fix: Avoid occasional crash when changing video devices or closing qTox.

There was an AV race condition caused by clearing the frame buffer while
the VideoFrame is in flight towards toxav. The fix is heavy-handed in
that we're now just copying the frame every time, even though we almost
never have this problem (only when changing devices). So we pay the cost
all the time even though it's rarely needed. However, this is a serious
crashing bug (heap-use-after-free), so I'd rather have it fixed.

.ci-scripts/macos_install_deps.sh

@@ -25,4 +25,5 @@ install_deps() {
     popd
     rm -rf "external/$dep"
   done
+  rmdir external
 }

.github/workflows/build-test-deploy.yaml

@@ -50,6 +50,8 @@ jobs:
         run: .ci-scripts/import-developer-keys.sh
       - name: Verify signatures
         if: github.event_name == 'pull_request'
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         run: tools/verify-release-assets.py
 
   update-nightly-tag:

src/core/coreav.cpp

@@ -408,8 +408,8 @@ void CoreAV::sendCallVideo(uint32_t callId, std::shared_ptr<VideoFrame> vframe)
     Toxav_Err_Send_Frame err;
     int retries = 0;
     do {
-        if (!toxav_video_send_frame(toxav.get(), callId, frame.width, frame.height, frame.y,
-                                    frame.u, frame.v, &err)) {
+        if (!toxav_video_send_frame(toxav.get(), callId, frame.width, frame.height, frame.y.data(),
+                                    frame.u.data(), frame.v.data(), &err)) {
             if (err == TOXAV_ERR_SEND_FRAME_SYNC) {
                 ++retries;
                 QThread::usleep(500);

src/platform/camera/avfoundation.mm

@@ -64,6 +64,7 @@
     QVector<QPair<QString, QString>> result;
 
 #if __MAC_OS_X_VERSION_MIN_REQUIRED >= 101400
+    CGRequestScreenCaptureAccess();
     const AVAuthorizationStatus authStatus =
         [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo];
     if (authStatus != AVAuthorizationStatusDenied && authStatus != AVAuthorizationStatusNotDetermined) {

src/video/videoframe.cpp

@@ -335,12 +335,19 @@ ToxYUVFrame VideoFrame::toToxYUVFrame(QSize frameSize)
 
     return toGenericObject(frameSize, AV_PIX_FMT_YUV420P, true, [frameSize](AVFrame* const frame) {
         // Converter function (constructs ToxAVFrame out of AVFrame*)
+        // TODO(iphydf): Be more efficient (less copying).
         return ToxYUVFrame{
             static_cast<std::uint16_t>(frameSize.width()),
             static_cast<std::uint16_t>(frameSize.height()),
-            frame->data[0],
-            frame->data[1],
-            frame->data[2],
+            // width * height
+            std::vector<uint8_t>(frame->data[0],
+                                 frame->data[0] + frameSize.width() * frameSize.height()),
+            // (width/2) * (height/2)
+            std::vector<uint8_t>(frame->data[1],
+                                 frame->data[1] + (frameSize.width() / 2) * (frameSize.height() / 2)),
+            // (width/2) * (height/2)
+            std::vector<uint8_t>(frame->data[2],
+                                 frame->data[2] + (frameSize.width() / 2) * (frameSize.height() / 2)),
         };
     });
 }
@@ -704,7 +711,7 @@ VideoFrame::toGenericObject(const QSize& dimensions, int pixelFormat, bool requi
         QReadLocker frameReadLock{&frameLock};
 
         // We return empty if the VideoFrame is no longer valid
-        if (frameBuffer.size() == 0) {
+        if (frameBuffer.empty()) {
             return {};
         }
 

src/video/videoframe.h

@@ -24,6 +24,7 @@ extern "C"
 #include <functional>
 #include <memory>
 #include <unordered_map>
+#include <vector>
 
 struct ToxYUVFrame
 {
@@ -34,9 +35,9 @@ struct ToxYUVFrame
     const std::uint16_t width;
     const std::uint16_t height;
 
-    const uint8_t* y;
-    const uint8_t* u;
-    const uint8_t* v;
+    const std::vector<uint8_t> y;
+    const std::vector<uint8_t> u;
+    const std::vector<uint8_t> v;
 };
 
 class VideoFrame