Use Quotient's BlurHash implementation, send BlurHashes with images

This adds support for sending blurhashes with images, which need to be
generated client-side. Quotient now supports this and the blurhash
implementation was also moved upstream.

src/app/CMakeLists.txt

@@ -12,8 +12,6 @@ add_library(neochat STATIC
     models/userdirectorylistmodel.h
     notificationsmanager.cpp
     notificationsmanager.h
-    blurhash.cpp
-    blurhash.h
     blurhashimageprovider.cpp
     blurhashimageprovider.h
     windowcontroller.cpp

src/app/blurhash.cpp

@@ -1,198 +0,0 @@
-// SPDX-FileCopyrightText: 2018 Wolt Enterprises
-// SPDX-License-Identifier: MIT
-
-#include "blurhash.h"
-
-#include <math.h>
-#include <stdbool.h>
-#include <stdlib.h>
-#include <string.h>
-#include <vector>
-
-namespace
-{
-const char chars[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz#$%*+,-.:;=?@[]^_{|}~";
-
-struct Color {
-    float r = 0;
-    float g = 0;
-    float b = 0;
-};
-
-inline int linearTosRGB(float value)
-{
-    float v = fmaxf(0, fminf(1, value));
-    if (v <= 0.0031308)
-        return v * 12.92 * 255 + 0.5;
-    else
-        return (1.055 * powf(v, 1 / 2.4) - 0.055) * 255 + 0.5;
-}
-
-inline float sRGBToLinear(int value)
-{
-    float v = (float)value / 255;
-    if (v <= 0.04045)
-        return v / 12.92;
-    else
-        return powf((v + 0.055) / 1.055, 2.4);
-}
-
-inline float signPow(float value, float exp)
-{
-    return copysignf(powf(fabsf(value), exp), value);
-}
-
-inline uint8_t clampToUByte(int *src)
-{
-    if (*src >= 0 && *src <= 255) {
-        return *src;
-    }
-    return (*src < 0) ? 0 : 255;
-}
-
-inline uint8_t *createByteArray(int size)
-{
-    return (uint8_t *)malloc(size * sizeof(uint8_t));
-}
-
-int decodeToInt(const char *string, int start, int end)
-{
-    int value = 0;
-    for (int iter1 = start; iter1 < end; iter1++) {
-        int index = -1;
-        for (int iter2 = 0; iter2 < 83; iter2++) {
-            if (chars[iter2] == string[iter1]) {
-                index = iter2;
-                break;
-            }
-        }
-        if (index == -1) {
-            return -1;
-        }
-        value = value * 83 + index;
-    }
-    return value;
-}
-
-void decodeDC(int value, Color *color)
-{
-    color->r = sRGBToLinear(value >> 16);
-    color->g = sRGBToLinear((value >> 8) & 255);
-    color->b = sRGBToLinear(value & 255);
-}
-
-void decodeAC(int value, float maximumValue, Color *color)
-{
-    int quantR = (int)floorf(value / (19 * 19));
-    int quantG = (int)floorf(value / 19) % 19;
-    int quantB = (int)value % 19;
-
-    color->r = signPow(((float)quantR - 9) / 9, 2.0) * maximumValue;
-    color->g = signPow(((float)quantG - 9) / 9, 2.0) * maximumValue;
-    color->b = signPow(((float)quantB - 9) / 9, 2.0) * maximumValue;
-}
-
-int decodeToArray(const char *blurhash, int width, int height, int punch, int nChannels, uint8_t *pixelArray)
-{
-    if (!isValidBlurhash(blurhash)) {
-        return -1;
-    }
-    if (punch < 1) {
-        punch = 1;
-    }
-
-    int sizeFlag = decodeToInt(blurhash, 0, 1);
-    int numY = (int)floorf(sizeFlag / 9) + 1;
-    int numX = (sizeFlag % 9) + 1;
-    int iter = 0;
-
-    Color color;
-    int quantizedMaxValue = decodeToInt(blurhash, 1, 2);
-    if (quantizedMaxValue == -1) {
-        return -1;
-    }
-
-    const float maxValue = ((float)(quantizedMaxValue + 1)) / 166;
-
-    const int colors_size = numX * numY;
-
-    std::vector<Color> colors(colors_size, {0, 0, 0});
-
-    for (iter = 0; iter < colors_size; iter++) {
-        if (iter == 0) {
-            int value = decodeToInt(blurhash, 2, 6);
-            if (value == -1) {
-                return -1;
-            }
-            decodeDC(value, &color);
-            colors[iter] = color;
-        } else {
-            int value = decodeToInt(blurhash, 4 + iter * 2, 6 + iter * 2);
-            if (value == -1) {
-                return -1;
-            }
-            decodeAC(value, maxValue * punch, &color);
-            colors[iter] = color;
-        }
-    }
-
-    int bytesPerRow = width * nChannels;
-    int x = 0, y = 0, i = 0, j = 0;
-    int intR = 0, intG = 0, intB = 0;
-
-    for (y = 0; y < height; y++) {
-        for (x = 0; x < width; x++) {
-            float r = 0, g = 0, b = 0;
-
-            for (j = 0; j < numY; j++) {
-                for (i = 0; i < numX; i++) {
-                    float basics = cos((M_PI * x * i) / width) * cos((M_PI * y * j) / height);
-                    int idx = i + j * numX;
-                    r += colors[idx].r * basics;
-                    g += colors[idx].g * basics;
-                    b += colors[idx].b * basics;
-                }
-            }
-
-            intR = linearTosRGB(r);
-            intG = linearTosRGB(g);
-            intB = linearTosRGB(b);
-
-            pixelArray[nChannels * x + 0 + y * bytesPerRow] = clampToUByte(&intR);
-            pixelArray[nChannels * x + 1 + y * bytesPerRow] = clampToUByte(&intG);
-            pixelArray[nChannels * x + 2 + y * bytesPerRow] = clampToUByte(&intB);
-
-            if (nChannels == 4) {
-                pixelArray[nChannels * x + 3 + y * bytesPerRow] = 255;
-            }
-        }
-    }
-    return 0;
-}
-}
-
-uint8_t *decode(const char *blurhash, int width, int height, int punch, int nChannels)
-{
-    int bytesPerRow = width * nChannels;
-    uint8_t *pixelArray = createByteArray(bytesPerRow * height);
-
-    if (decodeToArray(blurhash, width, height, punch, nChannels, pixelArray) == -1) {
-        return nullptr;
-    }
-    return pixelArray;
-}
-
-bool isValidBlurhash(const char *blurhash)
-{
-    const int hashLength = strlen(blurhash);
-
-    if (!blurhash || strlen(blurhash) < 6) {
-        return false;
-    }
-
-    int sizeFlag = decodeToInt(blurhash, 0, 1);
-    int numY = (int)floorf(sizeFlag / 9) + 1;
-    int numX = (sizeFlag % 9) + 1;
-
-    return hashLength == 4 + 2 * numX * numY;
-}

src/app/blurhash.h

@@ -1,28 +0,0 @@
-// SPDX-FileCopyrightText: 2018 Wolt Enterprises
-// SPDX-License-Identifier: MIT
-
-#pragma once
-
-#include <stdint.h>
-
-/**
- * @brief Returns the pixel array of the result image given the blurhash string.
- *
- * @param blurhash a string representing the blurhash to be decoded.
- * @param width the width of the resulting image.
- * @param height the height of the resulting image.
- * @param punch the factor to improve the contrast, default = 1.
- * @param nChannels the number of channels in the resulting image array, 3 = RGB, 4 = RGBA.
- *
- * @return A pointer to memory region where pixels are stored in (H, W, C) format.
- */
-uint8_t *decode(const char *blurhash, int width, int height, int punch, int nChannels);
-
-/**
- * @brief Checks if the Blurhash is valid or not.
- *
- * @param blurhash a string representing the blurhash.
- *
- * @return A bool (true if it is a valid blurhash, else false).
- */
-bool isValidBlurhash(const char *blurhash);

src/app/blurhashimageprovider.cpp

@@ -1,31 +1,97 @@
-// SPDX-FileCopyrightText: 2021 Tobias Fella <tobias.fella@kde.org>
-// SPDX-License-Identifier: LGPL-2.0-or-later
+// SPDX-FileCopyrightText: 2024 Joshua Goins <josh@redstrate.com>
+// SPDX-License-Identifier: MIT
 
 #include "blurhashimageprovider.h"
 
-#include <QImage>
-#include <QString>
+#include <Quotient/blurhash.h>
 
-#include "blurhash.h"
+/*
+ * Qt unfortunately re-encodes the base83 string in QML.
+ * The only special ASCII characters used in the blurhash base83 string are:
+ * #$%*+,-.:;=?@[]^_{|}~
+ * QUrl::fromPercentEncoding is too greedy, and spits out invalid characters
+ * for parts of valid base83 like %14.
+ */
+// clang-format off
+static const QMap<QLatin1String, QLatin1String> knownEncodings = {
+    {QLatin1String("%23A"), QLatin1String(":")},
+    {QLatin1String("%3F"), QLatin1String("?")},
+    {QLatin1String("%23"), QLatin1String("#")},
+    {QLatin1String("%5B"), QLatin1String("[")},
+    {QLatin1String("%5D"), QLatin1String("]")},
+    {QLatin1String("%40"), QLatin1String("@")},
+    {QLatin1String("%24"), QLatin1String("$")},
+    {QLatin1String("%2A"), QLatin1String("*")},
+    {QLatin1String("%2B"), QLatin1String("+")},
+    {QLatin1String("%2C"), QLatin1String(",")},
+    {QLatin1String("%2D"), QLatin1String("-")},
+    {QLatin1String("%2E"), QLatin1String(".")},
+    {QLatin1String("%3D"), QLatin1String("=")},
+    {QLatin1String("%25"), QLatin1String("%")},
+    {QLatin1String("%5E"), QLatin1String("^")},
+    {QLatin1String("%7C"), QLatin1String("|")},
+    {QLatin1String("%7B"), QLatin1String("{")},
+    {QLatin1String("%7D"), QLatin1String("}")},
+    {QLatin1String("%7E"), QLatin1String("~")},
+};
+// clang-format on
 
-BlurhashImageProvider::BlurhashImageProvider()
-    : QQuickImageProvider(QQuickImageProvider::Image)
+class AsyncImageResponseRunnable : public QObject, public QRunnable
 {
+    Q_OBJECT
+
+Q_SIGNALS:
+    void done(QImage image);
+
+public:
+    AsyncImageResponseRunnable(const QString &id, const QSize &requestedSize)
+        : m_id(id)
+        , m_requestedSize(requestedSize)
+    {
+        if (m_requestedSize.width() == -1)
+            m_requestedSize.setWidth(64);
+        if (m_requestedSize.height() == -1)
+            m_requestedSize.setHeight(64);
     }
 
-QImage BlurhashImageProvider::requestImage(const QString &id, QSize *size, const QSize &requestedSize)
+    void run() override
     {
-    if (id.isEmpty()) {
-        return QImage();
+        if (m_id.isEmpty())
+            return;
+
+        QString decodedId = m_id;
+        for (auto i = knownEncodings.constBegin(); i != knownEncodings.constEnd(); ++i)
+            decodedId.replace(i.key(), i.value());
+
+        Q_EMIT done(Quotient::BlurHash::decode(decodedId, m_requestedSize));
     }
-    *size = requestedSize;
-    if (size->width() == -1) {
-        size->setWidth(256);
+
+private:
+    QString m_id;
+    QSize m_requestedSize;
+};
+
+AsyncImageResponse::AsyncImageResponse(const QString &id, const QSize &requestedSize, QThreadPool *pool)
+{
+    const auto runnable = new AsyncImageResponseRunnable(id, requestedSize);
+    connect(runnable, &AsyncImageResponseRunnable::done, this, &AsyncImageResponse::handleDone);
+    pool->start(runnable);
 }
-    if (size->height() == -1) {
-        size->setHeight(256);
+
+void AsyncImageResponse::handleDone(QImage image)
+{
+    m_image = std::move(image);
+    Q_EMIT finished();
 }
-    auto data = decode(QUrl::fromPercentEncoding(id.toLatin1()).toLatin1().data(), size->width(), size->height(), 1, 3);
-    QImage image(data, size->width(), size->height(), size->width() * 3, QImage::Format_RGB888, free, data);
-    return image;
+
+QQuickTextureFactory *AsyncImageResponse::textureFactory() const
+{
+    return QQuickTextureFactory::textureFactoryForImage(m_image);
 }
+
+QQuickImageResponse *BlurHashImageProvider::requestImageResponse(const QString &id, const QSize &requestedSize)
+{
+    return new AsyncImageResponse(id, requestedSize, &pool);
+}
+
+#include "blurhashimageprovider.moc"

src/app/blurhashimageprovider.h

@@ -1,26 +1,25 @@
-// SPDX-FileCopyrightText: 2021 Tobias Fella <tobias.fella@kde.org>
-// SPDX-License-Identifier: LGPL-2.0-or-later
+// SPDX-FileCopyrightText: 2024 Joshua Goins <josh@redstrate.com>
+// SPDX-License-Identifier: MIT
 
 #pragma once
 
-#include <QQuickImageProvider>
+#include <QQuickAsyncImageProvider>
+#include <QThreadPool>
 
-/**
- * @class BlurhashImageProvider
- *
- * A QQuickImageProvider for blurhashes.
- *
- * @sa QQuickImageProvider
- */
-class BlurhashImageProvider : public QQuickImageProvider
+class AsyncImageResponse final : public QQuickImageResponse
 {
 public:
-    BlurhashImageProvider();
-
-    /**
-     * @brief Return an image for a given ID.
-     *
-     * @sa QQuickImageProvider::requestImage
-     */
-    QImage requestImage(const QString &id, QSize *size, const QSize &requestedSize) override;
+    AsyncImageResponse(const QString &id, const QSize &requestedSize, QThreadPool *pool);
+    void handleDone(QImage image);
+    QQuickTextureFactory *textureFactory() const override;
+    QImage m_image;
+};
+
+class BlurHashImageProvider : public QQuickAsyncImageProvider
+{
+public:
+    QQuickImageResponse *requestImageResponse(const QString &id, const QSize &requestedSize) override;
+
+private:
+    QThreadPool pool;
 };

src/app/main.cpp

@@ -292,7 +292,7 @@ int main(int argc, char *argv[])
         ShareHandler::instance().setText(parser.value(shareOption));
     }
 
-    engine.addImageProvider(u"blurhash"_s, new BlurhashImageProvider);
+    engine.addImageProvider(u"blurhash"_s, new BlurHashImageProvider);
 
     engine.loadFromModule("org.kde.neochat", "Main");
 

src/libneochat/neochatroom.cpp

@@ -18,6 +18,7 @@
 #include <qcoro/qcorosignal.h>
 
 #include <Quotient/avatar.h>
+#include <Quotient/blurhash.h>
 #include <Quotient/connection.h>
 #include <Quotient/csapi/account-data.h>
 #include <Quotient/csapi/directory.h>
@@ -241,7 +242,7 @@ QCoro::Task<void> NeoChatRoom::doUploadFile(QUrl url, QString body, std::optiona
     EventContent::FileContentBase *content;
     if (mime.name().startsWith("image/"_L1)) {
         QImage image(url.toLocalFile());
-        content = new EventContent::ImageContent(url, fileInfo.size(), mime, image.size(), fileInfo.fileName());
+        content = new EventContent::ImageContent(url, fileInfo.size(), mime, image.size(), fileInfo.fileName(), BlurHash::encode(image));
     } else if (mime.name().startsWith("audio/"_L1)) {
         content = new EventContent::AudioContent(url, fileInfo.size(), mime, fileInfo.fileName());
     } else if (mime.name().startsWith("video/"_L1)) {