2.3. Television Requirements
An Android Television device refers to an Android device implementation that is an entertainment interface for consuming digital media, movies, games, apps, and/or live TV for users sitting about ten feet away (a “lean back” or “10-foot user interface”).
Android device implementations are classified as a Television if they meet all the following criteria:
- Have provided a mechanism to remotely control the rendered user interface on the display that might sit ten feet away from the user.
- Have an embedded screen display with the diagonal length larger than 24 inches OR include a video output port, such as VGA, HDMI, DisplayPort, or a wireless port for display.
The additional requirements in the rest of this section are specific to Android Television device implementations.
2.3.1. Hardware
Television device implementations:
- [7.2.2/T-0-1] MUST support D-pad.
- [7.2.3/T-0-1] MUST provide the Home and Back functions.
- [7.2.3/T-0-2] MUST send both the normal and long press event of the Back function (
KEYCODE_BACK
) to the foreground application. - [7.2.6.1/T-0-1] MUST include support for game controllers and declare the
android.hardware.gamepad
feature flag. - [7.2.7/T] SHOULD provide a remote control from which users can access non-touch navigation and core navigation keys inputs.
If Television device implementations include a 3-axis gyroscope, they:
- [7.3.4/T-1-1] MUST be able to report events up to a frequency of at least 100 Hz.
- [7.3.4/T-1-2] MUST be capable of measuring orientation changes up to 1000 degrees per second.
Television device implementations:
- [7.4.3/T-0-1] MUST support Bluetooth and Bluetooth LE.
- [7.6.1/T-0-1] MUST have at least 4 GB of non-volatile storage available for application private data (a.k.a. “/data” partition).
If Television device implementations include a USB port that supports host mode, they:
- [7.5.3/T-1-1] MUST include support for an external camera that connects through this USB port but is not necessarily always connected.
If TV device implementations are 32-bit:
If TV device implementations are 64-bit:
Note that the “memory available to the kernel and userspace” above refers to the memory space provided in addition to any memory already dedicated to hardware components such as radio, video, and so on that are not under the kernel’s control on device implementations.
Television device implementations:
- [7.8.1/T] SHOULD include a microphone.
- [7.8.2/T-0-1] MUST have an audio output and declare
android.hardware.audio.output
.
2.3.2. Multimedia
Television device implementations MUST support the following audio encoding and decoding formats and make them available to third-party applications:
- [5.1/T-0-1] MPEG-4 AAC Profile (AAC LC)
- [5.1/T-0-2] MPEG-4 HE AAC Profile (AAC+)
- [5.1/T-0-3] AAC ELD (enhanced low delay AAC)
Television device implementations MUST support the following video encoding formats and make them available to third-party applications:
- [5.2/T-0-1] H.264
- [5.2/T-0-2] VP8
Television device implementations:
- [5.2.2/T-SR] Are STRONGLY RECOMMENDED to support H.264 encoding of 720p and 1080p resolution videos at 30 frames per second.
Television device implementations MUST support the following video decoding formats and make them available to third-party applications:
Television device implementations MUST support MPEG-2 decoding, as detailed in Section 5.3.1, at standard video frame rates and resolutions up to and including:
- [5.3.1/T-1-1] HD 1080p at 59.94 frames per second with Main Profile High Level.
- [5.3.1/T-1-2] HD 1080i at 59.94 frames per second with Main Profile High Level. They MUST deinterlace interlaced MPEG-2 video to its progressive equivalent (e.g. from 1080i at 59.94 frames per second to 1080p at 29.97 frames per second) and make it available to third-party applications.
Television device implementations MUST support H.264 decoding, as detailed in Section 5.3.4, at standard video frame rates and resolutions up to and including:
- [5.3.4/T-1-1] HD 1080p at 60 frames per second with Baseline Profile
- [5.3.4/T-1-2] HD 1080p at 60 frames per second with Main Profile
- [5.3.4/T-1-3] HD 1080p at 60 frames per second with High Profile Level 4.2
Television device implementations with H.265 hardware decoders MUST support H.265 decoding, as detailed in Section 5.3.5, at standard video frame rates and resolutions up to and including:
- [5.3.5/T-1-1] HD 1080p at 60 frames per second with Main Profile Level 4.1
If Television device implementations with H.265 hardware decoders support H.265 decoding and the UHD decoding profile, they:
- [5.3.5/T-2-1] MUST support UHD 3480p at 60 frames per second with Main10 Level 5 Main Tier profile
Television device implementations MUST support VP8 decoding, as detailed in Section 5.3.6, at standard video frame rates and resolutions up to and including:
- [5.3.6/T-1-1] HD 1080p at 60 frames per second decoding profile
Television device implementations with VP9 hardware decoders MUST support VP9 decoding, as detailed in Section 5.3.7, at standard video frame rates and resolutions up to and including:
- [5.3.7/T-1-1] HD 1080p at 60 frames per second with profile 0 (8 bit color depth)
If Television device implementations with VP9 hardware decoders support VP9 decoding and the UHD decoding profile, they:
- [5.3.7/T-2-1] MUST support UHD 3480p at 60 frames per second with profile 0 (8 bit color depth).
- [5.3.7/T-2-1] Are STRONGLY RECOMMENDED to support UHD 3480p at 60 frames per second with profile 2 (10 bit color depth).
Television device implementations:
- [5.5/T-0-1] MUST include support for system Master Volume and digital audio output volume attenuation on supported outputs, except for compressed audio passthrough output (where no audio decoding is done on the device).
If Television device implementations do not have a built in display, but instead support an external display connected via HDMI, they:
- [5.8/T-0-1] MUST set the HDMI output mode to select the maximum resolution that can be supported with either a 50Hz or 60Hz refresh rate.
- [5.8/T-SR] Are STRONGLY RECOMMENDED to provide a user configurable HDMI refresh rate selector.
- [5.8] SHOULD set the HDMI output mode refresh rate to either 50Hz or 60Hz, depending on the video refresh rate for the region the device is sold in.
If Television device implementations do not have a built in display, but instead support an external display connected via HDMI, they:
- [5.8/T-1-1] MUST support HDCP 2.2.
If Television device implementations do not support UHD decoding, but instead support an external display connected via HDMI, they:
- [5.8/T-2-1] MUST support HDCP 1.4
2.3.3. Software
Television device implementations:
- [3/T-0-1] MUST declare the features
android.software.leanback
and android.hardware.type.television
. - [3.2.3.1/T-0-1] MUST preload one or more applications or service components with an intent handler, for all the public intent filter patterns defined by the following application intents listed here.
- [3.4.1/T-0-1] MUST provide a complete implementation of the
android.webkit.Webview
API.
If Android Television device implementations support a lock screen,they:
- [3.8.10/T-1-1] MUST display the Lock screen Notifications including the Media Notification Template.
Television device implementations:
- [3.8.14/T-SR] Are STRONGLY RECOMMENDED to support picture-in-picture (PIP) mode multi-window.
- [3.10/T-0-1] MUST support third-party accessibility services.
- [3.10/T-SR] Are STRONGLY RECOMMENDED to preload accessibility services on the device comparable with or exceeding functionality of the Switch Access and TalkBack (for languages supported by the preinstalled Text-to-speech engine) accessibility services as provided in the talkback open source project.
If Television device implementations report the feature android.hardware.audio.output
, they:
- [3.11/T-SR] Are STRONGLY RECOMMENDED to include a TTS engine supporting the languages available on the device.
- [3.11/T-1-1] MUST support installation of third-party TTS engines.
Television device implementations:
- [3.12/T-0-1] MUST support TV Input Framework.
2.3.4. Performance and Power
- [8.1/T-0-1] Consistent frame latency. Inconsistent frame latency or a delay to render frames MUST NOT happen more often than 5 frames in a second, and SHOULD be below 1 frames in a second.
- [8.2/T-0-1] MUST ensure a sequential write performance of at least 5MB/s.
- [8.2/T-0-2] MUST ensure a random write performance of at least 0.5MB/s.
- [8.2/T-0-3] MUST ensure a sequential read performance of at least 15MB/s.
- [8.2/T-0-4] MUST ensure a random read performance of at least 3.5MB/s.
If Television device implementations include features to improve device power management that are included in AOSP or extend the features that are included in AOSP, they:
- [8.3/T-1-1] MUST provide user affordance to enable and disable the battery saver feature.
If Television device implementations do not have a battery they:
If Television device implementations have a battery they:
- [8.3/T-1-3] MUST provide user affordance to display all apps that are exempted from App Standby and Doze power-saving modes.
Television device implementations:
- [8.4/T-0-1] MUST provide a per-component power profile that defines the current consumption value for each hardware component and the approximate battery drain caused by the components over time as documented in the Android Open Source Project site.
- [8.4/T-0-2] MUST report all power consumption values in milliampere hours (mAh).
- [8.4/T-0-3] MUST report CPU power consumption per each process's UID. The Android Open Source Project meets the requirement through the
uid_cputime
kernel module implementation. - [8.4/T] SHOULD be attributed to the hardware component itself if unable to attribute hardware component power usage to an application.
- [8.4/T-0-4] MUST make this power usage available via the
adb shell dumpsys batterystats
shell command to the app developer.
2.3.5. Security Model
Television device implementations:
- [9.11/T-0-1] MUST back up the keystore implementation with an isolated execution environment.
- [9.11/T-0-2] MUST have implementations of RSA, AES, ECDSA and HMAC cryptographic algorithms and MD5, SHA1, and SHA-2 family hash functions to properly support the Android Keystore system's supported algorithms in an area that is securely isolated from the code running on the kernel and above. Secure isolation MUST block all potential mechanisms by which kernel or userspace code might access the internal state of the isolated environment, including DMA. The upstream Android Open Source Project (AOSP) meets this requirement by using the Trusty implementation, but another ARM TrustZone-based solution or a third-party reviewed secure implementation of a proper hypervisor-based isolation are alternative options.
- [9.11/T-0-3] MUST perform the lock screen authentication in the isolated execution environment and only when successful, allow the authentication-bound keys to be used. Lock screen credentials MUST be stored in a way that allows only the isolated execution environment to perform lock screen authentication. The upstream Android Open Source Project provides the Gatekeeper Hardware Abstraction Layer (HAL) and Trusty, which can be used to satisfy this requirement.
- [9.11/T-0-4] MUST support key attestation where the attestation signing key is protected by secure hardware and signing is performed in secure hardware. The attestation signing keys MUST be shared across large enough number of devices to prevent the keys from being used as device identifiers. One way of meeting this requirement is to share the same attestation key unless at least 100,000 units of a given SKU are produced. If more than 100,000 units of an SKU are produced, a different key MAY be used for each 100,000 units.
Note that if a device implementation is already launched on an earlier Android version, such a device is exempted from the requirement to have a keystore backed by an isolated execution environment and support the key attestation, unless it declares the android.hardware.fingerprint
feature which requires a keystore backed by an isolated execution environment.
If Television device implementations support a secure lock screen, they:
- [9.11/T-1-1] MUST allow the user to choose the Sleep timeout for transition from the unlocked to the locked state, with a minimum allowable timeout up to 15 seconds or less.
2.3.6. Developer Tools and Options Compatibility
Television device implementations: