Method and system for fast channel switching using standard RTSP messages

• US 7,921,222 B2
• Filed: 05/06/2008
• Issued: 04/05/2011
• Est. Priority Date: 05/06/2008
• Status: Active Grant

• Current Assignee: Masimo Corporation
• Original Assignee: Vantrix Corporation
• Inventors: Courtemanche, Marc
• Primary Examiner(s): JEAN GILLES, JUDE
• Application Number:
  US12/116,069
• Publication Number:
  US 20090282158A1
• Time in Patent Office: 1,064 Days
• Field of Search: 709/231, 709/220, 709/219, 709/228, 709/224
• US Class Current: 709/231
• CPC Class Codes: H04L 65/612 for unicast
• CPC Class Codes: H04L 65/613 for the control of the source by the destination control signals issued by the client directed to the server or network components specially adapted for selective content distribution H04N21/637
• 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: H04N 21/4384 involving operations to reduce the access time, e.g. fast-tuning for reducing channel switching latency
• CPC Class Codes: H04N 21/643 Communication protocols network streaming protocols, e.g. real-time transport protocol [RTP] or real-time control protocol [RTCP], H04L65/65
• CPC Class Codes: H04N 21/6437 Real-time Transport Protocol [RTP]

Abstract

Method and system for performing fast channel switching in client-server systems, in which live media streams sent by a streaming server under the RTSP protocol are played by the client, are described. The seek functionality in the media player is overloaded to provide switching between live media streams by using standard RTSP message in-band within a single RTSP session.

Claims

1. A method for switching between channels carrying live media streams transmitted from a streaming server to a client device, comprising a media player, under a Real Time Streaming Protocol (RTSP), the method comprising:

(a) launching a RTSP session by sending a RTSP message from the client device to the streaming server for enabling channel switching within the RTSP session, the RTSP message including information regarding a playlist file stored at the streaming server, the playlist file comprising a list of channels available for playing by the media player;

(b) at the client device, processing a request for channel switching from an original channel being played by the media player to a new channel from the playlist file, and sending another RTSP message including information regarding the new channel directly to the streaming server in-band within the RTSP session; and

(c) processing said another RTSP message at the streaming server, and transmitting the new channel to the client device.

2. The method of claim 1, wherein the step comprises:

overloading a seek functionality available in the media player to move backward and forward in a media stream stored in a computer readable medium; and

triggering the request for channel switching and generating said another RTSP message.

3. The method of claim 2, wherein the overloading the seek functionality comprises:

at the client device, receiving a seek request including a seek interval with an endpoint corresponding to an index of the new channel in the playlist file from the media player for switching to the new channel;

determining a range parameter corresponding to the index of the new channel in the playlist file from the seek interval; and

sending a PLAY RTSP message, including the range parameter, from the client device to the streaming server.

4. The method of claim 1, wherein the step (c) comprises:

identifying the new channel in the playlist file, including processing the information regarding the new channel; and

(b4) terminating transmitting the original channel, and transmitting the new channel to the client device without interrupting the RTSP session.

5. The method as described in claim 1, further comprising sending a response to the RTSP message, including specifying a maximum duration of the RTSP session for overloading the seek functionality of the media player, the step being performed before the step (b).

6. The method as described in claim 1, further comprising processing the new channel transmitted by the streaming server at the client device, the step being performed after the step (c).

7. The method of claim 6, wherein processing the new channel comprises buffering the new channel at the client device, and playing the new channel after a remaining part of the original channel that has arrived at the client device is played out.

21. A computer program product for switching between channels, carrying live media streams transmitted under a Real Time Streaming Protocol (RTSP) from a streaming server to a client device, comprising a media player, the computer program product comprising a computer readable medium having computer readable program code means embodied in said medium for causing said computer to perform the steps of the method as described in claim 1.

8. A method for switching between channels carrying live media streams transmitted from a streaming server to a client device under a Real Time Streaming Protocol (RTSP), the method comprising:

(a) launching a RTSP session by sending a RTSP message from the client device to the streaming server for enabling channel switching within the RTSP session, the RTSP message including information regarding a playlist file stored at the streaming server, the playlist file comprising a list of channels available for playing by the client device;

(b) at the client device, sending another RTSP message for switching from an original channel being played at the client to a new channel from the playlist file directly to the streaming server in-band within the RTSP session, said another RTSP message including information regarding the new channel; and

(c) processing said another RTSP message at the streaming server, and transmitting the new channel to the client device.

9. The method of claim 8, wherein the step (b) comprises:

overloading a seek functionality available at the client device to move backward and forward in a media stream stored in a computer readable medium; and

triggering a request for channel switching and generating the RTSP message.

10. The method of claim 9, wherein the overloading the seek functionality comprises:

at the client device, generating a seek interval with an endpoint corresponding to an index of the new channel in the playlist file for identifying the new channel;

determining a range parameter corresponding to the index of the new channel in the playlist file from the seek interval; and

sending a PLAY RTSP message, including the range parameter, from the client device to the streaming server.

11. The method of claim 8, wherein the step (c) further comprises:

identifying the new channel in the playlist file by processing the information regarding the new channel; and

terminating transmitting the original channel, and transmitting the new channel to the client device without interrupting the RTSP session.

12. A method for switching between channels carrying live media streams transmitted from a streaming server to a client device, including a media player, under a Real Time Streaming Protocol (RTSP), the method comprising:

(a) launching a RTSP session between the client device and the streaming server for streaming an original channel from a playlist comprising a list of channels for playing by the media player; and

(b) switching from the original channel to a new channel from the playlist in-band within the RTSP session, including overloading a seek functionality available in the media player to move backward and forward in a media stream stored in a computer readable medium, and triggering a request for switching between the original channel and the new channel.

13. The method of claim 12, wherein the step (b) further comprises:

at the client device, receiving a seek request including a seek interval with an endpoint corresponding to an index of the new channel in the playlist from the media player for switching to the new channel;

at the client device, determining a range parameter corresponding to the index of the new channel in the playlist from the seek interval;

sending a PLAY RTSP message, including the range parameter, from the client device directly to the streaming server; and

processing the PLAY RTSP message at the streaming server, and transmitting the new channel to the client device.

14. The method of claim 13, wherein the processing the PLAY RTSP message comprises:

(a14) identifying the new channel in the playlist, including processing the range parameter; and

(b14) terminating transmitting the original channel, and transmitting the new channel to the client device without interrupting the RTSP session.

15. A system for switching between channels carrying live media streams under a Real Time Streaming Protocol (RTSP), comprising:

a client device comprising a media player;

a streaming server transmitting the live media streams to the client device;

wherein the client device comprises;

a computer readable storage medium having computer readable instructions stored thereon for execution by a processor, forming;

(a) a first RTSP handler module, processing RTSP messages between the client device and the streaming server for switching between channels, and launching a RTSP session by sending a RTSP message from the client device to the streaming server for enabling switching between channels within the RTSP session, the RTSP message including information regarding a playlist file stored at the streaming server, the playlist file comprising a list of channels available for playing by the media player;

(b) a client fast channel switching module, processing a request for switching between channels from an original channel being played by the media player to a new channel from the playlist file, and sending another RTSP message through the RTSP handler module directly to the streaming server in-band within the RTSP session launched by the first RTSP handler module, said another RTSP message including information regarding the new channel; and

wherein the streaming server comprises;

a computer readable storage medium having computer readable instructions stored thereon for execution by a processor, forming;

(c) a server fast channel switching module, processing the another RTSP message, and transmitting the new channel to the client device.

16. The system of claim 15, wherein the client fast channel switching module comprises:

an interface module, receiving a seek request including a seek interval with an endpoint corresponding to an index of the new channel in the playlist file from the media player for overloading a seek functionality available in the media player for switching to the new channel; and

a first computation module, determining a range parameter corresponding to the index of the new channel in the playlist file from the seek interval, and sending a PLAY RTSP message, including the range parameter, from the client device to the streaming server.

17. The system of claim 15, wherein the server fast channel switching module comprises:

a second RTSP handler module, processing RTSP messages between the client device and the streaming server; and

a second computation module, identifying the new channel in the playlist file, including processing the information regarding the new channel.

18. The system of claim 15, wherein the client device further comprises a storage module, having a computer readable medium having computer readable instructions stored thereon for execution by a processor, for buffering the new channel and playing the new channel after a remaining part of the original channel that has arrived at the client device is played out.

19. A system for switching between channels carrying live media streams transmitted under a Real Time Streaming Protocol (RTSP), comprising:

a client device;

a streaming server transmitting the live media streams to the client device;

wherein the client device comprises;

a computer readable storage medium having computer readable instructions stored thereon for execution by a processor, forming;

(a) a RTSP handler module, processing RTSP messages between the client device and the streaming server for switching between channels, and launching a RTSP session by sending a RTSP message from the client device to the streaming server for enabling switching between channels within the RTSP session, the RTSP message including information regarding a playlist file stored at the streaming server, the playlist file comprising a list of channels available for playing by the client device; and

(b) a client fast channel switching module, sending another RTSP message through the RTSP handler module for switching from an original channel being played at the client device to a new channel from the playlist file directly to the streaming server in-band within the RTSP session, said another RTSP message including information regarding the new channel; and

wherein the streaming server comprises;

a computer readable storage medium having computer readable instructions stored thereon for execution by a processor, forming;

(c) a server fast channel switching module, processing the RTSP message sent from the channel switching module, and transmitting the new channel to the client device.

20. A system for switching between channels carrying live media streams transmitted under a Real Time Streaming Protocol (RTSP), comprising:

a client device comprising a media player;

a streaming server transmitting the live media streams to the client device;

wherein the client device comprises;

a computer readable storage medium having computer readable instructions stored thereon for execution by a processor, forming;

(a) a client fast channel switching module, launching a RTSP session between the client device and the streaming server for streaming an original channel from a playlist comprising a list of channels for playing by the media player; and

switching from the original channel to a new channel from the playlist in-band within the RTSP session, by overloading a seek functionality available in the media player to move backward and forward in a media stream stored in a computer readable medium, and triggering a request for switching between the original channel and the new channel; and

wherein the streaming server comprises;

a computer readable storage medium having computer readable instructions stored thereon for execution by a processor, forming;

(b) a server fast channel switching module, processing the request for switching received directly from the client device for transmitting the new channel to the client device.

22. A method for switching between channels carrying live media streams transmitted from a streaming server to a client device, having a media player, under a Real Time Streaming Protocol (RTSP), the method comprising:

launching a RTSP session between the client device and the streaming server for streaming an original channel from a playlist stored on the streaming server, the playlist comprising a list of channels for playing by the media player; and

switching from the original channel to a new channel in the playlist in-band within the RTSP session, including overloading an existing functionality of the media player to indicate an index of the new channel in the playlist, and triggering a request for switching between the original channel and the new channel.

23. A client device having a media player, comprising:

a client fast channel switching module, comprising a computer readable storage medium having computer readable instructions stored thereon for execution by a processor, for launching a RTSP session between the client device and a streaming server for streaming an original channel from a playlist stored on the streaming server, the playlist comprising a list of channels for playing by the media player; and

switching from the original channel to a new channel in the playlist in-band within the RTSP session, by overloading an existing functionality of the media player to indicate an index of the new channel in the playlist, and triggering a request for switching between the original channel and the new channel.