video sender: don't block for device params

Refs #67741

Change-Id: I985d07c4e1c913f7bcff6c6eeb029a673047ee43
Signed-off-by: Guillaume Roguez <guillaume.roguez@savoirfairelinux.com>

daemon/src/media/video/video_input.cpp

@@ -275,9 +275,12 @@ VideoInput::initFile(std::string path)
     return true;
 }
 
-std::future<DeviceParams>
+std::shared_future<DeviceParams>
 VideoInput::switchInput(const std::string& resource)
 {
+    if (resource == currentResource_)
+        return futureDecOpts_;
+
     RING_DBG("MRL: '%s'", resource.c_str());
 
     if (switchPending_) {
@@ -285,6 +288,8 @@ VideoInput::switchInput(const std::string& resource)
         return {};
     }
 
+    currentResource_ = resource;
+
     std::promise<DeviceParams> p;
     foundDecOpts_.swap(p);
 
@@ -294,7 +299,8 @@ VideoInput::switchInput(const std::string& resource)
         switchPending_ = true;
         if (!loop_.isRunning())
             loop_.start();
-        return foundDecOpts_.get_future();
+        futureDecOpts_   = foundDecOpts_.get_future();
+        return futureDecOpts_;
     }
 
     // Supported MRL schemes
@@ -323,16 +329,17 @@ VideoInput::switchInput(const std::string& resource)
         valid = initFile(suffix);
     }
 
-    /* Unsupported MRL or failed initialization */
-    if (valid) {
+    // Unsupported MRL or failed initialization
+    if (not valid) {
+        RING_ERR("Failed to init input for MRL '%s'\n", resource.c_str());
+        return {};
+    }
+
     switchPending_ = true;
     if (!loop_.isRunning())
         loop_.start();
-    }
-    else
-        RING_ERR("Failed to init input for MRL '%s'\n", resource.c_str());
-
-    return valid ? foundDecOpts_.get_future() : std::future<DeviceParams> {};
+    futureDecOpts_ = foundDecOpts_.get_future().share();
+    return futureDecOpts_;
 }
 
 int VideoInput::getWidth() const

daemon/src/media/video/video_input.h

@@ -63,17 +63,20 @@ public:
     int getPixelFormat() const;
     DeviceParams getParams() const;
 
-    std::future<DeviceParams> switchInput(const std::string& resource);
+    std::shared_future<DeviceParams> switchInput(const std::string& resource);
 
 private:
     NON_COPYABLE(VideoInput);
 
+    std::string currentResource_;
+
     MediaDecoder *decoder_  = nullptr;
     std::shared_ptr<SinkClient> sink_;
     std::atomic<bool> switchPending_ = {false};
 
     DeviceParams decOpts_;
     std::promise<DeviceParams> foundDecOpts_;
+    std::shared_future<DeviceParams> futureDecOpts_;
 
     bool emulateRate_       = false;
     ThreadLoop loop_;

daemon/src/media/video/video_rtp_session.cpp

@@ -49,6 +49,8 @@ namespace ring { namespace video {
 using std::map;
 using std::string;
 
+constexpr static auto NEWPARAMS_TIMEOUT = std::chrono::milliseconds(1000);
+
 VideoRtpSession::VideoRtpSession(const string &callID,
                                  const DeviceParams& localVideoParams) :
     RtpSession(callID), localVideoParams_(localVideoParams)
@@ -68,12 +70,12 @@ void VideoRtpSession::startSender()
             RING_WARN("Restarting video sender");
         }
 
-        std::future<DeviceParams> newParams;
         if (not conference_) {
             videoLocal_ = getVideoCamera();
             if (auto input = videoManager.videoInput.lock()) {
-                newParams = input->switchInput(input_);
-                if (newParams.valid())
+                auto newParams = input->switchInput(input_);
+                if (newParams.valid() &&
+                    newParams.wait_for(NEWPARAMS_TIMEOUT) == std::future_status::ready)
                     localVideoParams_ = newParams.get();
                 else
                     RING_WARN("No valid new video parameters.");