srd: add EDID 1.3 decoder

1 files changed, 469 insertions, 0 deletions

diff --git a/decoders/edid/edid.py b/decoders/edid/edid.py
new file mode 100644
index 0000000..b3ca128
--- /dev/null
+++ b/decoders/edid/edid.py
@@ -0,0 +1,469 @@
+##
+## This file is part of the sigrok project.
+##
+## Copyright (C) 2012 Bert Vermeulen <bert@biot.com>
+##
+## 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 3 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/>.
+##
+
+'''
+EDID 1.3 structure decoder.
+
+Details:
+https://en.wikipedia.org/wiki/Extended_display_identification_data
+'''
+
+# TODO:
+#    - EDID < 1.3
+#    - Signal level standard field in basic display parameters block
+#    - Additional color point descriptors
+#    - Additional standard timing descriptors
+#    - Extensions
+
+import sigrokdecode as srd
+import os
+
+EDID_HEADER = [0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00]
+OFF_VENDOR = 8
+OFF_VERSION = 18
+OFF_BASIC = 20
+OFF_CHROM = 25
+OFF_EST_TIMING = 35
+OFF_STD_TIMING = 38
+OFF_DET_TIMING = 54
+OFF_NUM_EXT = 126
+OFF_CHECKSUM = 127
+
+
+# Pre-EDID established timing modes
+est_modes = [
+    "720x400@70Hz",
+    "720x400@88Hz",
+    "640x480@60Hz",
+    "640x480@67Hz",
+    "640x480@72Hz",
+    "640x480@75Hz",
+    "800x600@56Hz",
+    "800x600@60Hz",
+    "800x600@72Hz",
+    "800x600@75Hz",
+    "832x624@75Hz",
+    "1024x768@87Hz(i)",
+    "1024x768@60Hz",
+    "1024x768@70Hz",
+    "1024x768@75Hz",
+    "1280x1024@75Hz",
+    "1152x870@75Hz"
+]
+
+# X:Y display aspect ratios, as used in standard timing modes
+xy_ratio = [
+    (16, 10),
+    (4, 3),
+    (5, 4),
+    (16, 9)
+]
+
+# Annotation types
+ANN_FIELDS = 0
+ANN_SECTIONS = 1
+
+class Decoder(srd.Decoder):
+    api_version = 1
+    id = 'edid'
+    name = 'EDID'
+    longname = 'Extended display identification data'
+    desc = 'A data structure describing the capabilities of a display device.'
+    license = 'gplv3+'
+    inputs = ['ddc2']
+    outputs = ['edid']
+    options = {}
+    annotations = [
+        ['EDID fields', 'EDID structure fields'],
+        ['EDID sections', 'EDID structure sections'],
+    ]
+
+    def __init__(self, **kwargs):
+        self.state = None
+        # Received data items, used as an index into samplenum/data
+        self.cnt = 0
+        # Start/end sample numbers per data item
+        self.sn = []
+        # Received data
+        self.cache = []
+
+    def start(self, metadata):
+        self.out_ann = self.add(srd.OUTPUT_ANN, 'edid')
+
+    def decode(self, ss, es, data):
+        if type(data) != int:
+            raise Exception('malformed ddc2 input: expected 1 byte')
+        self.cnt += 1
+        self.sn.append( [ss, es] )
+        self.cache.append(data)
+
+        if self.state is None:
+            # Wait for the EDID header
+            if self.cnt >= OFF_VENDOR:
+                if self.cache[-8:] == EDID_HEADER:
+                    # Throw away any garbage before the header
+                    self.sn = self.sn[-8:]
+                    self.cache = self.cache[-8:]
+                    self.state = 'edid'
+                    self.put(ss, es, self.out_ann, [0, ["EDID header"]])
+        elif self.state == 'edid':
+            if self.cnt == OFF_VERSION:
+                self.decode_vid(-10)
+                self.decode_pid(-8)
+                self.decode_serial(-6)
+                self.decode_mfrdate(-2)
+            elif self.cnt == OFF_BASIC:
+                version = "EDID version: %d.%d" % (self.cache[-2], self.cache[-1])
+                self.put(ss, es, self.out_ann, [0, [version]])
+            elif self.cnt == OFF_CHROM:
+                self.decode_basicdisplay(-5)
+            elif self.cnt == OFF_EST_TIMING:
+                self.decode_chromaticity(-10)
+            elif self.cnt == OFF_STD_TIMING:
+                self.decode_est_timing(-3)
+            elif self.cnt == OFF_DET_TIMING:
+                self.decode_std_timing(-16)
+            elif self.cnt == OFF_NUM_EXT:
+                self.decode_descriptors(-72)
+            elif self.cnt == OFF_CHECKSUM:
+                self.put(ss, es, self.out_ann, [0, ["Extensions present: %d" % self.cache[self.cnt-1]]])
+            elif self.cnt == OFF_CHECKSUM+1:
+                checksum = 0
+                for i in range(128):
+                    checksum += self.cache[i]
+                if checksum % 256 == 0:
+                    csstr = "OK"
+                else:
+                    csstr = "WRONG!"
+                self.put(ss, es, self.out_ann, [0, ["Checksum: %d (%s)" % (
+                                self.cache[self.cnt-1], csstr)]])
+                self.state = 'extensions'
+        elif self.state == 'extensions':
+            pass
+
+    def ann_field(self, start, end, annotation):
+        self.put(self.sn[start][0], self.sn[end][1], self.out_ann, [ANN_FIELDS, [annotation]])
+
+    def lookup_pnpid(self, pnpid):
+        pnpid_file = os.path.dirname(__file__) + '/pnpids.txt'
+        if os.path.exists(pnpid_file):
+            for line in open(pnpid_file).readlines():
+                if line.find(pnpid + ';') == 0:
+                    return line[4:].strip()
+        return ''
+
+    def decode_vid(self, offset):
+        pnpid = chr(64 + ((self.cache[offset] & 0x7c) >> 2))
+        pnpid += chr(64 + (((self.cache[offset] & 0x03) << 3)
+                           | ((self.cache[offset+1] & 0xe0) >> 5)))
+        pnpid += chr(64 + (self.cache[offset+1] & 0x1f))
+        vendor = self.lookup_pnpid(pnpid)
+        if vendor:
+            pnpid += " (%s)" % vendor
+        self.ann_field(offset, offset+1, pnpid)
+
+    def decode_pid(self, offset):
+        pidstr = "Product 0x%.2x%.2x" % (self.cache[offset+1], self.cache[offset])
+        self.ann_field(offset, offset+1, pidstr)
+
+    def decode_serial(self, offset):
+        serialnum = (self.cache[offset+3] << 24) \
+                + (self.cache[offset+2] << 16) \
+                + (self.cache[offset+1] << 8) \
+                + self.cache[offset]
+        serialstr = ''
+        is_alnum = True
+        for i in range(4):
+            if not chr(self.cache[offset+3-i]).isalnum():
+                is_alnum = False
+                break
+            serialstr += chr(self.cache[offset+3-i])
+        if is_alnum:
+            serial = serialstr
+        else:
+            serial = str(serialnum)
+        self.ann_field(offset, offset+3, "Serial " + serial)
+
+    def decode_mfrdate(self, offset):
+        datestr = ''
+        if self.cache[offset]:
+            datestr += "week %d, " % self.cache[offset]
+        datestr += str(1990 + self.cache[offset+1])
+        if datestr:
+            self.ann_field(offset, offset+1, "Manufactured " + datestr)
+
+    def decode_basicdisplay(self, offset):
+        # Video input definition
+        vid = self.cache[offset]
+        if vid & 0x80:
+            # Digital
+            self.ann_field(offset, offset, "Video input: VESA DFP 1.")
+        else:
+            # Analog
+            sls = (vid & 60) >> 5
+            self.ann_field(offset, offset, "Signal level standard: %.2x" % sls)
+            if vid & 0x10:
+                self.ann_field(offset, offset, "Blank-to-black setup expected")
+            syncs = ''
+            if vid & 0x08:
+                syncs += 'separate syncs, '
+            if vid & 0x04:
+                syncs += 'composite syncs, '
+            if vid & 0x02:
+                syncs += 'sync on green, '
+            if vid & 0x01:
+                syncs += 'Vsync serration required, '
+            if syncs:
+                self.ann_field(offset, offset, "Supported syncs: %s" % syncs[:-2])
+        # Max horizontal/vertical image size
+        if self.cache[offset+1] != 0 and self.cache[offset+2] != 0:
+            # Projectors have this set to 0
+            sizestr = "%dx%dcm" % (self.cache[offset+1], self.cache[offset+2])
+            self.ann_field(offset+1, offset+2, "Physical size: " + sizestr)
+        # Display transfer characteristic (gamma)
+        if self.cache[offset+3] != 0xff:
+            gamma = (self.cache[offset+3] + 100) / 100
+            self.ann_field(offset+3, offset+3, "Gamma: %1.2f" % gamma)
+        # Feature support
+        fs = self.cache[offset+4]
+        dpms = ''
+        if fs & 0x80:
+            dpms += 'standby, '
+        if fs & 0x40:
+            dpms += 'suspend, '
+        if fs & 0x20:
+            dpms += 'active off, '
+        if dpms:
+            self.ann_field(offset+4, offset+4, "DPMS support: %s" % dpms[:-2])
+        dt = (fs & 0x18) >> 3
+        dtstr = ''
+        if dt == 0:
+            dtstr = 'Monochrome'
+        elif dt == 1:
+            dtstr = 'RGB color'
+        elif dt == 2:
+            dtstr = 'non-RGB multicolor' 
+        if dtstr:
+            self.ann_field(offset+4, offset+4, "Display type: %s" % dtstr)
+        if fs & 0x04:
+            self.ann_field(offset+4, offset+4, "Color space: standard sRGB")
+        # Save this for when we decode the first detailed timing descriptor
+        self.have_preferred_timing = (fs & 0x02) == 0x02
+        if fs & 0x01:
+            gft = ''
+        else:
+            gft = 'not '
+        self.ann_field(offset+4, offset+4, "Generalized timing formula: %ssupported" % gft)
+
+    def convert_color(self, value):
+        # Convert from 10-bit packet format to float
+        outval = 0.0
+        for i in range(10):
+            if value & 0x01:
+                outval += 2 ** -(10-i)
+            value >>= 1
+        return outval
+
+    def decode_chromaticity(self, offset):
+        redx = (self.cache[offset+2] << 2) + ((self.cache[offset] & 0xc0) >> 6)
+        redy = (self.cache[offset+3] << 2) + ((self.cache[offset] & 0x30) >> 4)
+        self.ann_field(offset, offset+9, "Chromacity red: X %1.3f, Y %1.3f" % (
+                        self.convert_color(redx), self.convert_color(redy)))
+
+        greenx = (self.cache[offset+4] << 2) + ((self.cache[offset] & 0x0c) >> 6)
+        greeny = (self.cache[offset+5] << 2) + ((self.cache[offset] & 0x03) >> 4)
+        self.ann_field(offset, offset+9, "Chromacity green: X %1.3f, Y %1.3f" % (
+                        self.convert_color(greenx), self.convert_color(greeny)))
+
+        bluex = (self.cache[offset+6] << 2) + ((self.cache[offset+1] & 0xc0) >> 6)
+        bluey = (self.cache[offset+7] << 2) + ((self.cache[offset+1] & 0x30) >> 4)
+        self.ann_field(offset, offset+9, "Chromacity blue: X %1.3f, Y %1.3f" % (
+                        self.convert_color(bluex), self.convert_color(bluey)))
+
+        whitex = (self.cache[offset+8] << 2) + ((self.cache[offset+1] & 0x0c) >> 6)
+        whitey = (self.cache[offset+9] << 2) + ((self.cache[offset+1] & 0x03) >> 4)
+        self.ann_field(offset, offset+9, "Chromacity white: X %1.3f, Y %1.3f" % (
+                        self.convert_color(whitex), self.convert_color(whitey)))
+
+    def decode_est_timing(self, offset):
+        # Pre-EDID modes
+        bitmap = (self.cache[offset] << 9) \
+            + (self.cache[offset+1] << 1) \
+            + ((self.cache[offset+2] & 0x80) >> 7)
+        modestr = ''
+        for i in range(17):
+                if bitmap & (1 << (16-i)):
+                    modestr += est_modes[i] + ', '
+        if modestr:
+            self.ann_field(offset, offset+2, "Supported establised modes: %s" % modestr[:-2])
+
+    def decode_std_timing(self, offset):
+        modestr = ''
+        for i in range(0, 16, 2):
+            if self.cache[offset+i] == 0x01 and self.cache[offset+i+1] == 0x01:
+                # Unused field
+                continue
+            x = (self.cache[offset+i] + 31) * 8
+            ratio = (self.cache[offset+i+1] & 0xc0) >> 6
+            ratio_x, ratio_y = xy_ratio[ratio]
+            y = x / ratio_x * ratio_y
+            refresh = (self.cache[offset+i+1] & 0x3f) + 60
+            modestr += "%dx%d@%dHz, " % (x, y, refresh)
+        if modestr:
+            self.ann_field(offset, offset+2, "Supported standard modes: %s" % modestr[:-2])
+
+    def decode_detailed_timing(self, offset):
+        if offset == -72 and self.have_preferred_timing:
+            # Only on first detailed timing descriptor
+            section = 'Preferred'
+        else:
+            section = 'Detailed'
+        section += ' timing descriptor'
+        self.put(self.sn[offset][0], self.sn[offset+18][1],
+             self.out_ann, [ANN_SECTIONS, [section]])
+
+        pixclock = float((self.cache[offset+1] << 8) + self.cache[offset]) / 100
+        self.ann_field(offset, offset+1, "Pixel clock: %.2f MHz" % pixclock)
+
+        horiz_active = ((self.cache[offset+4] & 0xf0) << 4) + self.cache[offset+2]
+        self.ann_field(offset+2, offset+4, "Horizontal active: %d" % horiz_active)
+
+        horiz_blank = ((self.cache[offset+4] & 0x0f) << 8) + self.cache[offset+3]
+        self.ann_field(offset+3, offset+4, "Horizontal blanking: %d" % horiz_blank)
+
+        vert_active = ((self.cache[offset+7] & 0xf0) << 4) + self.cache[offset+5]
+        self.ann_field(offset+5, offset+7, "Vertical active: %d" % vert_active)
+
+        vert_blank = ((self.cache[offset+7] & 0x0f) << 8) + self.cache[offset+6]
+        self.ann_field(offset+6, offset+7, "Vertical blanking: %d" % vert_blank)
+
+        horiz_sync_off = ((self.cache[offset+11] & 0xc0) << 2) + self.cache[offset+8]
+        self.ann_field(offset+8, offset+11, "Horizontal sync offset: %d" % horiz_sync_off)
+
+        horiz_sync_pw = ((self.cache[offset+11] & 0x30) << 4) + self.cache[offset+9]
+        self.ann_field(offset+9, offset+11, "Horizontal sync pulse width: %d" % horiz_sync_pw)
+
+        vert_sync_off = ((self.cache[offset+11] & 0x0c) << 2) \
+                    + ((self.cache[offset+10] & 0xf0) >> 4)
+        self.ann_field(offset+10, offset+11, "Vertical sync offset: %d" % vert_sync_off)
+
+        vert_sync_pw = ((self.cache[offset+11] & 0x03) << 4) \
+                    + (self.cache[offset+10] & 0x0f)
+        self.ann_field(offset+10, offset+11, "Vertical sync pulse width: %d" % vert_sync_pw)
+
+        horiz_size = ((self.cache[offset+14] & 0xf0) << 4) + self.cache[offset+12]
+        vert_size = ((self.cache[offset+14] & 0x0f) << 8) + self.cache[offset+13]
+        self.ann_field(offset+12, offset+14, "Physical size: %dx%dmm" % (horiz_size, vert_size))
+
+        horiz_border = self.cache[offset+15]
+        if horiz_border:
+            self.ann_field(offset+15, offset+15, "Horizontal border: %d pixels" % horiz_border)
+        vert_border = self.cache[offset+16]
+        if vert_border:
+            self.ann_field(offset+16, offset+16, "Vertical border: %d lines" % vert_border)
+
+        features = 'Flags: '
+        if self.cache[offset+17] & 0x80:
+            features += 'interlaced, '
+        stereo = (self.cache[offset+17] & 0x60) >> 5
+        if stereo:
+            if self.cache[offset+17] & 0x01:
+                features += '2-way interleaved stereo ('
+                features += ['right image on even lines', 'left image on even lines',
+                             'side-by-side'][stereo-1]
+                features += '), '
+            else:
+                features += 'field sequential stereo ('
+                features += ['right image on sync=1', 'left image on sync=1',
+                             '4-way interleaved'][stereo-1]
+                features += '), '
+        sync = (self.cache[offset+17] & 0x18) >> 3
+        sync2 = (self.cache[offset+17] & 0x06) >> 1
+        posneg = ['negative', 'positive']
+        features += 'sync type '
+        if sync == 0x00:
+            features += 'analog composite (serrate on RGB)'
+        elif sync == 0x01:
+            features += 'bipolar analog composite (serrate on RGB)'
+        elif sync == 0x02:
+            features += 'digital composite (serrate on composite polarity ' \
+                    + (posneg[sync2 & 0x01]) + ')'
+        elif sync == 0x03:
+            features += 'digital separate ('
+            features += 'Vsync polarity ' + (posneg[sync2 >> 1])
+            features += ', Hsync polarity ' + (posneg[sync2 & 0x01])
+            features += ')'
+        features += ', '
+        self.ann_field(offset+17, offset+17, features[:-2])
+
+    def decode_descriptor(self, offset):
+        tag = self.cache[offset+3]
+        if tag == 0xff:
+            # Monitor serial number
+            text = bytes(self.cache[offset+5:][:13]).decode(encoding='cp437', errors='replace')
+            self.ann_field(offset, offset+17, "Serial number: %s" % text.strip())
+        elif tag == 0xfe:
+            # Text
+            text = bytes(self.cache[offset+5:][:13]).decode(encoding='cp437', errors='replace')
+            self.ann_field(offset, offset+17, "Info: %s" % text.strip())
+        elif tag == 0xfc:
+            # Monitor name
+            text = bytes(self.cache[offset+5:][:13]).decode(encoding='cp437', errors='replace')
+            self.ann_field(offset, offset+17, "Model name: %s" % text.strip())
+        elif tag == 0xfd:
+            # Monitor range limits
+            self.put(self.sn[offset][0], self.sn[offset+17][1], self.out_ann,
+                     [ANN_SECTIONS, ["Monitor range limits"]])
+            self.ann_field(offset+5, offset+5, "Minimum vertical rate: %dHz" % 
+                           self.cache[offset+5])
+            self.ann_field(offset+6, offset+6, "Maximum vertical rate: %dHz" % 
+                           self.cache[offset+6])
+            self.ann_field(offset+7, offset+7, "Minimum horizontal rate: %dkHz" % 
+                           self.cache[offset+7])
+            self.ann_field(offset+8, offset+8, "Maximum horizontal rate: %dkHz" % 
+                           self.cache[offset+8])
+            self.ann_field(offset+9, offset+9, "Maximum pixel clock: %dMHz" % 
+                           (self.cache[offset+9] * 10))
+            if self.cache[offset+10] == 0x02:
+                # Secondary GTF curve supported
+                self.ann_field(offset+10, offset+17, "Secondary timing formula supported")
+        elif tag == 0xfb:
+            # Additional color point data
+            self.put(self.sn[offset][0], self.sn[offset+17][1], self.out_ann,
+                     [ANN_SECTIONS, ["Additional color point data"]])
+        elif tag == 0xfa:
+            # Additional standard timing definitions
+            self.put(self.sn[offset][0], self.sn[offset+17][1], self.out_ann,
+                     [ANN_SECTIONS, ["Additional standard timing definitions"]])
+        else:
+            self.put(self.sn[offset][0], self.sn[offset+17][1], self.out_ann,
+                     [ANN_SECTIONS, ["Unknown descriptor"]])
+
+    def decode_descriptors(self, offset):
+        # 4 consecutive 18-byte descriptor blocks
+        for i in range(offset, 0, 18):
+            if self.cache[i] != 0 and self.cache[i+1] != 0:
+                self.decode_detailed_timing(i)
+            else:
+                if self.cache[i+2] == 0 or self.cache[i+4] == 0 or True:
+                    self.decode_descriptor(i)
+
+
+
+