Video playback with mpv

Add video playback with mpv

• Add the mpv widget
• Enable the widget only for video able documents
• Control the widget with a small set of buttons
• Seek mpv with slider that indicates the current position in the video
• Use std::chrono in the MpvControls to be sure to have the correct time unit...

Not mpv related changes

• Don't del and add docks if they are already present, just swap the contained widget => don't reset the position of the dock at sub-document updates

What it does not for now :

• Get rid of controls on MPV view when the dock goes fullscreen

src/UI/DocumentViews/MpvContainer.cc

@@ -149,20 +149,7 @@ MpvContainer::handleMpvEvent(mpv_event *event) noexcept
 
     case MPV_EVENT_COMMAND_REPLY:
         qDebug() << "Got return of" << event->reply_userdata;
-        switch (static_cast<AsyncCmdType>(event->reply_userdata)) {
-        case AsyncCmdType::None:
-            break;
-
-        case AsyncCmdType::LoadFile:
-            qDebug() << "MPV - CMD: File loaded by mpv";
-            isPlaybackPaused = false;
-            mpvPause();
-            break;
-
-        case AsyncCmdType::TogglePlayback:
-            qDebug() << "MPV - CMD: Playback was toggled";
-            break;
-        }
+        handleMpvEventCommandReply(static_cast<AsyncCmdType>(event->reply_userdata));
         break;
 
     // Explicitly ignored
@@ -187,6 +174,42 @@ MpvContainer::handleMpvEvent(mpv_event *event) noexcept
     }
 }
 
+void
+MpvContainer::handleMpvEventCommandReply(const AsyncCmdType type) noexcept
+{
+    int rc;
+
+    switch (type) {
+    case AsyncCmdType::None:
+        break;
+
+    case AsyncCmdType::LoadAssFile:
+    case AsyncCmdType::ReloadAss:
+        mpv_get_property(mpv, "sid", MPV_FORMAT_INT64, &sid);
+        qDebug() << "Load ASS file with id:" << sid;
+        break;
+    case AsyncCmdType::UnloadAss:
+        rc = mpv_get_property(mpv, "sid", MPV_FORMAT_INT64, &sid);
+        qDebug() << "Unloaded Ass, rc =" << rc << "and sid =" << sid;
+        if (rc != MPV_ERROR_SUCCESS)
+            sid = -1;
+        else
+            unloadAssFile();
+        break;
+
+    case AsyncCmdType::LoadFile:
+        qDebug() << "MPV - CMD: File loaded by mpv";
+        isPlaybackPaused = false;
+        mpvPause();
+        unloadAssFile();
+        break;
+
+    case AsyncCmdType::TogglePlayback:
+        qDebug() << "MPV - CMD: Playback was toggled";
+        break;
+    }
+}
+
 void
 MpvContainer::onMpvEvent() noexcept
 {
@@ -204,9 +227,24 @@ MpvContainer::loadFile(const QString &filename) noexcept
     if (filename.isEmpty())
         return;
 
-    const QByteArray c_filename = filename.toUtf8();
-    const char *argsLoad[]      = { "loadfile", c_filename.data(), nullptr };
-    printMpvError(mpv_command_async(mpv, AsyncCmdType::LoadFile, argsLoad));
+    const QByteArray cFileName = filename.toUtf8();
+    asyncCommand(AsyncCmdType::LoadFile, { "loadfile", cFileName.data(), nullptr });
+}
+
+void
+MpvContainer::loadAssFile(const QString &ass) noexcept
+{
+    if (ass.isEmpty())
+        return;
+
+    const QByteArray cFileName = ass.toUtf8();
+    asyncCommand(AsyncCmdType::LoadAssFile, { "sub-add", cFileName.data(), nullptr });
+}
+
+void
+MpvContainer::reloadAssFile() noexcept
+{
+    asyncCommand(AsyncCmdType::ReloadAss, { "sub-reload", nullptr });
 }
 
 void
@@ -235,6 +273,22 @@ MpvContainer::mpvPause() noexcept
 void
 MpvContainer::mpvTogglePlayback() noexcept
 {
-    const char *cmd[] = { "cycle", "pause", "up", nullptr };
-    printMpvError(mpv_command_async(mpv, AsyncCmdType::TogglePlayback, cmd));
+    asyncCommand(AsyncCmdType::TogglePlayback, { "cycle", "pause", "up", nullptr });
+}
+
+void
+MpvContainer::asyncCommand(const AsyncCmdType cmd,
+                           std::initializer_list<const char *> args) noexcept
+{
+    // NOTE: const_cast here, we have faith in MPV to not change the value of
+    // the temporary pointers here. Should be OK anyway because the `args` init
+    // list is a temporary and should be discarded afer the method call.
+    printMpvError(mpv_command_async(mpv, cmd, const_cast<const char **>(std::data(args))));
+}
+
+void
+MpvContainer::unloadAssFile() noexcept
+{
+    // XXX: Debug thing for now
+    asyncCommand(AsyncCmdType::UnloadAss, { "sub-remove", nullptr });
 }