While testing 360 video on our device with cobalt, the application renderer thread will call function SbPlayerGetCurrentFrame() frequently, but there is no SbDecodeTargetGetInfo() and SbDecodeTargetRelease() even we returned SbDecodeTarget object by function SbPlayerGetCurrentFrame(). In howto_decode_to_texture.md, it told that:
Once the application has acquired a valid SbDecodeTarget object through a call to SbPlayerGetCurrentFrame(), it will call SbDecodeTargetGetInfo() on it.
Does this mean that we don't return a valid SbDecodeTarget in function SbPlayerGetCurrentFrame(), if so, how does renderer thread check the SbDecodeTarget is valid or not?
The Cobalt version is 10.56829.
I found that we called SbPlayerGetCurrentFrame() without return the correct decode target, so that the renderer thread get invalid target object and don't call SbDecodeTargetGetInfo() and SbDecodeTargetRelease()
Related
My region is:
Region region = new Region("backgroundRegion", Identifier.parse("24DDF411-8CF1-440C87CD-E368DAF9C93E"), null, null);
When I start the program I get this message:
06-26 18:03:21.061 7394-7394/? D/BeaconReferenceApp: setting up background monitoring for beacons and power saving
But it doesn't enter in any didEnterRegion function
So, I removed this line: backgroundPowerSaver = new BackgroundPowerSaver(this);
And change scanning times, as it follows:
beaconManager.setBackgroundScanPeriod(1100l);
beaconManager.setBackgroundBetweenScanPeriod(10000l-1100l);
I checked my Beacon UUID and they are 24DDF411-8CF1-440C87CD-E368DAF9C93E
So what is wrong? Why the app doesn't go to the didEnterRegion function?
I already made it work to work with other than AltBeacons... (ranging function works ok!)
My final goal is to get current time when a beacon is discovered...
A few possibilities:
If you are already in the beacon region, you won't get a second callback until the beacon disappears (turn it off for 30 seconds or so, then turn it back on while the app is running.) Alternatively, you can look for a call do didDetermineStateForRegion which is always called when your app starts up, with a flag that tells you if you are inside or outside.
Make sure you have granted runtime permissions to location.
Make sure location is turned on for your phone in settings.
Make sure the beacon is transmitting that identifier using the Locate app https://play.google.com/store/apps/details?id=com.radiusnetworks.locate&hl=en
Make sure you have the proper BeaconParser configured. The question is tagged Eddystone, but shows an iBeacon or AltBeacon-style UUID as the first identifier. Do you have a custom beacon parser configured? What beacon type are you trying to detect?
I need to implement uvc1.5 spec in my device, I choose linux3.4 as my kernel, and I want to use the drivers/usb/gadget/webcam.c
as my function driver. But it doesn't function properly.
According to the signals captured by wireshark, when the host sends the GET_DEF request to the device, my device answer -ENOENT which results in a failure to the enumeration.
I find out that when the composite.c receives this kind of requests, it will forward them to f->set_up to continue.
The main part of f->set_up is:
uvc->event_setup_out = !(ctrl->bRequestType & USB_DIR_IN);
uvc->event_length = le16_to_cpu(ctrl->wLength);
memset(&v4l2_event, 0, sizeof(v4l2_event));
v4l2_event.type = UVC_EVENT_SETUP;
memcpy(&uvc_event->req, ctrl, sizeof(uvc_event->req));
v4l2_event_queue(&uvc->vdev, &v4l2_event);
The call of v4l2_event_queue is what puzzles me: who will handle this event?
I didn't see any code doing such event related initialization work.....
And my question is how to handle this event properly, so I can answer the GET_DEF request ?
It's a V4L2 event you should deal with in another place. You can receive v4l2 event through
rt = ioctl(dev->fd, VIDIOC_DQEVENT,&v4l2_event);
Then you can parse this v4l2_event, it maybe GET_CUR, GER_LEN,etc. So you can response those requests by yourself define.
I have a Main Thread that displays an interface, within another thread created from the main thread before the Main interface is shown, I create tow other windows sequentially:
I create the first window:
CWarningDlg warnDlg;
warnDlg.Create(NULL);
warnDlg.ShowWindow(SW_SHOW);
warnDlg.BringWindowToTop();
CMessageLoop _Loop ;
if(_MyAppModule.AddMessageLoop(&_Loop))
{
nRet = _Loop.Run();
_MyAppModule.RemoveMessageLoop();
}
warnDlg.DestroyWindow();
if (nRet == SOME_VALUE)
{
doSomethingElse();
}
Do something else has:
CActionDlg actDlg;
actDlg.Create(NULL);
actDlg.ShowWindow(SW_SHOW);
actDlg.BringWindowToTop();
CMessageLoop _Loop ;
if(_MyAppModule.AddMessageLoop(&_Loop))
{
CreateAnObject(); //this also launches an object Specific Worker Thread
nRet = _Loop.Run();
_MyAppModule.RemoveMessageLoop();
}
The function CreateAnObject calls some functions from a 'ComplexObject.DLL' that create an complex object which holds the THREAD ID of the thread that called the CREATION function, it gets it with ::GetCurrentThreadId(); , while creating this complex object the GetCurrentThreadId() returns the ID of the SECOND THREAD, which is GOOD.
Now, in my CActionDialog I receive notifications from this object usind ::SendMessage(), the SendMessage function is called from within a Worker thread that is specific to the Complex Object just created.
When I receive those notifications I need to access some of that complex object values, for that I call some other functions from 'ComplexObject.DLL' which verify using the ::GetCurrentThreadId() function that the ID of the calling thread is the same as the ID of thread that created that complex object. That verification fails for me, because the functions get called using the thread ID of the MAIN THREAD, that has the Main interface GUI.
Why is that? I cannot understand! (I hope I successfully explained myself).
The problem you seem to have, from your description at least, is that whatever external API you are using via CreateAnObject, it restricts its further use to creation thread. Taking it as is, you are limited to making calls from the creation thread only. Whenever your code running on other theads, including thread hosting CWarningDlg, needs to talk to this API, you need to transfer the call to the CActionDlg thread and proceed from there.
Synchronization can be SendMessage you already do, or something safer like PostMessage with event/message completion notification.
I am using Canon SDK to get the events from the camera. In the SDK, we register a callback function, which is called when a particular event occurs. I have built a Java wrapper, which communicates with the SDK.
But when the event is triggered, my window doesn't get the event directly. Infact on windows, this is how I get the event and dispatch it to myself:
private static final User32 lib = User32.INSTANCE;
boolean hasMessage = lib.PeekMessage( msg, null, 0, 0, 1 ); // peek and remove
if( hasMessage ){
lib.TranslateMessage( msg );
lib.DispatchMessage( msg ); //message gets dispatched and hence the callback function is called
}
Basically one peeps if the window has received an event or not and then proceeds. On Mac, one can do it using Cocoa by having a NSApplication and WindowServer sends events if any.
I am looking for similar alternative using X11. Any sample code/link will suffice.
PS: This a follow up question to this.
I suppose you are looking for XPeekEvent. The Xlib is very well documented and the manpage for XNextEvent(3) says:
The XPeekEvent function returns the first event from the event queue,
but it does not remove the event from the queue. If the queue is
empty, XPeekEvent flushes the output buffer and blocks until an event
is received. It then copies the event into the client-supplied XEvent
structure without removing it from the event queue.
Example code for displaying a basic Xwindow and a main event loop for handling events can be found (for example) on wikibooks.
I want to capture audio from the microphone of an iOS device and write it to a .caf file.
I'm able to connect a Remote IO audio unit to a multichannel mixer unit (MCMU) and attach a callback to the input of the MCMU. Inside that callback I can successfully write the audio data from the mic to a file using ExtAudioFileAsyncWrite().
I want to simplify things and remove the MCMU from the picture. My thinking is I can simply attach a callback to the output bus of the Remote IO's input scope and inside that callback call ExtAudioFileAsyncWrite().
However when I try this ExtAudioFileAsyncWrite() returns a -50 (paramError).
Is it not possible to attach a callback to the output bus of the input element of the Remote IO?
It is possible. You'll want to use AudioUnitSetProperty to set the kAudioOutputUnitProperty_SetInputCallback property. This callback will function much like a render callback, but will be called whenever the RemoteIO / mic has some new data for you (instead of as a request for data from your program).
Example:
AURenderCallbackStruct callbackInfo = {YourInputCallback, NULL};
AudioUnitSetProperty(remoteIO,
kAudioOutputUnitProperty_SetInputCallback,
kAudioUnitScope_Global,
0,
&callbackInfo,
sizeof(callbackInfo));
This will make the RemoteIO / mic call YourInputCallback whenever it has a new batch of samples. You can use this callback to call ExtAudioFileWriteAsync as you did before. Note that you'll have to call AudioUnitRender on the RemoteIO as well, to get the new samples out of it.
Regarding the -50 error, that's not a very helpful error diagnostic. It basically just says "there was an error with one of your parameters". Most likely your ExtAudioFile was NULL or not set up properly (in which case, one of the ExtAudioFile* functions you used on it earlier would have returned a more helpful error code you can use to diagnose it).