Changes in this update:
**Enhancements**
* Support was added for the `fr_CA` locale.
* The Executor has been optimized to run a single thread when there are active job in the queue, and to remain idle when there are not active jobs.
* An additional parameter of `alertType` has been added to the Alerts capability agent. This will allow observers of alerts to know the type of alert being delivered.
* Support for programmatic unload and load of PulseAudio Bluetooth modules was added. To enable this feature, there is a [new CMake option](https://github.com/alexa/avs-device-sdk/wiki/CMake-parameters#bluetooth): `BLUETOOTH_BLUEZ_PULSEAUDIO_OVERRIDE_ENDPOINTS`. Note that [libpulse-dev is a required dependency](https://github.com/alexa/avs-device-sdk/wiki/Dependencies#bluetooth) of this feature.
* An observer interface was added for when an active Bluetooth device connects and disconnects.
* The `BluetoothDeviceManagerInterface` instantiation was moved from `DefaultClient` to `SampleApp` to allow applications to override it.
* The `MediaPlayerInterface` now supports repeating playback of URL sources.
* The Kitt.AI wake word engine (WWE) is now compatible with GCC5+.
* Stop of ongoing alerts, management of MessageObservers, and management of CallStateObservers have been exposed through DefaultClient.
**Bug Fixes**
* [Issue 953](https://github.com/alexa/avs-device-sdk/issues/953) - The `MediaPlayerInterface` requirement that callbacks not be made upon a callers thread has been removed.
* [Issue 1136](https://github.com/alexa/avs-device-sdk/issues/1136) - Added a missing default virtual destructor.
* [Issue 1140](https://github.com/alexa/avs-device-sdk/issues/1140) - Fixed an issue where DND states were not synchronized to the AVS cloud after device reset.
* [Issue 1143](https://github.com/alexa/avs-device-sdk/issues/1143) - Fixed an issue in which the SpeechSynthesizer couldn't enter a sleeping state.
* [Issue 1183](https://github.com/alexa/avs-device-sdk/issues/1183) - Fixed an issue where alarm is not sounding for certain timezones
* Changing an alert's volume from the Alexa app now works when an alert is playing.
* Added missing shutdown handling for ContentDecrypter to prevent the `Stop` command from triggering a crash when SAMPLE-AES encrypted content was streaming.
* Fixed a bug where if the Notifications database is empty, due to a crash or corruption, the SDK initialization process enters an infinite loop when it retries to get context from the Notifications capability agent.
* Fixed a race condition that caused `AlertsRenderer` observers to miss notification that an alert has been completed.
**Known Issues**
* `PlaylistParser` and `IterativePlaylistParser` generate two HTTP requests (one to fetch the content type, and one to fetch the audio data) for each audio stream played.
* Music playback history isn't being displayed in the Alexa app for certain account and device types.
* On GCC 8+, issues related to `-Wclass-memaccess` will trigger warnings. However, this won't cause the build to fail and these warnings can be ignored.
* Android error ("libDefaultClient.so" not found) can be resolved by upgrading to ADB version 1.0.40
* When network connection is lost, lost connection status is not returned via local TTS.
* `ACL` may encounter issues if audio attachments are received but not consumed.
* `SpeechSynthesizerState` currently uses `GAINING_FOCUS` and `LOSING_FOCUS` as a workaround for handling intermediate state. These states may be removed in a future release.
* The Alexa app doesn't always indicate when a device is successfully connected via Bluetooth.
* Connecting a product to streaming media via Bluetooth will sometimes stop media playback within the source application. Resuming playback through the source application or toggling next/previous will correct playback.
* When a source device is streaming silence via Bluetooth, the Alexa app indicates that audio content is streaming.
* The Bluetooth agent assumes that the Bluetooth adapter is always connected to a power source. Disconnecting from a power source during operation is not yet supported.
* On some products, interrupted Bluetooth playback may not resume if other content is locally streamed.
* `make integration` is currently not available for Android. In order to run integration tests on Android, you'll need to manually upload the test binary file along with any input file. At that point, the adb can be used to run the integration tests.
* On Raspberry Pi running Android Things with HDMI output audio, beginning of speech is truncated when Alexa responds to user text-to-speech (TTS).
* When the sample app is restarted and network connection is lost, Reminder TTS does not play. Instead, the default alarm tone will play twice.
Changes in this update:
**Enhancements**
* New optional configuration for [EqualizerController](https://github.com/alexa/avs-device-sdk/blob/v1.10.0/Integration/AlexaClientSDKConfig.json#L154). The EqualizerController interface allows you to adjust equalizer settings on your product, such as decibel (dB) levels and modes.
* Added reference implementation of the EqualizerController for GStreamer-based (MacOS, Linux, and Raspberry Pi) and OpenSL ES-based (Android) MediaPlayers. Note: In order to use with Android, it must support OpenSL ES.
* New optional configuration for the [TemplateRuntime display card value](https://github.com/alexa/avs-device-sdk/blob/v1.10.0/Integration/AlexaClientSDKConfig.json#L144).
* A configuration file generator script, `genConfig.sh` is now included with the SDK in the **tools/Install** directory. `genConfig.sh` and it's associated arguments populate `AlexaClientSDKConfig.json` with the data required to authorize with LWA.
* Added Bluetooth A2DP source and AVRCP target support for Linux.
* Added Amazon for Business (A4B) support, which includes support for handling the new [RevokeAuthorization](https://developer.amazon.com/docs/alexa-voice-service/system.html#revokeauth) directive in the Settings interface. A new CMake option has been added to enable A4B within the SDK, `-DA4B`.
* Added locale support for IT and ES.
* The Alexa Communication Library (ACL), `CBLAUthDelegate`, and sample app have been enhanced to detect de-authorization using the new `z` command.
* Added `ExternalMediaPlayerObserver`, which receives notification of player state, track, and username changes.
* `HTTP2ConnectionInterface` was factored out of `HTTP2Transport` to enable unit testing of `HTTP2Transport` and re-use of `HTTP2Connection` logic.
**Bug Fixes**
* Fixed a bug in which `ExternalMediaPlayer` adapter playback wasn't being recognized by AVS.
* [Issue 973](https://github.com/alexa/avs-device-sdk/issues/973) - Fixed issues related to `AudioPlayer` where progress reports were being sent out of order or with incorrect offsets.
* An `EXPECTING`, state has been added to `DialogUXState` in order to handle `EXPECT_SPEECH` state for hold-to-talk devices.
* [Issue 948](https://github.com/alexa/avs-device-sdk/issues/948) - Fixed a bug in which the sample app was stuck in a listening state.
* Fixed a bug where there was a delay between receiving a `DeleteAlert` directive, and deleting the alert.
* [Issue 839](https://github.com/alexa/avs-device-sdk/issues/839) - Fixed an issue where speech was being truncated due to the `DialogUXStateAggregator` transitioning between a `THINKING` and `IDLE` state.
* Fixed a bug in which the `AudioPlayer` attempted to play when it wasn't in the `FOREGROUND` focus.
* `CapabilitiesDelegateTest` now works on Android.
* [Issue 950](https://github.com/alexa/avs-device-sdk/issues/950) - Improved Android Media Player audio quality.
* [Issue 908](https://github.com/alexa/avs-device-sdk/issues/908) - Fixed compile error on g++ 7.x in which includes were missing.