US20080240165A1 - Method and system for synchronization of content rendering - Google Patents

Method and system for synchronization of content rendering Download PDF

Info

Publication number
US20080240165A1
US20080240165A1 US11933194 US93319407A US2008240165A1 US 20080240165 A1 US20080240165 A1 US 20080240165A1 US 11933194 US11933194 US 11933194 US 93319407 A US93319407 A US 93319407A US 2008240165 A1 US2008240165 A1 US 2008240165A1
Authority
US
Grant status
Application
Patent type
Prior art keywords
time
rendering
device
master
content
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US11933194
Inventor
Edward Balassanian
Scott W. Bradley
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
IMPLICIT LLC
Original Assignee
Edward Balassanian
Bradley Scott W
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Family has litigation

Links

Images

Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L41/00Arrangements for maintenance or administration or management of packet switching networks
    • H04L41/04Architectural aspects of network management arrangements
    • GPHYSICS
    • G06COMPUTING; CALCULATING; COUNTING
    • G06FELECTRIC DIGITAL DATA PROCESSING
    • G06F17/00Digital computing or data processing equipment or methods, specially adapted for specific functions
    • G06F17/30Information retrieval; Database structures therefor ; File system structures therefor
    • G06F17/30017Multimedia data retrieval; Retrieval of more than one type of audiovisual media
    • G06F17/3005Presentation of query results
    • G06F17/30053Presentation of query results by the use of playlists
    • G06F17/30056Multimedia presentations, e.g. slide shows, multimedia albums
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04NPICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00Details of television systems
    • H04N5/76Television signal recording
    • H04N5/765Interface circuits between an apparatus for recording and another apparatus
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04NPICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00Details of television systems
    • H04N5/76Television signal recording
    • H04N5/765Interface circuits between an apparatus for recording and another apparatus
    • H04N5/775Interface circuits between an apparatus for recording and another apparatus between a recording apparatus and a television receiver

Abstract

A method and system for synchronizing the rendering of content at various rendering devices. Each rendering device has a device time and a rendering time. The synchronization system designates one of the rendering devices as a master rendering device and designates all other rendering devices as slave rendering devices. Each slave rendering device adjusts the rendering of its content to keep it in synchronization with the rendering of the content at the master rendering device. The master rendering device sends a message with its rendering time and corresponding device time to the slave rendering devices. Each slave rendering device, upon receiving the message from the master rendering device, determines whether it is synchronized with the master rendering time. If not, the slave rendering device adjusts the rendering of its content to compensate for the difference between the master rendering time and the slave rendering time.

Description

  • [0001]
    The following application is incorporated by reference as if fully set forth herein: U.S. application Ser. No. 10/322,335 filed Dec. 17, 2002.
  • TECHNICAL FIELD
  • [0002]
    The described technology relates to rendering of content at multiple rendering devices in a synchronized manner.
  • BACKGROUND
  • [0003]
    Multimedia presentations that are presented on different rendering devices (e.g., video display and stereo system) typically require that the different content of the presentation be rendered in a synchronized manner. For example, a multimedia presentation may include video, audio, and text content that should be rendered in a synchronized manner. The audio and text content may correspond to the dialogue of the video. Thus, the audio and text contents need to be rendered in a synchronized manner with the video content. Typically, the content of a multimedia presentation is stored at a single location, such as on a disk drive of a source device. To render the presentation, the source device retrieves each different type of content and sends it to the appropriate rendering device to effect the multimedia presentation. The source device then sends the content to the rendering devices in sufficient time so that the rendering devices can receive and render the content in a timely manner.
  • [0004]
    Various rendering devices, however, may have different time domains that make the rendering of the multimedia presentation in a synchronized manner difficult. For example, video and audio rendering devices may have system clocks that operate at slightly different frequencies. As a result, the video and audio content will gradually appear to the person viewing the presentation to be out of synchronization. The rendering of content in a synchronized manner is made even more difficult because some rendering devices may have multiple time domains. For example, an audio rendering device may have a system clock and a clock on a digital signal processing (“DSP”) interface card. In such a case, the combination of clocks may result in the presentation becoming even more quickly out of synchronization.
  • [0005]
    It would be desirable to have the technique that would facilitate the rendering of the multimedia presentation in a synchronized manner.
  • BRIEF DESCRIPTION OF THE DRAWINGS
  • [0006]
    FIG. 1 is a block diagram illustrating synchronization of rendering devices in one embodiment.
  • [0007]
    FIG. 2 is a diagram illustrating the calculation of the time domain differential between two devices.
  • [0008]
    FIG. 3 illustrates a time domain table for a rendering device in one embodiment.
  • [0009]
    FIG. 4 illustrates a block diagram of another embodiment of the synchronization system.
  • [0010]
    FIG. 5 is a block diagram illustrating components of a content rendering device in one embodiment.
  • [0011]
    FIG. 6 is a flow diagram illustrating the processing of the send time domain message component in one embodiment.
  • [0012]
    FIG. 7 is a flow diagram of the receive time domain message component in one embodiment.
  • [0013]
    FIG. 8 is a flow diagram illustrating the render content component in one embodiment.
  • [0014]
    FIG. 9 is a flow diagram illustrating the process of the send rendering time message component in one embodiment.
  • [0015]
    FIG. 10 is a block diagram illustrating the processing of the receive rendering time message component in one embodiment.
  • DETAILED DESCRIPTION
  • [0016]
    A method and system for synchronizing the rendering of content at various rendering devices is provided. In one embodiment, each rendering device has a device time and a rendering time. The device time is the time as indicated by a designated clock (e.g., system clock) of the rendering device. The rendering time is the time represented by the amount of content that has been rendered by that rendering device. For example, if a rendering device is displaying 30 frames of video per second, then the rendering time will be 15 seconds after 450 frames are displayed. The rendering time of content at a rendering device has a “corresponding” device time, which is the device time at which the rendering time occurred. For example, the rendering time of 15 seconds may have a corresponding device time of 30 minutes and 15 seconds when the rendering device initialized 30 minutes before the start of rendering the video. To help ensure synchronization of rendering devices, the synchronization system designates one of the rendering devices as a master rendering device and designates all other rendering devices as slave rendering devices. Each slave rendering device adjusts the rendering of its content to keep it in synchronization with the rendering of the content at the master rendering device. The master rendering device sends a message with its rendering time and corresponding device time to the slave rendering devices. Each slave rendering device, upon receiving the message from the master rendering device, determines whether it is synchronized with the master rendering time. If not, the slave rendering device adjusts the rendering of its content to compensate for the difference between the master rendering time and the slave rendering time. A slave rendering device can determine the amount it is out of synchronization by comparing its slave rendering time at a certain slave device time to the master rendering time at that same device time. Alternatively, the amount can be determined by comparing its slave device time at a certain rendering time to the master device time at that same rendering time. In another embodiment, the synchronization system can define a default rendering time for the synchronization. In such a case, the master rendering device need only include its effective device time that corresponds to the default rendering time in the message that is sent to the slave rendering devices. For example, the default rendering time might be the rendering time of zero. In such a case, the master rendering device can subtract its current rendering time from its current device time to give its effective device time at rendering time zero. A slave rendering device, knowing the default rendering time, can determine whether it is synchronized and the variation in rendering time between the master rendering device and the slave rendering device.
  • [0017]
    In one embodiment, the synchronization system allows for two sources of content to be synchronized even though the rendering times of the sources are not themselves synchronized. For example, two separate sources may be video transmitted via satellite and audio transmitted via land telephone lines. If audio is being transmitted and then a few seconds later the corresponding video starts to be transmitted, then the rendering times of zero for the audio and video will not correspond to a synchronized state. For example, the video at the video rendering time of zero should be rendered at the same time as the audio with the audio rendering time of five is rendered. This difference in rendering times is referred to as source offset. In addition, the difference in the propagation delay resulting from the different transmission paths of the video and audio may be variable and thus contribute to a variation in synchronization that is variable and is not known in advance.
  • [0018]
    To account for this lack of synchronization, the synchronization system allows a user (e.g., the person viewing the content) to manually account for the variation. For example, if the video and audio are rendered via a personal computer, the synchronization system may display a dial or a slider on a user interface that the user can adjust to indicate the difference in the rendering times. If the video is rendered five seconds after the corresponding audio, then the user can indicate via the user interface that the offset is five seconds. In such a case, the synchronization system may use the offset to adjust the rendering time of the audio so that the audio associated with the adjusted audio rendering time should be rendered at the same time as the video content with the same video rendering time. The synchronization system could buffer the audio to account for the offset.
  • [0019]
    The synchronization system in one embodiment factors in the differences in the time domains of the various rendering devices when evaluating synchronization. The rendering devices exchange device time information so that the rendering devices can account for the differences in the time domains of the other rendering devices. Each rendering device may send to the other rendering devices a time domain message that includes its current device time (i.e., send time) along with the time it received the last time domain message (i.e., receive time) from each of the other rendering devices and the send time of that last time domain message. When a rendering device receives such a time domain message, it calculates the time differential between its time domain and the time domain of the sending rendering device. In one embodiment, the synchronization system calculates the time domain differential by combining the difference in send and receive times for the last messages sent to and received from another device in a way that helps factor out the transmission time of the messages. A slave rendering device can then use this time domain differential to convert the master device time to the time domain of the slave when synchronizing the rendering of content. In one embodiment, each rendering device broadcasts at various times its time domain message. The time domain message includes a received time for a message received for each of the other rendering devices. Each rendering device receives the broadcast time domain message. The receiving rendering device can then calculate its time domain differential with the broadcasting rendering device. In this way, time domain differentials can be determined on a peer-to-peer basis without the need for a master device to keep a master time and by broadcasting the time domain messages, rather then sending separate time domain messages for each pair of devices.
  • [0020]
    FIG. 1 is a block diagram illustrating synchronization of rendering devices in one embodiment. The source device 101 distributes the content of a presentation to the video rendering device 102, the audio rendering device 103, and the text rendering device 104 via communications link 105. The source device may have the multimedia presentation stored locally, for example, on a disk drive, may dynamically generate the multimedia presentation, may receive content of the multimedia presentation from other sources, and so on. A multimedia presentation is any presentation that includes different content that is to be rendered in a synchronized manner. For example, the content could be video and audio content for a virtual ride in a theme park along with motion content to control the ride. As another example, the presentation may include light content that controls the display of a laser to be synchronized with audio content. Also, the “synchronization” of content may be different for different rendering devices. For example, audio content may be sent to multiple audio rendering devices with the expectation that some of the audio rendering devices may delay rendering for a certain period (e.g., 10 milliseconds) to achieve a desired audio effect. In such a case, the rendering is considered synchronized when the delay equals that period. The synchronization system designates one of the rendering devices as the master rendering device. In this example, the audio rendering device 103 is designated as the master rendering device, and the video rendering device 102 and text rendering device 104 are designated as slave rendering devices. After the source starts sending the content to the rendering devices, the audio rendering device broadcasts a master rendering time message with its master device time and master rendering time to the slave rendering devices on a periodic basis. In this example, since the communications link is point-to-point from the source device, the audio rendering device sends the message to the source device, which in turn forwards the message to the slave rendering devices. Upon receiving the master rendering time message, the slave rendering devices convert the master device time to their own time domains and then calculate the difference between their slave rendering time and the master rendering time at a certain point in time. In one embodiment, the synchronization system uses a device time at a calculated start of sending as the point in time. The slave rendering devices then adjusts the rendering as appropriate to compensate for the difference. The rendering device adjusts the rendering of their content in ways that are appropriate for their content. For example, if the video rendering device was one second behind the master audio rendering device, then it might skip the display of every other frame for the next two seconds to “speed up” to the master audio rendering device. Alternately, if the video rendering device was one second ahead of the master audio rendering device, then the video rendering device might display each of the next 30 frames twice to “slow down” to the master audio rendering device.
  • [0021]
    FIG. 2 is a diagram illustrating the calculation of the time domain differential between two devices. Device 1 initially sends to device 2 a time domain message 301 that includes its current device time, referred to as “sendtime1.” When device 2 receives the time domain message, it stores the sendtime1 along with the time it received the time domain message, referred to as “receivetime1.” Device 2 then sends to device 1 a time domain message 302 that includes its device time, referred to as “sendtime2,” along with sendtime1 and receivetime1. When device 1 receives the time domain message, it stores sendtime1, receivetime1, and sendtime2 along with its device time, referred to as “receivetime2.” Device 1 now has enough information to calculate the time domain differential according to the following formula:
  • [0022]
    Diff=((RT1−ST1)+(ST2−RT2))/2
  • [0000]
    where Diff is the time domain differential, RT is receive time, and ST is send time. Device 1 then sends a time domain message 303 to device 2 that includes its device time, referred to as “sendtime3” along with sendtime2 and receivetime2. When device 2 receives the time domain message, it stores sendtime2, receivetime2, and sendtime3 along with its device time, referred to as “receivetime3.” Device 2 now has enough information to calculate the time differential according to a similar formula.
  • [0023]
    This formula calculates the difference between the send time and the receive time for time domain messages between the two devices. If there was no variation in the time domains between the devices, then the send and receive times would reflect the communications link latency between sending and receiving the time domain messages. In one embodiment, the synchronization system assumes that the latency in transmitting a message from one device to another device is approximately the same as the latency in transmitting the message from the other device to the device. Thus, the synchronization system calculates the time domain difference by taking the average of the differences in the send and receive times of the messages. The receive time of the messages is represented by the following equations:
  • [0000]

    RT1=ST1+Diff+L
  • [0000]

    RT2=ST2−Diff+L
  • [0000]
    where Diff represents the time domain differential and L represents the latency of the communications link. These equations are equivalent to the following equations:
  • [0000]

    Diff=RT1−ST1−L
  • [0000]

    Diff=ST2−RT2+L
  • [0000]
    The average of these two equations is
  • [0000]

    Diff=((RT1−ST1−L)+(ST2−RT2+L))/2
  • [0000]
    The latency factors out of the equation to give the following equation:
  • [0000]

    Diff=((RT1−ST1)+(ST2−RT2))/2
  • [0024]
    FIG. 3 illustrates a time domain table for a rendering device in one embodiment. The time domain table of a device includes a row for each other device to which the device is connected. For example, the audio rendering device 103 of FIG. 1 would have a row for the source device 101, the video rendering device 102, and the text rendering device 104. In this example, the time domain table includes a node identifier column 301, a sendtime1 column 302, a receivetime1 column 303, a sendtime2 column 304, a receivetime2 column 305, and a time domain differential column 306. A positive time domain differential indicates the number of time units that this device is ahead of the other device, and a negative time domain differential indicates the number of time units that this device is behind the other device. Thus, in this example, the device time of the audio rendering device 103 is ahead of the device time of the source device 101 by 1000 time units. In contrast, the device time of the audio rendering device 103 is behind the device time of the video rendering device 102 by 495 time units. One skilled in the art will appreciate the time units can be any units appropriate to the desired synchronization accuracy, such as milliseconds, microseconds, and so on. One skilled in the art will appreciate the time domain messages need not include the times set by the receiving device. For example, the time domain message 302 need not include sendtime1 since device 1 could have stored that time locally.
  • [0025]
    FIG. 4 illustrates a block diagram of another embodiment of the synchronization system. In this example, the source device 400 performs the function of the master, and the video rendering device 401, the audio rendering device 402, and the text rendering device 403 are slaves. In particular, the source device, even though it does no rendering itself, may keep track of an idealized rendering time that may not correspond to the actual rendering time of any of the rendering devices. In such a situation, the master source device periodically sends a rendering time message that includes its device time along with the corresponding idealized rendering time to each of the rendering devices. The rendering devices can then adjust their rendering in the same manner as if the rendering time message is sent from a master rendering device. Alternatively, each rendering device can provide their device time and corresponding rendering time to the source device. The source device can then calculate the rendering time differential for each rendering device and provide that differential to the rendering devices to speed up or slow down their rendering as appropriate.
  • [0026]
    FIG. 5 is a block diagram illustrating components of a content rendering device in one embodiment. The content rendering device 500 includes a receive content component 501, a render content component 502, a send time domain message component 503, a receive time domain message component 504, a time domain table 505, a send rendering time message component 506, and a receive rendering time message component 507. The receive content component receives content from the source device and may store the content in a buffer for subsequent rendering. The rendering content component retrieves the buffered content and effects the rendering of the content. The send time domain message component sends time domain messages to the other devices. The send time domain message component may send the message upon occurrence of an event, such as when a timer expires, when a message is received, and so on. One skilled in the art will appreciate that the frequency of sending time domain messages can be adjusted to account for the anticipated drift between clocks of the rendering devices. The receive time domain message component receives the time domain messages sent by other devices and updates the time domain table as appropriate. The send rendering time message component is used when this content rendering device is a master rendering device to send a rendering time message to the other rendering devices. The receive rendering time message component receives the rendering time messages sent by the master device and calculates a rendering time differential that is used to adjust the rendering of the content. The devices may include a central processing unit, memory, input devices (e.g., keyboard and pointing devices), output devices (e.g., display devices), and storage devices (e.g., disk drives). The memory and storage devices are computer-readable media that may contain instructions that implement the synchronization system. In addition, data structures and message structures may be stored or transmitted via a data transmission medium, such as a signal on a communications link. Various communications links may be used, such as the Internet, a local area network, a wide area network, or a point-to-point dial-up connection.
  • [0027]
    FIG. 6 is a flow diagram illustrating the processing of the send time domain message component in one embodiment. In block 601, the component adds the identifier of this device to the time domain message. In block 602, the component adds the send time to the message. The send time is the current device time. In blocks 603-607, the component loops selecting each other device and adding times for that device to the time domain message then loops to block 603 to select the next device. In block 608, the component sends the time domain message to the other devices and then completes.
  • [0028]
    FIG. 7 is a flow diagram of the receive time domain message component in one embodiment. In decision block 701, if the identifier of this device is in the list of device identifiers in the message, then the component continues at block 702, else the component completes. In block 702, the component retrieves the current send time from the message and saves it in the time domain table. In block 703, the component retrieves the last send time from the message and saves it in the time domain table. In block 704, the component retrieves the last receive time from the message and saves it in the time domain table. In block 705, the component retrieves the device time as the current receive time and saves it in the time domain table. The time values may be saved by storing them in the time domain table in the row associated with the device that sent the message. In block 706, the component calculates the time domain differential. In block 707, the component smoothes the time domain differential. The time domain differential can be smoothed using various techniques such as averaging the last several time domain differentials using a decaying function to limit the impact of the oldest time domain differentials. In one embodiment, the synchronization system saves the values of the last eight pairs of time domain differentials (i.e., ST2−RT2 and RT1−ST1) and uses the average of the minimum value of the set of eight larger differentials and the maximum value of the set of eight smaller differentials as the time domain differential. The component then completes.
  • [0029]
    FIG. 8 is a flow diagram illustrating the render content component in one embodiment. In blocks 801-806, the component loops processing each block of content that is received from the source device. In block 801, the component selects the next block of content provided by the source device. The content may be buffered at this rendering device. In decision block 802, if all the blocks of content have already been selected, then the component completes, else the component continues at block 803. In decision block 803, if the rendering time differential is 0, then the component continues at block 806, else the component continues at block 804. The rendering time differential is calculated by the receive rendering time message component and adjusted by this component as the rendering of the content is adjusted. In block 804, the component adjusts the selected block to account for the rendering time differential. For example, if the content corresponds to video information, then the component may remove frames to effectively speed up the rendering or may duplicate frames to effectively slow down the rendering. In block 805, the component adjusts the rendering time differential to account for the adjustments to the selected block. For example, if the block corresponds to one second of video information and the adjustment was to duplicate every frame in the block, then the rendering time differential is adjusted by subtracting one second. The rendering time continues to reflect the amount of the content that has been effectively rendered. For example, if every frame is duplicated in a one second interval resulting in two seconds of adjusted content, the rendering time would only be increased by one second. In block 806, the component outputs the selected block, either adjusted or unadjusted to effect the rendering of that block of content. The component then loops to 801 to select the next block of content.
  • [0030]
    FIG. 9 is a flow diagram illustrating the process of the send rendering time message component in one embodiment. The component can be executed upon the occurrence of various events, such as when a timer expires. In block 901, the component adds the rendering time of this master device to the message. In block 902, the component retrieves the device time for this master device. In block 903, the component adds the device time to the message. In block 904, the component then broadcasts the message to the other rendering devices and then completes.
  • [0031]
    FIG. 10 is a block diagram illustrating the processing of the receive rendering time message component in one embodiment. In block 1001, the component extracts the master device time from the message. In block 1002, the component extracts the master rendering time from the message. In block 1003, the component converts the master device time to the time domain of this device. In block 1004, the component calculates the master start time by subtracting the master rendering time from the converted master device time. The master start time is in the time domain of this device and represents the time at which the master device effectively started rendering its content. In block 1005, the component calculates the slave start time of this device by subtracting the slave rendering time from the current slave device time. The slave start time indicates the time at which this slave device started rendering its content. In block 1006, the component calculates the rendering time differential by subtracting the slave start time from the master start time. The component then completes.
  • [0032]
    From the foregoing, it will be appreciated that specific embodiments of the invention have been described herein for purposes of illustration, but that various modifications may be made without deviating from the spirit and scope of the invention. The rendering devices can be components of the same physical device. For example, a DVD player may have a component that processes the video content and a separate component that processes the audio. The hardware and software of these components may result in a difference in rendering speed of the content, and thus the rendering can become out of synchronization over time. Accordingly, the invention is not limited except as by the appended claims.

Claims (25)

  1. 1. A method for synchronizing the rendering of content at a plurality of devices, the content having a rendering time, the method comprising:
    designating one of the devices as a master device and the other devices as slave devices;
    sending to each device content to be rendered at that device synchronized with the content sent to the other devices;
    sending from the master device to the slave devices an indication of when the master device renders content corresponding to a rendering time; and
    after receiving the indication at a slave device, adjusting based on the received indication the rendering of the content at the slave device to account for variation between when the master device and the slave device render content that should be rendered at the same time.
  2. 2. The method of claim 1 wherein the indication sent from the master device to the slave devices includes a master device time at which the master device renders content corresponding to a rendering time.
  3. 3. The method of claim 2 wherein the indication sent from the master device to the slave devices includes the corresponding rendering time.
  4. 4. The method of claim 2 wherein the corresponding rendering time is a default rendering time.
  5. 5. The method of claim 2 wherein the corresponding rendering time is time zero.
  6. 6. The method of claim 2 wherein the adjusting includes:
    calculating a difference between the master device time and a slave device time that correspond to the rendering time.
  7. 7. The method of claim 2 wherein the adjusting includes:
    calculating a difference between a master rendering time and a slave rendering time that correspond to the same master and slave device times.
  8. 8. The method of claim 2 wherein the adjusting includes:
    adjusting a device time so that the master device time and the slave device time are in the same time domain;
    calculating a master start time for the master device from the master device time that is in the same time domain as the slave device time and a master rendering time;
    calculating a slave start time for the slave device from the slave device time that is in the same time domain as the master device time and a slave rendering time; and
    calculating the difference between the slave start time and the master start time.
  9. 9. The method of claim 1 wherein the sending of the indication from the master device to the slave devices occurs at various times so that the slave devices can adjust the rendering of the content as appropriate.
  10. 10. The method of claim 1 wherein the adjusting accounts for variations in the time domain of the master device and the slave device.
  11. 11. The method of claim 1 wherein the content is sent from a single source to the master device and the slave devices.
  12. 12. The method of claim 1 wherein the content is sent from different sources to the master device and the slave devices.
  13. 13. The method of claim 12 including receiving a rendering time adjustment that indicates a difference in a master rendering time and a slave rendering time of content that is to be synchronized.
  14. 14. The method of claim 13 wherein a user specifies the rendering time adjustment.
  15. 15. The method of claim 14 wherein the user specifies the rendering time adjustment by indicating the amount of time the master device and the slave device are out of synchronization.
  16. 16. A method for synchronizing rendering of content at devices, each device having a device time and a rendering time, the device time of a device being in a time domain of the device, the method comprising:
    designating one of the devices as a master device and the one or more other devices as slave devices;
    sending to each device content to be rendered at that device synchronized with the content sent to the other devices;
    sending from the master device to the one or more slave devices a master device time corresponding to a master rendering time of the master device; and
    upon receiving the sent master device time at a slave device, adjusting the rendering of the content at the slave device to account for a difference in a slave rendering time and a master rendering time calculated based on the master device time adjusted for a difference in time domains of the slave device and the master device.
  17. 17. The method of claim 16 wherein the difference in a slave rendering time and a master rendering time is calculated by:
    converting the master device time to a time frame of the slave device;
    calculating a master start time for the master device from the converted master device time and the master rendering time;
    calculating a slave start time for the slave device from the slave device time and the slave rendering time; and
    calculating the difference between the slave start time and the master start time.
  18. 18. The method of claim 16 wherein the sending from the master device to the slave devices the master device time and the master rendering time occurs at various times so that the slave devices can adjust the rendering of the content as appropriate.
  19. 19. The method of claim 16 wherein the content is sent from different sources to the master device and the slave devices.
  20. 20. The method of claim 19 including receiving a rendering time adjustment that indicates a difference in a master rendering time and a slave rendering time of content that is to be synchronized.
  21. 21. The method of claim 20 wherein a user specifies the rendering time adjustment.
  22. 22. The method of claim 21 wherein the user specifies the rendering time adjustment by indicating the amount of time the master device and the slave device are out of synchronization.
  23. 23. A method for synchronizing rendering of content at devices, each device having a device time and a rendering time, the device time of a device being in a time domain of the device, the method comprising:
    designating one of the devices as a master device and the one or more other devices as slave devices; and
    for each slave device,
    calculating a difference in a master rendering time of the master device and slave rendering time of the slave device based on a master device time adjusted for a difference in time domains of the slave device and the master device; and
    rendering content at the slave device to account for the calculated difference.
  24. 24. The method of claim 23 including sending a master device time and a corresponding master rendering time to each slave device for use in calculating the difference.
  25. 25. The method of claim 24 wherein the master device sends the master device time and the corresponding master rendering time to the slave devices.
US11933194 2001-12-17 2007-10-31 Method and system for synchronization of content rendering Abandoned US20080240165A1 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US34157401 true 2001-12-17 2001-12-17
US10322335 US7391791B2 (en) 2001-12-17 2002-12-17 Method and system for synchronization of content rendering
US11933194 US20080240165A1 (en) 2001-12-17 2007-10-31 Method and system for synchronization of content rendering

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US11933194 US20080240165A1 (en) 2001-12-17 2007-10-31 Method and system for synchronization of content rendering
US12710146 US8406257B2 (en) 2001-12-17 2010-02-22 Method and system for synchronization of content rendering
US13850260 US8942252B2 (en) 2001-12-17 2013-03-25 Method and system synchronization of content rendering

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US10322335 Continuation US7391791B2 (en) 2001-12-17 2002-12-17 Method and system for synchronization of content rendering

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US12710146 Continuation US8406257B2 (en) 2001-12-17 2010-02-22 Method and system for synchronization of content rendering

Publications (1)

Publication Number Publication Date
US20080240165A1 true true US20080240165A1 (en) 2008-10-02

Family

ID=23338145

Family Applications (4)

Application Number Title Priority Date Filing Date
US10322335 Active 2025-04-01 US7391791B2 (en) 2001-12-17 2002-12-17 Method and system for synchronization of content rendering
US11933194 Abandoned US20080240165A1 (en) 2001-12-17 2007-10-31 Method and system for synchronization of content rendering
US12710146 Active 2023-08-03 US8406257B2 (en) 2001-12-17 2010-02-22 Method and system for synchronization of content rendering
US13850260 Active US8942252B2 (en) 2001-12-17 2013-03-25 Method and system synchronization of content rendering

Family Applications Before (1)

Application Number Title Priority Date Filing Date
US10322335 Active 2025-04-01 US7391791B2 (en) 2001-12-17 2002-12-17 Method and system for synchronization of content rendering

Family Applications After (2)

Application Number Title Priority Date Filing Date
US12710146 Active 2023-08-03 US8406257B2 (en) 2001-12-17 2010-02-22 Method and system for synchronization of content rendering
US13850260 Active US8942252B2 (en) 2001-12-17 2013-03-25 Method and system synchronization of content rendering

Country Status (2)

Country Link
US (4) US7391791B2 (en)
WO (1) WO2003054686A3 (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070230434A1 (en) * 2004-05-28 2007-10-04 Jean-Claude Thill Distributed Synchronization Method and System
US20100100923A1 (en) * 2006-11-06 2010-04-22 Panasonic Corporation Receiver
US20100254499A1 (en) * 2009-04-06 2010-10-07 Avaya Inc. Network synchronization over ip networks
US20100254411A1 (en) * 2009-04-06 2010-10-07 Avaya Inc. Network synchronization over ip networks
US20120200774A1 (en) * 2011-02-07 2012-08-09 Ehlers Sr Gregory Allen Audio and video distribution system with latency delay compensator

Families Citing this family (77)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7391791B2 (en) * 2001-12-17 2008-06-24 Implicit Networks, Inc. Method and system for synchronization of content rendering
US7627808B2 (en) * 2003-06-13 2009-12-01 Microsoft Corporation Computer media synchronization player
US8234395B2 (en) 2003-07-28 2012-07-31 Sonos, Inc. System and method for synchronizing operations among a plurality of independently clocked digital data processing devices
US9977561B2 (en) 2004-04-01 2018-05-22 Sonos, Inc. Systems, methods, apparatus, and articles of manufacture to provide guest access
US20080229335A1 (en) * 2004-06-04 2008-09-18 Apple Computer, Inc. Network media device
US8443038B2 (en) 2004-06-04 2013-05-14 Apple Inc. Network media device
US8797926B2 (en) 2004-06-04 2014-08-05 Apple Inc. Networked media station
US20070110074A1 (en) * 2004-06-04 2007-05-17 Bob Bradley System and Method for Synchronizing Media Presentation at Multiple Recipients
US8868698B2 (en) 2004-06-05 2014-10-21 Sonos, Inc. Establishing a secure wireless network with minimum human intervention
US7356567B2 (en) * 2004-12-30 2008-04-08 Aol Llc, A Delaware Limited Liability Company Managing instant messaging sessions on multiple devices
US7519845B2 (en) 2005-01-05 2009-04-14 Microsoft Corporation Software-based audio rendering
US7657829B2 (en) * 2005-01-20 2010-02-02 Microsoft Corporation Audio and video buffer synchronization based on actual output feedback
US7693873B2 (en) * 2005-10-13 2010-04-06 International Business Machines Corporation System, method and program to synchronize files in distributed computer system
US8761568B2 (en) * 2005-12-20 2014-06-24 Vestel Elektronik Sanayi Ve Ticaret A.S. Method and apparatus for synchronizing subtitles with a video
US20080075295A1 (en) 2006-08-31 2008-03-27 Mayman Avrum G Media playing from a docked handheld media device
US9202509B2 (en) 2006-09-12 2015-12-01 Sonos, Inc. Controlling and grouping in a multi-zone media system
US8788080B1 (en) 2006-09-12 2014-07-22 Sonos, Inc. Multi-channel pairing in a media system
US8483853B1 (en) 2006-09-12 2013-07-09 Sonos, Inc. Controlling and manipulating groupings in a multi-zone media system
US8079907B2 (en) * 2006-11-15 2011-12-20 Harmonix Music Systems, Inc. Method and apparatus for facilitating group musical interaction over a network
US8086752B2 (en) 2006-11-22 2011-12-27 Sonos, Inc. Systems and methods for synchronizing operations among a plurality of independently clocked digital data processing devices that independently source digital data
US20080229200A1 (en) * 2007-03-16 2008-09-18 Fein Gene S Graphical Digital Audio Data Processing System
US8576922B2 (en) * 2007-06-10 2013-11-05 Apple Inc. Capturing media in synchronized fashion
US8332898B2 (en) * 2007-08-09 2012-12-11 Echostar Technologies L.L.C. Apparatus, systems and methods to synchronize communication of content to a presentation device and a mobile device
US8341454B1 (en) 2007-12-28 2012-12-25 Marvell International Ltd. Rendering a video stream based on digital clock generated based on timing information
US7680154B2 (en) * 2007-12-31 2010-03-16 Intel Corporation Methods and apparatus for synchronizing networked audio devices
US8990360B2 (en) 2008-02-22 2015-03-24 Sonos, Inc. System, method, and computer program for remotely managing a digital device
KR100949931B1 (en) * 2008-06-04 2010-03-30 주식회사 에이앤비소프트 Rhythm action game method using a user equipment with key-pad and recording medium storing program implementing the same
US9607655B2 (en) 2010-02-17 2017-03-28 JBF Interlude 2009 LTD System and method for seamless multimedia assembly
US9190110B2 (en) * 2009-05-12 2015-11-17 JBF Interlude 2009 LTD System and method for assembling a recorded composition
US9042556B2 (en) 2011-07-19 2015-05-26 Sonos, Inc Shaping sound responsive to speaker orientation
US9665339B2 (en) 2011-12-28 2017-05-30 Sonos, Inc. Methods and systems to select an audio track
US9654821B2 (en) 2011-12-30 2017-05-16 Sonos, Inc. Systems and methods for networked music playback
US8600220B2 (en) 2012-04-02 2013-12-03 JBF Interlude 2009 Ltd—Israel Systems and methods for loading more than one video content at a time
US9733882B2 (en) * 2012-04-19 2017-08-15 Videro Llc Apparatus and method for coordinating visual experiences through visual devices, a master device, slave devices and wide area network control
US9729115B2 (en) 2012-04-27 2017-08-08 Sonos, Inc. Intelligently increasing the sound level of player
US9882995B2 (en) 2012-06-25 2018-01-30 Sonos, Inc. Systems, methods, apparatus, and articles of manufacture to provide automatic wireless configuration
US9674587B2 (en) 2012-06-26 2017-06-06 Sonos, Inc. Systems and methods for networked music playback including remote add to queue
US9715365B2 (en) 2012-06-27 2017-07-25 Sonos, Inc. Systems and methods for mobile music zones
US9106192B2 (en) 2012-06-28 2015-08-11 Sonos, Inc. System and method for device playback calibration
US8860882B2 (en) * 2012-09-19 2014-10-14 JBF Interlude 2009 Ltd—Israel Systems and methods for constructing multimedia content modules
US9009619B2 (en) 2012-09-19 2015-04-14 JBF Interlude 2009 Ltd—Israel Progress bar for branched videos
US9952576B2 (en) 2012-10-16 2018-04-24 Sonos, Inc. Methods and apparatus to learn and share remote commands
JP6215444B2 (en) 2013-03-15 2017-10-18 ソノズ インコーポレイテッド Media playback system controller having a plurality of graphical interface
US9257148B2 (en) 2013-03-15 2016-02-09 JBF Interlude 2009 LTD System and method for synchronization of selectably presentable media streams
US9684484B2 (en) 2013-05-29 2017-06-20 Sonos, Inc. Playback zone silent connect
US9703521B2 (en) 2013-05-29 2017-07-11 Sonos, Inc. Moving a playback queue to a new zone
US9798510B2 (en) 2013-05-29 2017-10-24 Sonos, Inc. Connected state indicator
US9953179B2 (en) 2013-05-29 2018-04-24 Sonos, Inc. Private queue indicator
US9832516B2 (en) 2013-06-19 2017-11-28 JBF Interlude 2009 LTD Systems and methods for multiple device interaction with selectably presentable media streams
US9530454B2 (en) 2013-10-10 2016-12-27 JBF Interlude 2009 LTD Systems and methods for real-time pixel switching
US9520155B2 (en) 2013-12-24 2016-12-13 JBF Interlude 2009 LTD Methods and systems for seeking to non-key frames
US9641898B2 (en) 2013-12-24 2017-05-02 JBF Interlude 2009 LTD Methods and systems for in-video library
US9226087B2 (en) 2014-02-06 2015-12-29 Sonos, Inc. Audio output balancing during synchronized playback
US9226073B2 (en) 2014-02-06 2015-12-29 Sonos, Inc. Audio output balancing during synchronized playback
US9408008B2 (en) 2014-02-28 2016-08-02 Sonos, Inc. Playback zone representations
US9219460B2 (en) 2014-03-17 2015-12-22 Sonos, Inc. Audio settings based on environment
US9705950B2 (en) 2014-04-03 2017-07-11 Sonos, Inc. Methods and systems for transmitting playlists
US9653115B2 (en) 2014-04-10 2017-05-16 JBF Interlude 2009 LTD Systems and methods for creating linear video from branched video
US9792026B2 (en) 2014-04-10 2017-10-17 JBF Interlude 2009 LTD Dynamic timeline for branched video
US9363255B2 (en) 2014-06-04 2016-06-07 Sonos, Inc. Cloud queue playhead
US9874997B2 (en) 2014-08-08 2018-01-23 Sonos, Inc. Social playback queues
US9910634B2 (en) 2014-09-09 2018-03-06 Sonos, Inc. Microphone calibration
US9959087B2 (en) 2014-09-24 2018-05-01 Sonos, Inc. Media item context from social media
US9860286B2 (en) 2014-09-24 2018-01-02 Sonos, Inc. Associating a captured image with a media item
US9723038B2 (en) 2014-09-24 2017-08-01 Sonos, Inc. Social media connection recommendations based on playback information
US9792957B2 (en) 2014-10-08 2017-10-17 JBF Interlude 2009 LTD Systems and methods for dynamic video bookmarking
US9665341B2 (en) 2015-02-09 2017-05-30 Sonos, Inc. Synchronized audio mixing
US9672868B2 (en) 2015-04-30 2017-06-06 JBF Interlude 2009 LTD Systems and methods for seamless media creation
US9928024B2 (en) 2015-05-28 2018-03-27 Bose Corporation Audio data buffering
US9729118B2 (en) 2015-07-24 2017-08-08 Sonos, Inc. Loudness matching
US9712912B2 (en) 2015-08-21 2017-07-18 Sonos, Inc. Manipulation of playback device response using an acoustic filter
US9911433B2 (en) 2015-09-08 2018-03-06 Bose Corporation Wireless audio synchronization
US9743207B1 (en) 2016-01-18 2017-08-22 Sonos, Inc. Calibration using multiple recording devices
US9798515B1 (en) 2016-03-31 2017-10-24 Bose Corporation Clock synchronization for audio playback devices
US9864574B2 (en) 2016-04-01 2018-01-09 Sonos, Inc. Playback device calibration based on representation spectral characteristics
US9860662B2 (en) 2016-04-01 2018-01-02 Sonos, Inc. Updating playback device configuration information based on calibration data
US9860670B1 (en) 2016-07-15 2018-01-02 Sonos, Inc. Spectral correction using spatial calibration

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5452435A (en) * 1993-03-31 1995-09-19 Kaleida Labs, Inc. Synchronized clocks and media players
US5530859A (en) * 1993-05-10 1996-06-25 Taligent, Inc. System for synchronizing a midi presentation with presentations generated by other multimedia streams by means of clock objects
US5623483A (en) * 1995-05-11 1997-04-22 Lucent Technologies Inc. Synchronization system for networked multimedia streams
US20020031196A1 (en) * 2000-06-27 2002-03-14 Thomas Muller Synchronisation
US7096271B1 (en) * 1998-09-15 2006-08-22 Microsoft Corporation Managing timeline modification and synchronization of multiple media streams in networked client/server systems
US7391791B2 (en) * 2001-12-17 2008-06-24 Implicit Networks, Inc. Method and system for synchronization of content rendering

Family Cites Families (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4569042A (en) * 1983-12-23 1986-02-04 At&T Bell Laboratories Time measurements in a transmission path
US5333299A (en) * 1991-12-31 1994-07-26 International Business Machines Corporation Synchronization techniques for multimedia data streams
JP2521016B2 (en) * 1991-12-31 1996-07-31 インターナショナル・ビジネス・マシーンズ・コーポレイション Multimedia de - data processing system
EP0695446B1 (en) * 1993-05-10 1997-09-03 Taligent, Inc. Multimedia synchronization system
US5602992A (en) * 1993-11-29 1997-02-11 Intel Corporation System for synchronizing data stream transferred from server to client by initializing clock when first packet is received and comparing packet time information with clock
US6041345A (en) * 1996-03-08 2000-03-21 Microsoft Corporation Active stream format for holding multiple media streams
US6009457A (en) * 1996-04-01 1999-12-28 Rocket Network, Inc. Distributed real-time communications system
US5661665A (en) * 1996-06-26 1997-08-26 Microsoft Corporation Multi-media synchronization
US5909431A (en) * 1996-06-28 1999-06-01 At&T Corp. Packet mode multimedia conferencing services over an ISDN wide area network
US5889515A (en) * 1996-12-09 1999-03-30 Stmicroelectronics, Inc. Rendering an audio-visual stream synchronized by a software clock in a personal computer
US5815689A (en) * 1997-04-04 1998-09-29 Microsoft Corporation Method and computer program product for synchronizing the processing of multiple data streams and matching disparate processing rates using a standardized clock mechanism
US6934759B2 (en) * 1999-05-26 2005-08-23 Enounce, Inc. Method and apparatus for user-time-alignment for broadcast works
US6859460B1 (en) * 1999-10-22 2005-02-22 Cisco Technology, Inc. System and method for providing multimedia jitter buffer adjustment for packet-switched networks
US6985966B1 (en) * 2000-03-29 2006-01-10 Microsoft Corporation Resynchronizing globally unsynchronized multimedia streams
US7756032B2 (en) * 2000-10-17 2010-07-13 Avaya Inc. Method and apparatus for communicating data within measurement traffic
US6766407B1 (en) * 2001-03-27 2004-07-20 Microsoft Corporation Intelligent streaming framework
US6643612B1 (en) * 2001-06-28 2003-11-04 Atrica Ireland Limited Mechanism and protocol for per connection based service level agreement measurement

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5452435A (en) * 1993-03-31 1995-09-19 Kaleida Labs, Inc. Synchronized clocks and media players
US5530859A (en) * 1993-05-10 1996-06-25 Taligent, Inc. System for synchronizing a midi presentation with presentations generated by other multimedia streams by means of clock objects
US5623483A (en) * 1995-05-11 1997-04-22 Lucent Technologies Inc. Synchronization system for networked multimedia streams
US7096271B1 (en) * 1998-09-15 2006-08-22 Microsoft Corporation Managing timeline modification and synchronization of multiple media streams in networked client/server systems
US20020031196A1 (en) * 2000-06-27 2002-03-14 Thomas Muller Synchronisation
US7391791B2 (en) * 2001-12-17 2008-06-24 Implicit Networks, Inc. Method and system for synchronization of content rendering

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070230434A1 (en) * 2004-05-28 2007-10-04 Jean-Claude Thill Distributed Synchronization Method and System
US7860040B2 (en) * 2004-05-28 2010-12-28 Thales Distributed synchronization method and system
US20100100923A1 (en) * 2006-11-06 2010-04-22 Panasonic Corporation Receiver
US8875217B2 (en) * 2006-11-06 2014-10-28 Panasonic Corporation Receiver
US20100254411A1 (en) * 2009-04-06 2010-10-07 Avaya Inc. Network synchronization over ip networks
US8238377B2 (en) * 2009-04-06 2012-08-07 Avaya Inc. Network synchronization over IP networks
US8401007B2 (en) 2009-04-06 2013-03-19 Avaya Inc. Network synchronization over IP networks
US20100254499A1 (en) * 2009-04-06 2010-10-07 Avaya Inc. Network synchronization over ip networks
US20120200774A1 (en) * 2011-02-07 2012-08-09 Ehlers Sr Gregory Allen Audio and video distribution system with latency delay compensator

Also Published As

Publication number Publication date Type
US20030221161A1 (en) 2003-11-27 application
WO2003054686A2 (en) 2003-07-03 application
US20100153512A1 (en) 2010-06-17 application
WO2003054686A3 (en) 2004-05-27 application
US8942252B2 (en) 2015-01-27 grant
US20130290461A1 (en) 2013-10-31 application
US8406257B2 (en) 2013-03-26 grant
US7391791B2 (en) 2008-06-24 grant

Similar Documents

Publication Publication Date Title
US6452974B1 (en) Synchronization of related audio and video streams
US20120192071A1 (en) System and method for synchronizing operations among a plurality of independently clocked digital data processing devices
US8233648B2 (en) Ad-hoc adaptive wireless mobile sound system
US5875354A (en) System for synchronization by modifying the rate of conversion by difference of rate between first clock and audio clock during a second time period
US6362854B1 (en) Effecting video transitions between video streams with a border
US8015306B2 (en) Method and apparatus for synchronizing playback of streaming media in multiple output devices
US7280103B2 (en) Display method, display apparatus and data write circuit utilized therefor
US6122381A (en) Stereophonic sound system
US6802019B1 (en) Method and system for synchronizing data
JP2006121553A (en) Video display unit
US20110122238A1 (en) Method And System For Synchronizing 3D Shutter Glasses To A Television Refresh Rate
US8020023B2 (en) Systems and methods for synchronizing operations among a plurality of independently clocked digital data processing devices without a voltage controlled crystal oscillator
Okino et al. New television with 2D/3D image conversion technologies
US20030198257A1 (en) Method of manually fine tuning audio synchronization of a home network
US6195086B1 (en) Method and apparatus for loosely synchronizing closed free running raster displays
US20060116164A1 (en) System and method for divided display on multiple mobile terminals
US5896116A (en) Liquid crystal display system
JPH07288850A (en) Stereoscopic video image display device
JP2000322039A (en) Display device, control device, and multiple screen display system
JPH11187367A (en) Video transmitter, video receiver and video transmitting system using these
JP2008252422A (en) Synchronized multi-screen reproduction system, display control terminal, synchronized multi-screen reproduction method, and program
JPH07298311A (en) Stereoscopic video display device
US20060233266A1 (en) Content processing device, content transmitting device, content receiving device, content distribution system, content synchronization program, and recording medium
CN1367611A (en) Three-D video image digital coding method
JP2003298879A (en) Method and device for displaying moving picture

Legal Events

Date Code Title Description
AS Assignment

Owner name: IMPLICIT, LLC, WASHINGTON

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:IMPLICIT NETWORKS, INC.;REEL/FRAME:032372/0119

Effective date: 20131018