Digital content buffer for adaptive streaming

• US 20080086570A1
• Filed: 10/10/2006
• Published: 04/10/2008
• Est. Priority Date: 10/10/2006
• Status: Active Grant

• Current Assignee: Allot Communications Limited
• Original Assignee: Ortiva Wireless Incorporated (Allot Ltd.)
• Inventors: Wen, Jiangtao, Dey, Sujit, Wong, Douglas, Arole, Parag, Takebuchi, Yusuke
• Granted Patent: US 7,743,161 B2
• Time in Patent Office: Days
• US Class Current: 709/231
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/612 for unicast
• CPC Class Codes: H04L 65/70 Media network packetisation
• CPC Class Codes: H04L 65/752 adapting media to network capabilities
• CPC Class Codes: H04L 65/80 Responding to QoS
• CPC Class Codes: H04N 19/107 between spatial and temporal predictive coding, e.g. picture refresh
• CPC Class Codes: H04N 19/12 Selection from among a plurality of transforms or standards, e.g. selection between discrete cosine transform [DCT] and sub-band transform or selection between H.263 and H.264
• CPC Class Codes: H04N 19/162 User input
• CPC Class Codes: H04N 19/164 Feedback from the receiver or from the transmission channel
• CPC Class Codes: H04N 19/169 characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding
• CPC Class Codes: H04N 19/172 the region being a picture, frame or field
• CPC Class Codes: H04N 19/40 using video transcoding, i.e. partial or full decoding of a coded input stream followed by re-encoding of the decoded output stream
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• CPC Class Codes: H04N 21/2187 Live feed
• CPC Class Codes: H04N 21/23106 involving caching operations prefetching while addressing of a memory level in which the access to the desired data or data block requires associative addressing means within memory systems or architectures G06F12/0862; caching at an intermediate stage in a data network H04L67/568
• CPC Class Codes: H04N 21/23439 for generating different versions
• CPC Class Codes: H04N 21/2402 Monitoring of the downstream path of the transmission network, e.g. bandwidth available traffic monitoring in data switching networks H04L43/00; monitoring data switching networks utilization H04L43/0876
• CPC Class Codes: H04N 21/2662 Controlling the complexity of the video stream, e.g. by scaling the resolution or bitrate of the video stream based on the client capabilities
• CPC Class Codes: H04N 21/6131 involving transmission via a mobile phone network wireless downlink channel access H04W74/006
• CPC Class Codes: H04N 21/8456 by decomposing the content in the time domain, e.g. in time segments

Abstract

Network transmission of live digital content from sources to receiving devices is enabled with real-time encoding, customization, and transmission of the live content according to user preferences, receiving device characteristics, network conditions and the like. Content, such as advertising customized to user profile and user location, may be conveniently inserted into the live content. Source-to-screen delay from sources to receiving devices is reduced and channel switching is supported.

Claims

1. A method of processing digital content for streaming of live content network transport, the method comprising:

encoding a digital content clip according to epoch intervals comprising one or more consecutive predetermined portions of the digital content clip, wherein the encoding generates prepped content that comprises at least one encoded representation of each epoch interval, such that each epoch interval comprises a different consecutive portion of the digital content clip;

storing the prepped content for a predetermined number of epoch intervals into a streaming buffer of a network data store;

selecting one of the prepped content epoch intervals for reading from the streaming buffer;

streaming an encoded representation of the selected prepped content epoch interval, in accordance with current network condition between the network data store and the receiving device, by network transport directed to the receiving device.

2. The method as defined in claim 1, wherein the encoding generates prepped content that comprises a single encoded representation of each epoch.

3. The method as defined in claim 1, wherein the encoding generates prepped content that comprises a multiple encoded representations of each epoch.

4. The method as defined in claim 3, wherein the multiple encoded representations comprise representations that are encoded according to an estimated received quality metric.

5. The method as defined in claim 1, where the streaming buffer comprises a buffer having a single queue adapted to contain the encoded representations of the predetermined number of epoch intervals.

6. The method as defined in claim 1, where the streaming buffer comprises a buffer having multiple queues, with each said queue adapted to contain a single encoded representations of the predetermined number of epoch intervals.

7. The method as defined in claim 1, where the streaming buffer comprises a buffer having multiple queues, with each said queue adapted to contain multiple encoded representations of the predetermined number of epoch intervals.

8. The method as defined in claim 1, where the streaming buffer is a cyclic buffer.

9. The method as defined in claim 1, where the streaming buffer is an acyclic buffer.

10. The method as defined in claim 1, wherein the streaming buffer includes a recursive buffer.

11. The method as defined in claim 10, wherein the recursive buffer includes a cyclic streaming buffer.

12. The method as defined in claim 10, wherein the recursive buffer includes an acyclic streaming buffer.

13. The method as defined in claim 10, wherein the recursive buffer includes a recursive streaming buffer.

14. The method as defined in claim 1, wherein the streaming buffer contains a plurality of queue slots, each of which stores an epoch interval of prepped content, and wherein the store of at least one of the streaming buffer queue slots is replaced with an association to a recursive buffer that contains a plurality of lower level queue slots.

15. The method as defined in claim 14, wherein the lower level queue slots contain prepped content that is read from the recursive buffer when the corresponding prepped content epoch interval is selected from the streaming buffer.

16. The method as defined in claim 1, wherein streaming one of the prepped content epoch intervals comprises:

detecting an encoding error condition;

selecting alternate prepped content from a queue other than the queue from which selecting was being performed at the time of detecting the error condition.

17. The method as defined in claim 16, wherein selecting alternate prepped content comprises selecting from a recursive buffer that contains a plurality of lower level queue slots.

18. The method as defined in claim 17, wherein the lower level queue slots contain prepped content that is read from a recursive buffer when the corresponding prepped content epoch interval is selected from the streaming buffer.

19. The method as defined in claim 1, wherein the epoch interval is selected in accordance to the temporal resolution of a counter.

20. The method as defined in claim 19, wherein the counter is a UTC counter.

21. The method as defined in claim 19, wherein the counter is an SMPTE LTC counter.

22. The method as defined in claim 1, wherein the epoch interval is selected to minimize latency in media delivery.

23. The method as defined in claim 22, wherein the latency is measured in the time elapsed between media content appearing at the input of the encoder, and the streamed encoded representation appearing at the receiving device.

24. The method as defined in claim 1, wherein storing into the streaming buffer is performed by a writer and occurs substantially simultaneously with retrieving from the streaming buffer by a reader, and the streaming and reading are performed according to an epoch interval separation distance.

25. The method as defined in claim 24, wherein storing into the streaming buffer and retrieving from the streaming buffer are performed according to selecting an epoch based a common counter, epoch interval, and an epoch offset.

26. The method as defined in claim 25, wherein the value of the common counter is distributed via NTP.

27. The method as defined in claim 25, wherein the value of the common counter is distributed via audio signal carrying SMPTE LTC.

28. The method as defined in claim 25, wherein the epoch offset of the reader is determined in accordance with a level of service parameter.

29. The method as defined in claim 28, wherein the level of service parameter relates to a user level identifier.

30. The method as defined in claim 25, wherein the epoch offset of the reader is selected to guarantee exclusive access of epoch chosen by the writer.

31. The method as defined in claim 25, wherein the level of service parameter relates to latency in media delivery.

32. The method as defined in claim 25, wherein storing into the streaming buffer by writers is further controlled by write enable signal.

33. The method as defined in claim 1, wherein streaming an encoded representation is performed in accordance with at least two parameters selected from among current network condition, receiving device configuration, and prepped content type.

34. The method as defined in claim 1, wherein streaming comprises selecting a plurality of prepped content epoch intervals such that each selected prepped content epoch interval is transported to a different one of a plurality of receiving devices.

35. The method as defined in claim 1, further comprising:

switching from the selected prepped content epoch interval corresponding to the original streaming buffer to a different prepped content epoch interval corresponding to a different streaming buffer such that the different prepped content epoch interval is selected for streaming by network transport directed to the receiving device with no change to the selected prepped content epoch interval of the streaming buffer.

36. The method as defined in claim 35, wherein switching is initiated in response to a user command at the receiving device.

37. The method as defined in claim 35, wherein switching is initiated in response to a counter.

38. The method as defined in claim 37, wherein the counter is a UTC counter.

39. The method as defined in claim 37, wherein the counter is an SMPTE Linear Time Code (LTC) counter.

40. The method as defined in claim 35, wherein switching is initiated in response to a command received at the streaming server buffer.

41. The method as defined in claim 35, wherein switching is initiated in response to a characteristic of the receiving device.

42. The method as defined in claim 41, wherein the characteristic comprises usage history of the receiving device.

43. The method as defined in claim 41, wherein the characteristic comprises a user level identifier.

44. The method as defined in claim 41, wherein the characteristics comprises the geographical location of the receiving device.

45. The method as defined in claim 35, wherein switching is initiated in response to a cue in the prepped content.

46. The method as defined in claim 45, wherein the cue is a DTMF tone in an audio portion of the prepped content.

47. The method as defined in claim 45, wherein the cue is a signal in a vertical blanking interval in a video portion of the prepped content.

48. The method as defined in claim 35, wherein the different streaming buffer comprises an encoded different digital content clip source different from that of the original streaming buffer.

49. The method as defined in claim 35, wherein latency in switching is determined by the epoch interval.

50. The method as defined in claim 1, wherein the encoding of a chosen epoch interval comprises encoding of a subset of data from previous epoch.

51. The method as defined in claim 50, wherein the encoding of a subset of data from a previous epoch modifies operating state of the encoder.

52. The method as defined in claim 51, wherein the encoding of the selected epoch commences with the modified state of the encoder.

53. The method as defined in claim 50, wherein the encoded subset of data from a previous epoch is removed from the prepped content of the selected epoch interval.

54. A system for processing digital content for streaming of live content network transport, the system comprising:

a network communications interface;

a streaming encoder that encodes a digital content clip according to epoch intervals comprising one or more consecutive predetermined portions of the digital content clip, wherein the streaming encoder generates prepped content that comprises multiple encoded representations of each epoch interval, such that each epoch interval comprises a different consecutive portion of the digital content clip and each of the multiple encoded representations comprises a different encoded representation of the corresponding digital content clip epoch interval;

a streaming buffer comprising a network data store that receives the prepped content from the streaming encoder for a predetermined number of epoch intervals;

a streaming server that selects one of the prepped content epoch intervals for reading from the streaming buffer in accordance with current network condition between the network data store and the receiving device for streaming the selected prepped content epoch interval by network transport directed to the receiving device.

55. The system as defined in claim 54, wherein the multiple encoded representations comprise representations that are encoded according to an estimated received quality metric.

56. The system as defined in claim 54, where the streaming buffer comprises a buffer having multiple queues adapted to contain the multiple encoded representations of the predetermined number of epoch intervals.

57. The system as defined in claim 56, where the streaming buffer is a cyclic buffer.

58. The system as defined in claim 56, where the streaming buffer is a linear buffer.

59. The system as defined in claim 56, wherein the streaming buffer includes a recursive buffer.

60. The system as defined in claim 56, wherein storing into the streaming buffer occurs substantially simultaneously with reading from the streaming buffer, and the streaming and reading are performed according to an epoch interval separation distance.

61. The system as defined in claim 60, wherein the epoch interval separation distance is determined in accordance with a level of service parameter.

62. The system as defined in claim 61, wherein the level of service parameter relates to network latency.

63. The system as defined in claim 61, wherein the level of service parameter relates to a user level identifier.

64. The system as defined in claim 54, wherein the streaming server selects in accordance with at least two parameters selected from among current network condition, receiving device configuration, and prepped content type.

65. The system as defined in claim 54, wherein the streaming server selects a plurality of prepped content epoch intervals such that each selected prepped content epoch interval is transported to a different one of a plurality of receiving devices.

66. The system as defined in claim 54, wherein the streaming server further switches from the selected prepped content epoch interval to a different prepped content epoch interval corresponding to an encoded different digital content clip such that the different prepped content epoch interval is selected for streaming by network transport directed to the receiving device with no change to the selected prepped content epoch interval of the streaming buffer.

67. The system as defined in claim 66, wherein the different prepped content epoch interval is read from the streaming buffer.

68. The system as defined in claim 66, wherein the different prepped content epoch interval comprises a live content clip that is read from an external prepped content buffer.

69. The system as defined in claim 66, further comprising:

switching from the different prepped content epoch interval back to the selected prepped content epoch interval for streaming by network transport directed to the receiving device.

70. The system as defined in claim 66, wherein the encoded different digital content clip is received from a source different from that of the digital content clip.

71. A program product for use in a computer system that executes program instructions recorded in a computer-readable media to perform a method for processing digital content for streaming of live content network transport, the program product comprising:

a recordable media;

a program of computer-readable instructions executable by the computer system to perform operations comprising;

encoding a digital content clip according to epoch intervals comprising one or more consecutive predetermined portions of the digital content clip, wherein the encoding generates prepped content that comprises multiple encoded representations of each epoch interval, such that each epoch interval comprises a different consecutive portion of the digital content clip and each of the multiple encoded representations comprises a different encoded representation of the corresponding digital content clip epoch interval;

storing the prepped content for a predetermined number of epoch intervals into a streaming buffer of a network data store;

selecting one of the prepped content epoch intervals for reading from the streaming buffer in accordance with current network condition between the network data store and the receiving device for streaming the selected prepped content epoch interval by network transport directed to the receiving device.

72. The program product as defined in claim 71, wherein the multiple encoded representations comprise representations that are encoded according to an estimated received quality metric.

73. The program product as defined in claim 71, wherein the streaming buffer comprises a buffer having multiple queues adapted to contain the multiple encoded representations of the predetermined number of epoch intervals.

74. The program product as defined in claim 73, where the streaming buffer is a cyclic buffer.

75. The program product as defined in claim 73, where the streaming buffer is a linear buffer.

76. The program product as defined in claim 73, wherein the streaming buffer includes a recursive buffer.

77. The program product as defined in claim 73, wherein storing into the streaming buffer occurs substantially simultaneously with reading from the streaming buffer, and the streaming and reading are performed according to an epoch interval separation distance.

78. The program product as defined in claim 77, wherein the epoch interval separation distance is determined in accordance with a level of service parameter.

79. The program product as defined in claim 78, wherein the level of service parameter relates to network latency.

80. The program product as defined in claim 78, wherein the level of service parameter relates to a user level identifier.

81. The program product as defined in claim 71, wherein selecting is performed in accordance with at least two parameters selected from among current network condition, receiving device configuration, and prepped content type.

82. The program product as defined in claim 71, wherein selecting comprises selecting a plurality of prepped content epoch intervals such that each selected prepped content epoch interval is transported to a different one of a plurality of receiving devices.

83. The program product as defined in claim 71, further comprising:

switching from the selected prepped content epoch interval to a different prepped content epoch interval corresponding to an encoded different digital content clip such that the different prepped content epoch interval is selected for streaming by network transport directed to the receiving device with no change to the selected prepped content epoch interval of the streaming buffer.

84. The program product as defined in claim 83, wherein the different prepped content epoch interval is read from the streaming buffer.

85. The program product as defined in claim 83, wherein the different prepped content epoch interval comprises a live content clip that is read from an external prepped content buffer.

86. The program product as defined in claim 83, further comprising:

switching from the different prepped content epoch interval back to the selected prepped content epoch interval for streaming by network transport directed to the receiving device.

87. The program product as defined in claim 83, wherein the encoded different digital content clip is received from a source different from that of the digital content clip