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Select best resolution available #906

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Select best resolution available #906

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8ca5936
select the best resolution available that is closest to the surface v…
May 22, 2020
072135e
Merge branch 'master' into dev-resolution-select
Redth Jan 18, 2021
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200 changes: 140 additions & 60 deletions ZXing.Net.Mobile/Android/CameraAccess/CameraController.android.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -8,6 +8,7 @@
using Android.Runtime;
using Android.Views;
using ApxLabs.FastAndroidCamera;
using Xamarin.Essentials;
using Camera = Android.Hardware.Camera;

namespace ZXing.Mobile.CameraAccess
Expand All @@ -20,6 +21,7 @@ public class CameraController
readonly CameraEventsListener cameraEventListener;
int cameraId;
IScannerSessionHost scannerHost;
bool needResetCameraBuffers = false;

public CameraController(SurfaceView surfaceView, CameraEventsListener cameraEventListener, IScannerSessionHost scannerHost)
{
Expand All @@ -35,16 +37,27 @@ public CameraController(SurfaceView surfaceView, CameraEventsListener cameraEven
public CameraResolution CameraResolution { get; private set; }

public int LastCameraDisplayOrientationDegree { get; private set; }
public static int LastPreviewWidth { get; private set; }
public static int LastPreviewHeight { get; private set; }

public void RefreshCamera()
{
if (holder == null) return;

ApplyCameraSettings();

try
{
ApplyCameraSettings();

Camera.SetPreviewDisplay(holder);

//if ApplyCameraSettings detected a resolution change
//the camera was re-created and we need to reset the buffer and re-set the preview callback
if (needResetCameraBuffers)
{
SetupCameraBuffers();
Camera.SetNonMarshalingPreviewCallback(cameraEventListener);
needResetCameraBuffers = false;
}
Camera.StartPreview();
}
catch (Exception ex)
Expand All @@ -53,6 +66,21 @@ public void RefreshCamera()
}
}

void SetupCameraBuffers()
{
var previewParameters = Camera.GetParameters();
var previewSize = previewParameters.PreviewSize;
var bitsPerPixel = ImageFormat.GetBitsPerPixel(previewParameters.PreviewFormat);

var bufferSize = (previewSize.Width * previewSize.Height * bitsPerPixel) / 8;
const int NUM_PREVIEW_BUFFERS = 5;
for (uint i = 0; i < NUM_PREVIEW_BUFFERS; ++i)
{
using (var buffer = new FastJavaByteArray(bufferSize))
Camera.AddCallbackBuffer(buffer);
}
}

public void SetupCamera()
{
if (Camera != null)
Expand All @@ -64,29 +92,14 @@ public void SetupCamera()

if (Camera == null) return;

perf = PerformanceCounter.Start();
ApplyCameraSettings();
perf = PerformanceCounter.Start();

try
{
ApplyCameraSettings();
Camera.SetPreviewDisplay(holder);


var previewParameters = Camera.GetParameters();
var previewSize = previewParameters.PreviewSize;
var bitsPerPixel = ImageFormat.GetBitsPerPixel(previewParameters.PreviewFormat);


var bufferSize = (previewSize.Width * previewSize.Height * bitsPerPixel) / 8;
const int NUM_PREVIEW_BUFFERS = 5;
for (uint i = 0; i < NUM_PREVIEW_BUFFERS; ++i)
{
using (var buffer = new FastJavaByteArray(bufferSize))
Camera.AddCallbackBuffer(buffer);
}

SetupCameraBuffers();
Camera.StartPreview();

Camera.SetNonMarshalingPreviewCallback(cameraEventListener);
}
catch (Exception ex)
Expand Down Expand Up @@ -215,6 +228,41 @@ void OpenCamera()
}
}

CameraResolution GetResolutionForCameraPreview(IList<Camera.Size> supportedPreviewSizes)
{
CameraResolution resolution = null;

if (supportedPreviewSizes != null)
{
var availableResolutions = supportedPreviewSizes.Select(sps => new CameraResolution
{
Width = sps.Width,
Height = sps.Height
});

// Try and get a desired resolution from the options selector
resolution = scannerHost.ScanningOptions.GetResolution(availableResolutions.ToList());

// If the user did not specify a resolution, let's try and find a suitable one
if (resolution == null)
{
resolution = GetOptimalResolutionForCameraPreview(supportedPreviewSizes);
}
}

// Google Glass requires this fix to display the camera output correctly
if (Build.Model.Contains("Glass"))
{
resolution = new CameraResolution
{
Width = 640,
Height = 360
};
}

return resolution;
}

void ApplyCameraSettings()
{
if (Camera == null)
Expand All @@ -226,6 +274,23 @@ void ApplyCameraSettings()
if (Camera == null) return;

var parameters = Camera.GetParameters();

//Get the resolution first to see if it has changed
//if it has changed the camera needs to be destroyed and re-created
//so that the buffer size can be updated
//because GetOptimalResolutionForCameraPreview uses the SurfaceView size and its dimensions
//will likely change upon rotation especially when using a ZXingScannerFragment
var resolution = GetResolutionForCameraPreview(parameters.SupportedPreviewSizes);
if (LastPreviewWidth != 0 && LastPreviewHeight != 0 && (resolution.Width != LastPreviewWidth || resolution.Height != LastPreviewHeight))
{
needResetCameraBuffers = true;
ShutdownCamera();
LastPreviewHeight = 0;
LastPreviewWidth = 0;
ApplyCameraSettings();
return;
}

parameters.PreviewFormat = ImageFormatType.Nv21;

var supportedFocusModes = parameters.SupportedFocusModes;
Expand Down Expand Up @@ -254,64 +319,79 @@ void ApplyCameraSettings()
parameters.SetPreviewFpsRange(selectedFps[0], selectedFps[1]);
}

CameraResolution resolution = null;
var supportedPreviewSizes = parameters.SupportedPreviewSizes;
if (supportedPreviewSizes != null)
{
var availableResolutions = supportedPreviewSizes.Select(sps => new CameraResolution
{
Width = sps.Width,
Height = sps.Height
});

// Try and get a desired resolution from the options selector
resolution = scannerHost.ScanningOptions.GetResolution(availableResolutions.ToList());

// If the user did not specify a resolution, let's try and find a suitable one
if (resolution == null)
{
foreach (var sps in supportedPreviewSizes)
{
if (sps.Width >= 640 && sps.Width <= 1000 && sps.Height >= 360 && sps.Height <= 1000)
{
resolution = new CameraResolution
{
Width = sps.Width,
Height = sps.Height
};
break;
}
}
}
}

// Google Glass requires this fix to display the camera output correctly
if (Build.Model.Contains("Glass"))
{
resolution = new CameraResolution
{
Width = 640,
Height = 360
};
// Glass requires 30fps
parameters.SetPreviewFpsRange(30000, 30000);
}

// Hopefully a resolution was selected at some point
if (resolution != null)
{
Android.Util.Log.Debug(MobileBarcodeScanner.TAG,
"Selected Resolution: " + resolution.Width + "x" + resolution.Height);

Android.Util.Log.Debug(MobileBarcodeScanner.TAG, "Selected Resolution: " + resolution.Width + "x" + resolution.Height);
CameraResolution = resolution;

parameters.SetPreviewSize(resolution.Width, resolution.Height);
LastPreviewWidth = resolution.Width;
LastPreviewHeight = resolution.Height;
}

Camera.SetParameters(parameters);

SetCameraDisplayOrientation();
}

/// <summary>
/// Determines the resolution to use for the camera preview that maintains the closest available
/// aspect ratio to the surface view the camera is being displayed on.
/// using the surface view is especially important if a fragment is being used which may have a much different ratio than the main display
/// </summary>
/// <param name="availableResolutions">Contains all available combinations that camera can use. Dimensions are assuming the camera is in landscape orientation</param>
/// <returns></returns>
CameraResolution GetOptimalResolutionForCameraPreview(IList<Camera.Size> availableResolutions)
{
CameraResolution res = null;
var sortedOptimalResolultionResults = new SortedDictionary<double, CameraResolution>();

var surfaceViewRatio = surfaceView.Height / (double)surfaceView.Width;

//the SupportedPreviewSizes from the camera are already sorted highest resolution to smallest,
//but in case a non-sorted list is passed in, sort them
var sortedResolutions = availableResolutions.OrderByDescending(r => r.Height).ToList();
for (var i = 0; i < sortedResolutions.Count; i++)
{
double resolutionDifference;
var r = sortedResolutions[i];

//The Android.Hardware.Camera.Size class assumes all dimensions are with respect to a landscape orientation
//so if orientation is portrait switch them
var orientationHeight = r.Width;
var orientationWidth = r.Height;

//and if its landscape leave alone
if (DeviceDisplay.MainDisplayInfo.Orientation == DisplayOrientation.Landscape)
{
orientationHeight = r.Height;
orientationWidth = r.Width;
}

var cameraDisplayAspectRatio = orientationHeight / orientationWidth;

resolutionDifference = Math.Abs(surfaceViewRatio - cameraDisplayAspectRatio);

//since the Android.Hardware.Camera API lives in the UpsideDown world switch the width/height back
if (DeviceDisplay.MainDisplayInfo.Orientation == DisplayOrientation.Portrait)
res = new CameraResolution() { Width = (int)orientationHeight, Height = (int)orientationWidth };
else res = new CameraResolution() { Width = (int)orientationWidth, Height = (int)orientationHeight };

//there may be resolutions available that have the same aspect ratio.
//by using the sorted list we will guarantee that we are getting the best resolution available
if (!sortedOptimalResolultionResults.ContainsKey(resolutionDifference))
sortedOptimalResolultionResults.Add(resolutionDifference, res);
}
return sortedOptimalResolultionResults.First().Value;
}

void AutoFocus(int x, int y, bool useCoordinates)
{
if (Camera == null) return;
Expand Down