Select camera capture rate and verify 30/60 fps pacing

tools/chatgui/src/call_camera_source.h

@@ -10,7 +10,7 @@ class CallCameraSource : public QObject {
     Q_OBJECT
 public:
     virtual CallCameraDevices devices() = 0;
-    virtual bool start(const QByteArray& device, int width, int height) = 0;
+    virtual bool start(const QByteArray& device, int width, int height, int fps) = 0;
     virtual void stop() = 0;
 signals:
     void devicesChanged();

tools/chatgui/src/call_camera_worker.cpp

@@ -49,7 +49,7 @@ public:
         }
         return result;
     }
-    bool start(const QByteArray& device, int width, int height) override {
+    bool start(const QByteArray& device, int width, int height, int fps) override {
         QCameraDevice selected;
         for (const auto& item : QMediaDevices::videoInputs()) if (item.id() == device) selected = item;
         if (selected.isNull()) { emit error(QStringLiteral("Camera is unavailable")); return false; }
@@ -59,18 +59,18 @@ public:
         QCameraFormat best;
         for (const auto& format : selected.videoFormats()) {
             if (!stream_video_camera_supports(format.resolution(), format.minFrameRate(), format.maxFrameRate(),
-                {QSize(width, height), 1})) continue;
+                {QSize(width, height), fps})) continue;
             if (best.isNull() || format.maxFrameRate() < best.maxFrameRate()) best = format;
         }
         if (best.isNull()) {
-            DEBUG_ERROR(DEBUG_CATEGORY_CALL, "camera mode unavailable device=%s size=%dx%d fps=30", device.constData(), width, height);
+            DEBUG_ERROR(DEBUG_CATEGORY_CALL, "camera mode unavailable device=%s size=%dx%d output_fps=%d", device.constData(), width, height, fps);
             emit error(QStringLiteral("Selected camera mode is unavailable")); return false;
         }
         camera->setCameraFormat(best);
         const auto format = camera->cameraFormat();
-        DEBUG_INFO(DEBUG_CATEGORY_CALL, "camera selected device=%s size=%dx%d pixel=%d fps=%.3f..%.3f",
+        DEBUG_INFO(DEBUG_CATEGORY_CALL, "camera selected device=%s size=%dx%d pixel=%d capture_fps=%.3f..%.3f output_fps=%d",
             device.constData(), format.resolution().width(), format.resolution().height(), format.pixelFormat(),
-            format.minFrameRate(), format.maxFrameRate());
+            format.minFrameRate(), format.maxFrameRate(), fps);
         connect(camera.get(), &QCamera::activeChanged, this, [this, device](bool active) {
             if (active) rate.activate(device); else rate.restore();
         });
@@ -211,7 +211,7 @@ class CameraWorker : public QObject {
                       post = !slot->posted; slot->posted = true; }
                     if (post) QMetaObject::invokeMethod(this, [this, slot, revision] { convert(slot, revision); }, Qt::QueuedConnection);
                 }, Qt::DirectConnection);
-            if (source->start(device, width, height)) stage(QStringLiteral("running"));
+            if (source->start(device, width, height, fps)) stage(QStringLiteral("running"));
         } else return false;
         return true;
     }

tools/chatgui/tests/test_call_camera_capture.cpp

@@ -1,5 +1,6 @@
 #include "../src/call_camera_source.h"
 #include "../src/call_camera_buffer.h"
+#include "../src/call_video_cadence.h"
 #include "../../../src/call/call_video_playout.h"
 #include "debug_config.h"
 #include <QtTest>
@@ -73,12 +74,13 @@ public:
         });
     }
     CallCameraDevices devices() override {
-        return {{QStringLiteral("Test camera"), "red", {{QSize(1920, 1080), 30}, {QSize(1280, 720), 30}, {QSize(640, 480), 30}}}};
+        return {{QStringLiteral("Test camera"), "red", {{QSize(1920, 1080), 30}, {QSize(1280, 720), 30},
+            {QSize(640, 480), 30}, {QSize(640, 480), 60}}}};
     }
-    bool start(const QByteArray& id, int w, int h) override {
+    bool start(const QByteArray& id, int w, int h, int fps) override {
         device = id; width = w; height = h; record("start:" + id);
         if (id == "start-stall") QThread::sleep(60);
-        timer.setInterval(id == "fast" ? 5 : 33);
+        timer.setInterval(id == "fast" ? 3 : 1000 / fps);
         timer.start(); return true;
     }
     void stop() override {
@@ -115,21 +117,40 @@ private slots:
         path = directory.filePath(QString::number(QDateTime::currentMSecsSinceEpoch()));
         qputenv("UTUN_CAMERA_TEST_LOG", path.toUtf8());
     }
-    void fastCameraKeepsThirtyFps() {
+    void captureCadence() {
+        for (int input : {50, 100, 330}) for (int output : {30, 50, 60}) {
+            if (output > input) continue;
+            CallVideoCadence cadence(output); unsigned accepted = 0;
+            for (int i = 0; i < input * 3; ++i) if (cadence.accept(1000000 + i * 1000000ll / input)) ++accepted;
+            qInfo("capture cadence input=%d output=%d accepted=%u/3s", input, output, accepted);
+            QVERIFY(std::abs(int(accepted) - output * 3) <= 1);
+            QVERIFY(!cadence.accept(1000000));
+            QVERIFY(cadence.accept(5000000)); QVERIFY(!cadence.accept(5000001));
+        }
+        CallVideoCadence jitter(30); unsigned accepted = 0;
+        for (int i = 0; i < 90; ++i) if (jitter.accept(1000000 + i * 1000000ll / 30 + (i % 2 ? 700 : -700))) ++accepted;
+        QCOMPARE(accepted, 90u);
+    }
+    void fastCameraKeepsSelectedFps_data() {
+        QTest::addColumn<int>("fps"); QTest::newRow("30") << 30; QTest::newRow("60") << 60;
+    }
+    void fastCameraKeepsSelectedFps() {
+        QFETCH(int, fps);
         auto capture = std::make_unique<CallCameraCapture>();
         CallCameraDevices devices;
         connect(capture.get(), &CallCameraCapture::devicesChanged, this, [&](const CallCameraDevices& value) { devices = value; });
         unsigned frames = 0;
         connect(capture.get(), &CallCameraCapture::frameReady, this, [&](const QImage&, qint64, qint64) { ++frames; });
         QSignalSpy errors(capture.get(), &CallCameraCapture::failed);
-        capture->configure(true, "fast", 640, 480);
+        capture->configure(true, "fast", 640, 480, fps);
         QTRY_VERIFY_WITH_TIMEOUT(frames >= 5, 3000);
         QCOMPARE(devices.size(), 1); QCOMPARE(devices.front().id, QByteArray("red"));
         QVERIFY(devices.front().modes.contains({QSize(1920, 1080), 30}));
+        QVERIFY(devices.front().modes.contains({QSize(640, 480), 60}));
         const unsigned before = frames; QElapsedTimer timer; timer.start(); QTest::qWait(2000);
-        const double fps = (frames - before) * 1000.0 / timer.elapsed();
-        qInfo("fast camera converted output fps=%.2f frames=%u", fps, frames - before);
-        QVERIFY(fps >= 25.0); QVERIFY(fps <= 31.0); QCOMPARE(errors.size(), 0);
+        const double actual = (frames - before) * 1000.0 / timer.elapsed();
+        qInfo("fast camera converted target=%d output_fps=%.2f frames=%u", fps, actual, frames - before);
+        QVERIFY(actual >= fps * 0.85); QVERIFY(actual <= fps + 1); QCOMPARE(errors.size(), 0);
         const qint64 child = pid(); capture.reset(); QTRY_VERIFY_WITH_TIMEOUT(!alive(child), 3000);
     }
     void latestFrameAndGeneration_data() {