SYNCHRONIZING DIGITAL AUDIO AND ANALOG VIDEO FROM A PORTABLE MEDIA DEVICE
First Claim
1. A method of presenting an audio/video track using a portable media device and an accessory device, the method comprising, by the portable media device:
- receiving from the accessory device audio latency information;
determining a video delay time based on the audio latency information;
sending digital audio data to the accessory, the digital audio data corresponding to an audio portion of the audio/video track; and
providing an analog video signal to a video display, the analog video signal corresponding to a video portion of the audio/video track,wherein the analog video signal is delayed, relative to the digital audio signal, by the video delay time.
1 Assignment
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Accused Products
Abstract
A portable media device (PMD) can produce an isochronous audio/video experience when the PMD provides a digital audio signal to the accessory while displaying analog video on an accessory-independent display. The accessory can communicate audio latency information to the PMD. The PMD can delay a video portion of a presentation, relative to providing the digital audio signal to the accessory, based on the audio latency information communicated by the accessory. As a result, the user may perceive an isochronous presentation of the audio and video portions of the presentation.
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Citations
35 Claims
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1. A method of presenting an audio/video track using a portable media device and an accessory device, the method comprising, by the portable media device:
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receiving from the accessory device audio latency information; determining a video delay time based on the audio latency information; sending digital audio data to the accessory, the digital audio data corresponding to an audio portion of the audio/video track; and providing an analog video signal to a video display, the analog video signal corresponding to a video portion of the audio/video track, wherein the analog video signal is delayed, relative to the digital audio signal, by the video delay time. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method of presenting an audio/video track using a portable media device and an accessory device, the method comprising, by the accessory device:
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receiving from the portable media device a first sample rate for digital audio data corresponding to an audio portion of a first audio/video track; determining, based at least in part on the first sample rate, an audio latency parameter value; sending the audio latency parameter value to the portable media device, wherein the portable media device uses the audio latency parameter to determine a delay time for a video portion of the first audio/video track; receiving the digital audio data corresponding to the audio portion of the first audio/video track from the portable media device; processing the digital audio data to produce an analog audio signal, wherein processing of the digital audio data occurs with a latency corresponding to the audio latency parameter value; and delivering the analog audio signal to a speaker. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A method of synchronizing a video presentation on a portable media device with a corresponding audio presentation on an accessory device, the method comprising:
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determining an audio latency characteristic for a digital audio signal propagating through the accessory device; storing audio latency information corresponding to the audio latency characteristic in the accessory device; coupling the portable media device to the accessory device; and providing the audio latency information from the accessory device to the portable media device. - View Dependent Claims (18, 19, 20, 21)
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22. A method of synchronizing a video presentation on a portable media device with a corresponding audio presentation on an audio accessory device, the method comprising:
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coupling the portable mobile device to the audio accessory device; sending, from the audio accessory device to the portable media device, a command providing an audio latency parameter for the audio accessory device; providing digital audio data for the audio presentation from the portable media device to the audio accessory device; and delaying presentation of the video presentation by an amount of time determined from the audio latency parameter.
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23. An accessory for use with a portable media device, the accessory comprising:
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an audio processing path configured to produce an analog audio signal from a digital audio signal; an interface configured to communicate with a portable media device, the interface being configured to receive a digital audio signal from the portable media device and further configured to exchange with the portable media device commands and information related to the presentation of digital audio data; and a controller coupled to the interface and to the audio processing path, the controller being configured to; send a first command to the portable media device via the interface, the first command providing to the portable media device audio latency information corresponding to a latency characteristic of the audio processing path; receive digital audio data from the portable media device via the interface; and deliver the digital audio data to the audio processing path. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30, 31)
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32. A portable media device for use with an accessory, the portable media device comprising:
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a video path configured to produce an analog video signal; an interface configured to communicate with an accessory, the interface being configured to send a digital audio signal to the accessory and further configured to exchange with the accessory device commands and information related to the presentation of digital audio data; and a processor coupled to the interface and to the video path, the processor being configured to; receive a first command from the accessory via the interface, the first command providing to the portable media device audio latency information corresponding to a latency characteristic of the accessory; determine a video delay time for a video portion of an audio/video track based on the audio latency information; send digital audio data for an audio portion of the audio/video track to the accessory via the interface; and deliver the video portion of the audio/video track to the video path, wherein the delivery of the video portion is delayed, relative to sending the digital audio data to the accessory, by the video delay time. - View Dependent Claims (33, 34, 35)
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Specification