System having client sending edit commands to server during transmission of continuous media from one clip in play list for editing the play list

• US 5,892,915 A
• Filed: 05/05/1997
• Issued: 04/06/1999
• Est. Priority Date: 04/25/1997
• Status: Expired due to Term

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: EMC Corporation (Dell Technologies Inc.)
• Inventors: Forecast, John, Duso, Wayne W.
• Primary Examiner(s): Meky, Moustafa M.
• Application Number:
  US08/851,560
• Time in Patent Office: 701 Days
• Field of Search: 395/200.33, 395/200.49, 395/200.57, 395/200.56, 395/200.59, 348/7, 348/12, 348/13, 348/552, 348/906
• US Class Current: 709/219
• CPC Class Codes: G11B 27/10 Indexing; Addressing; Timing or synchronising; Measuring tape travel
• CPC Class Codes: H04L 65/1063 Application servers providing network services systems providing special services to telephonic subscribers H04M3/42
• CPC Class Codes: H04L 65/1069 Session establishment or de-establishment
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/611 for multicast or broadcast systems for broadcast or conference H04L12/18; arrangements for broadcast or distribution combined with broadcast H04H20/00; arrangements for broadcast applications with a direct linkage to broadcast information or to broadcast space-time H04H60/00; selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS], H04W4/06
• 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 65/80 Responding to QoS

Abstract

A protocol and interface provides continuous play over multiple clips for extended periods of time, allows a play-list to be edited dynamically after being given to the video server and during playback of clips in the play-list, allows some notion of "current time" to be used during the streaming of continuous media data, and supports features of the "Louth Automation" video disk communications protocol. Preferably, the client application first creates a session with a play-list containing a fixed number of entries; the number should be as small as possible consistent with the client'"'"'s requirements. The client edits this play-list by appending the first few clips and then starts the session playing. Each time transmission of video data of a clip is completed, the clip is removed from the head of the play-list, all other clips are moved down, and a callback is issued to the client with the current, updated, play-list. A callback is also issued with the updated play-list to acknowledge each edit command. Preferably, there is a limit as to how close to air-time a clip normally may be deleted or new material inserted, in order to ensure continuity of transmission of the video stream of each clip. To allow live break-ins or other "emergency" operations, however, the session may be paused and later resumed and subsequent clips may be "trimmed" to reduce their play times to recover the time lost to the break-in.

Claims

1. A method of communication between a client and a continuous media server in a data network, said method comprising the steps of:

(a) the client sending a first command to the server requesting the server to allocate server resources for a broadcast session including transmission of continuous media data from the server to a destination in the data network; and

then

(b) the server receiving the first command and in response allocating server resources for the broadcast session and returning to the client an acknowledgement that server resources have been allocated for the broadcast session; and

then

(c) the client receiving the acknowledgement and in response transmitting to the server at least a second command specifying a play-list of continuous media clips from which continuous media data are to be transmitted from the server to said destination during the broadcast session; and

then

(d) the server receiving said at least a second command and thereafter beginning the broadcast session by transmitting continuous media data from a first clip in the play-list to said destination; and

then

(e) the client sending to the server play-list edit commands during the transmission of continuous media data from at least one clip in the play-list for editing the play-list including the addition of at least one additional clip to the play-list, and the server receiving the play-list edit commands and in response editing the play-list during the broadcast session without interruption of the transmission of continuous media data from the server to said destination.

2. The method as claimed in claim 1, wherein the acknowledgement that server resources have been allocated for the broadcast session includes a session handle transmitted by the server to the client, and the second command includes the session handle.

3. The method as claimed in claim 1, wherein the second command is substantially identical in format to the play-list edit commands.

4. The method as claimed in claim 3, which includes:

the client transmitting to the server a third command for initiating the broadcast session; and

the server receiving the third command and in response to the third command beginning the broadcast session by transmitting continuous media data from the first clip in the play-list to said destination.

5. The method as claimed in claim 1, wherein the server returns to the client an acknowledgement of each play-list edit command, and the acknowledgement of each play-list edit command includes an edited version of the play-list resulting from the server editing the play-list in accordance with said each play-list edit command.

6. The method as claimed in claim 1, wherein the server transmits to the client an indication that transmission from a clip is complete each time the server has completed transmission of continuous media data from a clip in the play-list during the broadcast session.

7. The method as claimed in claim 6, wherein said indication that transmission from a clip is complete includes a current version of the play-list.

8. The method as claimed in claim 1, wherein the server transmits to the client an indication that the play-list is empty when transmission of continuous media data from a last clip in the play-list is finished and the play-list becomes empty.

9. The method as claimed in claim 1, wherein the server de-allocates the server resources when the play-list is empty for more than a certain amount of time.

10. The method as claimed in claim 1, wherein the server checks whether or not each of said play-list edit commands specifies a change of continuous media too close to broadcast time to avoid an interruption of transmission of the continuous media data from the server to said destination, and when one of said play-list edit commands is found to specify a change of continuous media too close to broadcast time to avoid an interruption of transmission of the continuous media data from the server to said destination, not editing the play-list in response to said one of said play-list edit commands, and instead returning an error message to the client.

11. A method of communication between a client and a continuous media server in a data network, said method comprising the steps of:

(a) the server conducting a broadcast session for the client by transmitting continuous media data from clips in a play-list to a destination in said data network, beginning with continuous media data from a first clip in the play-list;

(b) the client sending to the server play-list edit commands during the transmission of continuous media data from at least one clip in the play-list for editing the play-list including the addition of at least one additional clip to the play-list, and the server receiving the play-list edit commands and in response editing the play-list during the broadcast session without interruption of the transmission of continuous media data from the server to said destination;

wherein the server checks whether or not each of said play-list edit commands specifies a change of continuous media too close to broadcast time to avoid an interruption of transmission of the continuous media data from the server to said destination, and when one of said play-list edit commands is found to specify a change of continuous media too close to broadcast time to avoid an interruption of transmission of the continuous media data from the server to said destination, not editing the play-list in response to said one of said play-list edit commands, and instead returning an error message to the client.

12. The method as claimed in claim 11, wherein the server returns to the client an edited version of the play-list when the server edits the play-list in response to each of the play-list edit commands.

13. The method as claimed in claim 11, wherein the server transmits to the client an indication that transmission from a clip is complete each time the server has completed transmission of continuous media data from a clip in the play-list during the broadcast session.

14. The method as claimed in claim 13, wherein said indication that transmission from a clip is complete includes a current version of the play-list.

15. The method as claimed in claim 13, wherein the server transmits to the client an indication that the play-list is empty when transmission of continuous media data from a last clip in the play-list is finished and the play-list becomes empty.

16. A method of communication between a client and a continuous media server in a data network, said method comprising the steps of:

(a) the client sending a first command to the server requesting the server to create a broadcast session for the transmission of continuous media data from the server to a client-specified destination in the data network; and

then

(b) the server receiving the first command and in response allocating server resources for the broadcast session and returning to the client a session handle identifying the allocated server resources; and

then

(c) the client receiving the session handle and in response transmitting to the server at least one play-list edit command including the session handle and specifying at least one continuous media clip to be transmitted from the server to said destination during the broadcast session; and

then

(d) the server receiving said at least one play-list edit command, producing an edited version of the play-list in accordance with said at least one play-list edit command, and acknowledging the play-list edit command by returning to the client the edited version of the play-list; and

then

(e) the client receiving the edited version of the play-list and thereafter transmitting a command for beginning the broadcast session; and

then

(f) the server receiving the command for beginning the broadcast session and in response beginning the broadcast session by transmitting continuous media data from a first clip in the play-list to said destination; and

then

(g) the client sending to the server additional play-list edit commands during the transmission of continuous media data from at least one clip in the play-list for editing the play-list including the addition of at least one additional clip to the play-list, and the server receiving the additional play-list edit commands and in response editing the play-list during the broadcast session without interruption of the transmission of continuous media data from the server to said destination.

17. The method as claimed in claim 16, wherein the server transmits to the client an indication that transmission from a clip is complete each time the server has completed transmission of continuous media data from a clip in the play-list during the broadcast session.

18. The method as claimed in claim 17, wherein said indication that transmission from a clip is complete includes a current version of the play-list.

19. The method as claimed in claim 16, wherein the server transmits to the client an indication that the play-list is empty when transmission of continuous media data from a last clip in the play-list is finished and the play-list becomes empty, and wherein the server de-allocates the server resources when the play-list is empty for more than a certain amount of time.

20. The method as claimed in claim 16, wherein the client sends to the server a pause command for interrupting the transmission of continuous media data during the broadcast session, and a resume command for resuming the transmission of continuous media data during the broadcast session, and wherein the command for beginning the broadcast session is substantially identical in format to the resume command.

21. The method as claimed in claim 16, wherein the server checks whether or not each of said play-list edit commands specifies a change of continuous media too close to broadcast time to avoid an interruption of transmission of the continuous media data from the server to said destination, and when one of said play-list edit commands is found to specify a change of continuous media too close to broadcast time to avoid an interruption of transmission of the continuous media data from the server to said destination, not editing the play-list in response to said one of said play-list edit commands, and instead returning an error message to the client.

22. A continuous media server for use in a data network, said continuous media server comprising:

data storage for storing clips of continuous media data; and

a controller for communicating with clients in the data network and being coupled to the data storage for controlling transmission of continuous media data from the data storage to destinations in the data network;

wherein the controller is programmed for;

(a) receiving from a client a first command requesting the server to allocate server resources for a broadcast session including transmission of continuous media data from the server to a destination in the data network, and in response allocating server resources for the broadcast session and returning to the client an acknowledgement that server resources have been allocated for the broadcast session;

(b) receiving from the client a second command specifying a play-list of continuous media clips from which continuous media data are to be transmitted from the server to said destination during the broadcast session, and thereafter beginning a broadcast session by transmitting continuous media data from a first clip in the play-list to said destination; and

(c) receiving from the client play-list edit commands during the transmission of continuous media data from at least one clip in the play-list for editing the play-list including the addition of at least one additional clip to the play-list, and in response editing the play-list during the broadcast session without interruption of the transmission of continuous media data from the server to said destination.

23. The continuous media server as claimed in claim 22, wherein the controller is programmed for including a session handle in the acknowledgement that server resources have been allocated for the broadcast session, and for receiving back the session handle in the second command.

24. The continuous media server as claimed in claim 22, wherein the second command is substantially identical in format to the play-list edit commands.

25. The continuous media server as claimed in claim 24, wherein the controller is programmed for receiving from the client a third command for initiating the broadcast session, and in response beginning the broadcast session by transmitting continuous media data from the first clip in the play-list to said destination.

26. The continuous media server as claimed in claim 22, wherein the controller is programmed for returning to the client an acknowledgement of each play-list edit command, and the acknowledgement of each play-list edit command includes an edited version of the play-list resulting from the server editing the play-list in accordance with said each play-list edit command.

27. The continuous media server as claimed in claim 22, wherein the controller is programmed for transmitting to the client an indication that transmission from a clip is complete each time the server has completed transmission of continuous media data from a clip in the play-list during the broadcast session.

28. The continuous media server as claimed in claim 27, wherein the controller is programmed for including a current version of the play-list in said indication that transmission from a clip is complete.

29. The continuous media server as claimed in claim 22, wherein the controller is programmed for transmitting to the client an indication that the play-list is empty when transmission of continuous media data from a last clip in the play-list is finished and the play-list becomes empty.

30. The continuous media server as claimed in claim 22, wherein the controller is programmed for de-allocating the server resources when the play-list is empty for more than a certain amount of time.

31. The continuous media server as claimed in claim 22, wherein the controller is programmed for checking whether or not each of said play-list edit commands specifies a change of continuous media too close to broadcast time to avoid an interruption of transmission of the continuous media data from the server to said destination, and when one of said play-list edit commands is found to specify a change of continuous media too close to broadcast time to avoid an interruption of transmission of the continuous media data from the server to said destination, for not editing the play-list in response to said one of said play-list edit commands, and instead returning an error message to the client.

32. A continuous media server for use in a data network, said continuous media server comprising:

data storage for storing clips of continuous media data; and

a controller for communicating with clients in the data network and being coupled to the data storage for controlling transmission of continuous media data from the data storage to destinations in the data network;

wherein the controller is programmed for;

(a) conducting a broadcast session for the client in which the server transmits continuous media data from clips in a play-list to a destination in said data network, beginning with continuous media data from a first clip in the play-list; and

(b) receiving from the client play-list edit commands during the transmission of continuous media data from at least one clip in the play-list, and in response editing the play-list during the broadcast session, including the addition of at least one additional clip to the play-list, without interruption of the transmission of continuous media data from the server to said destination;

wherein the controller is programmed for checking whether or not each of said play-list edit commands specifies a change of continuous media too close to broadcast time to avoid an interruption of transmission of the continuous media data from the server to said destination, and when one of said play-list edit commands is found to specify a change of continuous media too close to broadcast time to avoid an interruption of transmission of the continuous media data from the server to said destination, not editing the play-list in response to said one of said play-list edit commands, and instead returning an error message to the client.

33. The continuous media server as claimed in claim 32, wherein the controller is programmed for returning to the client an edited version of the play-list when the controller edits the play-list in response to each of the play-list edit commands.

34. The continuous media server as claimed in claim 32, wherein the controller is programmed for transmitting to the client an indication that transmission from a clip is complete each time the server has completed transmission of continuous media data from a clip in the play-list during the broadcast session.

35. The continuous media server as claimed in claim 34, wherein the controller is programmed for including a current version of the play-list in said indication that transmission from a clip is complete.

36. The continuous media server as claimed in claim 32, wherein the controller is programmed for transmitting to the client an indication that the play-list is empty when transmission of continuous media data from a last clip in the play-list is finished and the play-list becomes empty.

37. A continuous media server for use in a data network, said continuous media server comprising:

data storage for storing clips of continuous media data; and

a controller for communicating with clients in the data network and being coupled to the data storage for controlling transmission of continuous media data from the data storage to destinations in the data network;

wherein the controller is programmed for;

(a) receiving from the client a command requesting the server to create a broadcast session for the transmission of continuous media data from the server to a client-specified destination in the data network, and in response allocating server resources for the broadcast session and returning to the client a session handle identifying the allocated server resources;

(b) receiving from the client at least one play-list edit command including the session handle and specifying at least one continuous media clip to be transmitted from the server to said destination during the broadcast session, editing a play-list for the session in accordance with the play-list edit command to produce an edited version of the play-list, and returning to the client the edited version of the play-list;

(c) receiving from the client a command for beginning the broadcast session and in response beginning the broadcast session by beginning transmission of continuous media data from a first clip in the play-list to said destination; and

(d) receiving from the client additional play-list edit commands during the transmission of continuous media data from at least one clip in the play-list, and in response editing the play-list during the broadcast session without interruption of the transmission of continuous media data from the server to said destination.

38. The continuous media server as claimed in claim 37, wherein the controller is programmed for transmitting to the client an indication that transmission from a clip is complete each time the server has completed transmission of continuous media data from a clip in the play-list during the broadcast session.

39. The continuous media server as claimed in claim 38, wherein the controller is programmed for including a current version of the play-list in the indication that transmission from a clip is complete.

40. The continuous media server as claimed in claim 37, wherein the controller is programmed for transmitting to the client an indication that the play-list is empty when transmission of continuous media data from a last clip in the play-list is finished and the play-list becomes empty, and for de-allocating the server resources when the play-list is empty for more than a certain amount of time.

41. The continuous media server as claimed in claim 37, wherein the controller is programmed for receiving from the client a pause command for interrupting the transmission of continuous media data during the broadcast session, and for receiving from the client a resume command for resuming the transmission of continuous media data during the broadcast session, and wherein the command for beginning the broadcast session is substantially identical in format to the resume command.

42. The continuous media server as claimed in claim 37, wherein the controller is programmed for checking whether or not each of said play-list edit commands specifies a change of continuous media too close to broadcast time to avoid an interruption of transmission of the continuous media data from the server to said destination, and when one of said play-list edit commands is found to specify a change of continuous media too close to broadcast time to avoid an interruption of transmission of the continuous media data from the server to said destination, for not editing the play-list in response to said one of said play-list edit commands, and instead returning an error message to the client.

43. A program storage device storing a program executable by a continuous media server in a data network, said program being executable by the server for:

(a) controlling the server for receiving from a client a first command requesting the server to allocate server resources for a broadcast session including transmission of continuous media data from the server to a destination in the data network, and in response allocating server resources for the broadcast session and returning to the client an acknowledgement that server resources have been allocated for the broadcast session;

(b) controlling the server for receiving from the client a second command specifying a play-list of continuous media clips from which continuous media data are to be transmitted from the server to said destination during the broadcast session, and thereafter beginning a broadcast session by transmitting continuous media data from a first clip in the play-list to said destination; and

(c) controlling the server for receiving from the client play-list edit commands during the transmission of continuous media data from at least one clip in the play-list, and in response editing the play-list, including the addition of at least one additional clip to the play-list, without interruption of the transmission of continuous media data from the server to said destination during the broadcast session.

44. The program storage device as claimed in claim 43, wherein program is executable by the server for including a session handle in the acknowledgement that server resources have been allocated for the broadcast session includes a session handle, and for receiving back the session handle in the second command.

45. The program storage device as claimed in claim 43, wherein the second command is substantially identical in format to the play-list edit commands.

46. The program storage device as claimed in claim 45, wherein the program is executable by the server for receiving from the client a third command for initiating the broadcast session, and in response beginning the broadcast session by transmitting continuous media data from the first clip in the play-list to said destination.

47. The program storage device as claimed in claim 43, wherein the program is executable by the server for returning to the client an acknowledgement of each play-list edit command, and for including, in the acknowledgement of each play-list edit command, an edited version of the play-list resulting from the server editing the play-list in accordance with said each play-list edit command.

48. The program storage device as claimed in claim 43, wherein the program is executable by the server for transmitting to the client an indication that transmission from a clip is complete each time the server has completed transmission of continuous media data from a clip in the play-list during the broadcast session.

49. The program storage device as claimed in claim 48, wherein the program is executable by the server for including a current version of the play-list in said indication that transmission from a clip is complete.

50. The program storage device as claimed in claim 43, wherein the program is executable by the server for transmitting to the client an indication that the play-list is empty when transmission of continuous media data from a last clip in the play-list is finished and the play-list becomes empty.

51. The program storage device as claimed in claim 43, wherein the program is executable by the server for de-allocating the server resources when the play-list is empty for more than a certain amount of time.

52. The program storage device as claimed in claim 43, wherein the program is executable by the server for checking whether or not each of said play-list edit commands specifies a change of continuous media too close to broadcast time to avoid an interruption of transmission of the continuous media data from the server to said destination, and when one of said play-list edit commands is found to specify a change of continuous media too close to broadcast time to avoid an interruption of transmission of the continuous media data from the server to said destination, for not editing the play-list in response to said one of said play-list edit commands, and instead returning an error message to the client.

53. A program storage device storing a program executable by a continuous media server in a data network, said program being executable by the server for:

(a) controlling the server for conducting a broadcast session for the client in which the server transmits continuous media data from clips in a play-list to a destination in said data network, beginning with continuous media data from a first clip in the play-list; and

(b) controlling the server for receiving from the client play-list edit commands during the transmission of continuous media data from at least one clip in the play-list, and in response editing the play-list during the broadcast session, including the addition of at least one additional clip to the play-list, without interruption of the transmission of continuous media data from the server to said destination;

wherein the program is executable by the server for checking whether or not each of said play-list edit commands specifies a change of continuous media too close to broadcast time to avoid an interruption of transmission of the continuous media data from the server to said destination, and when one of said play-list edit commands is found to specify a change of continuous media too close to broadcast time to avoid an interruption of transmission of the continuous media data from the server to said destination, for not editing the play-list in response to said one of said play-list edit commands, and instead returning an error message to the client.

54. The program storage device as claimed in claim 53, wherein the program is executable by the server for returning to the client an edited version of the play-list when the controller edits the play-list in response to each of the play-list edit commands.

55. The program storage device as claimed in claim 53, wherein the program is executable by the server for transmitting to the client an indication that transmission from a clip is complete each time the server has completed transmission of continuous media data from a clip in the play-list during the broadcast session.

56. The program storage device as claimed in claim 55, wherein the program is executable by the server for including a current version of the play-list in said indication that transmission from a clip is complete.

57. The program storage device as claimed in claim 53, wherein the program is executable by the server for transmitting to the client an indication that the play-list is empty when transmission of continuous media data from a last clip in the play-list is finished and the play-list becomes empty.

58. A program storage device storing a program executable by a continuous media server in a data network, said program being executable by the server for:

(a) controlling the server for receiving from the client a command requesting the server to create a broadcast session for the transmission of continuous media data from the server to a client-specified destination in the data network, and in response allocating server resources for the broadcast session and returning to the client a session handle identifying the allocated server resources;

(b) controlling the server for receiving from the client at least one play-list edit command including the session handle and specifying at least one continuous media clip to be transmitted from the server to said destination during the broadcast session, and for editing a play-list for the session in accordance with the play-list edit command to produce an edited version of the play-list, and for returning to the client the edited version of the play-list;

(c) controlling the server for receiving from the client a command for beginning the broadcast session and in response beginning the broadcast session by beginning transmission of continuous media data from a first clip in the play-list to said destination; and

(d) controlling the server for receiving from the client additional play-list edit commands during the transmission of continuous media data from at least one clip in the play-list, and in response editing the play-list during the broadcast session without interruption of the transmission of continuous media data from the server to said destination.

59. The program storage device as claimed in claim 58, wherein the program is executable by the server for transmitting to the client an indication that transmission from a clip is complete each time the server has completed transmission of continuous media data from a clip in the play-list during the broadcast session.

60. The program storage device as claimed in claim 59, wherein the program is executable by the server for including a current version of the play-list in the indication that transmission from a clip is complete.

61. The program storage device as claimed in claim 58, wherein the program is executable by the server for transmitting to the client an indication that the play-list is empty when transmission of continuous media data from a last clip in the play-list is finished and the play-list becomes empty, and for de-allocating the server resources when the play-list is empty for more than a certain amount of time.

62. The program storage device as claimed in claim 58, wherein the program is executable by the server for receiving from the client a pause command for interrupting the transmission of continuous media data during the broadcast session, and for receiving from the client a resume command for resuming the transmission of continuous media data during the broadcast session, and wherein the command for beginning the broadcast session is substantially identical in format to the resume command.

63. The program storage device as claimed in claim 58, wherein the program is executable by the server for checking whether or not each of said play-list edit commands specifies a change of continuous media too close to broadcast time to avoid an interruption of transmission of the continuous media data from the server to said destination, and when one of said play-list edit commands is found to specify a change of continuous media too close to broadcast time to avoid an interruption of transmission of the continuous media data from the server to said destination, for not editing the play-list in response to said one of said play-list edit commands, and instead returning an error message to the client.