C++ BMediaRoster::GetVideoInput方法代码示例

status_t
MediaWindow::InitMedia(bool first)
{
	status_t err = B_OK;
	BMediaRoster* roster = BMediaRoster::Roster(&err);

	if (first && err != B_OK) {
		BAlert* alert = new BAlert("start_media_server",
			B_TRANSLATE("Could not connect to the media server.\n"
			"Would you like to start it ?"),
			B_TRANSLATE("Quit"),
			B_TRANSLATE("Start media server"), NULL,
			B_WIDTH_AS_USUAL, B_WARNING_ALERT);
		if (alert->Go()==0)
			return B_ERROR;

		fAlert = new MediaAlert(BRect(0, 0, 300, 60),
			"restart_alert", B_TRANSLATE(
				"Restarting media services\nStarting media server"
				B_UTF8_ELLIPSIS "\n"));
		fAlert->Show();

		Show();

		launch_media_server();
	}

	Lock();

	bool isVideoSelected = true;
	if (!first && fListView->ItemAt(0) && fListView->ItemAt(0)->IsSelected())
		isVideoSelected = false;

	if ((!first || (first && err) ) && fAlert) {
		BAutolock locker(fAlert);
		if (locker.IsLocked())
			fAlert->TextView()->SetText(
				B_TRANSLATE("Ready for use" B_UTF8_ELLIPSIS));
	}

	while (fListView->CountItems() > 0)
		delete fListView->RemoveItem((int32)0);
	_EmptyNodeLists();

	// Grab Media Info
	_FindNodes();

	// Add video nodes first. They might have an additional audio
	// output or input, but still should be listed as video node.
	_AddNodeItems(fVideoOutputs, MediaListItem::VIDEO_TYPE);
	_AddNodeItems(fVideoInputs, MediaListItem::VIDEO_TYPE);
	_AddNodeItems(fAudioOutputs, MediaListItem::AUDIO_TYPE);
	_AddNodeItems(fAudioInputs, MediaListItem::AUDIO_TYPE);

	fAudioView->AddOutputNodes(fAudioOutputs);
	fAudioView->AddInputNodes(fAudioInputs);
	fVideoView->AddOutputNodes(fVideoOutputs);
	fVideoView->AddInputNodes(fVideoInputs);

	// build our list view
	DeviceListItem* audio = new DeviceListItem(B_TRANSLATE("Audio settings"),
		MediaListItem::AUDIO_TYPE);
	fListView->AddItem(audio);

	MediaListItem* video = new DeviceListItem(B_TRANSLATE("Video settings"),
		MediaListItem::VIDEO_TYPE);
	fListView->AddItem(video);

	MediaListItem* mixer = new AudioMixerListItem(B_TRANSLATE("Audio mixer"));
	fListView->AddItem(mixer);

	fListView->SortItems(&MediaListItem::Compare);
	_UpdateListViewMinWidth();

	// Set default nodes for our setting views
	media_node default_node;
	dormant_node_info node_info;
	int32 outputID;
	BString outputName;

	if (roster->GetAudioInput(&default_node) == B_OK) {
		roster->GetDormantNodeFor(default_node, &node_info);
		fAudioView->SetDefaultInput(&node_info);
			// this causes our listview to be updated as well
	}

	if (roster->GetAudioOutput(&default_node, &outputID, &outputName)==B_OK) {
		roster->GetDormantNodeFor(default_node, &node_info);
		fAudioView->SetDefaultOutput(&node_info);
		fAudioView->SetDefaultChannel(outputID);
			// this causes our listview to be updated as well
	}

	if (roster->GetVideoInput(&default_node)==B_OK) {
		roster->GetDormantNodeFor(default_node, &node_info);
		fVideoView->SetDefaultInput(&node_info);
			// this causes our listview to be updated as well
	}

	if (roster->GetVideoOutput(&default_node)==B_OK) {
//.........这里部分代码省略.........

status_t
MediaWindow::_InitMedia(bool first)
{
	status_t err = B_OK;
	BMediaRoster* roster = BMediaRoster::Roster(&err);

	if (first && err != B_OK) {
		BAlert* alert = new BAlert("start_media_server",
			B_TRANSLATE("Could not connect to the media server.\n"
				"Would you like to start it ?"),
			B_TRANSLATE("Quit"),
			B_TRANSLATE("Start media server"), NULL,
			B_WIDTH_AS_USUAL, B_WARNING_ALERT);
		alert->SetShortcut(0, B_ESCAPE);
		if (alert->Go() == 0)
			return B_ERROR;

		Show();

		launch_media_server();
	}

	Lock();

	bool isVideoSelected = true;
	if (!first && fListView->ItemAt(0) != NULL
		&& fListView->ItemAt(0)->IsSelected())
		isVideoSelected = false;

	while (fListView->CountItems() > 0)
		delete fListView->RemoveItem((int32)0);
	_EmptyNodeLists();

	// Grab Media Info
	_FindNodes();

	// Add video nodes first. They might have an additional audio
	// output or input, but still should be listed as video node.
	_AddNodeItems(fVideoOutputs, MediaListItem::VIDEO_TYPE);
	_AddNodeItems(fVideoInputs, MediaListItem::VIDEO_TYPE);
	_AddNodeItems(fAudioOutputs, MediaListItem::AUDIO_TYPE);
	_AddNodeItems(fAudioInputs, MediaListItem::AUDIO_TYPE);

	fAudioView->AddOutputNodes(fAudioOutputs);
	fAudioView->AddInputNodes(fAudioInputs);
	fVideoView->AddOutputNodes(fVideoOutputs);
	fVideoView->AddInputNodes(fVideoInputs);

	// build our list view
	DeviceListItem* audio = new DeviceListItem(B_TRANSLATE("Audio settings"),
		MediaListItem::AUDIO_TYPE);
	fListView->AddItem(audio);

	MidiListItem* midi = new MidiListItem(B_TRANSLATE("MIDI Settings"));
	fListView->AddItem(midi);

	MediaListItem* video = new DeviceListItem(B_TRANSLATE("Video settings"),
		MediaListItem::VIDEO_TYPE);
	fListView->AddItem(video);

	MediaListItem* mixer = new AudioMixerListItem(B_TRANSLATE("Audio mixer"));
	fListView->AddItem(mixer);

	fListView->SortItems(&MediaListItem::Compare);
	_UpdateListViewMinWidth();

	// Set default nodes for our setting views
	media_node defaultNode;
	dormant_node_info nodeInfo;
	int32 outputID;
	BString outputName;

	if (roster->GetAudioInput(&defaultNode) == B_OK) {
		roster->GetDormantNodeFor(defaultNode, &nodeInfo);
		fAudioView->SetDefaultInput(&nodeInfo);
			// this causes our listview to be updated as well
	}

	if (roster->GetAudioOutput(&defaultNode, &outputID, &outputName) == B_OK) {
		roster->GetDormantNodeFor(defaultNode, &nodeInfo);
		fAudioView->SetDefaultOutput(&nodeInfo);
		fAudioView->SetDefaultChannel(outputID);
			// this causes our listview to be updated as well
	}

	if (roster->GetVideoInput(&defaultNode) == B_OK) {
		roster->GetDormantNodeFor(defaultNode, &nodeInfo);
		fVideoView->SetDefaultInput(&nodeInfo);
			// this causes our listview to be updated as well
	}

	if (roster->GetVideoOutput(&defaultNode) == B_OK) {
		roster->GetDormantNodeFor(defaultNode, &nodeInfo);
		fVideoView->SetDefaultOutput(&nodeInfo);
			// this causes our listview to be updated as well
	}

	if (first)
		fListView->Select(fListView->IndexOf(mixer));
	else if (isVideoSelected)
//.........这里部分代码省略.........

void
NodeHarnessWin::MessageReceived(BMessage *msg)
{
	status_t err;

	switch (msg->what)
	{
	case BUTTON_CONNECT:
		mIsConnected = true;

		// set the button states appropriately
		mConnectButton->SetEnabled(false);
		mStartButton->SetEnabled(true);

		// set up the node network
		{
			BMediaRoster* r = BMediaRoster::Roster();

			// find a node that can handle an audio file
#if TEST_WITH_AUDIO
			entry_ref inRef;
			dormant_node_info info;

			::get_ref_for_path("/boot/optional/sound/virtual (void)", &inRef);
			err = r->SniffRef(inRef, B_BUFFER_PRODUCER | B_FILE_INTERFACE, &info);
			ErrorCheck(err, "couldn't find file reader node\n");

			err = r->InstantiateDormantNode(info, &mConnection.producer, B_FLAVOR_IS_LOCAL);
			ErrorCheck(err, "couldn't instantiate file reader node\n");

			bigtime_t dummy_length;			// output = media length; we don't use it
			err = r->SetRefFor(mConnection.producer, inRef, false, &dummy_length);
			ErrorCheck(err, "unable to SetRefFor() to read that sound file!\n");
#else
			r->GetVideoInput(&mConnection.producer);
#endif

			entry_ref logRef;
			::get_ref_for_path("/tmp/node_log", &logRef);

			mLogNode = new LoggingConsumer(logRef);
			err = r->RegisterNode(mLogNode);
			ErrorCheck(err, "unable to register LoggingConsumer node!\n");
			// make sure the Media Roster knows that we're using the node
			r->GetNodeFor(mLogNode->Node().node, &mConnection.consumer);

			// trim down the log's verbosity a touch
			mLogNode->SetEnabled(LOG_HANDLE_EVENT, false);

			// fire off a window with the LoggingConsumer's controls in it
			BParameterWeb* web;
			r->GetParameterWebFor(mConnection.consumer, &web);
			BView* view = BMediaTheme::ViewFor(web);
			BWindow* win = new BWindow(BRect(250, 200, 300, 300), "Controls",
				B_TITLED_WINDOW, B_ASYNCHRONOUS_CONTROLS);
			win->AddChild(view);
			win->ResizeTo(view->Bounds().Width(), view->Bounds().Height());
			win->Show();

			// set the nodes' time sources
			r->GetTimeSource(&mTimeSource);
			r->SetTimeSourceFor(mConnection.consumer.node, mTimeSource.node);
			r->SetTimeSourceFor(mConnection.producer.node, mTimeSource.node);

			// got the nodes; now we find the endpoints of the connection
			media_input logInput;
			media_output soundOutput;
			int32 count;
			err = r->GetFreeOutputsFor(mConnection.producer, &soundOutput, 1, &count);
			ErrorCheck(err, "unable to get a free output from the producer node");
			err = r->GetFreeInputsFor(mConnection.consumer, &logInput, 1, &count);
			ErrorCheck(err, "unable to get a free input to the LoggingConsumer");

			// fill in the rest of the Connection object
			mConnection.source = soundOutput.source;
			mConnection.destination = logInput.destination;

			// got the endpoints; now we connect it!
			media_format format;
#if TEST_WITH_AUDIO
			format.type = B_MEDIA_RAW_AUDIO;			// !!! hmmm.. how to fully wildcard this?
			format.u.raw_audio = media_raw_audio_format::wildcard;
#else
			format.type = B_MEDIA_RAW_VIDEO;			// !!! hmmm.. how to fully wildcard this?
			format.u.raw_video = media_raw_video_format::wildcard;
#endif
			err = r->Connect(mConnection.source, mConnection.destination, &format, &soundOutput, &logInput);
			ErrorCheck(err, "unable to connect nodes");
			mConnection.format = format;

			// for video input, we need to set the downstream latency for record -> playback
			bigtime_t latency;
			r->GetLatencyFor(mConnection.producer, &latency);
			printf("Setting producer run mode latency to %" B_PRIdBIGTIME "\n", latency);
			r->SetProducerRunModeDelay(mConnection.producer, latency + 6000);

			// preroll first, to be a good citizen
			r->PrerollNode(mConnection.consumer);
			r->PrerollNode(mConnection.producer);

//.........这里部分代码省略.........