Streaming Media System and Method

• US 20070180137A1
• Filed: 01/27/2007
• Published: 08/02/2007
• Est. Priority Date: 01/28/2006
• Status: Active Grant

• Current Assignee: Roku, Inc.
• Original Assignee: Blackfire Research Corporation
• Inventors: Rajapakse, Ravi
• Granted Patent: US 8,677,002 B2
• Time in Patent Office: Days
• US Class Current: 709/231
• CPC Class Codes: H04L 65/65 Network streaming protocols, e.g. real-time transport protocol [RTP] or real-time control protocol [RTCP]
• CPC Class Codes: H04L 65/762 at the source reformatting of additional data in video distribution servers H04N21/2355
• CPC Class Codes: H04L 65/80 Responding to QoS
• CPC Class Codes: H04L 69/28 Timers or timing mechanisms used in protocols
• CPC Class Codes: H04N 21/2368 Multiplexing of audio and video streams
• CPC Class Codes: H04N 21/23805 Controlling the feeding rate to the network, e.g. by controlling the video pump
• CPC Class Codes: H04N 21/242 Synchronization processes, e.g. processing of PCR [Program Clock References] arrangements for synchronising broadcast or distribution via plural systems in broadcast distribution systems H04H20/18
• CPC Class Codes: H04N 21/4341 Demultiplexing of audio and video streams
• CPC Class Codes: H04N 21/6131 involving transmission via a mobile phone network wireless downlink channel access H04W74/006
• CPC Class Codes: H04N 21/6405 Multicasting data broadcast and multicast in packet switching networks H04L12/18
• CPC Class Codes: H04N 21/8106 involving special audio data, e.g. different tracks for different languages
• CPC Class Codes: H04N 21/8547 involving timestamps for synchronizing content

Abstract

A system and method for streaming media on a wireless network is provided. In one aspect, the system includes a streaming device driver; a multidestination wireless streaming protocol module, a multitank level algorithm module, a synchronization mechanism module, and an autoequalizing speaker and drive system module. The system and method minimize latency, dropout, jitter, and synchronization issues associated with media streaming while optimizing performance and output quality of the media.

Claims

1. A media arrangement for streaming media in a network, the arrangement comprising:

a source providing media comprising a plurality of channels;

a streaming media system receiving media provided by the source and outputting a media stream; and

a plurality of destination devices, wherein each destination device in the plurality of destination devices receives and outputs a channel of the streamed media from the streaming media system, the output of the streamed media by the plurality of destination devices is synchronized in time.

2. The media arrangement of claim 1, wherein the source is a handheld portable computing device.

3. The media arrangement of claim 1, wherein the plurality of destination devices are physically located over a wide area and networked by a combination of wireless and wired IP networks, and each channel of the streamed media can be output on one or more destination devices.

4. The media arrangement of claim 1, wherein the streaming media system further comprises a streaming device driver that represents the streaming media system as a standard audio device to a software application.

5. The media arrangement of claim 1, wherein the streaming media system further comprises a wireless streaming protocol module for managing streaming contention.

6. The media arrangement of claim 1, wherein the streaming media system further comprises a synchronization mechanism module for enabling the plurality of destination devices to output the media synchronized in time.

7. The media arrangement of claim 6, wherein the synchronization mechanism module comprises:

a plurality of frame data packets sent to the plurality of destination devices during a data window; and

a plurality of time check packets sent to the plurality of destination devices during a control window; and

a time check acknowledgment packet sent to the source, the time check acknowledgment packet having;

a clock stamp;

a frame number of a last frame sent of a frame data packet in the plurality of frame data packets, the frame number sent to the source; and

an elapsed clock count, wherein the source uses the time check acknowledgment packet to compute global times at which a same frame was output at each destination and to send each destination an advance or retard message.

8. The media arrangement of claim 1, wherein the streaming media system comprises:

a multidestination streaming protocol module using an IP-based communication network to communicate between the source and the plurality of destination devices, the multidestination streaming protocol module having;

a data window time period during which only the source requests and gains access to a communication channel and transmits data to the plurality of destination devices; and

a control window time period during which each destination device in the plurality of destination devices uses a Carrier Sense Multiple Access With Collision Avoidance mechanism to gain access to the communication channel and transmit information to the source.

9. The media arrangement of claim 1, wherein the streaming media system further comprises an autoequalizing speaker and drive system module associated with the plurality of destination devices.

10. The media arrangement of claim 9, wherein the autoequalizing speaker and drive system module comprises:

a diaphragm;

a voice coil associated with the diaphragm;

a sensor associated with the voice coil, the sensor for sensing a signal related to the movement of the diaphragm and the voice coil; and

an electro magnet coil associated with the sensor, the electro magnet coil for providing a modulated magnetic field for the voice coil.

11. The media arrangement of claim 1, wherein the source includes a streaming device driver that performs at least one precompensation activity based on performance characteristics obtained from one of the plurality of destination devices.

12. An audio system comprising:

a plurality of destination devices for outputting media synchronized in time; and

a source for streaming media, the source having a software application and a streaming device driver, the source coupled to the plurality of destination devices, the streaming device driver representing the plurality of destination devices to the source and to the software application as a standard audio device connected to the source.

13. The audio system of claim 12, wherein the streaming device driver further performs at least one precompensation activity based on performance characteristics obtained from one of the plurality of destination devices.

14. The audio system of claim 12, wherein the source is a handheld portable computing device.

15. The audio system of claim 12, wherein each destination device further comprises an autoequalizing speaker and drive system module.

16. The audio system of claim 12, wherein the plurality of destination devices and the source are coupled by an IP based wireless network.

17. The audio system of claim 12, wherein:

the software application provides audio via multiple audio channels;

the streaming device driver intercepts each audio channel and streams each intercepted audio channel; and

the source includes a wireless means for transmitting to a corresponding destination device in the plurality of destination devices a streamed audio channel.

18. The audio system of claim 12, wherein the streaming device driver performs an audio processing function on the intercepted and streamed audio channel.

19. The audio system of claim 12, wherein the audio processing function is a precompensation function.

20. A method for synchronizing a time output of data samples at multiple destination devices receiving a packet data stream, the method comprising:

broadcasting a time check message from a source to a predetermined set of destination devices;

upon receipt of the broadcasted time check message, each destination device in the predetermined set of destination devices intercepting the time check message at a Link layer of an IP network stack at each destination device in the predetermined set of destination devices and recording a time check message receipt time;

sending an acknowledge message from each destination device in the predetermined set of destination devices to the source, the acknowledge message indicating the recorded time check message receipt time; and

the source using the acknowledge messages to determine content of an adjust output time message sent to each destination device in the predetermined set of destination devices, the determined content of the adjust output time message determining the time of output of subsequent data samples at each destination device in the predetermined set of destination devices.

21. The method of claim 20 further comprising:

recording a time elapsed between receipt of the time check message and an event at the destination device in the predetermined set of destination devices;

including in the acknowledge message from each destination device in the predetermined set of destination devices to the source, the recorded time elapsed between receipt of the time check message and the event at the destination device in the predetermined set of destination devices; and

using the acknowledge message to determine content of the adjust output time message sent to each destination device in the predetermined set of destination devices, the determined content of the adjust time message indicating either to advance the time of the next data sample output or to retard the time of the next data sample output.

22. A speaker comprising:

a diaphragm;

a voice coil associated with the diaphragm; and

a sensor associated with the diaphragm, the sensor for sensing a signal related to the movement of the diaphragm and the voice coil.

23. The speaker of claim 22, further comprising an electro magnet coil, the electro magnet coil providing a modulated magnetic field for the voice coil.

24. The speaker of claim 23, further comprising:

a sensor module associated with the sensor, the sensor module processing the signal sensed by the sensor;

a magnet drive module for driving the magnet coil that provides a magnetic field for the voice coil;

a voice coil drive module for providing a signal to the voice coil;

an audio receiver module for receiving in an audio input signal and providing the signal to the drive controller; and

a drive controller that uses the audio signal from the audio receiver module together with the sense information from the sensor module to provide signals to the magnet drive module and voice coil modules to cause the diaphragm to move in a manner that produces sound waves that correctly represents the input audio signal.

25. The speaker of claim 24, wherein the signals provided to the magnet coil and voice coil are pulse trains whose relative phase or relative pulse width are adjusted by the drive controller.

26. The speaker of claim 22, wherein the sensor is one from the group of:

a magnetic flux sensor, an optical detector and an infrared sensor.

27. The speaker of claim 24, wherein the driver controller uses prior stored information regarding the speaker or information provided by a source to adjust the input audio signal such that a generated audio wave represents the input audio signal more accurately.