CWAC-Camera: Taking Pictures. Made (Somewhat) Sensible.

Taking pictures or videos using a third-party app is fairly straightforward, using ACTION_IMAGE_CAPTURE or ACTION_VIDEO_CAPTURE. However, you as the developer have little control over what happens with the image or video, other than indicating where the result gets stored. Plus, different camera apps have slightly different behavior, meaning that you are prone to getting inconsistent results.

Taking pictures or videos using the built-in Camera class directly is eminently possible, but is full of edge and corner cases, not to mention its own set of per-device idiosyncracies. As a result, a ton of code is required to successfully show a preview, take a picture, and take a video.

CWAC-Camera is an effort to standardize that "ton of code" and hide it behind a scalable API. Here, "scalable" means "simple things are simple, but complex things may be a bit complex".

In addition to what is written here, JavaDocs are also available.

Library Objectives

The #1 objective of this library is maximum compatibility with hardware. As such, this library will not be suitable for all use cases.

The targeted use case is an app that might otherwise have relied upon ACTION_IMAGE_CAPTURE, but needs greater reliablilty and somewhat greater control (e.g., capture images directly to internal storage).

If you are trying to write "a camera app" — an app whose primary job is to take pictures — this library may be unsuitable for you.

Installation

If you are using Gradle, or otherwise can use AAR artifacts, there are two such artifacts, mirroring the contents of the two project JARs: one for native API Level 11 fragments, one for ActionBarSherlock.

To integrate the core AAR, the Gradle recipe is:

repositories {
    maven {
        url "https://repo.commonsware.com.s3.amazonaws.com"
    }
}

dependencies {
    compile 'com.commonsware.cwac:camera:0.6.+'
}

To integrate the -v9 AAR for ActionBarSherlock support, the Gradle recipe is:

repositories {
    mavenCentral();

    maven {
        url "https://repo.commonsware.com.s3.amazonaws.com"
    }
}

dependencies {
    compile('com.commonsware.cwac:camera-v9:0.6.+') {
      exclude module: 'support-v4'
    }

    compile 'com.android.support:support-v4:18.0.+'
}

(where you can choose your own version number for the support-v4 dependency as desired)

You are also welcome to clone this repo and use camera/ and camera-v9/ as Android library projects in source form.

If you are using Eclipse, Ant, or otherwise need JAR files, there are two JARs in the releases area of the repo:

  • cwac-camera-X.Y.Z.jar represents the core classes, used in all environments
  • cwac-camera-v9-X.Y.Z.jar adds support for ActionBarSherlock

(where X.Y.Z is the version number of the project, such as 0.6.10)

NOTE: The JAR name, as of v0.6.8, has a cwac- prefix, to help distinguish it from other JARs.

Users of the JARs will also want to copy the contents of the camera/res/xml/ directory into their project, as that directory contains XML resources that help the library deal with device-specific idiosyncrasies.

Note that the JAR format for this project will be discontinued when the library reaches version 1.0. That will not be until mid-2014, but it is something that you should keep in mind.

If you are upgrading a project using CWAC-Camera to a new edition of the library, please see the "Upgrading" section below.

Basic Usage

Step #1: Install the JARs or AARs as described above.

Step #2: Add a CameraFragment to your UI. You have two versions of CameraFragment to choose from:

  • com.commonsware.cwac.camera.CameraFragment for use with native API Level 11+ fragments

  • com.commonsware.cwac.camera.acl.CameraFragment for use with the Android Support package's backport of fragments and ActionBarSherlock, supporting API Level 9 and 10

(note: if you choose the latter, your project will also need to have the ActionBarSherlock library project)

The CameraFragment is responsible for rendering your preview, so you need to size and position it as desired.

Step #3: Call takePicture() on the CameraFragment when you want to take a picture, which will be stored in the default digital photos directory (e.g., DCIM) on external storage as Photo_yyyyMMdd_HHmmss.jpg, where yyyyMMdd_HHmmss is replaced by the current date and time. Note that takePicture() can throw an IllegalStateException if you call it before the preview is ready or if you call it while auto-focus is occurring.

Step #3b: Call startRecording() and stopRecording() on the CameraFragment to record a video. NOTE that this is presently only available on com.commonsware.cwac.camera.CameraFragment for use with native API Level 11+ fragments. The resulting video will be stored in the default videos directory (e.g., Movies) on external storage as Video_yyyyMMdd_HHmmss.mp4, where yyyyMMdd_HHmmss is replaced by the current date and time.

Step #4: Add appropriate <uses-permission> elements to your manifest. For what is described in the preceding steps, you would need the CAMERA, RECORD_AUDIO, and WRITE_EXTERNAL_STORAGE permissions. RECORD_AUDIO is for the video recording using startRecording(); if you are only taking still photos, you will not need that permission.

And that's it.

CameraFragment (and its underlying CameraView) will handle:

  • Showing the preview using an optimal preview frame size, and managing the aspect ratio of the on-screen preview View so that your previews do not appear stretched

  • Dealing with configuration changes and screen rotation, so your camera activity can work in portrait or landscape

  • Following the appropriate recipes for taking still pictures and videos, including choosing the largest-available image size for the resolution

  • Opening and closing the camera at the appropriate times, so when you are in the foreground you have exclusive camera access, but other apps will have access to the camera while your activity is not in the foreground

  • And more!

Simple Configuration and Usage

Of course, there are probably plenty of things that you will want to configure about the process of taking photos and videos. There are many hooks in CWAC-Camera to allow you to do just that.

Much of this configuration involves creating a custom CameraHost. CameraHost is your primary interface with the CWAC-Camera classes for configuring the behavior of the camera. CameraHost is an interface, one that you are welcome to implement in full. Most times, though, you will be better served extending SimpleCameraHost, the default implementation of CameraHost, so that you can override only those methods where you want behavior different from the default.

SimpleCameraHost also offers SimpleCameraHost.Builder that you can use for some simple configuration, instead of creating a subclass of SimpleCameraHost and overriding methods. Create an instance of the Builder (passing in a Context to the constructor, such as your activity), call the various builder-style setters for configuration, and call build() to get your customized SimpleCameraHost instance.

You can pass your customized instance of CameraHost to setHost() on your CameraFragment, to replace the default. Do this in onCreate() of a CameraFragment subclass (or, if practical, just after instantiating your fragment) to ensure that the right CameraHost is used everywhere.

PictureTransaction

The takePicture() method has a zero-argument version that just takes a picture. It also has a one-argument version, where the argument is an instance of PictureTransaction. This will allow you to configure details of this particular picture to be taken. You can create a PictureTransaction using its constructor, which takes an instance of your CameraHost as a parameter.

Various sections below will mention using builder-style setters on PictureTransaction to control how a picture is taken.

PictureTransaction has a tag(Object) method that allow you to attach arbitrary data to the transaction, without having to bother with a subclass. You can retrieve that object later via the zero-argument tag() method.

Controlling the Names and Locations of Output Files

There are a series of methods that you can override on SimpleCameraHost to control where photos and videos are stored once taken. These methods will be called for each takePicture() or startRecording() call, so you can create customized results for each distinct photo or video.

Specifically:

  • Override getPhotoFilename() to return the base name of the file to use to store the photo

  • Override getPhotoDirectory() to return the name of the directory in which to store the photo

  • Override getPhotoPath() to return the complete File object pointing to the desired file in the desired directory (the default implementation combines the results of getPhotoDirectory() and getPhotoFilename(), so overriding getPhotoPath() replaces all of that)

There are equivalent getVideoFilename(), getVideoDirectory(), and getVideoPath() for controlling the output of the next video to be taken.

SimpleCameraHost.Builder offers photoDirectory() and videoDirectory() setters, where you provide the File pointing to your desired directory.

By default, if you are using SimpleCameraHost, your image will be indexed by the MediaStore. If you do not want this, override scanSavedImage() to return false in your SimpleCameraHost subclass (or, call scanSavedImage() and pass in a boolean to use by default). This is called on a per-image basis.

Controlling Which Camera is Used

If you override useFrontFacingCamera() on SimpleCameraHost to return true, the front-facing camera will be used, instead of the default rear-facing camera. You can also call useFrontFacingCamera() on your SimpleCameraHost.Builder, passing in a boolean default value to use.

Or, override getDeviceId() (available on CameraHost), and you can provide the ID of the specific camera you want. This would involve your choosing an available camera based on your own criteria. See the JavaDocs for Android's Camera class, notably getNumberOfCameras() and getCameraInfo() for more. You can also call deviceId() on SimpleCameraHost to supply the camera ID to use.

Controlling FFC Mirror Correction

By default, the pictures taken from the front-facing camera are a mirror image of what is shown on the preview. If you wish for the front-facing camera photos to match the preview, override mirrorFFC() on your CameraHost and have it return true, and CWAC-Camera will reverse the image for you before saving it. Or, call mirrorFFC() on your SimpleCameraHost.Builder, supplying a boolean value to use as the default. Or, call mirrorFFC() on your PictureTransaction, to control this for an individual picture.

Handling Exceptions

There are some exceptions that are thrown by the Camera class (and kin, like MediaRecorder). Those are passed to your host's handleException() method. The default implementation displays a Toast and logs the message to LogCat as an error, but you probably will want to replace that with something else that integrates better with your UI.

Supporting "Full-Bleed Preview"

The original default behavior of CameraFragment and CameraView was to show the entire preview, as supplied by the underlying Camera API. Since the aspect ratio of the preview frames may be different than the aspect ratio of the CameraView, this results in a "letterbox" effect, where the background will show through on one axis on the sides.

The new default behavior is to completely fill the CameraView, at the cost of cropping off some of the actual preview frame, what is known as "full-bleed preview" (stealing some terminology from the world of print media).

To control this behavior:

  • Have your CameraHost return true or false from useFullBleedPreview()

  • Or, call useFullBleedPreview() on your SimpleCameraHost.Builder, passing in a boolean value to use by default.

Note that the pictures and videos taken by this library are unaffected by useFullBleedPreview(). Hence, if useFullBleedPreview() returns true, the picture or video may contain additional content on the edges that was not visible in the preview.

Wrapping the Preview UI

From a UI standpoint, the CameraFragment solely handles the preview pane. Presumably, you will need more to your UI than this, such as buttons to allow users to take pictures or record videos. You have two major options here:

  1. You can put that UI as a peer to the CameraFragment, such as by having action bar items, as the demo apps do.

  2. You can subclass CameraFragment and override onCreateView(). Chain to the superclass to get the CameraFragment's own UI, then wrap that in your own container with additional widgets, and return the combined UI from your onCreateView(). You can see this in the main demo app, which adds a SeekBar or VerticalSeekBar for zoom levels.

It is also possible to replace onCreateView() completely with your own implementation, or otherwise use CameraView from a layout resource. This is covered later in this document.

Auto-Focus

You can call autoFocus() on CameraFragment or CameraView to trigger any auto-focus behavior that you have configured via setFocusMode() on Camera.Parameters. You can call cancelAutoFocus() on CameraFragment or CameraView to ensure that auto-focus mode has been canceled.

Note that auto-focus is only available in certain conditions, notably when the preview mode is enabled. You can call isAutoFocusAvailable() on CameraFragment or CameraView to determine if auto-focus is presently available for use. Calling autoFocus() when auto-focus is not available will have no effect.

CameraHost implementations will need to implement an onAutoFocus() method, coming from the Camera.AutoFocusCallback interface that CameraHost extends. SimpleCameraHost has a default implementation of onAutoFocus() that plays a device-standard sound upon completion (API Level 16+ only).

CameraHost implementations will also need autoFocusAvailable() and autoFocusUnavailable() methods, to be notified when auto-focus is available or not. This can be used to trigger whether action bar items are enabled, etc. SimpleCameraHost has no-op implementations of these callbacks.

Single-Shot Mode

By default, the result of taking a picture is to return the CameraFragment to preview mode, ready to take the next picture. If, instead, you only need the one picture, or you want to send the user to some other bit of UI first and do not want preview to start up again right away, override useSingleShotMode() in your CameraHost to return true. Or, call useSingleShotMode() on your SimpleCameraHost.Builder, passing in a boolean to use by default. Or, call useSingleShotMode() on your PictureTransaction, to control this for an individual picture.

You will then probably want to use your own saveImage() implementation in your CameraHost to do whatever you want instead of restarting the preview. For example, you could start another activity to do something with the image. However, bear in mind that an Intent is limited to ~1MB, and so passing an image to another activity via a Intent extra is likely to be unreliable. You will need to do something else, such as (carefully) use a static data member.

Preview mode will re-enable automatically after an onPause()/onResume() cycle of your CameraFragment, or you can call restartPreview() on your CameraFragment (or CameraView).

Zoom Support

To zoom the camera, call zoomTo() on the CameraView or CameraFragment, supplying the integer zoom level that you want. This level must be between 0 and what Camera.Parameters returns from getMaxZoom(). The adjustPreviewParameters() callback method in your CameraHost is a good time to get this value and configure your UI (e.g., SeekBar) to allow the user to zoom the camera.

zoomTo() returns a ZoomTransaction. This has a series of builder-style methods (a.k.a., a fluent interface) that allow you to configure the transaction, where the methods return the transaction so you can chain on the next call. The configuration methods are:

  • onComplete() to supply a Runnable to be executed when we have reached the zoom level

  • onChange() to supply a Camera.OnZoomChangeListener to be called as we progress to the desired zoom level

Once configured, call go() to run the transaction.

If the camera supports smooth zoom, the zoom transaction will take a few moments, and you can cancel the operation by calling cancel() on the ZoomTransaction. If the camera does not support smooth zoom, the zoom level is just immediately changed.

Note that your OnZoomChangeListener supplied to onChange() will be called before the onComplete() Runnable, if you happen to supply both.

The main demo app adds a SeekBar and VerticalSeekBar to control zoom levels, so you can see how this is used.

Note that some devices lie about their zoom capabilities. For example, the Motorola RAZR i's front-facing camera apparently does not support zoom, where getMaxZoom() still returns a positive value. doesZoomReallyWork() on your CameraFragment or CameraView will return false if zoom is known to be broken for the current camera on the current device. In this case, do not zoom, or your code may go "boom".

Camera? #FAIL

If getCameraId() of your CameraHost returns a negative value, CameraView will assume that there are no valid cameras (e.g., your app is running on a game console). In addition to avoiding anything that tries to touch the camera, your CameraHost will be called with onCameraFail(), where you will be supplied with a FailureReason of NO_CAMERAS_REPORTED.

If anything else goes wrong when trying to open the camera (e.g., a device admin policy has disabled the camera), your onCameraFail() method will be called with a FailureReason of UNKNOWN.

While SimpleCameraHost has a trivial onCameraFail() implementation (just logging to LogCat), you are strongly encouraged to override this and inform your users of the problem.

Fixing Up Images... And Your Heap

There are a few fixups that the library performs on your images, to provide consistent output. The biggest one is to rotate the image to the proper orientation, rather than rely on EXIF headers, as not all image viewers use those headers.

The problem is that these fixups take a lot of heap space. By default, the library will always try to perform these fixups, and for a high-resolution image on a low-memory device, an OutOfMemoryError may result.

You have two means of managing this, and you are welcome to apply one or both of them:

  1. You can add android:largeHeap="true" to the <application> element of your manifest. On API Level 11+ devices, you will get more heap space, making it more likely that the fixup will succeed. However, this will hurt the user, in that your app will tend to kick other apps out of memory more quickly, which the user may not appreciate.

  2. Your CameraHost can return a value between 0.0f and 1.0f from maxPictureCleanupHeapUsage(). The default implementation on SimpleCameraHost returns 1.0f, which says "the byte[] of image data from the camera can be as big as our heap limit, and we should still try to do the cleanup work". A value of 0.0f would indicate that the cleanup work should never be done, and the images will be saved in their natural state. A value in between represents a portion of the heap space; if the byte[] is that size or smaller, go ahead and try to do the fixups. Note that this determination is made on the compressed JPEG byte[] length, not the size of the decoded Bitmap, and the JPEG may be compressed ~90% compared to its uncompressed size.

Advanced Configuration

In addition to the configuration hooks specified above, you can do more to tailor how photos and videos are taken.

Controlling Preview Sizes

Your CameraHost will be called with getRecordingHint(), to determine if the preview should be optimized for possible video recording, or not (i.e., only still images will be taken). You can return a CameraHost.RecordingHint enum: STILL_ONLY, VIDEO_ONLY, or ANY.

Usually, your CameraHost will be called with getPreviewSize(), where you need to return a valid Camera.Size indicating the desired size of the preview frames. getPreviewSize() is passed:

  • the display orientation, in degrees, with 0 indicating landscape, 90 indicating portrait, etc.

  • the available width and height for the preview

  • the Camera.Parameters object, from which you can determine the valid preview sizes by calling getSupportedPreviewSizes()

The CameraUtils class contains three static methods with stock algorithms for choosing the preview size:

  1. getOptimalPreviewSize() uses the algorithm found in the SDK camera sample app

  2. getBestAspectPreviewSize() finds the preview size that most closely matches the aspect ratio of our available space

  3. getBestAspectPreviewSize(double) finds the preview size that offers the biggest preview size that only differs from the desired aspect ratio by the supplied closeEnough value (closeEnough of 0.0d would give the same results as does getBestAspectPreviewSize())

SimpleCameraHost uses getBestAspectPreviewSize() for the default implementation of getPreviewSize(). You can override getPreviewSize() and substitute in your own selection algorithm. Just make sure that the returned size is one of the ones returned by getSupportedPreviewSizes().

If getRecordingHint() returns ANY or VIDEO_ONLY, though, CameraHost supplies the preview size via getPreferredPreviewSizeForVideo() instead of getPreviewSize(). If you wish to use a different preview size for video, return it, otherwise return null and we will use the results from getPreviewSize() instead. getPreferredPreviewSizeForVideo() is passed a Camera.Size as a hint from the device for a value to use, instead of anything you might get yourself from Camera.Parameters -- while using the hinted value is probably a good idea (if it is not null), it is not required.

Controlling Picture Sizes

Similarly, your CameraHost will be called with getPictureSize(), for you to return the desired Camera.Size of the still images taken by the camera. You are simply passed the Camera.Parameters, on which you can call getSupportedPictureSizes() to find out the possible picture sizes that you can choose from.

The CameraUtils class has a pair of methods for simple algorithms for choosing a picture size:

  1. getLargestPictureSize() returns the Camera.Size that is the largest in area

  2. getSmallestPictureSize() returns the Camera.Size that is the smallest in area

SimpleCameraHost uses getLargestPictureSize() for the default implementation of getPictureSize(). You can override getPictureSize() and substitute in your own selection algorithm. Just make sure that the returned size is one of the ones returned by getSupportedPictureSizes().

Arbitrary Preview Configuration

When setting up the camera preview, your CameraHost will be called with adjustPreviewParameters(), passing in a Camera.Parameters. Here, you can make any desired adjustments to the camera preview, except the preview size (which you should be handling in getPreviewSize()). adjustPreviewParameters() returns the revised Camera.Parameters, where the stock implementation in SimpleCameraHost just returns the passed-in parameters unmodified.

Arbitrary Photo Configuration

Shortly after you call takePicture() on your CameraFragment, your CameraHost will be called with adjustPictureParameters(), passing in a Camera.Parameters. Here, you can make any desired adjustments to the parameters related to taking photos, except the image size (which you should be handling in getPictureSize()). adjustPictureParameters() returns the revised Camera.Parameters, where the stock implementation in SimpleCameraHost just returns the passed-in parameters unmodified.

Arbitrary Video Configuration

Shortly after you call startRecording(), your CameraHost will be called with:

  • configureRecorderAudio()

  • configureRecorderProfile()

  • configureRecorderOutput()

in that order. Here, you can help tailor the way videos get recorded. Each of these is passed the ID of the camera being used for recording plus the MediaRecorder instance that does the actual recording.

The stock SimpleCameraHost does the following:

  • In configureRecorderAudio(), SimpleCameraHost calls setAudioSource(MediaRecorder.AudioSource.CAMCORDER) on the MediaRecorder

  • In configureRecorderProfile(), SimpleCameraHost calls setProfile(CamcorderProfile.get(cameraId, CamcorderProfile.QUALITY_HIGH)) on the MediaRecorder

  • In configureRecorderOutput(), SimpleCameraHost calls setOutputFile(getVideoPath().getAbsolutePath()) on the MediaRecorder (where getVideoPath() was described earlier in this document)

While these are reasonable defaults, you are welcome to override these implementations to do something else.

Overriding Photo Saving

The default SimpleCameraHost logic for saving photos uses the getPhotoPath() and related methods discussed above. Actually saving the photo is done in saveImage(PictureTransaction, byte[]), called on your CameraHost, where SimpleCameraHost has a saveImage(PictureTransaction, byte[]) implementation that writes the supplied byte[] out to the desired location.

You are welcome to override saveImage(PictureTransaction, byte[]) and do something else with the byte[], such as send it over the Internet. saveImage(PictureTransaction, byte[]) is called on a background thread, so you do not have to do your own asynchronous work.

Another use for this is to find out when the saving is complete, so that you can use the resulting image. Just override saveImage(PictureTransaction, byte[]), chain to the superclass implementation, and when that returns, the image is ready for use.

There is also a saveImage(PictureTransaction, Bitmap) callback, giving you a decoded Bitmap instead of a byte[].

By default, saveImage(PictureTransaction, byte[]) will be called, and not saveImage(PictureTransaction, Bitmap). To change this, call needBitmap(boolean) and/or needByteArray(boolean) on your PictureTransaction, passing that PictureTransaction to takePicture().

Note that if you say that you need the Bitmap, you are responsible for the Bitmap (e.g., calling recycle() on it) once it is handed to your host.

Controlling the Shutter Callback

You can subclass PictureTransaction and override onShutter() to do something when the shutter is pressed.

Also, your CameraHost implementation can return a Camera.ShutterCallback object via getShutterCallback(), which will be used in the underlying takePicture() call on the Android Camera, giving you control to play a "shutter click" sound. SimpleCameraHost returns null from getShutterCallback(), to give you the device default behavior.

Detecting Faces

If you wish to use the face detection APIs available on API Level 14+, do the following:

  1. Have your CameraHost implementation also implement Camera.FaceDetectionListener.

  2. Override adjustPreviewParameters() in your CameraHost and take that opportunity to check the value of getMaxNumDetectedFaces(), a method on Camera.Parameters. If that returns 0, face detection is not supported by the device. NOTE: a better API for this may be added in the future.

  3. Override autoFocusAvailable() in your CameraHost, and if face detection is enabled, call startFaceDetection() on your CameraFragment or CameraView. NOTE: a dedicated callback for this may be added in the future — this is a stop-gap to allow this fix to go in a patch release

  4. Similarly, override autoFocusUnavailable() in your CameraHost and, if face detection is enabled, call stopFaceDetection() on your CameraFragment or CameraView. NOTE: a dedicated callback for this may be added in the future.

Note that this capability was added to version 0.5.1 of this library. Also note that, while you can safely call startFaceDetection() and stopFaceDetection() regardless of API level, getMaxNumDetectedFaces() should only be called on API Level 14+ devices, or you will be hit with a VerifyError or the equivalent.

Choosing a DeviceProfile

CameraHost exists to provide a hook for you to determine how your app should handle taking pictures and videos. DeviceProfile, on the other hand, provides information about how the device handles taking pictures and videos. Different devices do slightly different things when working with the camera. Sometimes this is based on API level, sometimes it is based on how the device manufacturer tinkered with Android, and sometimes it is based on the underlying camera hardware. DeviceProfile provides a place for the CWAC-Camera project to isolate these differences.

CameraHost has a getDeviceProfile() method that should return an instance of the DeviceProfile to use for the device that is running the app. The implementation of getDeviceProfile() on SimpleCameraHost calls the static getInstance() method on DeviceProfile, which chooses a DeviceProfile based on internal heuristics. If you encounter problems with certain devices, you can detect those in your getDeviceProfile() method and return a DeviceProfile that addresses your needs, otherwise settling for using the library's own choice of DeviceProfile.

Note that SimpleCameraHost.Builder also has a deviceProfile() setter method that you can call, passing in a DeviceProfile that will be used as the default, replacing the system default.

The stock DeviceProfile is largely driven by XML resources. These resources' names are of the form cwac_camera_profile_XXX_YYY, where XXX is the Build.MANUFACTURER and YYY is the Build.MODEL. Both Build.MANUFACTURER and BUILD.MODEL are converted to lowercase and have non-alphanumeric values converted to underscores, to ensure that we wind up with a valid resource filename. Each of those XML resource files has a <deviceProfile> root element, containing child elements for different values that can be overridden:

  • <doesZoomActuallyWork> (a boolean, true or false) overrides the default zoom detection logic, with false meaning that the device lies and zoom is not really supported

  • <maxPictureHeight> (an integer) is the largest number of pixels high to use for the camera picture; a Camera.Size taller than this is ignored

  • <minPictureHeight> (an integer) is the smallest number of pixels high to use for the camera picture; a Camera.Size shorter than this is ignored

  • <pictureDelay> (an integer) is a time in milliseconds to delay taking the picture after updating Camera.Parameters with the picture settings, for devices that seem to reset themselves when the parameters are updated, resulting in messed-up pictures

  • <portraitFFCFlipped> (a boolean, true or false) indicates if the image cleanup work needs to flip the image if it was taken in portrait mode from the front-facing camera

  • <useDeviceOrientation> (a boolean, true or false) indicates if we should skip the setRotation() call on Camera.Parameters due to a device bug, and instead should just use physical orientation in the image cleanup phase to get the picture to turn out right

  • <useTextureView> (a boolean, true or false) overrides the default choice of whether to use a SurfaceView or a TextureView for the preview, normally driven by API level

  • <recordingHint> (ANY, STILL_ONLY, VIDEO_ONLY) indicates whether we should use a specific type of preview and image capture, based upon the intended use of the Camera (this exists solely to work around some device bugs)

So long as the resource exists with the right filename, the library should pick it up, so you can add ones in your app if needed.

Working Directly with CameraView

If you wish to eschew fragments, you are welcome to work with CameraView directly. To do this:

  • Add it in Java code by calling its one-parameter constructor, taking your Activity as a parameter. At the present time, CameraView does not support being placed in a layout resource.

  • Call setHost() on the CameraView as early as possible, to make sure that the CameraView is working with the right CameraHost implementation. Alternatively, override getHost() and return the right CameraHost there.

  • Forward the onResume() and onPause() lifecycle events from your activity or fragment to the CameraView.

Otherwise, CameraView should work as a regular View... so long as you do not try to use it in a layout resource.

Using CameraView in a Layout Resource

If you want to use CameraView in a layout resource, you can, but your activity will need to implement the CameraHostProvider interface. This has one required method: getCameraHost(), which returns the CameraHost instance to be used with the CameraView. You would implement this in lieu of calling setHost() yourself.

If you want to take advantage of this and use your own layout in a CameraFragment subclass, simply override onCreateView() and do what you want. The only requirement, other than the CameraHostProvider mentioned above, is that your onCreateView() needs to call the setCameraView() method, supplying the CameraView instance to the superclass.

The demo-layout/ directory contains a small sample project that demonstrates this technique.

Flash Modes

CameraView, as well as CameraFragment, has a getFlashMode() which returns the flash mode from Camera.Parameters.

To adjust the flash mode, you can call flashMode() on your PictureTransaction to specify a mode to apply when the picture is taken. Or, call setFlashMode() on CameraView or CameraFragment when needed. Or, you can manually configure the Camera.Parameters object in adjustPictureParameters() and/or adjustPreviewParameters().

The CameraUtils class has a findBestFlashModeMatch() method that takes a Camera.Parameters object, plus one or more String names of flash modes (e.g., Camera.Parameters.FLASH_MODE_ON), and returns the mode that appears first in your list of strings that is supported by the current camera.

Third-Party Code

kenyee has an implementation of CameraFragment that simply extends from the Android Support package's backport of fragments, for use with the AppCompat backport of the action bar.

Known Limitations

These are above and beyond the bugs filed for this project:

  1. Taking videos in portrait mode is not supported.

  2. While a picture or video is being taken, on some devices, the aspect ratio of the preview gets messed up. The aspect ratio is corrected by CWAC-Camera once the picture or video is completed, but more work is needed to try to prevent this in the first place, or at least mask it a bit better for photos.

  3. The Samsung Galaxy Ace refuses to honor a portrait preview in an activity that itself supports portrait or landscape. If you lock your activity to only display in landscape, the Galaxy Ace will probably work.

Upgrading

If you are moving from an older to a newer edition of CWAC-Camera, here are some upgrade notes which may help.

From 0.5.x to 0.6.0 and Higher

If you implemented CameraHost or extended SimpleCameraHost, note that four callback methods now receive a PictureTransaction as the first parameter:

  • adjustPictureParameters(PictureTransaction xact, Camera.Parameters parameters)
  • getPictureSize(PictureTransaction xact, Camera.Parameters parameters)
  • saveImage(PictureTransaction xact, Bitmap bitmap)
  • saveImage(PictureTransaction xact, byte[] image)

Conversely, all of the old EXIF-related behaviors are now gone. If you created custom DeviceProfiles, they will need to be adjusted to remove the encodesRotationToExif() and rotateBasedOnExif() methods. Also, any custom CameraHost implementation will need to have its rotateBasedOnExif() method removed.

If you implemented your own DeviceProfile classes, note that they might now be able to be replaced by XML resources instead.

Taking pictures now involves a PictureTransaction, though the existing takePicture() methods are still supported.

Also note that full-bleed previews are now the default, though you can override that to revert back to the original behavior if desired.

From 0.4.x to 0.5.0 and Higher

CameraHost used to have mayUseForVideo(), returning a boolean. That is now getRecordingHint(), returning a CameraHost.RecordingHint value: STILL_ONLY, VIDEO_ONLY, or ANY. SimpleCameraHost was modified to return ANY, so the default behavior should be the same as before. Hence, you should only need to worry about this if you overrode mayUseForVideo() or implemented your own CameraHost.

CameraHost now has an onCameraFail() method that takes a FailureReason parameter. FailureReason is an enum, with values of NO_CAMERAS_REPORTED and UNKNOWN at present. This will be called if CameraView could not access a camera. SimpleCameraHost has an implementation of onCameraFail() that just logs a message to LogCat, but you are encouraged to supply your own implementation that does something more.

From 0.2.x/0.3.0 to 0.4.0 and Higher

CameraHost now requires implementers supply mayUseForVideo() (true if the preview should be optimized for possible use in video recording) and getPreferredPreviewSizeForVideo() (returns the preview size to use in case mayUseForVideo() returns true). SimpleCameraHost provides stock implementations of these, but if you created your own CameraHost from scratch, you will need to add your own versions of these methods.

From 0.1.x to 0.2.0 and Higher

CameraHost now extends Camera.AutoFocusCallback, requiring an implementation of onAutoFocus(). SimpleCameraHost shows a basic implementation that, on API Level 16+, plays the device-standard "hey! you're focused now!" sound.

From 0.0.x to 0.1.0 and Higher

Developers moving from v0.0.x to v0.1.x should note that you now need to pass a Context into the constructor of SimpleCameraHost. This can be any Context, as SimpleCameraHost retrieves the Application singleton from it, so you do not have to worry about memory leaks.

Tested Devices

The columns indicate what version of the library that the various devices have been tested on. The numbers in the columns indicate the Android OS version the device was running. The Info column contains the Build.MANUFACTURER and Build.PRODUCT values for the device.

Device Info 0.5.0 0.6.0 Issues
Acer Iconia Tab A700 Acer/a700_pa_cus1 4.1.1 4.1.1
Amazon Kindle Fire HD Amazon/Kindle Fire 4.0.4 4.0.4 107
Amazon Kindle Fire HDX 8.9 Amazon/apollo 4.2.2 4.2.2 75
ASUS MEMO Pad FHD 10 asus/US_epad 4.2.2 4.3
ASUS Transformer Infinity (TF700) asus/US_epad 4.2.1 4.2.1
Galaxy Nexus samsung/yakju 4.3 4.3
Google Nexus 4 LGE/occam 4.4 4.4.2
Google Nexus 5 LGE/hammerhead 4.4 4.4.2
Google Nexus 7 (2012) asus/nakasi 4.4 4.4.2 72
Google Nexus 7 (2013) asus/razor 4.4 4.4.2
Google Nexus 10 samsung/mantaray 4.4 4.4.2
Google Nexus One ??? 2.3.6 2.3.6
Google Nexus S samsung/soju 4.1.2 4.1.2
HTC Droid Incredible 2 ??? 2.3.4 2.3.4
HTC One S HTC/ville 4.1.1 4.1.1 76
HTC One M7 Google Play Edition HTC/m7_google 4.4.2
HTC Thunderbolt HTC/htc_mecha 4.0.4
Lenovo ThinkPad Tablet LENOVO/ThinkPadTablet 4.0.3 4.0.3 38 111
LG G2 (LG-D802) LGE/g2_open_com 4.2.2
LG G Pad 8.3 (LG-V510) ??? 4.4.2
Motorola RAZR i motorola/XT890_rtgb 4.1.2 4.1.2
Nokia X Nokia/RM-980 4.1.2
Samsung Galaxy Ace (GT-S5830M) ??? 2.3.6 2.3.6
Samsung Galaxy Ace 3 (GT-S7270L) samsung/loganub 4.2.2 92
Samsung Galaxy Camera (EK-GC110) samsung/gd1wifiue 4.1.2 105
Samsung Galaxy Grand (GT-I9090L) samsung/baffinssvj 4.1.2 4.2.2
Samsung Galaxy Note 2 (GT-N7100) samsung/t03gxx 4.1.2 4.1.2 19
Samsung Galaxy Pocket Neo (GT-S5312) samsung/corsicadd 4.1.2
Samsung Galaxy S3 (GT-I9300) samsung/m0xx 4.1.2 4.3 77
Samsung Galaxy S3 (SGH-T999) samsung/d2tmo 4.3
Samsung Galaxy S4 (GT-I9500) samsung/ja3gxx 4.3 4.3
Samsung Galaxy S4 (SGH-I337) samsung/jflteuc 4.2.2 4.2.2
Samsung Galaxy S4 Zoom (SM-C105A) samsung/mprojectlteuc 4.2.2
Samsung Galaxy S5 (SM-G900H) ??? 4.4
Samsung Galaxy Tab 2 7.0 (GT-P3113) samsung/espressowifiue 4.2.2 4.2.2 107
SONY Ericsson Xperia Play ??? 2.3.6 2.3.6 113
SONY Xperia E Sony/C1505_1270-4354 4.1.1 4.1.1 45
SONY Xperia S LT26i Sony Ericsson/LT26i_1257-4921 4.1.2
SONY Xperia Z Sony/C6603_1270-7689 4.2.2 4.3
SONY Xperia Z Ultra Sony/C6802 4.2.2 4.3
SONY Xperia Z2 Tablet Sony/SGP521 4.4.2

Dependencies

This project depends on the Android Support package and ActionBarSherlock at compile time, if you are using the Android library project. It also depends on the Android Support package and ActionBarSherlock at runtime if you are using the .acl flavor of CameraFragment.

Version

This is version v0.6.9 of this module, meaning it is coming along nicely.

Demo

In the demo/ sub-project you will find a sample project demonstrating the use of CameraFragment for the native API Level 11 implementation of fragments. The demo-v9/ sub-project has a similar sample for the CameraFragment that works with ActionBarSherlock. The demo-layout/ sub-project demonstrates using CameraView in your own layout resource, with the CameraHostProvider interface and the setCameraView() call on the CameraFragment.

License

The code in this project is licensed under the Apache Software License 2.0, per the terms of the included LICENSE file.

Questions

If you have questions regarding the use of this code, please post a question on StackOverflow tagged with commonsware-cwac and android after searching to see if there already is an answer. Be sure to indicate what CWAC module you are having issues with, and be sure to include source code and stack traces if you are encountering crashes.

If you have encountered what is clearly a bug, or if you have a feature request, please post an issue. Be certain to include complete steps for reproducing the issue.

Do not ask for help via Twitter.

Also, if you plan on hacking on the code with an eye for contributing something back, please open an issue that we can use for discussing implementation details. Just lobbing a pull request over the fence may work, but it may not.

Release Notes

  • v0.6.10: addressed memory leaks and crashes due to inconsistent pause handling
  • v0.6.9: updated Gradle, fixed -v9 manifest for merging, "fixed" issue #176
  • v0.6.8: yet more bug fixes, added cwac- prefix to JAR
  • v0.6.7: extended S3 bug fix to AT&T model
  • v0.6.6: fixed S3 bug, added sample full-screen activity
  • v0.6.5: yet more various bug fixes
  • v0.6.4: various bug fixes
  • v0.6.3: various bug fixes
  • v0.6.2: synchronized the -v9 CameraFragment with the main one
  • v0.6.1: fixed issue with Motorola device support
  • v0.6.0: full-bleed preview, faster image processing, DeviceProfile overhaul, added PictureTransaction, etc.
  • v0.5.4: refactored into two libraries, added Gradle support and AAR artifacts
  • v0.5.2: face detection, zoom, and demo bug fixes
  • v0.5.1: added face detection support
  • v0.5.0: zoom support, layout resource support, JavaDocs, etc.
  • v0.4.3: override getPreferredPreviewSizeForVideo() — if too low, use getPreviewSize()
  • v0.4.2: fixed bug with Droid Incredible 2
  • v0.4.1: added getFlashMode(), added DeviceProfile control over minimum picture height
  • v0.4.0: fixed bug in getBestAspectPreviewSize(), added hooks for device overrides for video preview sizes, improved support for HTC One
  • v0.3.0: improved support for auto-focus, Samsung Galaxy Camera, etc.
  • v0.2.1: CyanogenMod devices will now use SurfaceView regardless of API level
  • v0.2.0: auto-focus support, single-shot mode, Droid Incredible 2 fixes
  • v0.1.1: improved support for Nexus 4 and Galaxy Tab 2
  • v0.1.0: Nexus S crash fixed, added support for indexing images to MediaStore
  • v0.0.4: Nexus S EXIF issue fixed, added saveImage(Bitmap) callback
  • v0.0.3: shutter callback support, bug fixes
  • v0.0.2: bug fixes
  • v0.0.1: initial release

Who Made This?

CommonsWare

Built With

Share this project:
×

Updates