From f2532842b53cf6c7129133da9cfd3ed929793bf5 Mon Sep 17 00:00:00 2001
From: Jakob Ketterl <jakob.ketterl@gmx.de>
Date: Fri, 16 Feb 2024 15:37:17 +0100
Subject: [PATCH] first implementation of sstv decoding

---
 csdr/chain/sstv.py             | 16 +++++++++
 htdocs/css/openwebrx.css       | 13 ++++++++
 htdocs/index.html              |  1 +
 htdocs/lib/DemodulatorPanel.js |  2 +-
 htdocs/lib/MessagePanel.js     | 61 ++++++++++++++++++++++++++++++++++
 htdocs/openwebrx.js            |  4 +--
 owrx/dsp.py                    |  3 ++
 owrx/feature.py                | 18 ++++++++++
 owrx/modes.py                  |  1 +
 owrx/sstv.py                   | 61 ++++++++++++++++++++++++++++++++++
 10 files changed, 177 insertions(+), 3 deletions(-)
 create mode 100644 csdr/chain/sstv.py
 create mode 100644 owrx/sstv.py

diff --git a/csdr/chain/sstv.py b/csdr/chain/sstv.py
new file mode 100644
index 00000000..b559bf79
--- /dev/null
+++ b/csdr/chain/sstv.py
@@ -0,0 +1,16 @@
+from owrx.sstv import SstvParser
+from csdr.chain.demodulator import SecondaryDemodulator, FixedAudioRateChain
+from pycsdr.modules import FmDemod
+from csdrsstv.modules import SstvDecoder
+
+
+class Sstv(SecondaryDemodulator, FixedAudioRateChain):
+    def __init__(self):
+        super().__init__([
+            FmDemod(),
+            SstvDecoder(),
+            SstvParser(),
+        ])
+
+    def getFixedAudioRate(self) -> int:
+        return 12000
diff --git a/htdocs/css/openwebrx.css b/htdocs/css/openwebrx.css
index fae76378..6ad30442 100644
--- a/htdocs/css/openwebrx.css
+++ b/htdocs/css/openwebrx.css
@@ -1440,3 +1440,16 @@ img.openwebrx-mirror-img
 .under-construction:hover .under-construction-description {
 	max-height: 500px;
 }
+
+.openwebrx-message-panel#openwebrx-panel-sstv-message {
+	min-height: initial;
+}
+
+.sstv-canvas-container {
+	width: 320px;
+	height: 256px;
+}
+
+.sstv-canvas-container canvas {
+	width: 100%;
+}
diff --git a/htdocs/index.html b/htdocs/index.html
index 1e1c4c43..35c48904 100644
--- a/htdocs/index.html
+++ b/htdocs/index.html
@@ -81,6 +81,7 @@
                 <div class="openwebrx-panel openwebrx-message-panel" id="openwebrx-panel-ism-message" style="display: none; width: 619px;" data-panel-name="ism-message"></div>
                 <div class="openwebrx-panel openwebrx-message-panel" id="openwebrx-panel-hfdl-message" style="display: none; width: 619px;" data-panel-name="hfdl-message"></div>
                 <div class="openwebrx-panel openwebrx-message-panel" id="openwebrx-panel-vdl2-message" style="display: none; width: 619px;" data-panel-name="vdl2-message"></div>
+                <div class="openwebrx-panel openwebrx-message-panel" id="openwebrx-panel-sstv-message" style="display: none" data-panel-name="sstv-message"></div>
                 <div class="openwebrx-panel openwebrx-meta-panel" id="openwebrx-panel-metadata-m17" style="display: none;" data-panel-name="metadata-m17">
                     <div class="openwebrx-meta-slot">
                         <div class="openwebrx-meta-user-image">
diff --git a/htdocs/lib/DemodulatorPanel.js b/htdocs/lib/DemodulatorPanel.js
index 6f35e6b7..06eb8f47 100644
--- a/htdocs/lib/DemodulatorPanel.js
+++ b/htdocs/lib/DemodulatorPanel.js
@@ -169,7 +169,7 @@ DemodulatorPanel.prototype.updatePanels = function() {
     // WSJT-X modes share the same panel
     toggle_panel("openwebrx-panel-wsjt-message", ['ft8', 'wspr', 'jt65', 'jt9', 'ft4', 'fst4', 'fst4w', "q65", "msk144"].indexOf(modulation) >= 0);
     // these modes come with their own
-    ['js8', 'packet', 'pocsag', 'adsb', 'ism', 'hfdl', 'vdl2'].forEach(function(m) {
+    ['js8', 'packet', 'pocsag', 'adsb', 'ism', 'hfdl', 'vdl2', 'sstv'].forEach(function(m) {
         toggle_panel('openwebrx-panel-' + m + '-message', modulation === m);
     });
 
diff --git a/htdocs/lib/MessagePanel.js b/htdocs/lib/MessagePanel.js
index 0bb2d5ac..bbe366af 100644
--- a/htdocs/lib/MessagePanel.js
+++ b/htdocs/lib/MessagePanel.js
@@ -809,4 +809,65 @@ $.fn.vdl2MessagePanel = function() {
         this.data('panel', new Vdl2MessagePanel(this));
     }
     return this.data('panel');
+};
+
+SstvMessagePanel = function(el) {
+    MessagePanel.call(this, el);
+    this.currentLine = 0;
+}
+
+SstvMessagePanel.prototype = Object.create(MessagePanel.prototype);
+
+SstvMessagePanel.prototype.render = function() {
+    $(this.el).append($(
+        '<div class="sstv-container">' +
+            '<div class="sstv-canvas-container">' +
+                '<canvas class="sstv-canvas" width="320" height="256"></canvas>' +
+            '</div>' +
+        '</div>'
+    ));
+    this.canvas = $(this.el).find('canvas').get(0)
+    this.context = this.canvas.getContext('2d');
+};
+
+SstvMessagePanel.prototype.supportsMessage = function(message) {
+    return message['mode'] === 'SSTV';
+};
+
+SstvMessagePanel.prototype.pushMessage = function(message) {
+    if ('vis' in message) {
+        console.info("got vis: " + message.vis);
+    }
+    if ('resolution' in message) {
+        console.info("got resolution: ", message.resolution);
+        this.pixels = message.resolution.width;
+        this.lines = message.resolution.height;
+        this.canvas.width = this.pixels;
+        this.canvas.height = this.lines;
+        this.currentLine = 0;
+    }
+    if ('line' in message) {
+        var line = this.context.createImageData(this.pixels, 1);
+        for (var i = 0; i < this.pixels; i++) {
+            line.data[i * 4] = message.line[i * 3];
+            line.data[i * 4 + 1] = message.line[i * 3 + 1];
+            line.data[i * 4 + 2] = message.line[i * 3 + 2];
+            // alpha
+            line.data[i * 4 + 3] = 255;
+        }
+        this.context.putImageData(line, 0, this.currentLine);
+        this.currentLine = (this.currentLine + 1) % this.lines;
+    }
+};
+
+SstvMessagePanel.prototype.clearMessages = function() {
+    this.context.clearRect(0, 0, this.canvas.width, this.canvas.height);
+    this.currentLine = 0;
+};
+
+$.fn.sstvMessagePanel = function() {
+    if (!this.data('panel')) {
+        this.data('panel', new SstvMessagePanel(this));
+    }
+    return this.data('panel');
 };
\ No newline at end of file
diff --git a/htdocs/openwebrx.js b/htdocs/openwebrx.js
index 1ab27d3f..4ba10904 100644
--- a/htdocs/openwebrx.js
+++ b/htdocs/openwebrx.js
@@ -865,7 +865,7 @@ function on_ws_recv(evt) {
                         break;
                     case 'secondary_demod':
                         var value = json['value'];
-                        var panels = ['wsjt', 'packet', 'pocsag', 'adsb', 'ism', 'hfdl', 'vdl2'].map(function(id) {
+                        var panels = ['wsjt', 'packet', 'pocsag', 'adsb', 'ism', 'hfdl', 'vdl2', 'sstv'].map(function(id) {
                             return $('#openwebrx-panel-' + id + '-message')[id + 'MessagePanel']();
                         });
                         panels.push($('#openwebrx-panel-js8-message').js8());
@@ -1470,7 +1470,7 @@ function secondary_demod_init() {
         .mousedown(secondary_demod_canvas_container_mousedown)
         .mouseenter(secondary_demod_canvas_container_mousein)
         .mouseleave(secondary_demod_canvas_container_mouseleave);
-    ['wsjt', 'packet', 'pocsag', 'adsb', 'ism', 'hfdl'].forEach(function(id){
+    ['wsjt', 'packet', 'pocsag', 'adsb', 'ism', 'hfdl', 'vdl2', 'sstv'].forEach(function(id){
         $('#openwebrx-panel-' + id + '-message')[id + 'MessagePanel']();
     })
     $('#openwebrx-panel-js8-message').js8();
diff --git a/owrx/dsp.py b/owrx/dsp.py
index 625254ea..ba11884c 100644
--- a/owrx/dsp.py
+++ b/owrx/dsp.py
@@ -655,6 +655,9 @@ class DspManager(SdrSourceEventClient, ClientDemodulatorSecondaryDspEventClient)
         elif mod == "vdl2":
             from csdr.chain.dumpvdl2 import DumpVDL2
             return DumpVDL2()
+        elif mod == "sstv":
+            from csdr.chain.sstv import Sstv
+            return Sstv()
 
     def setSecondaryDemodulator(self, mod):
         demodulator = self._getSecondaryDemodulator(mod)
diff --git a/owrx/feature.py b/owrx/feature.py
index 93fad5da..f074159c 100644
--- a/owrx/feature.py
+++ b/owrx/feature.py
@@ -92,6 +92,7 @@ class FeatureDetector(object):
         "redsea": ["redsea"],
         "dab": ["csdreti", "dablin"],
         "mqtt": ["paho_mqtt"],
+        "sstv": ["csdrsstv"],
     }
 
     def feature_availability(self):
@@ -688,3 +689,20 @@ class FeatureDetector(object):
             return True
         except ImportError:
             return False
+
+    def has_csdrsstv(self):
+        """
+        TODO
+        """
+        required_version = LooseVersion("0.1")
+
+        try:
+            from csdrsstv.modules import csdrsstv_version
+            from csdrsstv.modules import version as pycsdrsstv_version
+
+            return (
+                    LooseVersion(csdrsstv_version) >= required_version
+                    and LooseVersion(pycsdrsstv_version) >= required_version
+            )
+        except ImportError:
+            return False
diff --git a/owrx/modes.py b/owrx/modes.py
index f5ea047e..30af0511 100644
--- a/owrx/modes.py
+++ b/owrx/modes.py
@@ -140,6 +140,7 @@ class Modes(object):
         DigitalMode("rtty170", "RTTY 45/170", underlying=["usb", "lsb"]),
         DigitalMode("rtty450", "RTTY 50N/450", underlying=["lsb", "usb"]),
         DigitalMode("rtty85", "RTTY 50N/85", underlying=["lsb", "usb"]),
+        DigitalMode("sstv", "SSTV", underlying=["usb", "lsb"], bandpass=Bandpass(1100, 2400)),
         WsjtMode("ft8", "FT8"),
         WsjtMode("ft4", "FT4"),
         WsjtMode("jt65", "JT65"),
diff --git a/owrx/sstv.py b/owrx/sstv.py
new file mode 100644
index 00000000..8175aec9
--- /dev/null
+++ b/owrx/sstv.py
@@ -0,0 +1,61 @@
+from pycsdr.types import Format
+from csdr.module import ThreadModule
+import pickle
+import struct
+
+import logging
+
+logger = logging.getLogger(__name__)
+
+
+class SstvParser(ThreadModule):
+    def __init__(self):
+        super().__init__()
+
+    def run(self):
+        stash = bytes()
+        lines = 0
+        pixels = 0
+        synced = False
+        while self.doRun:
+            data = self.reader.read()
+            if data is None:
+                self.doRun = False
+            else:
+                stash += data
+                while not synced and len(stash) >= 10:
+                    synced = stash[:4] == bytes(b"SYNC")
+                    if synced:
+                        (vis, pixels, lines) = struct.unpack("hhh", stash[4:10])
+                        stash = stash[10:]
+                        logger.debug("got image data: VIS = %i resolution: %i x %i", vis, pixels, lines)
+                        message = {
+                            "mode": "SSTV",
+                            "vis": vis,
+                            "resolution": {
+                                "width": pixels,
+                                "height": lines
+                            }
+                        }
+                        self.writer.write(pickle.dumps(message))
+                    else:
+                        logger.debug("search for sync...")
+                        # go search for sync... byte by byte.
+                        stash = stash[1:]
+                while synced and len(stash) >= pixels * 3:
+                    line = [x for x in stash[:pixels * 3]]
+                    stash = stash[pixels * 3:]
+                    message = {
+                        "mode": "SSTV",
+                        "line": line,
+                    }
+                    self.writer.write(pickle.dumps(message))
+                    lines -= 1
+                    if lines == 0:
+                        synced = False
+
+    def getInputFormat(self) -> Format:
+        return Format.CHAR
+
+    def getOutputFormat(self) -> Format:
+        return Format.CHAR