src/devices/camera/versioning.jd

page.title=Camera version support
@jd:body

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    <h2>In this document</h2>
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<p>The Android 5.0 (Lollipop) platform release adds a new app-level camera framework. This
document outlines some logistical details that OEMs and SoC vendors need to
know.</p>

<h2 id=glossary>Terms</h2>

<p>The following terms are used in this document:</p>

<ul>
  <li><em>Camera API1</em>: The app-level camera framework on KitKat and earlier devices, exposed
through the <code>android.hardware.Camera</code> class.
  <li><em>Camera API2</em>: The app-level camera framework on 5.0 and later
devices, exposed through the<code> android.hardware.camera2</code> package.
  <li><em>Camera HAL</em>: The camera module layer that SoC vendors implement. The app-level public
frameworks are built on top of the camera HAL.
  <li><em>Camera HAL3.2</em>: The version of the camera device HAL that is
being released with Lollipop. KitKat launched with an earlier version (Camera HAL3.1).
  <li><em>Camera API1 CTS</em>: The set of camera Compatibility Test Suite (CTS) tests that run on top of
Camera API1.
  <li><em>Camera API2 CTS</em>: An additional set of camera CTS tests that run on top of Camera API2.
</ul>

<h2 id=camera_api2_overview>Camera API2 overview</h2>

<p>The new camera frameworks expose lower-level camera control to the app,
including efficient zero-copy burst/streaming flows and per-frame controls of
exposure, gain, white balance gains, color conversion, denoising, sharpening,
and more. See this <a
href="https://www.youtube.com/watch?v=92fgcUNCHic&feature=youtu.be&t=29m50s">brief
video overview from the Google I/O 2014 conference</a> for additional details.
</p>

<h2 id=camera_api1_availability_and_deprecation_in_l>Camera API1 availability and deprecation in Android 5.0</h2>

<p>The Camera API1 interfaces are still available for apps to use on Android
5.0 and later devices, and camera apps built on top of Camera API1 should work
as before. Camera API1 is being marked as deprecated in Lollipop, indicating that it
will be phased out over time and new platform development will focus on Camera
API2. However, we expect this phase-out period to be lengthy, and Camera API1
apps will continue to be supported in Android for some time to come.</p>

<p>All earlier camera HAL versions, including Camera HAL1.0, will also continue to
be supported.</p>

<h2 id=camera_api2_capabilities_and_support_levels>Camera API2 capabilities and support levels</h2>

<p>Android 5.0 and later devices feature Camera API2, however they may not fully support all of
the new features of Camera API2. The
<code>android.info.supportedHardwareLevel</code> property that apps can query
through the Camera API2 interfaces report one of three support levels:
<code>LEGACY</code>, <code>FULL</code>, and <code>LIMITED</code>.</p>

<p><em>Legacy</em> devices expose a level of capabilities through the Camera API2 interfaces that
are approximately the same as is exposed to apps through the Camera API1
interfaces; the legacy frameworks code conceptually translates Camera API2
calls into Camera API1 calls under the hood. Legacy devices do not support
the new Camera API2 features including per-frame controls.</p>

<p><em>Full</em> devices support all of the major capabilities of Camera API2. Full devices by
necessity must have a Camera HAL version of 3.2 (shipping with Android 5.0) or later.</p>

<p><em>Limited</em> devices are in between: They support some of the new Camera API2 capabilities,
but not all of them, and must also comprise a Camera HAL version of 3.2 or later.</p>

<p>Individual capabilities are exposed via the<code>
android.request.availableCapabilities</code> property in the Camera API2
interfaces. Full devices require both the <code>MANUAL_SENSOR</code> and
<code>MANUAL_POST_PROCESSING</code> capabilities, among others. There is also a
<code>RAW</code> capability that is optional even for full devices. Limited
devices can advertise any subset of these capabilities, including none of them. However,
the <code>BACKWARD_COMPATIBLE</code> capability must always be defined.</p>

<p>The supported hardware level of the device, as well as the specific Camera API2
capabilities it supports, are available as the following feature flags to allow
Play Store filtering of Camera API2 camera apps; a device must define the
feature flag if any of its attached camera devices supports the feature.</p>

<ul>
  <li><code>android.hardware.camera.hardware_level.full</code>
  <li><code>android.hardware.camera.capability.raw</code>
  <li><code>android.hardware.camera.capability.manual_sensor</code>
  <li><code>android.hardware.camera.capability.manual_post_processing</code>
</ul>

<h2 id=cts_requirements>CTS requirements</h2>

<p>Android 5.0 and later devices must pass both Camera API1 CTS and Camera API2
CTS. And as always, devices are required to pass the CTS Verifier camera
tests.</p>

<p>To add some context: For devices that don’t feature a Camera HAL3.2
implementation and are not capable of supporting the full Camera API2
interfaces, the Camera API2 CTS tests must still be passed. However, in this
case the device will be running in Camera API2 <em>legacy</em> mode (in which
the Camera API2 calls are conceptually just mapped to Camera
API1 calls); and any Camera API2 CTS tests that relate to features or
capabilities beyond Camera API1 have logic that will skip them in the case of
old (legacy) devices.</p>

<p>On a legacy device, the Camera API2 CTS tests that are not skipped are purely
using the existing public Camera API1 interfaces and capabilities (with no new
requirements), and any bugs that are exposed (which will in turn cause a Camera
API2 CTS failure) are bugs that were already present in the device’s existing
Camera HAL and would also be a bug that could be easily hit by existing Camera
API1 apps. The expectation is that there should be very few bugs of this
nature. Nevertheless, any such bugs will need to be fixed.</p>