Sending QJsonArray over socket

Kris Revi · wrote on 14 Apr 2021, 17:04

Code Qt Side

void MainWindow::selectedImageDisplay(QString img)
{
    QImage imageObject;    // Make a new imageObject
    imageObject.load(img); // Load the image from path

    imageObject = imageObject.convertToFormat(QImage::Format_RGB16);

    QJsonArray RGB565;
    for(int y = 0; y < imageObject.height(); y++)
    {
        const quint16 *line = reinterpret_cast<const quint16*>(imageObject.constScanLine(y));
        for(int x = 0; x < imageObject.width(); x++)
        {
            RGB565 << *(line++);
        }
    }

    qDebug() << RGB565;
    socket.sendCommandStrip(QString("pixArt"), RGB565);
}

Code ESP32 Side

class MatrixSocket
{ 
    public:
        static void webSocketEvent(uint8_t num, WStype_t type, uint8_t *payload, size_t length)
        {
            Serial.println("Incoming data from socket!");

            IPAddress ip = webSocket.remoteIP(num);

            const size_t CAPACITY = JSON_ARRAY_SIZE(128); // Json Array Size (128x128 image size)

            DynamicJsonDocument inData(CAPACITY);
            StaticJsonDocument<512> outData;

            DeserializationError err = deserializeJson(inData, payload);

            switch (err.code())
            {
                case DeserializationError::Ok:
                    Serial.println("Deserialization succeeded");
                    break;
                case DeserializationError::EmptyInput:
                    Serial.println("Empty input!");
                    break;
                case DeserializationError::IncompleteInput:
                    Serial.println("Incomplete input!");
                    break;
                case DeserializationError::InvalidInput:
                    Serial.println("Invalid input!");
                    break;
                case DeserializationError::NoMemory:
                    Serial.println("Not enough memory");
                    break;
                case DeserializationError::NotSupported:
                    Serial.println("Not Supported");
                    break;
                case DeserializationError::TooDeep:
                    Serial.println("Too Deep");
                    break;
                default:
                    Serial.println("Deserialization failed");
                    break;
            }

            String outJsonData;

            if (inData["reqDeviceInfo"] && inData["reqDeviceInfo"] == "yes")
            {
                outData["ledtype"]              = "MATRIX";
                
                serializeJson(outData, outJsonData);
                webSocket.sendTXT(num, outJsonData);

                Serial.println("Sending out data!");
            }

            if (inData["pixArt"])
            { 
                Serial.println("Pixel Data Incoming!");
                JsonArray src = inData["pixArt"].as<JsonArray>();
                int i = 0;
                for (JsonVariant p : src)
                {
                    if (i >= 256) break; // just to be safe!
                    pixelArt[i++] = p.as<uint16_t>();
                }
            }

            switch (type)
            {
                case WStype_CONNECTED:
                    Serial.printf("[SOCKET][STATUS][%u] Connected from %d.%d.%d.%d url: %s \n", num, ip[0], ip[1], ip[2], ip[3], payload);
                break;

                case WStype_DISCONNECTED: 
                    Serial.printf("[SOCKET][STATUS] [%u] Disconnected! \n", num);
                break;

                case WStype_ERROR:
                    Serial.println("[SOCKET][ERROR] Oh Shit! \n");
                break;

                /*case WStype_TEXT:
                case WStype_BIN:
                case WStype_FRAGMENT_TEXT_START:
                case WStype_FRAGMENT_BIN_START:
                case WStype_FRAGMENT:
                case WStype_FRAGMENT_FIN:*/

                default:
                break;
                
            }
        }

Problem
When printing out the QJsonArray RGB565 after it's done i get this https://pastebin.com/3zgVpfkG big ass array (and that is fine)
but when it sends it over to my ESP32 all i get is

Incoming data from socket!
Empty input!
[SOCKET][STATUS] [0] Disconnected!

then i get disconnected :S why? what am i doing wrong?

Christian Ehrlicher · wrote on 14 Apr 2021, 17:48

Then print out what you really receive to see if it's what you're sending. Also print out what you really send on the sender side.

Kris Revi · wrote on 14 Apr 2021, 18:15

So i did this

void Socket::sendCommandStrip(const QString &bName, const QJsonValue bValue)
{
    m_webSocket.sendTextMessage(QJsonDocument(QJsonObject{{bName, bValue}}).toJson(QJsonDocument::Compact));
    qDebug() << QJsonDocument(QJsonObject{{bName, bValue}}).toJson(QJsonDocument::Compact);
}

and got

"{\"pixArt\":[]}"

now my question is, why? :S

@Christian-Ehrlicher

if i do this

socket.sendCommandStrip(QString("pixArt"), QJsonValue(RGB565).toArray());

i get the correct output (im not copying all 16k + here)

"{\"pixArt\":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,30912,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,30912,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,30912,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,30912,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,30912,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,30912,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,30912,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,30912,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,30912,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,30912,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,30912,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,30912,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,30912,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,61888,

it ends with this

0,0,0,0,0,0,0,0,0]}"
[SOCKET][INFO] We are closing the connection

again it disconnects me after :S

on the ESP32 side i get this

Incoming data from socket!
Empty input!
[SOCKET][STATUS] [0] Disconnected!

Christian Ehrlicher · 14 Apr 2021, 18:50

I said you should output what you really send, not what you pass to a function you wrote.

Kris Revi · wrote on 14 Apr 2021, 18:50

@Christian-Ehrlicher that is what i send....

qDebug() << QJsonDocument(QJsonObject{{bName, bValue}}).toJson(QJsonDocument::Compact);

Christian Ehrlicher · 14 Apr 2021, 19:02

So what do you get on the esp side?

Kris Revi · wrote on 14 Apr 2021, 19:02

@Christian-Ehrlicher the same as stated above

Incoming data from socket!
Empty input!
[SOCKET][STATUS] [0] Disconnected!

it claims inData['pixArt'] is empty and the disconnects me :S

Christian Ehrlicher · 14 Apr 2021, 19:15

@Kris-Revi said in Sending QJsonArray over socket:

the same as stated above

I don't want processed output but the raw data (for the third time...)

Kris Revi · 14 Apr 2021, 22:44

@Christian-Ehrlicher
like this?

            JsonArray test = inData["pixArt"];

            Serial.println(test);
            Serial.println(inData["pixArt"].as<JsonArray>());

this just gives me

Incoming data from socket!
0
0
Empty input!
[SOCKET][STATUS] [0] Disconnected!

Christian Ehrlicher · wrote on 14 Apr 2021, 19:19

I'm giving up... don't know what's so hard to print out the raw incoming data. Good luck.

JKSH · wrote on 14 Apr 2021, 22:44

@Kris-Revi said in Sending QJsonArray over socket:

like this?

No. Please show us your payload. What does it look like before you passed it into deserializeJson()? (This is what @Christian-Ehrlicher meant by "raw data")

Also:

What is the value of length in webSocketEvent()?
Converting an image into a QJsonArray is very expensive and inefficient. What is the purpose using QJsonArray here?