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Fix the sync issue between the Preview.Show() and the QWidget.update()

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1. Add a mutex between the Preview.Show() and the QWidget.update().
2. Speed up the Preview.Show() -- change the floating point to integer,
            merge some plus and multiplying operation and remove some data copy.

Signed-off-by: zejian.su <zejian.su@starfivetech.com>
This commit is contained in:
zejian.su
2023-12-05 10:43:10 +08:00
parent 9e675a54e3
commit 1769165661
1 changed files with 291 additions and 0 deletions
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package/starfive/libcamera-apps/0009-Fix-the-sync-issue-between-the-Preview.Show-and-the-.patch
+291
View File
@@ -0,0 +1,291 @@
From e9e9555cac3c11c70277824d82d5b3fbd5e4afd2 Mon Sep 17 00:00:00 2001
From: "zejian.su" <zejian.su@starfivetech.com>
Date: Fri, 1 Dec 2023 16:30:27 +0800
Subject: [PATCH 2/2] Fix the sync issue between the Preview.Show() and the
QWidget.update() 1. Add a mutex between the Preview.Show() and the
QWidget.update(). 2. Speed up the Preview.Show() -- change the floating point
to integer, merge some plus and multiplying operation and remove some data
copy.
Signed-off-by: zejian.su <zejian.su@starfivetech.com>
---
preview/qt_preview.cpp | 183 +++++++++++++++++++++++++----------------
1 file changed, 113 insertions(+), 70 deletions(-)
diff --git a/preview/qt_preview.cpp b/preview/qt_preview.cpp
index 8196a8e..ef3c8a4 100644
--- a/preview/qt_preview.cpp
+++ b/preview/qt_preview.cpp
@@ -41,16 +41,47 @@ class MyWidget : public QWidget
public:
MyWidget(QWidget *parent, int w, int h) : QWidget(parent), size(w, h)
{
- image = QImage(size, QImage::Format_RGB888);
- image.fill(0);
+ for(int i = 0; i < 2; i++) {
+ buffers_[i].image = QImage(size, QImage::Format_RGB888);
+ buffers_[i].image.fill(0);
+ availableBuffers_.push_back(&buffers_[i]);
+ }
}
QSize size;
- QImage image;
+
+ struct ImageBuffer {
+ QImage image;
+ uint8_t frameCounter;
+
+ ImageBuffer() : frameCounter(0) {};
+ } buffers_[2];
+
+ std::list<ImageBuffer *> freeBuffers_;
+ std::list<ImageBuffer *> availableBuffers_;
+
+ std::mutex buffers_available_mutex_;
+ std::mutex buffers_free_mutex_;
protected:
void paintEvent(QPaintEvent *) override
{
QPainter painter(this);
- painter.drawImage(rect(), image, image.rect());
+ {
+ ImageBuffer *buffer = nullptr;
+ {
+ std::lock_guard<std::mutex> lock(buffers_available_mutex_);
+ if(!availableBuffers_.size())
+ return;
+ buffer = availableBuffers_.back();
+ availableBuffers_.pop_back();
+ }
+
+ painter.drawImage(rect(), buffer->image, buffer->image.rect());
+
+ {
+ std::lock_guard<std::mutex> lock(buffers_free_mutex_);
+ freeBuffers_.push_back(buffer);
+ }
+ }
}
QSize sizeHint() const override { return size; }
};
@@ -58,7 +89,7 @@ protected:
class QtPreview : public Preview
{
public:
- QtPreview(Options const *options) : Preview(options), frame_counter_(0)
+ QtPreview(Options const *options) : Preview(options)
{
window_width_ = options->preview_width;
window_height_ = options->preview_height;
@@ -67,6 +98,8 @@ public:
// This preview window is expensive, so make it small by default.
if (window_width_ == 0 || window_height_ == 0)
window_width_ = 512, window_height_ = 384;
+
+ frameCounter_ = 0;
// As a hint, reserve twice the binned width for our widest current camera (V3)
tmp_stripe_.reserve(4608);
thread_ = std::thread(&QtPreview::threadFunc, this, options);
@@ -83,100 +116,105 @@ public:
void SetInfoText(const std::string &text) override { main_window_->setWindowTitle(QString::fromStdString(text)); }
virtual void Show(int fd, libcamera::Span<uint8_t> span, StreamInfo const &info) override
{
- if((frame_counter_++) & 1) {
- // Return the buffer to the camera system.
- done_callback_(fd);
- return;
+ MyWidget::ImageBuffer *buffer = nullptr;
+ {
+ std::lock_guard<std::mutex> lock(pane_->buffers_free_mutex_);
+ if(pane_->freeBuffers_.size() > 0) {
+ buffer = pane_->freeBuffers_.front();
+ pane_->freeBuffers_.pop_front();
+ }
+ }
+
+ if(!buffer) {
+ std::lock_guard<std::mutex> lock(pane_->buffers_available_mutex_);
+ if(!pane_->availableBuffers_.size()) {
+ done_callback_(fd);
+ return;
+ }
+ buffer = pane_->availableBuffers_.front();
+ pane_->availableBuffers_.pop_front();
}
-
// Quick and simple nearest-neighbour-ish resampling is used here.
// We further share U,V samples between adjacent output pixel pairs
// (even when downscaling) to speed up the conversion.
unsigned x_step = (info.width << 16) / window_width_;
unsigned y_step = (info.height << 16) / window_height_;
- // Choose the right matrix to convert YUV back to RGB.
- static const float YUV2RGB[3][9] = {
- { 1.0, 0.0, 1.402, 1.0, -0.344, -0.714, 1.0, 1.772, 0.0 }, // JPEG
- { 1.164, 0.0, 1.596, 1.164, -0.392, -0.813, 1.164, 2.017, 0.0 }, // SMPTE170M
- { 1.164, 0.0, 1.793, 1.164, -0.213, -0.533, 1.164, 2.112, 0.0 }, // Rec709
+ static const uint32_t YUV2RGB[3][9] = {
+ { 128, 0, 179, 128, 44, 91, 128, 227, 0 }, // JPEG
+ { 149, 0, 204, 149, 50, 104, 149, 258, 0 }, // SMPTE170M
+ { 149, 0, 230, 149, 27, 68, 149, 270, 0 }, // Rec709
};
- int offsetY;
- float coeffY, coeffVR, coeffUG, coeffVG, coeffUB;
- if (info.colour_space == libcamera::ColorSpace::Smpte170m)
+ static const int RGBOFFSET[3][3] = {
+ {24960, -15232, 31104}, {28496, -17328, 35408}, {31824, -9776, 36944}
+ };
+
+ uint32_t coeffY, coeffVR, coeffUG, coeffVG, coeffUB;
+ const int * rgbOffset = nullptr;
+ if(info.colour_space == libcamera::ColorSpace::Smpte170m)
{
- offsetY = 16;
coeffY = YUV2RGB[1][0];
coeffVR = YUV2RGB[1][2];
coeffUG = YUV2RGB[1][4];
coeffVG = YUV2RGB[1][5];
coeffUB = YUV2RGB[1][7];
- }
- else if (info.colour_space == libcamera::ColorSpace::Rec709)
+ rgbOffset = RGBOFFSET[1];
+ } else if(info.colour_space == libcamera::ColorSpace::Rec709)
{
- offsetY = 16;
coeffY = YUV2RGB[2][0];
coeffVR = YUV2RGB[2][2];
coeffUG = YUV2RGB[2][4];
coeffVG = YUV2RGB[2][5];
coeffUB = YUV2RGB[2][7];
- }
- else
+ rgbOffset = RGBOFFSET[2];
+ } else
{
- offsetY = 0;
coeffY = YUV2RGB[0][0];
coeffVR = YUV2RGB[0][2];
coeffUG = YUV2RGB[0][4];
coeffVG = YUV2RGB[0][5];
coeffUB = YUV2RGB[0][7];
- if (info.colour_space != libcamera::ColorSpace::Sycc)
- LOG(1, "QtPreview: unexpected colour space " << libcamera::ColorSpace::toString(info.colour_space));
+ rgbOffset = RGBOFFSET[0];
}
- // Because the source buffer is uncached, and we want to read it a byte at a time,
- // take a copy of each row used. This is a speedup provided memcpy() is vectorized.
- tmp_stripe_.resize(2 * info.stride);
- uint8_t const *Y_start = span.data();
- uint8_t const *UV_start = Y_start + info.height * info.stride;
- uint8_t *Y_row = &tmp_stripe_[0];
- uint8_t *U_row = Y_row + info.stride;
- uint8_t *V_row = U_row + (info.stride >> 1);
-
- // Possibly this should be locked in case a repaint is happening? In practice the risk
- // is only that there might be some tearing, so I don't think we worry. We could speed
- // it up by getting the ISP to supply RGB, but I'm not sure I want to handle that extra
- // possibility in our main application code, so we'll put up with the slow conversion.
- for (unsigned int y = 0; y < window_height_; y++)
+ uint8_t const * Y_start = span.data();
+ uint8_t const * UV_start = Y_start + info.height * info.stride;
+ int src_ypos = y_step >> 1;
+ uint32_t Y2 = 0;
+ uint32_t U2 = coeffUG | (coeffUB << 16);
+ uint32_t V2 = coeffVR | (coeffVG << 16);
+ uint16_t * y2 = (uint16_t *)&Y2;
+ uint32_t U;
+ uint32_t V;
+ uint16_t * u2 = (uint16_t *)&U;
+ uint16_t * v2 = (uint16_t *)&V;
+
+ for(unsigned int y = 0; y < window_height_; y++, src_ypos += y_step)
{
- unsigned row = (y * y_step) >> 16;
- uint8_t *dest = pane_->image.scanLine(y);
- unsigned x_pos = x_step >> 1;
-
- memcpy(Y_row, Y_start + row * info.stride, info.stride);
- //memcpy(U_row, Y_start + ((4 * info.height + row) >> 1) * (info.stride >> 1), info.stride >> 1);
- //memcpy(V_row, Y_start + ((5 * info.height + row) >> 1) * (info.stride >> 1), info.stride >> 1);
- uint8_t const *cur_uv = UV_start + (row >> 1) * info.width;
- for(unsigned int uv_idx = 0; uv_idx < info.width >> 1; uv_idx++, cur_uv += 2)
- U_row[uv_idx] = cur_uv[0], V_row[uv_idx] = cur_uv[1];
-
- for (unsigned int x = 0; x < window_width_; x += 2)
+ const uint8_t * src_y = Y_start + (src_ypos >> 16) * info.width;
+ const uint8_t * src_uv = UV_start + (src_ypos >> 17) * info.width;
+ uint8_t * dest = buffer->image.scanLine(y);
+ uint32_t x_pos = x_step >> 1;
+
+ for(unsigned int x = 0; x < window_width_; x += 2)
{
- int Y0 = Y_row[x_pos >> 16];
+ y2[0] = src_y[x_pos >> 16];
x_pos += x_step;
- int Y1 = Y_row[x_pos >> 16];
- int U = U_row[x_pos >> 17];
- int V = V_row[x_pos >> 17];
+ y2[1] = src_y[x_pos >> 16];
+ U = src_uv[(x_pos >> 16) & 0xfffffffe];
+ V = src_uv[(x_pos >> 16) | 1];
x_pos += x_step;
- Y0 -= offsetY;
- Y1 -= offsetY;
- U -= 128;
- V -= 128;
- int R0 = coeffY * Y0 + coeffVR * V;
- int G0 = coeffY * Y0 + coeffUG * U + coeffVG * V;
- int B0 = coeffY * Y0 + coeffUB * U;
- int R1 = coeffY * Y1 + coeffVR * V;
- int G1 = coeffY * Y1 + coeffUG * U + coeffVG * V;
- int B1 = coeffY * Y1 + coeffUB * U;
+
+ Y2 *= coeffY;
+ U *= U2;
+ V *= V2;
+
+ int R0 = ((int)y2[0] + (int)v2[0] - rgbOffset[0]) >> 7;
+ int G0 = ((int)y2[0] - (int)u2[0] - (int)v2[1] - rgbOffset[1]) >> 7;
+ int B0 = ((int)y2[0] + (int)u2[1] - rgbOffset[2]) >> 7;
+ int R1 = ((int)y2[1] + (int)v2[0] - rgbOffset[0]) >> 7;
+ int G1 = ((int)y2[1] - (int)u2[0] - (int)v2[1] - rgbOffset[1]) >> 7;
+ int B1 = ((int)y2[1] + (int)u2[1] - rgbOffset[2]) >> 7;
*(dest++) = std::clamp(R0, 0, 255);
*(dest++) = std::clamp(G0, 0, 255);
*(dest++) = std::clamp(B0, 0, 255);
@@ -186,6 +224,12 @@ public:
}
}
+ {
+ std::lock_guard<std::mutex> lock(pane_->buffers_available_mutex_);
+ buffer->frameCounter = ++frameCounter_;
+ pane_->availableBuffers_.push_back(buffer);
+ }
+
pane_->update();
// Return the buffer to the camera system.
@@ -193,7 +237,7 @@ public:
}
// Reset the preview window, clearing the current buffers and being ready to
// show new ones.
- void Reset() override {frame_counter_ = 0;}
+ void Reset() override {}
// Check if preview window has been shut down.
bool Quit() override { return main_window_->quit; }
// There is no particular limit to image sizes, though large images will be very slow.
@@ -228,8 +272,7 @@ private:
std::mutex mutex_;
std::condition_variable cond_var_;
std::vector<uint8_t> tmp_stripe_;
-
- unsigned int frame_counter_;
+ uint8_t frameCounter_;
};
Preview *make_qt_preview(Options const *options)
--
2.34.1