MANAGED MULTIPLEXING OF VIDEO IN AN ADAPTIVE BIT RATE ENVIRONMENT

• US 20110126248A1
• Filed: 11/19/2010
• Published: 05/26/2011
• Est. Priority Date: 11/24/2009
• Status: Active Grant

• Current Assignee: Imagine Communications Limited (Gores Broadcast Holdings LLC)
• Original Assignee: RGB Networks, Inc. (Gores Broadcast Holdings LLC)
• Inventors: Fisher, Yuval, Tom, Adam S.
• Granted Patent: US 10,003,851 B2
• Time in Patent Office: Days
• US Class Current: 725/95
• CPC Class Codes: H04N 21/2365 Multiplexing of several video streams
• CPC Class Codes: H04N 21/26216 involving the channel capacity, e.g. network bandwidth admission control, resource allocation in open networks H04L12/5692; flow control in packet networks H04L47/10; establishing a schedule or organising the servicing of application requests taking into account QoS H04L67/61
• 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 21/4347 Demultiplexing of several video streams
• CPC Class Codes: H04N 21/47202 for requesting content on demand, e.g. video on demand
• CPC Class Codes: H04N 7/17318 Direct or substantially direct transmission and handling of requests

Abstract

Methods and apparatus for delivering video programs are provided. A plurality of video programs are provided in a fragmented, adaptive bit rate format. A request for a respective video program from the plurality of video programs is received from each of a plurality of clients. The requested video programs are multiplexed for delivery to the clients in a multiplex over a shared, fixed-bit-rate transmission channel. The requests may be for the same or different video programs. The requests for the video programs may occur at the same or at different times. In the fragmented, adaptive bit rate format, the fragment delivered to the client may not be the same as the requested fragment and is dependent on multiple criteria, including the bitrate and quality of the requested and delivered fragments, the total available delivery bandwidth, and other fragment requests made on the channel. The resulting multiplex may be either a constant bit rate multiplex or a variable bit rate multiplex.

Claims

1. A video delivery method, comprising:

providing a plurality of video programs in a fragmented, adaptive bit rate format;

receiving, from each of a plurality of clients, a request for a respective video program from the plurality of video programs; and

multiplexing the requested video programs for delivery to the clients in a multiplex over a shared, fixed-bit-rate transmission channel.

2. The video delivery method of claim 1, wherein the requests are for the same or different video programs.

3. The video delivery method of claim 1, wherein the requests for the video programs occur at the same or at different times.

4. The video delivery method of claim 1, wherein the video programs are stored on or provided via a server.

5. The video delivery method of claim 4, wherein in the fragmented, adaptive bit rate format, several versions of each video program are provided at correspondingly different bit rates, and each version of each program is divided into fragments.

6. The video delivery method of claim 5, wherein:

the server is an HTTP server; and

the requests comprise HTTP requests for the fragments of the respective video programs requested by each of the clients.

7. The video delivery method of claim 6, further comprising:

providing an HTTP proxy for receiving the HTTP requests from the clients and for providing the fragments of the respective video programs from the HTTP server to the clients in the multiplex over the fixed-bit-rate transmission channel.

8. The video delivery method of claim 7, wherein the HTTP proxy is one of a script, service, or process running on the same device as the HTTP server providing the video programs.

9. The video delivery method of claim 7, wherein each request includes an identification of the video program requested and a desired bit rate for an initial or next fragment of the requested video program.

10. The video delivery method of claim 9, wherein:

the HTTP proxy returns at least one fragment of the requested video program to the client at the desired bit rate or returns at least one fragment with a different bit rate based on predetermined criteria.

11. The video delivery method of claim 10, wherein the predetermined criteria comprises at least one of:

a number or type of other video programs are being requested in the same fixed-bit-rate transmission channel by other clients;

an identity of the requesting client;

a subscription plan of the requesting client;

video quality levels of other video programs;

a combined bandwidth being requested by all clients;

a desired bandwidth or video quality set by a service provider providing the transmission channel;

a predetermined fixed bit rate set by the service provider; and

instantaneous bit rates of the other video programs.

12. The video delivery method of claim 11, wherein the multiplex comprises a constant bit rate multiplex.

13. The video delivery method of claim 11, wherein the multiplex comprises a variable bit rate multiplex.

14. The video delivery method of claim 10, wherein, for each client and the respective requested video program:

each request results in the receipt of at least one fragment of the video program;

subsequent requests are sent by the client and processed by the HTTP proxy after receipt of a prior request; and

a bit rate of subsequent received fragments is dependent on one of the corresponding request, the bit rate of a prior received fragment, or the predetermined criteria.

15. The video delivery method of claim 10, wherein:

the client comprises one of an end user or a content distribution network; and

in the event the HTTP proxy delivers the fragment with a different bit rate than requested, the HTTP proxy includes information specifying a change in the bit rate of the delivered fragment.

16. The video delivery method of claim 7, wherein the multiplex comprises a constant bit rate multiplex.

17. The video delivery method of claim 16, wherein, for each client and the respective requested video program:

each request results in the receipt of at least one fragment of the video program;

subsequent requests are sent by the client and processed by the HTTP proxy after receipt by the client of a prior request until the entire video program or a desired portion of the video program is received; and

each fragment of the respective video program is selected from one version of the video program and provided at the corresponding bit rate.

18. The video delivery method of claim 17, wherein the bit rate of the fragments for each requested video program is set by a service provider so that all requested video programs fit within the fixed-bit-rate transmission channel.

19. The video delivery method of claim 7, wherein the multiplex comprises a variable bit rate multiplex.

20. The video delivery method of claim 19, wherein:

for each requested program, the HTTP proxy monitors a quantization level of the fragments of each version of the requested program;

in response to each request, the HTTP proxy delivers to the clients fragments taken from one or more of the versions of each program having the same or substantially the same quantization level.

21. The video delivery method of claim 20, wherein:

each request is processed by the HTTP proxy to determine when to provide a next fragment;

any indication of a desired bit rate contained in the client request is ignored by the HTTP proxy and instead the bit rate of all provided fragments are selected based on the quantization level.

22. The video delivery method of claim 19, wherein:

the HTTP proxy monitors the bandwidth being requested by each client and the bit rates of the next fragments to be provided for each requested video program to determine if the total bit rates of all fragments to be provided exceeds a bit rate of the fixed-bit-rate transmission channel;

if the total bit rates exceed the bit rate of fixed-bit-rate transmission channel, the HTTP proxy will provide fragments from a lower bit rate version for one or more of the requested video programs such that the next fragments to be provided fit within the fixed-bit-rate transmission channel.

23. The video delivery method of claim 22, wherein:

in order to determine which of the one or more requested programs fragments from the lower bit rate version should be selected from, the HTTP proxy analyzes each video program requested and chooses the one or more video programs based on a perceptual quality heuristic.

24. An apparatus for delivering video programs, comprising:

means for providing a plurality of video programs in a fragmented, adaptive bit rate format;

means for receiving, from each of a plurality of clients, a request for a respective video program from the plurality of video programs; and

a multiplexer for multiplexing the requested video programs for delivery to the clients in a multiplex over a shared, fixed-bit-rate transmission channel.