cv/video-widget: make it work without opencv

1 files changed, 172 insertions, 0 deletions

diff --git a/video/video-widget.cpp b/video/video-widget.cpp
new file mode 100644
index 00000000..cbb77755
--- /dev/null
+++ b/video/video-widget.cpp
@@ -0,0 +1,172 @@
+/* Copyright (c) 2014-2016, 2019 Stanislaw Halik <sthalik@misaki.pl>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ */
+
+#ifdef OTR_HAS_OPENCV
+#   include <opencv2/imgproc.hpp>
+#endif
+
+#include "video-widget.hpp"
+#include "compat/check-visible.hpp"
+#include "compat/math.hpp"
+
+#include <cstddef>
+#include <cstring>
+
+#ifdef OTR_VIDEO_HAS_OPENCV
+#   include <opencv2/imgproc.hpp>
+#endif
+
+#include <QPainter>
+
+void cv_video_widget::init_image_nolock()
+{
+    texture = QImage(W, H, QImage::Format_ARGB32);
+    texture.setDevicePixelRatio(devicePixelRatioF());
+}
+
+cv_video_widget::cv_video_widget(QWidget* parent) : QWidget(parent)
+{
+    W = width(); H = height();
+    init_image_nolock(); texture.fill(Qt::gray);
+
+    connect(&timer, &QTimer::timeout, this, &cv_video_widget::update_and_repaint, Qt::DirectConnection);
+    timer.start(65);
+}
+
+#ifdef OTR_HAS_OPENCV
+void cv_video_widget::update_image(const cv::Mat& frame)
+{
+    QMutexLocker l(&mtx);
+
+    if (freshp)
+        return;
+
+    if (W < 1 || H < 1 || frame.rows < 1 || frame.cols < 1)
+        return;
+
+    cv::Mat const* __restrict frame_scaled = nullptr;
+
+    if (frame3.cols != W || frame3.rows != H)
+    {
+        frame3 = cv::Mat(H, W, frame.type());
+        frame2 = cv::Mat(H, W, CV_8UC4);
+
+        if (!frame2.isContinuous() || !frame3.isContinuous())
+            std::abort();
+    }
+
+    if (frame.cols != W || frame.rows != H)
+    {
+        cv::resize(frame, frame3, { W, H }, 0, 0, cv::INTER_NEAREST);
+        frame_scaled = &frame3;
+    }
+    else if (!frame.isContinuous())
+    {
+        frame.copyTo(frame3);
+        frame_scaled = &frame3;
+    }
+    else
+        frame_scaled = &frame;
+
+    freshp = true;
+
+    int color_cvt = 0;
+    constexpr int nchannels = 4;
+
+    switch (frame_scaled->channels())
+    {
+    case 1:
+        color_cvt = cv::COLOR_GRAY2BGRA;
+        break;
+    case 3:
+        color_cvt = cv::COLOR_BGR2BGRA;
+        break;
+    case nchannels:
+        break;
+    default:
+        unreachable();
+        break;
+    }
+
+    cv::Mat const* frame_color;
+
+    if (color_cvt != cv::COLOR_COLORCVT_MAX)
+    {
+        cv::cvtColor(*frame_scaled, frame2, color_cvt);
+        frame_color = &frame2;
+    }
+    else
+        frame_color = frame_scaled;
+
+    int stride = frame_color->step.p[0], rows = frame_color->rows;
+    int nbytes = rows * stride;
+    vec.resize(nbytes); vec.shrink_to_fit();
+    std::memcpy(vec.data(), frame_color->data, nbytes);
+
+    texture = QImage((const unsigned char*) vec.data(), W, H, stride, QImage::Format_ARGB32);
+    texture.setDevicePixelRatio(devicePixelRatioF());
+}
+#endif
+
+void cv_video_widget::update_image(const QImage& img)
+{
+    QMutexLocker l(&mtx);
+
+    if (freshp)
+        return;
+    freshp = true;
+
+    unsigned nbytes = (unsigned)(img.bytesPerLine() * img.height());
+    vec.resize(nbytes); vec.shrink_to_fit();
+    std::memcpy(vec.data(), img.constBits(), nbytes);
+
+    texture = QImage((const unsigned char*) vec.data(), img.width(), img.height(), img.bytesPerLine(), img.format());
+    texture.setDevicePixelRatio(devicePixelRatioF());
+}
+
+void cv_video_widget::paintEvent(QPaintEvent*)
+{
+    QMutexLocker foo(&mtx);
+
+    if (texture.width() != W || texture.height() != H)
+    {
+        init_image_nolock();
+        texture.fill(Qt::gray);
+    }
+
+    QPainter painter(this);
+    painter.drawImage(rect(), texture);
+}
+
+void cv_video_widget::update_and_repaint()
+{
+    if (!check_is_visible())
+        return;
+
+    QMutexLocker l(&mtx);
+
+    if (freshp)
+    {
+        freshp = false;
+        repaint();
+    }
+}
+
+void cv_video_widget::resizeEvent(QResizeEvent*)
+{
+    QMutexLocker l(&mtx);
+    double dpr = devicePixelRatioF();
+    W = iround(width() * dpr);
+    H = iround(height() * dpr);
+    init_image_nolock();
+}
+
+void cv_video_widget::get_preview_size(int& w, int& h)
+{
+    QMutexLocker l(&mtx);
+    w = W; h = H;
+}