From: Uwe Hermann Date: Fri, 29 Aug 2014 21:50:56 +0000 (+0200) Subject: spdif: Refactor and reduce nesting level. X-Git-Tag: libsigrokdecode-0.4.0~182 X-Git-Url: https://sigrok.org/gitweb/?p=libsigrokdecode.git;a=commitdiff_plain;h=eb148e7a78ed4c3b9615b41d9c967cb5f403fa0f spdif: Refactor and reduce nesting level. --- diff --git a/decoders/spdif/pd.py b/decoders/spdif/pd.py index 6f92e0e..83cc338 100644 --- a/decoders/spdif/pd.py +++ b/decoders/spdif/pd.py @@ -91,6 +91,131 @@ class Decoder(srd.Decoder): 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.') @@ -98,7 +223,7 @@ class Decoder(srd.Decoder): for (self.samplenum, pins) in data: data = pins[0] - # Initialize first self.olddata with the first sample value. + # Initialize self.olddata with the first sample value. if self.olddata == None: self.olddata = data continue @@ -106,131 +231,25 @@ class Decoder(srd.Decoder): # First we need to recover the clock. if self.olddata == data: self.pulse_width += 1 - else: - # 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: - # Find first pulse width. - if self.pulse_width != 0: - self.clocks.append(self.pulse_width) - self.state = 1 - - elif self.state == 1: - # Find second pulse width. - 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 - - elif self.state == 2: - # Find third pulse width. - if (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)): - 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 - - elif self.state == 3: - # Decode the stream. - pulse = self.get_pulse_type(self.pulse_width) - - if self.seen_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 - else: - # This is probably the start of a preamble, so go - # ahead and 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 - - elif self.state == 4: - 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 + 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 -