Seamless switching between different playback speeds of time-scale modified data streams

• US 7,237,254 B1
• Filed: 03/29/2000
• Issued: 06/26/2007
• Est. Priority Date: 03/29/2000
• Status: Expired due to Fees

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Omoigui, Nosakhare D.
• Primary Examiner(s): Koenig; Andrew Y.
• Application Number:
  US09/539,170
• Time in Patent Office: 2,645 Days
• Field of Search: 725/88, 725/102, 725/93, 725/94
• US Class Current: 725/94
• CPC Class Codes: H04N 21/23424 involving splicing one content stream with another content stream, e.g. for inserting or substituting an advertisement
• CPC Class Codes: H04N 21/2343 involving reformatting operations of video signals for distribution or compliance with end-user requests or end-user device requirements video transcoding H04N19/40; media packet handling at the source H04L65/762
• CPC Class Codes: H04N 21/2393 involving handling client requests scheduling or organising the servicing of application requests H04L67/60
• CPC Class Codes: H04N 21/44224 Monitoring of user activity on external systems, e.g. Internet browsing
• CPC Class Codes: H04N 21/47202 for requesting content on demand, e.g. video on demand
• CPC Class Codes: H04N 21/6587 Control parameters, e.g. trick play commands, viewpoint selection
• CPC Class Codes: H04N 7/17318 Direct or substantially direct transmission and handling of requests

Abstract

In a network environment, multimedia content is streamed from a server computer to a client computer via the network. A user of the client computer can alter the speed at which the multimedia content is played; either speeding up or slowing down the playback. The client seamlessly switches between the different playback speeds, reducing breaks and/or delays between the time the user selects the new playback speed and the time the multimedia content begins being played back at the new speed.

Claims

1. A system for rendering a stream of data at different playback speeds, comprising:

a component of a server that sends the stream of data for a first playback speed from the server to a client via a network;

a component of the client that receives the stream of data;

a component of the client that renders the received stream of data at the client at the first playback speed, switches the rendering of the received stream of data from the first playback speed to a second playback speed that is greater than the first playback speed, and notifies the server of the second playback speed; and

a component of the server that, upon receiving notification of the second playback speed, initially sends to the client the stream of data that is timeline-modified for a third playback speed that is greater than the second playback speed and then sends to the client a stream of data that is timeline-modified for the second playback speed;

wherein the component of the client that switches the rendering does so before the client starts receiving from the server the stream of data for the second playback speed and

wherein the client renders the data sent for the third playback speed at the second playback speed.

2. The system of claim 1 wherein the component of the client that switches the rendering of the stream of data does so upon receiving an indication from a user to switch the playback speed without waiting to receive data for the second playback speed.

3. The system of claim 1 wherein the component of the server that sends the stream of data for the second playback speed does so when the client has a sufficient portion of the stream of data buffered.

4. The system of claim 1 wherein the switching from the first playback speed to the second playback speed results in no user-noticeable delay in the switching.

5. The system of claim 4 wherein the switching from the first playback speed to the second playback speed results in no user-noticeable pause in the rendering.

6. The system of claim 1 wherein the data includes video and audio data.

7. A server system for providing to a client a stream of data for different playback speeds, comprising:

a component that sends to the client via a network the stream of data for a first playback speed;

a component that receives from the client a notification of a second playback speed that is greater than the first playback speed; and

a component that initially sends to the client the stream of data that is timeline-modified for a third playback speed that is greater than the second playback speed and then sends to the client the stream of data that is timeline-modified for the second playback speed to accommodate when the client switches to the second playback speed before it starts receiving the stream of data for the second playback speed and wherein the client renders the data sent for the third playback speed at the second playback speed.

8. The server system of claim 7 wherein the data includes video and audio data.

9. The server system of claim 7 to further accommodate when the client switches the rendering of the stream of data upon receiving an indication from a user to switch the playback speed.

10. A method for rendering a stream of data at different playback speeds, the method comprising:

receiving from a server via a network a stream of data for a first playback speed;

rendering the received stream of data at the first playback speed

switching the rendering of the received stream of data from at the first playback speed to at a second playback speed that is greater than the first playback speed;

notifying the server of the second playback speed; and

after switching the rendering, initially receiving from the server the stream of data that is timeline-modified for a third playback speed that is greater than the second playback speed and then receiving from the server the stream of data that is timeline-modified for the second playback speed wherein the data received for the third playback speed are rendered at the switched second playback speed.

11. The method of claim 10 wherein the switching of the rendering of the stream of data is done upon receiving an indication from a user to switch the playback speed.

12. The method of claim 10 including receiving from the server the stream of data for the second playback speed at a speed required for the second playback speed when a sufficient portion of the stream of data has been buffered.

13. The method of claim 10 wherein the switching from the first playback speed to the second playback speed results in no user-noticeable delay in the switching.

14. The method of claim 13 wherein the switching from the first playback speed to the second playback speed results in no user-noticeable pause in the rendering.

15. The method of claim 10 wherein the data includes video and audio data.

16. A system that streams a video with frames from a server to a client at different playback speeds, a playback speed faster than a normal playback speed being simulated by skipping frames of the video, comprising:

a component that sends frames of the video for a first playback speed;

a component that receives an indication of a second playback speed that is greater than the first playback speed; and

a component that upon receiving the indication,

initially sends frames of the video that are timeline-modified for a third playback speed that is greater than the second playback speed; and

then sends frames of the video that are timeline-modified for the second playback speed

so that the client renders the frames of the video for the third playback speed and the second playback speed at the second playback speed.