feat: use ffmpeg to render http camera stream

deps/FFMPEG/FFMPEG.cmake

@@ -69,14 +69,14 @@ else ()
             --disable-filters
             --enable-filter=*null*,afade,*fifo,*format,*resample,aeval,allrgb,allyuv,atempo,pan,*bars,color,*key,crop,draw*,eq*,framerate,*_qsv,*_vaapi,*v4l2*,hw*,scale,volume,test*
             --disable-protocols
-            --enable-protocol=file,fd,pipe,rtp,tcp,udp
+            --enable-protocol=file,fd,pipe,http,rtp,tcp,udp
             --disable-muxers
             --enable-muxer=rtp
             --disable-encoders
             --disable-decoders
             --enable-decoder=*aac*,h264*,mp3*,mjpeg,rv*
             --disable-demuxers
-            --enable-demuxer=h264,mp3,mov,rtsp,sdp
+            --enable-demuxer=h264,mp3,mov,mpjpeg,rtsp,sdp
             --disable-zlib
             --disable-avdevice
         BUILD_IN_SOURCE ON

src/slic3r/GUI/MediaPlayCtrl.cpp

@@ -290,7 +290,6 @@ void refresh_agora_url(char const* device, char const* dev_ver, char const* chan
 void MediaPlayCtrl::Play()
 {
     switch (current_mode()) {
-    case CameraStreamMode::http:
     case CameraStreamMode::http_snapshot:
         if (!m_next_retry.IsValid() || wxDateTime::Now() < m_next_retry)
             return;
@@ -300,14 +299,13 @@ void MediaPlayCtrl::Play()
             Stop(_L("Please confirm if the printer is connected."));
             return;
         }
-        if (auto agent = wxGetApp().getAgent())
-            agent->command_start_camera(m_machine);
         m_button_play->SetIcon("media_stop");
         m_web_ctrl->Load(wxURI(m_url), current_mode());
         m_web_ctrl->Play();
         m_last_state = wxMEDIASTATE_PLAYING;
         SetStatus(_L("Playing..."), false);
         return;
+    case CameraStreamMode::http:
     case CameraStreamMode::rtsp:
         if (m_next_retry.IsValid() && wxDateTime::Now() < m_next_retry)
             return;
@@ -769,7 +767,8 @@ void MediaPlayCtrl::load()
 {
     m_last_state = MEDIASTATE_LOADING;
     SetStatus(_L("Loading..."));
-    if (current_mode() != CameraStreamMode::rtsp) {
+    const auto mode = current_mode();
+    if (mode != CameraStreamMode::rtsp && mode != CameraStreamMode::http) {
         std::string file_h264 = data_dir() + "/video.h264";
         std::string file_info = data_dir() + "/video.info";
         BOOST_LOG_TRIVIAL(info) << "MediaPlayCtrl dump video to " << file_h264;

src/slic3r/GUI/StatusPanel.cpp

@@ -2308,8 +2308,8 @@ void StatusPanel::update_camera_state(MachineObject* obj)
 
     auto agent = wxGetApp().getAgent();
     const auto camera_mode = agent ? agent->get_camera_stream_mode() : CameraStreamMode::none;
-    const bool has_printer_webcam = camera_mode == CameraStreamMode::http || camera_mode == CameraStreamMode::http_snapshot;
+    const bool use_webview = camera_mode == CameraStreamMode::http_snapshot;
-    if (has_printer_webcam) {
+    if (use_webview) {
         //m_camera_switch_button->Hide();
         if (!m_custom_camera_view->IsShown()) {
             // why: do not reload the WebView URL per tick, or redirects can cause a reload loop.
@@ -2317,11 +2317,15 @@ void StatusPanel::update_camera_state(MachineObject* obj)
             m_custom_camera_view->Show();
             m_media_ctrl->Hide();
         }
-    } else if (m_custom_camera_view->IsShown()) {
+    } else {
+        if (m_custom_camera_view->IsShown()) {
             m_custom_camera_view->Hide();
-        m_media_ctrl->Show();
+            // Stop the snapshot WebView before switching to native playback
+            // or leaving the camera mode.
             m_media_play_ctrl->StopWebStream();
         }
+        m_media_ctrl->Show();
+    }
 
     //sdcard
     auto sdcard_state = obj->GetStorage()->get_sdcard_state();
@@ -2354,7 +2358,7 @@ void StatusPanel::update_camera_state(MachineObject* obj)
         m_last_recording = obj->is_recording() ? 1 : 0;
     }
 
-    if (has_printer_webcam) {
+    if (use_webview) {
         if (m_bitmap_recording_img->IsShown()) {
             m_bitmap_recording_img->Hide();
             m_panel_monitoring_title->Layout();
@@ -2417,7 +2421,7 @@ void StatusPanel::update_camera_state(MachineObject* obj)
         m_camera_popup->update(show_vcamera);
     }
 
-    m_setting_button->Show(!has_printer_webcam);
+    m_setting_button->Show(!use_webview);
 }
 
 StatusPanel::StatusPanel(wxWindow *parent, wxWindowID id, const wxPoint &pos, const wxSize &size, long style, const wxString &name)

src/slic3r/GUI/wxMediaCtrl3.cpp

@@ -188,14 +188,14 @@ void wxMediaCtrl3::bambu_log(void *ctx, int level, tchar const *msg2)
     BOOST_LOG_TRIVIAL(info) << msg.ToUTF8().data();
 }
 
-int wxMediaCtrl3::rtsp_interrupt_callback(void *opaque)
+int wxMediaCtrl3::ffmpeg_interrupt_callback(void *opaque)
 {
     auto *ctrl = static_cast<wxMediaCtrl3 *>(opaque);
     std::lock_guard<std::mutex> lock(ctrl->m_mutex);
     return ctrl->m_url != ctrl->m_active_url;
 }
 
-int wxMediaCtrl3::PlayRtsp(std::shared_ptr<wxURI> const &url, std::unique_lock<std::mutex> &lock)
+int wxMediaCtrl3::PlayFfmpeg(std::shared_ptr<wxURI> const &url, std::unique_lock<std::mutex> &lock)
 {
     if (avformat_network_init() < 0)
         return 2;
@@ -206,7 +206,9 @@ int wxMediaCtrl3::PlayRtsp(std::shared_ptr<wxURI> const &url, std::unique_lock<s
         return 2;
     }
 
-    format_context->interrupt_callback = {&wxMediaCtrl3::rtsp_interrupt_callback, this};
+    format_context->interrupt_callback = {&wxMediaCtrl3::ffmpeg_interrupt_callback, this};
+    format_context->flags |= AVFMT_FLAG_NOBUFFER;
+    format_context->max_delay = 0;
     m_active_url = url;
 
     auto finish = [&](int error) {
@@ -219,8 +221,20 @@ int wxMediaCtrl3::PlayRtsp(std::shared_ptr<wxURI> const &url, std::unique_lock<s
     };
 
     const std::string uri = url->BuildURI().ToUTF8().data();
+    const wxString scheme = url->GetScheme();
+    const bool http_stream = scheme.CmpNoCase("http") == 0 || scheme.CmpNoCase("https") == 0;
     AVDictionary *options = nullptr;
+    if (http_stream) {
+        // This is a live multipart MJPEG stream. Keep FFmpeg from building a
+        // read-ahead buffer, otherwise the UI can display frames several
+        // seconds behind the camera.
+        av_dict_set(&options, "fflags", "nobuffer", 0);
+        av_dict_set(&options, "avioflags", "direct", 0);
+        av_dict_set(&options, "probesize", "32", 0);
+        av_dict_set(&options, "analyzeduration", "0", 0);
+    } else {
         av_dict_set(&options, "rtsp_transport", "tcp", 0);
+    }
     lock.unlock();
     int error = avformat_open_input(&format_context, uri.c_str(), nullptr, &options);
     av_dict_free(&options);
@@ -278,7 +292,12 @@ int wxMediaCtrl3::PlayRtsp(std::shared_ptr<wxURI> const &url, std::unique_lock<s
                     break;
                 if (frame.IsOk())
                     m_frame = frame;
-                CallAfter([this] { Refresh(); });
+                if (!m_refresh_pending.exchange(true)) {
+                    CallAfter([this] {
+                        m_refresh_pending.store(false);
+                        Refresh();
+                    });
+                }
             }
         }
         av_packet_unref(packet);
@@ -301,10 +320,11 @@ void wxMediaCtrl3::PlayThread()
         if (!url->HasScheme())
             break;
         const wxString scheme = url->GetScheme();
-        const bool generic_rtsp = scheme.CmpNoCase("rtsp") == 0 || scheme.CmpNoCase("rtsps") == 0;
+        const bool generic_ffmpeg = scheme.CmpNoCase("http") == 0 || scheme.CmpNoCase("https") == 0 ||
+                                    scheme.CmpNoCase("rtsp") == 0 || scheme.CmpNoCase("rtsps") == 0;
         int error = 0;
-        if (generic_rtsp) {
+        if (generic_ffmpeg) {
-            error = PlayRtsp(url, lk);
+            error = PlayFfmpeg(url, lk);
         } else {
             lk.unlock();
             Bambu_Tunnel tunnel = nullptr;

src/slic3r/GUI/wxMediaCtrl3.h

@@ -16,6 +16,7 @@ wxDECLARE_EVENT(EVT_MEDIA_CTRL_STAT, wxCommandEvent);
 void wxMediaCtrl_OnSize(wxWindow * ctrl, wxSize const & videoSize, int width, int height);
 
 #define BAMBU_DYNAMIC
+#include <atomic>
 #include <condition_variable>
 #include <thread>
 #ifndef _WIN32
@@ -56,10 +57,10 @@ protected:
     void DoSetSize(int x, int y, int width, int height, int sizeFlags) override;
 
     static void bambu_log(void *ctx, int level, tchar const *msg);
-    static int rtsp_interrupt_callback(void *opaque);
+    static int ffmpeg_interrupt_callback(void *opaque);
 
     void PlayThread();
-    int PlayRtsp(std::shared_ptr<wxURI> const &url, std::unique_lock<std::mutex> &lock);
+    int PlayFfmpeg(std::shared_ptr<wxURI> const &url, std::unique_lock<std::mutex> &lock);
 
     void NotifyStopped();
 
@@ -83,6 +84,7 @@ private:
     std::mutex m_mutex;
     std::condition_variable m_cond;
     std::thread m_thread;
+    std::atomic_bool m_refresh_pending{false};
 };
 
 #endif /* wxMediaCtrl3_h */