Adaptive progressive download

• US 8,504,713 B2
• Filed: 05/28/2010
• Issued: 08/06/2013
• Est. Priority Date: 05/28/2010
• Status: Active Grant

• Current Assignee: Allot Communications Limited
• Original Assignee: Allot Communications Limited
• Inventors: Arya, Ashwani, Arole, Parag
• Primary Examiner(s): Lim, Krisna
• Application Number:
  US12/790,728
• Publication Number:
  US 20110296046A1
• Time in Patent Office: 1,166 Days
• Field of Search: 709/231, 709/232
• US Class Current: 709/231
• CPC Class Codes: H04L 65/752 adapting media to network capabilities
• CPC Class Codes: H04L 65/762 at the source reformatting of additional data in video distribution servers H04N21/2355
• CPC Class Codes: H04L 65/80 Responding to QoS

Abstract

Data packets to be transferred over a network as part of a temporally ordered content stream are obtained by an adaptive progressive download (APD) server. The APD server divides the data packets of the content stream into epochs of contiguous data, the epochs including a current epoch. The APD server determines a bit rate available on the network for transferring the current epoch and calculates an estimate of a playback time of the content stream buffered at a computer to which the content stream is being transferred and played back. The calculation of the estimate is based at least in part on the bit rate available on the network and an encoding bit rate of the content stream. The APD server controls the transfer of the content stream over the network in accordance with the estimated playback time.

Claims

1. A method of streaming data over a network, the method comprising:

at an adaptive progressive server which streams content to a user playback equipment, dividing data packets of an intercepted content stream into epochs of contiguous data such that content of each epoch can be independently transrated for transfer over a network as part of a temporally ordered content stream, the epochs including a current epoch;

at the adaptive progressive server which streams content to the user playback equipment, determining a bit rate available on the network for transferring the current epoch from the adaptive progressive server to the user playback equipment;

at the adaptive progressive server which streams content to the user playback equipment, estimating a temporal amount of the content stream that is buffered at the user playback equipment to which the content stream is being transferred, wherein the estimating is based at least in part on (a) the bit rate available on the network, as determined by the adaptive progressive server, and (b) an encoding bit rate of the intercepted content stream, as determined by the adaptive progressive server; and

at the adaptive progressive server which streams content to the user playback equipment, controlling the transfer of the content stream over the network in accordance with the temporal amount of buffered content stream estimated by the adaptive progressive server, and trans-rating in real time one or more epochs from a first bitrate to a second, lower, bitrate to reduce an average video bitrate to a level suitable for transport with current network conditions.

2. The method of claim 1, wherein the epochs comprise data packets encapsulated in a container wrapper format for network transfer, wherein the method comprises:

at the adaptive progressive server which streams content to the user playback equipment, dividing the content stream into epochs such that each epoch corresponds to approximately five to seven seconds of audio/video content.

3. The method of claim 1, comprising:

at the adaptive progressive server which streams content to the user playback equipment, estimating that the temporal amount of the content stream that is buffered at the user playback equipment is below a lower threshold,

at the adaptive progressive server which streams content to the user playback equipment, determining a bit rate at which to re-encode in real time the current epoch to maintain the temporal amount of the content stream that is buffered at the user playback equipment above the lower threshold; and

transferring the current epoch, over the network towards the user playback equipment;

wherein estimating the temporal amount of the content stream that is buffered at the user playback equipment comprises;

at the adaptive progressive server that streams content to the user playback equipment, (A) tracking a duration, in seconds of viewing time, of the epochs that were delivered to the user playback equipment via a delivery interface;

(B) tracking an average video rate of the epochs;

(C) tracking an estimated network bandwidth being utilized to transport the content stream;

(D) tracking previous estimates of the temporal amount of content buffered at the user playback equipment based on timestamps of multiplexed audio/video being sent over the network.

4. The method of claim 3, comprising:

at the adaptive progressive server that streams content to the user playback equipment, increasing the transfer rate of the real time re-encoded current epoch into a container wrapper for transfer over the network toward the user playback equipment to increase playback time of content stream, buffered at the user playback equipment, above the lower threshold.

5. The method of claim 1, comprising:

at the adaptive progressive server that streams content to the user playback equipment, estimating that the temporal amount of buffered content stream is above an upper threshold, and

at the adaptive progressive server that streams content to the user playback equipment, slowing the transfer of the current epoch over the network to maintain playback time of content stream, buffered at the user playback equipment, below the upper threshold.

6. A method of streaming data over a network, the method comprising:

at a Deep Packet Inspection (DPI) router that routes packets of audio/video content to a user playback equipment, intercepting data packets being transferred over the network, identifying that the data packets are part of a temporally ordered content stream, and forwarding the temporally ordered content stream to a demultiplexing subsystem of an adaptive progressive server;

at said adaptive progressive server that routes packets of audio/video content to the user playback equipment, dividing the intercepted data packets of the content stream into epochs of contiguous data, the epochs including a current epoch, wherein the dividing comprises dividing the intercepted data packets into epochs such that each epoch corresponds to approximately five to seven seconds of audio/video content;

at said adaptive progressive server that routes packets of audio/video content to the user playback equipment, determining a bit rate available on the network for transferring the current epoch;

at said adaptive progressive server that routes packets of audio/video content to the user playback equipment, estimating a temporal amount of the content stream that is buffered at the user playback equipment to which the content stream is being transferred,

wherein the estimating at said adaptive progressive server is based at least in part on cal the bit rate available on the network, as determined by the adaptive progressive server, and (b) an encoding bit rate of the content stream, as determined by the adaptive progressive server; and

at said adaptive progressive server, estimating that the temporal amount of the content stream that is buffered at the user playback equipment is above a threshold, and slowing transfer of the current epoch over the network toward said user playback equipment.

7. The method of claim 6, comprising:

at the adaptive progressive server, dividing the intercepted data packets into audio content epochs and video content epochs, and multiplexing in real time the audio and video content epochs into a contiguous data stream with a container wrapper format configured to be transferred over the network toward said user playback equipment.

8. A system for streaming data over a network, the system comprising:

a controller connected between a hosting web server that hosts audio/video content and a user playback equipment, wherein the controller

(A) divides data packets of an intercepted content stream into epochs of contiguous data such that content of each epoch can be independently transrated for transfer over a network as part of a temporally ordered content stream, the epochs including a current epoch,

(B) determines a bit rate available on the network for transferring the current epoch from said controller to the user playback equipment, and

(C) estimates a temporal amount of the content stream that is buffered at the user playback equipment to which the content stream is being transferred, by taking into account at least (a) the bit rate available on the network, as determined by said controller, and (b) an encoding bit rate of the intercepted content stream, as determined by said controller;

and

a delivery interface that (i) controls the transfer of the intercepted content stream over the network toward the user playback equipment in accordance with the playback time estimated by the controller, and (ii) trans-rates in real time one or more epochs from a first bitrate to a second, lower, bitrate to reduce an average video bitrate to a level suitable for transport with current network conditions.

9. The system of claim 8, wherein the epochs comprise data packets that are encapsulated in a container wrapper format for network transfer.

10. The system of claim 8, wherein, if the calculated estimate of the playback time is below a lower threshold, the controller:

determines a bit rate at which to re-encode the current epoch to maintain the playback time of the buffered content stream above the lower threshold; and

transfers the re-encoded current epoch over the network toward the user playback equipment.

11. The system of claim 10, wherein the controller is to increase the transfer of the re-encoded current epoch into a container wrapper format for transfer over the network to increase the playback time of the buffered content stream above the lower threshold.

12. The system of claim 8, wherein, if the calculated estimate of the playback time is above an upper threshold, the delivery interface slows the transfer of the current epoch over the network to maintain the playback time of the buffered content stream below the upper threshold.

13. A system for streaming data over a network, the system comprising:

a controller connected between a hosting web server that hosts audio/video content and a user playback equipment, wherein the controller

(A) intercepts data packets being transferred over a network from said hosting web server to said user playback equipment,

(B) identifies the intercepted data packets as being part of at least one temporally ordered content stream,

(C) divides the data packets of the content stream into epochs of contiguous data, the epochs including a current epoch,

(D) determines a bit rate available on the network for transferring the current epoch from said controller to the user playback equipment, and

(E) estimates a temporal amount of the content stream that is buffered at the user playback equipment to which the content stream is being transferred, by taking into account at least (a) the bit rate available on the network, as estimated by said controller, and (b) a video bit rate at which the epoch is encoded, as determined by said controller;

and

a delivery interface that slows the transfer of the current epoch over the network toward the user playback equipment if the calculated estimate is above a threshold.

14. The system of claim 13, wherein the controller is to divide the intercepted data packets into audio content epochs and video content epochs, and to multiplex the audio content epochs and the video content epochs into a contiguous data stream with a container wrapper format configured to be transferred over the network toward said user playback equipment.

15. A computer-readable memory having a computer-readable program embodied therein for directing operation of a computer system for streaming data over a network, the computer-readable program including computer executable instructions for processing in accordance with the following:

at an adaptive progressive server which streams content to a user playback equipment, dividing data packets of an intercepted content stream into epochs of contiguous data such that content of each epoch can be independently transrated for transfer over a network as part of a temporally ordered content stream, the epochs including a current epoch;

at the adaptive progressive server which streams content to the user playback equipment, determining a bit rate available on the network for transferring the current epoch from the adaptive progressive server to the user playback equipment;

at the adaptive progressive server which streams content to the user playback equipment, estimating a temporal amount of the content stream that is buffered at the user playback equipment to which the content stream is being transferred, wherein the estimating is based at least in part on (a) the bit rate available on the network, as determined by the adaptive progressive server, and (b) an encoding bit rate of the intercepted content stream, as determined by the adaptive progressive server; and

at the adaptive progressive server which streams content to the user playback equipment, controlling the transfer of the content stream over the network toward the user playback equipment in accordance with the playback time estimated by the adaptive progressive server, and trans-rating in real time one or more epochs from a first bitrate to a second, lower, bitrate.

16. The computer-readable memory of claim 15, wherein the epochs comprise data packets that are encapsulated in a container wrapper format for network transfer.

17. The computer-readable memory of claim 15, wherein, if the calculated estimate of the playback time is below a lower threshold, the controlling comprises:

determining a bit rate at which to re-encode the current epoch to maintain the playback time of the buffered content stream above the lower threshold; and

transferring the re-encoded current epoch toward the network.

18. The computer-readable memory of claim 17, wherein the controlling comprises increasing the transfer rate of the re-encoded current epoch for transfer over the network to increase the playback time of the buffered content stream above the lower threshold.

19. The computer-readable memory of claim 15, wherein, if the calculated estimate of the playback time is above an upper threshold, the controlling comprises slowing the transfer of the current epoch over the network to maintain the playback time of the buffered content stream below the upper threshold.

20. A computer-readable memory having a computer-readable program embodied therein for directing operation of a computer system for streaming data over a network, the computer-readable program including computer executable instructions for processing in accordance with the following:

at a Deep Packet Inspection (DPI) router that routes packets of audio/video content to a user playback equipment, intercepting data packets being transferred over the network, identifying that the data packets are part of a temporally ordered content stream, and forwarding the temporally ordered content stream to a demultiplexing subsystem of an adaptive progressive server;

at said adaptive progressive server that routes packets of audio/video content to the user playback equipment, dividing the intercepted data packets of the content stream into epochs of contiguous data, the epochs including a current epoch, wherein the dividing comprises dividing the intercepted data packets into epochs such that each epoch corresponds to approximately five to seven seconds of audio/video content;

at said adaptive progressive server that routes packets of audio/video content to the user playback equipment, determining a bit rate available on the network for transferring the current epoch;

at said adaptive progressive server that routes packets of audio/video content to the user playback equipment, estimating a temporal amount of the content stream that is buffered at the user playback equipment to which the content stream is being transferred,

wherein the estimating at said adaptive progressive server is based at least in part on (a) the bit rate available on the network, as determined by the adaptive progressive server, and (b) an encoding bit rate of the content stream, as determined by the adaptive progressive server; and

at said adaptive progressive server, estimating that the temporal amount of the content stream that is buffered at the user playback equipment is above a threshold, and slowing transfer of the current epoch over the network toward said user playback equipment.