Methods and apparatus for synchronization of media playback within a wireless network
AssigneeApple Inc.
InventorsRichard Powell, Daniel Naito, James Hollabaugh, Daniel Klingler
Life of this patent
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Abstract
Methods and apparatus for synchronization of media playback within a wireless network. In one embodiment, the present disclosure is directed to precision synchronization over time, based on repeated measurements of a common time reference. In one exemplary embodiment, the common time reference is a Time Synchronization Function (TSF) of a Wireless Local Area Network (WLAN). In another exemplary embodiment of the present disclosure, the application processor and the modem processor measure a pulse width and the aforementioned common time reference in order to adjust media playback.
Claims21
-20. (canceled)
A method for asynchronous sample rate conversion of media data transmitted within a network, the method comprising:
- initiating capture of one or more observed timelines associated with the media data;
- identifying an anchor pair associated with the media data, the anchor pair being indicative that a first time reference corresponding to a network time matches a second time reference corresponding to first one or more media samples received from the network;
- for one or more media samples received subsequent to the first one or more media samples, and based at least in part on the identifying of the anchor pair, determining a difference between an ideal timeline and an observed timeline;
- adjusting a rate scalar parameter of the media data based at least on the determined difference;
- and
- scheduling playback of the media data.
A computerized media apparatus configured to receive media, the computerized media apparatus comprising:
- a first processor apparatus;
- a data interface in data communication with the processor apparatus and configured to receive media data;
- an asynchronous sample rate converter;
- and
- a non-transitory computer-readable apparatus comprising a memory subsystem, the memory subsystem comprising a plurality of computer-executable instructions configured to, when executed by the first processor apparatus, cause the media apparatus to:
- receive data indicative of one or more observed timelines associated with the media data;
- determine an anchor point associated with the media data, the anchor point comprising a first time reference corresponding to a network time and a second time reference corresponding to one or more first media samples of the media data;
- determine an error between an ideal timeline and an observed timeline for one or more second media samples based at least on the determination of the anchor point;
- and
- adjust a rate associated with the media data based at least on the determined error.
A non-transitory computer-readable apparatus comprising a storage medium, the storage medium comprising a computer program having a plurality of instructions configured to, when executed by a processor apparatus, enable a computerized apparatus to:
- responsive to initiation of audio playback, capture a plurality of observed time values associated with audio data;
- identify anchor data associated with the audio data, the anchor data comprising a network time reference and a sample time associated with the audio data;
- determine a difference between an ideal time value and a given one of the plurality of observed time values;
- adjust a rate associated with the audio data based on the determined difference;
- schedule playback of the audio data based on the adjusted rate.
Dependencies are inferred from the claim text.