log frameserver stderr in viewer console

vfxpipe/vfxpipe.cpp

@@ -16,12 +16,13 @@
 
 namespace VfxPipe {
 
-std::tuple<int, uint32_t> spawnProcess(int* pipeReadStdout, int* pipeWriteStdin, const std::string& url, ErrorHandler errorHandler)
+std::tuple<int, uint32_t> spawnProcess(int* pipeReadStdout, int* pipeWriteStdin, int* pipeReadStderr, const std::string& url, ErrorHandler errorHandler)
 {
     int fdsToChildStdin[2];
     int fdsFromChildStdout[2];
+    int fdsFromChildStderr[2];
 
-    if (pipe(fdsToChildStdin) == -1 || pipe(fdsFromChildStdout) == -1) {
+    if (pipe(fdsToChildStdin) == -1 || pipe(fdsFromChildStdout) == -1 || (pipeReadStderr && pipe(fdsFromChildStderr) == -1)) {
         errorHandler(std::string("vfxpipe pipe failed: ") + strerror(errno));
         return { -1, 0 };
     }
@@ -37,7 +38,8 @@ std::tuple<int, uint32_t> spawnProcess(int* pipeReadStdout, int* pipeWriteStdin,
     // In the child
     if (pid == 0) {
         if (dup2(fdsToChildStdin[0], STDIN_FILENO) == -1
-            || dup2(fdsFromChildStdout[1], STDOUT_FILENO) == -1) {
+            || dup2(fdsFromChildStdout[1], STDOUT_FILENO) == -1
+            || (pipeReadStderr && dup2(fdsFromChildStderr[1], STDERR_FILENO) == -1)) {
             errorHandler(std::string("vfxpipe dup2 failed: ") + strerror(errno));
             exit(1);
         }
@@ -46,6 +48,10 @@ std::tuple<int, uint32_t> spawnProcess(int* pipeReadStdout, int* pipeWriteStdin,
         close(fdsFromChildStdout[1]);
         close(fdsToChildStdin[0]);
         close(fdsToChildStdin[1]);
+        if (pipeReadStderr) {
+            close(fdsFromChildStderr[0]);
+            close(fdsFromChildStderr[1]);
+        }
 
         Dl_info info;
         auto fptr = &spawnProcess;
@@ -72,10 +78,13 @@ std::tuple<int, uint32_t> spawnProcess(int* pipeReadStdout, int* pipeWriteStdin,
     // In the parent
 
     *pipeWriteStdin = fdsToChildStdin[1];
+    close(fdsToChildStdin[0]);
     *pipeReadStdout = fdsFromChildStdout[0];
-
     close(fdsFromChildStdout[1]);
-    close(fdsToChildStdin[0]);
+    if (pipeReadStderr) {
+        *pipeReadStderr = fdsFromChildStderr[0];
+        close(fdsFromChildStderr[1]);
+    }
 
     uint32_t sinkCount = 0;
     if (!dataIO(*pipeReadStdout, reinterpret_cast<std::byte*>(&sinkCount), sizeof(sinkCount), read, errorHandler)) {
@@ -101,10 +110,10 @@ FrameServer::~FrameServer()
         close(pipeWriteStdin);
 }
 
-bool FrameServer::initialize(ErrorHandler errorHandler)
+bool FrameServer::initialize(ErrorHandler errorHandler, int* pipeReadStderr)
 {
     if (!pid) {
-        std::tie(pid, sinkCount) = spawnProcess(&pipeReadStdout, &pipeWriteStdin, url, errorHandler);
+        std::tie(pid, sinkCount) = spawnProcess(&pipeReadStdout, &pipeWriteStdin, pipeReadStderr, url, errorHandler);
         if (pid == -1) {
             errorHandler("vfxpipe failed to spawn process");
             return false;

vfxpipe/vfxpipe.h

@@ -98,7 +98,7 @@ class FrameServer {
 public:
     FrameServer(const std::string& url);
     ~FrameServer();
-    bool initialize(ErrorHandler errorHandler);
+    bool initialize(ErrorHandler errorHandler, int* pipeReadStderr = nullptr);
     bool renderFrame(double time, const std::vector<SourceVideoFrame>& sourceFrames, RenderedVideoFrame& outputFrame, ErrorHandler errorHandler);
     std::string& getUrl() { return url; }
     uint32_t getSinkCount() { return sinkCount; }

viewer/viewer.cpp

@@ -19,6 +19,7 @@
 #include <QScrollArea> // for QScrollArea
 #include <QSize> // for QSize, operator!=
 #include <QSlider> // for QSlider
+#include <QSocketNotifier>
 #include <QSpinBox> // for QSpinBox
 #include <QStatusBar> // for QStatusBar
 #include <QStringBuilder> // for operator%, QConcatenable<>::type, QStringBuilder
@@ -32,6 +33,7 @@
 #include <algorithm> // for max
 #include <cstddef> /* IWYU pragma: keep */ /* IWYU pragma: no_include <ext/type_traits> */ // for byte
 #include <string> // for string
+#include <unistd.h>
 #include <vector> // for vector
 
 void errorHandler(std::string msg)
@@ -44,6 +46,7 @@ Viewer::Viewer()
     , sizeLabel(0)
     , timeSpinBox(0)
     , frameServer(0)
+    , errorNotifier(0)
 {
     setupUi(this);
 
@@ -81,6 +84,16 @@ void Viewer::messageHandler(QtMsgType type, const QMessageLogContext& context, c
     logTextEdit->appendPlainText(result);
 }
 
+void Viewer::onErrorReadyRead(QSocketDescriptor fd, QSocketNotifier::Type)
+{
+    char data[2048];
+    ssize_t n = read(fd, data, sizeof(data) - 1);
+    if (n > 0) {
+        data[n] = 0;
+        logTextEdit->appendPlainText(QString(data));
+    }
+}
+
 void Viewer::setContentUIEnabled(bool enable)
 {
     timeSpinBox->setEnabled(enable);
@@ -162,7 +175,9 @@ void Viewer::handleResize()
 
 void Viewer::on_timeSlider_valueChanged(int value)
 {
+    timeSpinBox->blockSignals(true);
     timeSpinBox->setValue(sliderTimeValue(value));
+    timeSpinBox->blockSignals(false);
     renderContent();
 }
 
@@ -223,8 +238,13 @@ void Viewer::createContent(const QString& fileName)
 
     logTextEdit->clear();
 
-    if (frameServer->initialize(errorHandler))
+    delete errorNotifier;
+    int pipeReadStderr = 0;
+    if (frameServer->initialize(errorHandler, &pipeReadStderr)) {
+        errorNotifier = new QSocketNotifier(pipeReadStderr, QSocketNotifier::Read, this);
+        connect(errorNotifier, &QSocketNotifier::activated, this, &Viewer::onErrorReadyRead);
         setContentUIEnabled(true);
+    }
 
     setupImages(frameServer->getSinkCount(), scrollArea->widget()->size());
     renderContent();

viewer/viewer.h

@@ -9,10 +9,12 @@
 #include <QMainWindow> // for QMainWindow
 #include <QMessageLogContext> // for QtMsgType
 #include <QObject> // for Q_OBJECT, slots
+#include <QSocketNotifier>
 #include <QString> // for QString
 class QDoubleSpinBox;
 class QLabel;
 class QSize;
+
 namespace VfxPipe {
 class FrameServer;
 }
@@ -34,6 +36,7 @@ private slots:
     void on_addParameterButton_clicked();
     void on_deleteParameterButton_clicked();
     void onImageChanged();
+    void onErrorReadyRead(QSocketDescriptor, QSocketNotifier::Type);
 
 private:
     void createContent(const QString& fileName);
@@ -47,4 +50,5 @@ private slots:
     QLabel* imageLabel;
     QImage renderImage;
     VfxPipe::FrameServer* frameServer;
+    QSocketNotifier* errorNotifier;
 };