Apple Inc.

Brett D George

Daniel C Klingler

Niel David Warren

Adam E Kriegel

Matthew Xavier Mora

Girault W Jones

Michael F Jean

Felipe Ferreri Tonello

Do Kyung Kim

Paul W Glendenning

William P Cornelius

Josh P De Cesare

Gregory F Hughes

Rohit Kumar Gupta

Ronald Nadim Isaac

Michael W Murphy

Rajabali M Koduri

Changki Min

Anthony J Chivetta

Raymond B Montagne

David A Leech

Girault W Jones, Jr

Ion Valentin Pistol

Girault Jones

Santo S Sapienza

Matthew X Mora

Techniques for improving the handling of peripherals in a computer system, including through the use of a DMA control circuit that helps manage the flow of data between memory and the peripherals via an intermediate storage buffer. The DMA control circuit is configured to control timing of DMA transfers between sample buffers in the memory and the intermediate storage buffer. The DMA control circuit may output a priority value of the DMA control circuit for accesses to memory, where the priority value based on stored quality of service (QoS) information and current channel data buffer levels for different DMA channels. The DMA control circuit may separately arbitrate between multiple active transmit and receive channels. Still further, the DMA control circuit may store, for a given data transfer over a particular DMA channel, timestamp information indicative of completion of the DMA and peripheral-side operations.

DMA control circuit with quality of service indications

A system and method to process audio data received over the ARC or eARC interface of HDMI from audio sources are provided. A media device may receive compressed audio data in a number of data formats. The media device may convert between the audio formats provided by the audio sources and the audio formats supported by audio playback devices. The media device may inspect frames of audio data to determine if the frames are to be decoded. The frame may be decoded and subsequently encoded into the data formats supported by the audio playback devices. To reduce latency, the media device may enable a pass-through mode to bypass the decoding of the frames to allow the frames to be decoded at the audio playback devices. A bi-directional loopback application may route audio data received over the ARC or eARC interface from the audio sources to the audio playback devices.

Audio return channel data loopback

Techniques are disclosed relating to providing audio prompts. In one embodiment, a computing device includes a display, an audio circuit coupled to a speaker, first and second processors, and memory. The memory has first program instructions executable by the first processor to provide, via a first operating system of the computing device, a visual prompt to the display to cause the display to present the visual prompt to a user and send, to the second processor, a request to provide an audio prompt corresponding to the visual prompt via the speaker to the user. The computing device also includes memory having second program instructions executable by the second processor to, in response to the request, provide, via a second operating system, an instruction to the audio circuit to play the audio prompt via the speaker.

Audio accessibility assistance

A system and method to mitigate the temporary loss of the input sampling clocks when receiving audio data over the ARC or eARC interface of HDMI are provided. A media device may substitute an externally generated clock derived from a local crystal oscillator of the media device for the missing input sampling clock. The external clock may be synchronized to the frequency of the input sampling clock. The media device may synchronize the external clock to the audio data when there is a loss of the input sampling clock. When the input sampling clock of the audio data reappears, the media device may switch back from the external clock to the input sampling clock. When transitioning between the input sampling clock and the external clock, the media device may insert zero padding into the audio data samples to mute any potential glitch in the sound from an audio playback device.

Audio return channel clock switching

Methods and apparatus for processing media signals. In one embodiment, a data processing device processes fixed and variable rate data using a first and second processing unit. The processing comprises real-time processing of audio/video signals by a graphics processing unit (GPU) and/or central processing unit (CPU). The processing units process data efficiently by establishing one processor as always processing variable rate data, and using one or more schemes for determining processor will process fixed rate data. A shared memory enables the processors to communicate with one another in order to determine which will process the fixed rate data. In one scheme for determining which of the processors will process the fixed rate data the second processor need merely be unlocked. In another embodiment, the second processor must be unlocked and immediately available.

Apparatus and methods for processing of media signals

Methods and apparatus for efficiently transporting data through network tunnels. In one embodiment, a tunneled device advertises certain capabilities to peer devices of a network, and discovers capabilities of peer devices of the network. In a second embodiment, each device of a tunneled network derives a network parameter from a transit protocol parameter for use in data networking.

Methods and apparatus for transporting data through network tunnels

Growing community of inventors

Mountain View, CA, United States of America

Brett D George