Abstract: An illustrative example method of controlling an engine of a vehicle, includes determining a target pressure curve for a cylinder of the engine for a first combustion cycle, determining a heat release model for the cylinder for the first combustion cycle, determining a mass flow of fuel from the heat release model to achieve the target pressure curve during the first combustion cycle, and automatically controlling opening of an injector of the cylinder of the engine during the first combustion cycle to provide the determined mass flow of fuel to the cylinder. The method includes determining a real pressure curve during the first combustion cycle and automatically adjusting at least one of the heat release model or the mass flow for a second, subsequent combustion cycle based on a difference between the target pressure curve and the real pressure curve.

Abstract: Disclosed herein are systems and methods for establishing a metadata exchange channel between a media playback system and a networked microphone system, wherein the networked microphone system comprises a networked microphone device and a networked microphone server. After establishing the metadata exchange channel, the media playback system experiences a metadata exchange triggering event. In response to experiencing the metadata exchange triggering event, the media playback system provides metadata to the networked microphone system via the metadata exchange channel.

Abstract: Examples described herein involve maintaining a database of audio processing algorithms. Maintaining the database may involve generating or updating audio processing algorithm entries. In one example, generating an audio processing algorithm may involve a computing device causing a playback device to play a first audio signal in a playback zone, receiving (i) data indicating one or more characteristics of a playback zone, and (ii) data indicating a second audio signal detected by a microphone of the playback device in the playback zone. Based on the second audio signal and a characteristic of the playback device, an audio processing algorithm may be determined. The an association between the determined audio processing algorithm at least one of the one or more characteristics of the playback zone may be stored in the database.

Abstract: A computing device may maintain a database of representative spectral characteristics. The computing device may also receive particular spectral data associated with a particular playback environment corresponding to the particular playback device. Based on the particular spectral data, the computing device may identify one of the representative spectral characteristics from the database that substantially matches the particular spectral data, and then identify, in the database, an audio processing algorithm based on a) the identified representative spectral characteristic and b) at least one characteristic of the particular playback device. The computing device may then transmit, to the particular playback device, data indicating the identified audio processing algorithm.

Abstract: A computing device may transmit playback device configuration information to a given playback device. The computing device may then receive calibration data corresponding to each playback device of a plurality of playback devices, and receive playback device characteristic data indicating at least one playback device characteristic for each playback device of the plurality of playback devices. Based on at least the received calibration data and the received playback device characteristic data, the computing device may determine updated playback device configuration information and transmit data indicating the updated playback device configuration information to the given playback device.

Abstract: Disclosed herein are systems and methods for establishing a metadata exchange channel between a media playback system and a networked microphone system, wherein the networked microphone system comprises a networked microphone device and a networked microphone server. After establishing the metadata exchange channel, the media playback system experiences a metadata exchange triggering event. In response to experiencing the metadata exchange triggering event, the media playback system provides metadata to the networked microphone system via the metadata exchange channel.

Abstract: Disclosed herein are systems and methods for establishing a metadata exchange channel between a media playback system and a networked microphone system, wherein the networked microphone system comprises a networked microphone device and a networked microphone server. After establishing the metadata exchange channel, the media playback system experiences a metadata exchange triggering event. In response to experiencing the metadata exchange triggering event, the media playback system provides metadata to the networked microphone system via the metadata exchange channel.

Abstract: A computing device may transmit playback device configuration information to a given playback device. The computing device may then receive calibration data corresponding to each playback device of a plurality of playback devices, and receive playback device characteristic data indicating at least one playback device characteristic for each playback device of the plurality of playback devices. Based on at least the received calibration data and the received playback device characteristic data, the computing device may determine updated playback device configuration information and transmit data indicating the updated playback device configuration information to the given playback device.

Abstract: A computing device may maintain a database of representative spectral characteristics. The computing device may also receive particular spectral data associated with a particular playback environment corresponding to the particular playback device. Based on the particular spectral data, the computing device may identify one of the representative spectral characteristics from the database that substantially matches the particular spectral data, and then identify, in the database, an audio processing algorithm based on a) the identified representative spectral characteristic and b) at least one characteristic of the particular playback device. The computing device may then transmit, to the particular playback device, data indicating the identified audio processing algorithm.

Abstract: A playback device may have a network interface configured to communicate with a network microphone device over a communication network. A processor of the playback device may comprise instructions, which when executed, cause the processor to obtain acoustics of an environment in which the playback device is located; identify a network microphone device; and send the acoustics to the network microphone device to cause the network microphone device to apply the acoustics to voice input received by the network microphone device.

Abstract: Systems, methods, apparatus, and articles of manufacture to learn and share remote commands are disclosed. An example method to configure a playback device to be controlled by a remote control includes receiving by the playback device a first code for a first command from the remote control. The example method includes identifying by the playback device a second code for a second command based on the received first code. The example method includes receiving by the playback device the second code from the remote control. The example method includes executing the second command by the playback device.

Abstract: A playback device comprises a network interface configured to communicate with a network microphone device. A processor of the playback device comprises instructions, which when executed, cause the processor to receive a message associated with the network microphone device; and adjust a volume of audio content below a volume of content associated with the network microphone device based on the message.

Abstract: Methods and apparatus for identifying a music service based on a user command. A content type is identified from a received user command and a music service is selected that supports the content type. A selected music service can then transmit audio content associated with the content type for playback.

Abstract: Multiple aspects of systems and methods for voice control and related features and functionality for various embodiments of media playback devices, networked microphone devices, microphone-equipped media playback devices, and speaker-equipped networked microphone devices are disclosed and described herein, including but not limited to designating and managing default networked devices, audio response playback, room-corrected voice detection, content mixing, music service selection, metadata exchange between networked playback systems and networked microphone systems, handling loss of pairing between networked devices, actions based on user identification, and other voice control of networked devices.

Abstract: Disclosed herein are systems and methods for receiving a voice command and determining an appropriate action for the media playback system to execute based on user identification. The systems and methods receive a voice command for a media playback system, and determines whether the voice command was received from a registered user of the media playback system. In response to determining that the voice command was received from a registered user, the systems and methods configure an instruction for the media playback system based on content from the voice command and information in a user profile for the registered user.

Abstract: A signal from a sensor may be received indicative of an acceleration of a moving component of a transducer at a location where the sensor is mounted. A position the moving component may be determined based on the acceleration. The position of the moving component may be compared with a reference to output a measure of distortion associated with the transducer. Nonlinearities in audio output by the transducer may be corrected based on the measure of distortion.

Abstract: Disclosed herein are systems and methods for establishing a metadata exchange channel between a media playback system and a networked microphone system, wherein the networked microphone system comprises a networked microphone device and a networked microphone server. After establishing the metadata exchange channel, the media playback system experiences a metadata exchange triggering event. In response to experiencing the metadata exchange triggering event, the media playback system provides metadata to the networked microphone system via the metadata exchange channel.

Abstract: Systems and methods disclosed herein include (i) receiving a voice command via a networked microphone device configured to receive voice commands for a media playback system, wherein the media playback system comprises a primary media playback device configured to perform a function and/or provide a first feedback in response to voice commands received via the networked microphone device, (ii) determining that the primary media playback device is not available to perform a function and/or provide the first feedback in response to the voice command, and (iii) in response to determining that the primary media playback device is not available to perform a function and/or provide the first feedback in response to the voice command, instructing a fallback device to perform a function and/or provide a second feedback in response to the voice command.

Abstract: A playback device may have a network interface configured to communicate with a network microphone device over a communication network. A processor of the playback device may comprise instructions, which when executed, cause the processor to obtain acoustics of an environment in which the playback device is located; identify a network microphone device; and send the acoustics to the network microphone device to cause the network microphone device to apply the acoustics to voice input received by the network microphone device.

Abstract: A first signal may be received indicative of audio to be played by a speaker. A second signal may be received which comprises (i) a voice input received by a microphone and (ii) at least a portion of the audio played by the speaker at a same time that the microphone receives the voice input. Based on the first signal, nonlinearities output by the speaker which played the audio may be determined. At least the nonlinearities from the second signal may be removed to output a third signal comprising substantially the voice input received at the microphone.