	177	[3, ['Sample 0x%x' % int(sam, 2), '0x%x' % int(sam, 2)]])
	178	self.putx(aux_audio_data[0][1], sample[19][2], \
	179	[4, ['Audio 0x%x' % int(sam_rot, 2), '0x%x' % int(sam_rot, 2)]])
	180	if validity[0][0] == 0:
	181	self.putx(validity[0][1], validity[0][2], [5, ['V']])
	182	else:
	183	self.putx(validity[0][1], validity[0][2], [5, ['E']])
	184	self.putx(subcode_data[0][1], subcode_data[0][2],
	185	[6, ['S: %d' % subcode_data[0][0]]])
	186	self.putx(channel_status[0][1], channel_status[0][2],
	187	[7, ['C: %d' % channel_status[0][0]]])
	188	self.putx(parity[0][1], parity[0][2], [8, ['P: %d' % parity[0][0]]])
	189
	190	self.subframe = []
	191	self.seen_preamble = False
	192	self.bitcount = 0
	193
5302d1e9	194	def decode_preamble(self):
eb148e7a	195	if self.preamble_state == 0:
58636105	196	self.preamble.append(self.get_pulse_type())
eb148e7a UH	197	self.preamble_state = 1
eb148e7a UH	198	elif self.preamble_state == 1:
58636105	199	self.preamble.append(self.get_pulse_type())
eb148e7a UH	200	self.preamble_state = 2
eb148e7a UH	201	elif self.preamble_state == 2:
58636105	202	self.preamble.append(self.get_pulse_type())
eb148e7a	203	self.preamble_state = 0
5302d1e9	204	self.state = 'DECODE STREAM'
eb148e7a	205	if self.preamble == [2, 0, 1, 0]:
cc16130e	206	self.puty([1, ['Preamble W', 'W']])
eb148e7a	207	elif self.preamble == [2, 2, 1, 1]:
cc16130e	208	self.puty([1, ['Preamble M', 'M']])
eb148e7a	209	elif self.preamble == [2, 1, 1, 2]:
cc16130e	210	self.puty([1, ['Preamble B', 'B']])
eb148e7a	211	else:
868fd207	212	self.puty([1, ['Unknown Preamble', 'Unknown Prea.', 'U']])
eb148e7a UH	213	self.preamble = []
	214	self.seen_preamble = True
	215	self.bitcount = 0
	216	self.first_one = True
	217
	218	self.last_preamble = self.samplenum
	219
5e39fa54	220	def decode(self):
cb6d4c6d GW	221	if not self.samplerate:
	222	raise SamplerateError('Cannot decode without samplerate.')
	223
5e39fa54 UH	224	# Throw away first detected edge as it might be mangled data.
	225	self.wait({0: 'e'})
	226
	227	while True:
	228	# Wait for any edge (rising or falling).
	229	(data,) = self.wait({0: 'e'})
	230	self.pulse_width = self.samplenum - self.samplenum_prev_edge - 1
	231	self.samplenum_prev_edge = self.samplenum
	232
	233	if self.state == 'GET FIRST PULSE WIDTH':
	234	self.find_first_pulse_width()
	235	elif self.state == 'GET SECOND PULSE WIDTH':
	236	self.find_second_pulse_width()
	237	elif self.state == 'GET THIRD PULSE WIDTH':
	238	self.find_third_pulse_width()
	239	elif self.state == 'DECODE STREAM':
	240	self.decode_stream()
	241	elif self.state == 'DECODE PREAMBLE':
	242	self.decode_preamble()