[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 __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.putx(self.ss_edge, self.samplenum, [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.putx(self.ss_edge, self.samplenum, [1, ['Preamble W', 'W']])
            elif self.preamble == [2, 2, 1, 1]:
                self.putx(self.ss_edge, self.samplenum, [1, ['Preamble M', 'M']])
            elif self.preamble == [2, 1, 1, 2]:
                self.putx(self.ss_edge, self.samplenum, [1, ['Preamble B', 'B']])
            else:
                self.putx(self.ss_edge, self.samplenum, [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
	58	def __init__(self, **kwargs):
	59	self.state = 0
	60	self.olddata = None
	61	self.ss_edge = None
	62	self.first_edge = True
	63	self.pulse_width = 0
	64
65	self.clocks = []
66	self.range1 = 0
67	self.range2 = 0
68
69	self.preamble_state = 0
70	self.preamble = []
71	self.seen_preamble = False
72	self.last_preamble = 0
73
74	self.first_one = True
75	self.subframe = []
76
77	def start(self):
78	self.out_ann = self.register(srd.OUTPUT_ANN)
79
80	def metadata(self, key, value):
81	if key == srd.SRD_CONF_SAMPLERATE:
82	self.samplerate = value
83
84	def get_pulse_type(self, pulse):
85	if self.range1 == 0 or self.range2 == 0:
86	return -1
87	if pulse >= self.range2:
88	return 2
89	elif pulse >= self.range1:
90	return 0
91	else:
92	return 1
93
eb148e7a UH	94	def find_first_pulse_width(self):
	95	if self.pulse_width != 0:
	96	self.clocks.append(self.pulse_width)
	97	self.state = 1
	98
	99	def find_second_pulse_width(self):
	100	if self.pulse_width > (self.clocks[0] * 1.3) or \
	101	self.pulse_width < (self.clocks[0] * 0.7):
	102	self.clocks.append(self.pulse_width)
	103	self.state = 2
	104
	105	def find_third_pulse_width(self):
	106	if not ((self.pulse_width > (self.clocks[0] * 1.3) or \
	107	self.pulse_width < (self.clocks[0] * 0.7)) \
	108	and (self.pulse_width > (self.clocks[1] * 1.3) or \
	109	self.pulse_width < (self.clocks[1] * 0.7))):
	110	return
	111
	112	self.clocks.append(self.pulse_width)
	113	self.clocks.sort()
	114	self.range1 = (self.clocks[0] + self.clocks[1]) / 2
	115	self.range2 = (self.clocks[1] + self.clocks[2]) / 2
	116	spdif_bitrate = int(self.samplerate / (self.clocks[2] / 1.5))
	117	self.ss_edge = 0
	118
	119	self.putx(self.ss_edge, self.samplenum, [0, \
	120	['Signal Bitrate: %d Mbit/s (=> %d kHz)' % \
	121	(spdif_bitrate, (spdif_bitrate/ (2 * 32)))]])
	122
	123	clock_period_nsec = 1000000000 / spdif_bitrate
	124
	125	self.last_preamble = self.samplenum
	126
	127	# We are done recovering the clock, now let's decode the data stream.
	128	self.state = 3
	129
	130	def decode_stream(self):
	131	pulse = self.get_pulse_type(self.pulse_width)
	132
	133	if not self.seen_preamble:
	134	# This is probably the start of a preamble, decode it.
	135	if pulse == 2:
	136	self.preamble.append(self.get_pulse_type(self.pulse_width))
	137	self.state = 4 # Decode a preamble.
	138	self.ss_edge = self.samplenum - self.pulse_width - 1
	139	return
	140
	141	# We've seen a preamble.
	142	if pulse == 1 and self.first_one:
	143	self.first_one = False
	144	self.subframe.append([pulse, self.samplenum - \
	145	self.pulse_width - 1, self.samplenum])
	146	elif pulse == 1 and not self.first_one:
	147	self.subframe[-1][2] = self.samplenum
	148	self.putx(self.subframe[-1][1], self.samplenum, [2, ['1']])
	149	self.bitcount += 1
	150	self.first_one = True
	151	else:
	152	self.subframe.append([pulse, self.samplenum - \
	153	self.pulse_width - 1, self.samplenum])
	154	self.putx(self.samplenum - self.pulse_width - 1,
	155	self.samplenum, [2, ['0']])
	156	self.bitcount += 1
	157
158	if self.bitcount == 28:
159	aux_audio_data = self.subframe[0:4]
160	sam, sam_rot = '', ''
161	for a in aux_audio_data:
162	sam = sam + str(a[0])
163	sam_rot = str(a[0]) + sam_rot
164	sample = self.subframe[4:24]
165	for s in sample:
166	sam = sam + str(s[0])
167	sam_rot = str(s[0]) + sam_rot
168	validity = self.subframe[24:25]
169	subcode_data = self.subframe[25:26]
170	channel_status = self.subframe[26:27]
171	parity = self.subframe[27:28]
172
173	self.putx(aux_audio_data[0][1], aux_audio_data[3][2], \
174	[3, ['Aux 0x%x' % int(sam, 2), '0x%x' % int(sam, 2)]])
175	self.putx(sample[0][1], sample[19][2], \
176	[3, ['Sample 0x%x' % int(sam, 2), '0x%x' % int(sam, 2)]])
177	self.putx(aux_audio_data[0][1], sample[19][2], \
178	[4, ['Audio 0x%x' % int(sam_rot, 2), '0x%x' % int(sam_rot, 2)]])
179	if validity[0][0] == 0:
180	self.putx(validity[0][1], validity[0][2], [5, ['V']])
181	else:
182	self.putx(validity[0][1], validity[0][2], [5, ['E']])
183	self.putx(subcode_data[0][1], subcode_data[0][2],
184	[6, ['S: %d' % subcode_data[0][0]]])
185	self.putx(channel_status[0][1], channel_status[0][2],
186	[7, ['C: %d' % channel_status[0][0]]])
187	self.putx(parity[0][1], parity[0][2], [8, ['P: %d' % parity[0][0]]])
188
189	self.subframe = []
190	self.seen_preamble = False
191	self.bitcount = 0
192
193	def handle_preamble(self):
194	if self.preamble_state == 0:
195	self.preamble.append(self.get_pulse_type(self.pulse_width))
196	self.preamble_state = 1
197	elif self.preamble_state == 1:
198	self.preamble.append(self.get_pulse_type(self.pulse_width))
199	self.preamble_state = 2
200	elif self.preamble_state == 2:
201	self.preamble.append(self.get_pulse_type(self.pulse_width))
202	self.preamble_state = 0
203	self.state = 3
204	if self.preamble == [2, 0, 1, 0]:
205	self.putx(self.ss_edge, self.samplenum, [1, ['Preamble W', 'W']])
206	elif self.preamble == [2, 2, 1, 1]:
207	self.putx(self.ss_edge, self.samplenum, [1, ['Preamble M', 'M']])
208	elif self.preamble == [2, 1, 1, 2]:
209	self.putx(self.ss_edge, self.samplenum, [1, ['Preamble B', 'B']])
210	else:
211	self.putx(self.ss_edge, self.samplenum, [1, ['Unknown Preamble', 'Unkown Prea.', 'U']])
212	self.preamble = []
213	self.seen_preamble = True
214	self.bitcount = 0
215	self.first_one = True
216
217	self.last_preamble = self.samplenum
218
cb6d4c6d GW	219	def decode(self, ss, es, data):
	220	if not self.samplerate:
	221	raise SamplerateError('Cannot decode without samplerate.')
	222
	223	for (self.samplenum, pins) in data:
	224	data = pins[0]
	225
eb148e7a	226	# Initialize self.olddata with the first sample value.
cb6d4c6d GW	227	if self.olddata == None:
	228	self.olddata = data
	229	continue
	230
	231	# First we need to recover the clock.
	232	if self.olddata == data:
	233	self.pulse_width += 1
eb148e7a	234	continue
cb6d4c6d	235
eb148e7a UH	236	# Found rising or falling edge.
	237	if self.first_edge:
	238	# Throw away first detected edge as it might be mangled data.
	239	self.first_edge = False
cb6d4c6d	240	self.pulse_width = 0
eb148e7a UH	241	else:
	242	if self.state == 0:
	243	self.find_first_pulse_width()
	244	elif self.state == 1:
	245	self.find_second_pulse_width()
	246	elif self.state == 2:
	247	self.find_third_pulse_width()
	248	elif self.state == 3:
	249	self.decode_stream()
	250	elif self.state == 4:
	251	self.handle_preamble()
	252
	253	self.pulse_width = 0
cb6d4c6d GW	254
cb6d4c6d GW	255	self.olddata = data