How can i scale my application on different displays (sizes) in same manner and proportions?
(I tried compatible-mode, different styles with different font sizes, but it did not suit me)
When i got task for scaling application that was built for Nexus7 (7 inches) to device with 14' display after many hours researching i found best way to do that. I override standard configuration and displayMetrics while my Application is initializing. Look at the code sample:
//change dinsity for xlarge with mdpi displays for same proportions as Nexus7
if (context.getResources().getBoolean(R.bool.bool_screen_xlarge)) {
// final int densityValue = DisplayMetrics.DENSITY_LOW; //120
// final int densityValue = DisplayMetrics.DENSITY_MEDIUM; //160
// final int densityValue = 213; //213 Nexus 7 2012
// final int densityValue = DisplayMetrics.DENSITY_HIGH; //240
final int densityValue = DisplayMetrics.DENSITY_XHIGH; //320
final float densityFactor = (float) densityValue / DisplayMetrics.DENSITY_DEFAULT; //1.5f for example
Resources resources = context.getResources();
DisplayMetrics displayMetrics = resources.getDisplayMetrics();
Configuration configuration = resources.getConfiguration();
configuration.fontScale = densityFactor;
if (Build.VERSION.SDK_INT > Build.VERSION_CODES.JELLY_BEAN) configuration.densityDpi = densityValue;
displayMetrics.xdpi = densityValue * (displayMetrics.xdpi / displayMetrics.densityDpi);
displayMetrics.ydpi = densityValue * (displayMetrics.ydpi / displayMetrics.densityDpi);
displayMetrics.density = densityFactor;
displayMetrics.densityDpi = densityValue;
displayMetrics.scaledDensity = densityFactor;
}
This code you should put to Application::onCreate() method.
R.bool.bool_screen_xlarge - is variable in different resource directories (res/value, res/value-xlarge-mdpi and so on) for simple recognizing current display metrics.
Related
I have been trying to use NDI SDK 4.5, in a Objective-C iOS-13 app, to broadcast camera capture from iPhone device.
My sample code is in public Github repo: https://github.com/bharatbiswal/CameraExampleObjectiveC
Following is how I send CMSampleBufferRef sampleBuffer:
CVPixelBufferRef pixelBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
NDIlib_video_frame_v2_t video_frame;
video_frame.xres = VIDEO_CAPTURE_WIDTH;
video_frame.yres = VIDEO_CAPTURE_HEIGHT;
video_frame.FourCC = NDIlib_FourCC_type_UYVY; // kCVPixelFormatType_420YpCbCr8BiPlanarFullRange
video_frame.line_stride_in_bytes = VIDEO_CAPTURE_WIDTH * VIDEO_CAPTURE_PIXEL_SIZE;
video_frame.p_data = CVPixelBufferGetBaseAddress(pixelBuffer);
NDIlib_send_send_video_v2(self.my_ndi_send, &video_frame);
I have been using "NewTek NDI Video Monitor" to receive the video from network. However, even though it shows as source, the video does not play.
Has anyone used NDI SDK in iOS to build broadcast sender or receiver functionalities? Please help.
You should use kCVPixelFormatType_32BGRA in video settings. And NDIlib_FourCC_type_BGRA as FourCC in NDIlib_video_frame_v2_t.
Are you sure about your VIDEO_CAPTURE_PIXEL_SIZE ?
When I worked with NDI on macos I had the same black screen problem and it was due to a wrong line stride.
Maybe this can help : https://developer.apple.com/documentation/corevideo/1456964-cvpixelbuffergetbytesperrow?language=objc ?
Also it seems the pixel formats from core video and NDI don't match.
On the core video side you are using Bi-Planar Y'CbCr 8-bit 4:2:0, and on the NDI side you are using NDIlib_FourCC_type_UYVY which is Y'CbCr 4:2:2.
I cannot find any Bi-Planar Y'CbCr 8-bit 4:2:0 pixel format on the NDI side.
You may have more luck using the following combination:
core video: https://developer.apple.com/documentation/corevideo/1563591-pixel_format_identifiers/kcvpixelformattype_420ypcbcr8planarfullrange?language=objc
NDI: NDIlib_FourCC_type_YV12
Hope this helps!
In my experience, you have two mistake. To use CVPixelBuffer's CVPixelBufferGetBaseAddress, the CVPixelBufferLockBaseAddress method must be called first. Otherwise, it returns a null pointer.
https://developer.apple.com/documentation/corevideo/1457128-cvpixelbufferlockbaseaddress?language=objc
Secondly, NDI does not support YUV420 biplanar. (The default format for iOS cameras.) More precisely, NDI only accepts one data pointer. In other words, you have to merge the biplanar memory areas into one, and then pass it in NV12 format. See the NDI document for details.
So your code should look like this: And if sending asynchronously instead of NDIlib_send_send_video_v2, a strong reference to the transferred memory area must be maintained until the transfer operation by the NDI library is completed.
CVPixelBufferRef pixelBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
CVPixelBufferLockBaseAddress(pixelBuffer, 0);
int width = (int)CVPixelBufferGetWidth(pixelBuffer);
int height = (int)CVPixelBufferGetHeight(pixelBuffer);
OSType pixelFormat = CVPixelBufferGetPixelFormatType(pixelBuffer);
NDIlib_FourCC_video_type_e ndiVideoFormat;
uint8_t* pixelData;
int stride;
if (pixelFormat == kCVPixelFormatType_32BGRA) {
ndiVideoFormat = NDIlib_FourCC_type_BGRA;
pixelData = (uint8_t*)CVPixelBufferGetBaseAddress(pixelBuffer); // Or copy for asynchronous transmit.
stride = width * 4;
} else if (pixelFormat == kCVPixelFormatType_420YpCbCr8BiPlanarFullRange) {
ndiVideoFormat = NDIlib_FourCC_type_NV12;
pixelData = (uint8_t*)malloc(width * height * 1.5);
uint8_t* yPlane = (uint8_t*)CVPixelBufferGetBaseAddressOfPlane(pixelBuffer, 0);
int yPlaneBytesPerRow = (int)CVPixelBufferGetBytesPerRowOfPlane(pixelBuffer, 0);
int ySize = yPlaneBytesPerRow * height;
uint8_t* uvPlane = (uint8_t*)CVPixelBufferGetBaseAddressOfPlane(pixelBuffer, 1);
int uvPlaneBytesPerRow = (int)CVPixelBufferGetBytesPerRowOfPlane(pixelBuffer, 1);
int uvSize = uvPlaneBytesPerRow * height;
stride = yPlaneBytesPerRow;
memcpy(pixelData, yPlane, ySize);
memcpy(pixelData + ySize, uvPlane, uvSize);
} else {
return;
}
NDIlib_video_frame_v2_t video_frame;
video_frame.xres = width;
video_frame.yres = height;
video_frame.FourCC = ndiVideoFormat;
video_frame.line_stride_in_bytes = stride;
video_frame.p_data = pixelData;
NDIlib_send_send_video_v2(self.my_ndi_send, &video_frame); // synchronous sending.
CVPixelBufferUnlockBaseAddress(pixelBuffer, 0);
// For synchrnous sending case. Free data or use pre-allocated memory.
if (pixelFormat == kCVPixelFormatType_420YpCbCr8BiPlanarFullRange) {
free(pixelData);
}
I have a desktop Qt-based application that fetches a sound stream from the network and plays it using QAudioOutput. I want to provide a volume control to the user so that he can reduce the volume. My code looks like this:
float volume_control = get_user_pref(); // user provided volume level {0.0,1.0}
for (;;) {
AVPacket *retrieved_pkt = get_decoded_packet_stream(); // from network stream
AVPacket *work_pkt
= change_volume(retrieved_pkt, volume_control); // this is what I need
// remaining code to play the work_pkt ...
}
How do I implement change_volume() or is there any off the shelf function that I can use?
Edit: Adding codec-related info as requested in the comments
QAudioFormat format;
format.setFrequency(44100);
format.setChannels(2);
format.setSampleSize(16);
format.setCodec("audio/pcm");
format.setByteOrder(QAudioFormat::LittleEndian);
format.setSampleType(QAudioFormat::SignedInt);
The following code works just fine.
// audio_buffer is a byte array of size data_size
// volume_level is a float between 0 (silent) and 1 (original volume)
int16_t * pcm_data = (int16_t*)(audio_buffer);
int32_t pcmval;
for (int ii = 0; ii < (data_size / 2); ii++) { // 16 bit, hence divided by 2
pcmval = pcm_data[ii] * volume_level ;
pcm_data[ii] = pcmval;
}
Edit: I think there is a significant scope of optimization here, since my solution is compute-intensive. I guess avcodec_decode_audio() can be used to speed it up.
I have a USB weighing from stamps.com (Model 510: http://www.stamps.com/postage-online/digital-postage-scales/)
I was able to find the drivers to make it stand alone online, but my next question is how do I read the weight of the object on the scale in my classic ASP page / VBScript.
Does anyone have any suggestions where I should begin my search?
I'm not sure if this is applicable to your specific model but there's an article at http://nicholas.piasecki.name/blog/2008/11/reading-a-stamps-com-usb-scale-from-c-sharp/ where the author has written C# code to read from the scale because it conforms to basic USB HID (human input device) standards. The author made use of Mike OBrien's HID library https://github.com/mikeobrien/HidLibrary
They start off getting the raw bytes:
HidDeviceData inData;
HidDevice[] hidDeviceList;
HidDevice scale;
hidDeviceList = HidDevices.Enumerate(0x1446, 0x6A73);
if (hidDeviceList.Length > 0)
{
int waitTries;
scale = hidDeviceList[0];
waitTries = 0;
scale.Open();
if (scale.IsConnected)
{
inData = scale.Read(250);
for (int i = 0; i < inData.Data.Length; ++i)
{
Console.WriteLine("Byte {0}: {1:X}", i, inData.Data[i]);
}
}
scale.Close();
scale.Dispose();
}
Then go on to reverse engineer the payload and construct a function to get the weight in ounces:
private void GetStampsComModel2500iScaleWeight(out decimal? ounces, out bool? isStable)
{
HidDeviceData inData;
HidDevice[] hidDeviceList;
HidDevice scale;
isStable = null;
ounces = null;
hidDeviceList = HidDevices.Enumerate(0x1446, 0x6A73);
if (hidDeviceList.Length > 0)
{
int waitTries;
scale = hidDeviceList[0];
waitTries = 0;
scale.Open();
// For some reason, the scale isn't always immediately available
// after calling Open(). Let's wait for a few milliseconds before
// giving up.
while (!scale.IsConnected && waitTries < 10)
{
Thread.Sleep(50);
waitTries++;
}
if (scale.IsConnected)
{
inData = scale.Read(250);
ounces = (Convert.ToDecimal(inData.Data[4]) +
Convert.ToDecimal(inData.Data[5]) * 256) / 10;
isStable = inData.Data[1] == 0x4;
}
scale.Close();
scale.Dispose();
}
}
In order to read the weight from your classic ASP page/VBScript (on the server, right?) the easiest solution looks to be turning the working C# class into a COM component. There are tutorials you can follow to create the C# COM Component and register it on the server, then you would call it from VBScript like:
Dim app
Set app = Server.CreateObject("MyScaleComponent")
I'm writing a program to solve an 8 tile sliding puzzle for an AI class. in theory this is pretty easy, but the number of node states generated is pretty large (estimated 180,000 or so). We're comparing different heuristic functions in class, so my code has to be able to handle even some very inefficient functions. I'm getting "OutOfMemoryError: Java heap space" when using java's PriorityQueue class. Heres the relevant code withing my solver function: (the error is on the openList.add(temp); line)
public void solve(char[] init,int searchOrder)
{
State initial = new State(init,searchOrder); //create initial state
openList = new PriorityQueue<State>(); //create open list
closedList = new LinkedList<State>(); // create closed list
generated = new HashSet(); //Keeps track of all nodes generated to cut down search time
openList.add(initial); //add initial state to the open list
State expanded,temp = null,solution = null; //State currently being expanded
int nodesStored = 0, nodesExpanded = 0;
boolean same; //used for checking for state redundancy
TreeGeneration:
while(openList.size() > 0)
{
expanded = openList.poll();
closedList.addLast(expanded);
for (int k = 0; k < 4; k++)
{
if (k == 0)
{
temp = expanded.moveLeft();
}
else if (k == 1)
{
temp = expanded.moveRight();
}
else if (k == 2)
{
temp = expanded.moveAbove();
}
else
{
temp = expanded.moveBelow();
}
if(temp.isSolution())
{
solution = temp;
nodesStored = openList.size() + closedList.size();
nodesExpanded = closedList.size();
break TreeGeneration;
}
if(!generated.contains(temp))
{
// System.out.println(temp.toString());
openList.add(temp); // error here
generated.add(temp);
}
// System.out.println(openList.toString());
}
}
Am I doing something wrong here, or should I be using something else to handle this quantity of data? Thanks.
By default, JVM starts with 64 MB heap space, you can increase this amount by passing a parameter like below;
java -Xmx1024m YOUR_CLASS
this gives 1024 MB heap space in memory, you can change the amount of memory as you need.
If you are using NetBeans, Netbeans doesn't scale heap space automatically, you can achieve this by following below steps;
1- Right click on your project
2- Navigate to Set Configuration -> Customize
3-Add -Xmx256m into VM Options then click Ok
Now, you can run your project with custom heap space.
Here's a stupid question.
How do you read files in a playn game? I tried using File and Scanner like I usually do in a standard java program:
void readFromFile(){
int x;
int y;
int pixel;
int[][] board;
try{
Scanner scan = new Scanner(new File(in));
x = scan.nextInt();
y = scan.nextInt();
pixel = scan.nextInt();
Point start = new Point(scan.nextInt(), scan.nextInt());
Point dir = new Point(scan.nextInt(), scan.nextInt());
Point end = new Point(scan.nextInt(), scan.nextInt());
int antRoads = scan.nextInt();
board = new int[x][y];
for (int i = 0; i < y; i++){
for (int j = 0; j < x; j++){
board[i][j] = scan.nextInt();
}
}
lev = new Level(board, start, dir, end, antRoads, pixel, x, y);
} catch(FileNotFoundException e){
System.out.println(e);
}
}
I tested File.canRead(), canWrite() and can Execute() and they all returned false.
Am I supposed to use assetMannager().getText() or something? If that's the case can someone tell me how it works? (or what is and how ResourceCallback works?)
My goal is to have a folder named "Maps" filled with maps in regular text-format just like the standard Image folder.
Regards,
Torgeir
You cannot do normal file I/O in a PlayN game, because the games are compiled into JavaScript and run in the browser (when using the HTML5 backend), and the browser supports no file I/O (at least not the general purpose file I/O you would need for these purposes).
Browsers also do not even support the idea of a byte stream, or any sort of binary I/O (this may eventually arrive, but it will be ages before it's supported for all browsers).
So you have to use AssetManager.getText to read data files. You can encode them in JSON if you like and use PlayN.json() to decode them, or you can use your own custom string-based format.
If you don't plan to deploy using the HTML5 backend, you can create a "LevelReader" interface and implement that interface in your Android or iOS backend and make use of the native file I/O capabilities on those platforms.