Media Stream Scheduling for Hiccup-Free Fast-Channel-Change in the Presence of Network Chokepoints

• US 20090013080A1
• Filed: 09/10/2008
• Published: 01/08/2009
• Est. Priority Date: 10/10/2003
• Status: Abandoned Application

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Green, Dustin L.
• Application Number:
  US12/208,214
• Publication Number:
  US 20090013080A1
• Time in Patent Office: Days
• US Class Current: 709/227
• CPC Class Codes: H04L 65/764 at the destination reformatting of additional data in video clients H04N21/4355
• CPC Class Codes: H04N 21/238 Interfacing the downstream path of the transmission network, e.g. adapting the transmission rate of a video stream to network bandwidth; Processing of multiplex streams hybrid fiber coaxial [HFC] networks for downstream channel allocation for video distribution H04L12/2801; flow control in packet networks H04L47/10; real-time communication protocols in data switching networks H04L65/00; scheduling or organising the servicing of application requests H04L67/60
• CPC Class Codes: H04N 21/23805 Controlling the feeding rate to the network, e.g. by controlling the video pump
• CPC Class Codes: H04N 21/2387 Stream processing in response to a playback request from an end-user, e.g. for trick-play
• 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 21/242 Synchronization processes, e.g. processing of PCR [Program Clock References] arrangements for synchronising broadcast or distribution via plural systems in broadcast distribution systems H04H20/18
• 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 21/4384 involving operations to reduce the access time, e.g. fast-tuning for reducing channel switching latency

Abstract

An implementation, as described herein, facilitates fast start-up of a new media stream while avoiding temporal interruption (i.e., “hiccups”) of the presentation of that new media stream. At least one implementation, described herein, coordinates the delivery of multiple simultaneous media streams on a media-stream network. Its coordination accounts for traversal of bandwidth-restricted chokepoints; quickly stopping delivery of one or more media streams from the set of streams; quickly initiating delivery and presentation of one or more new media streams not previously in the set (i.e., a “channel change”); and producing clean playback of all of the streams in the set, despite their different timelines. This abstract itself is not intended to limit the scope of this patent. The scope of the present invention is pointed out in the appending claims.

Claims

1. A computer-readable medium having processor-executable instructions that, when executed by a processor, performs a method comprising:

receiving a request to start a new media stream from a media-stream presentation device on a media-stream network having one or more bandwidth-limiting chokepoints therein;

calculating an available data-rate reservation through the network to the presentation device using a portion of the new media stream, wherein the available data-rate is limited by the one or more chokepoints in the network;

inserting data associated with the portion of the new media stream into a schedule of outgoing media streams being sent via the network; and

generating a profile that indicates the conditions under which the presentation device should start presenting the portion of the new media stream.

2. A medium as recited in claim 1, wherein the inserting further comprises scheduling data which is not proximate the start of the new stream to be delivered before designated decode time(s) of that data.

3. A medium as recited in claim 1, wherein the generating further comprises determining a number of packets by identifying a value representing how much extra data would be required before startup in order to avoid underflow due to playback of a particular frame at a particular time.

4. A medium as recited in claim 3, wherein the generating further comprises determining a start time that would be required to cause the particular frame to play at the particular time.

5. A medium as recited in claim 4, wherein the generating further comprises determining a separate maximum value for each of several possible ranges of start times of the determined value representing how much extra data would be required to avoid underflow due to all known frames and the possible ranges of start times.

6. A medium as recited in claim 1, wherein the method further comprises determining a dynamic bandwidth capacity of the one or more chokepoints over a defined amount of time.

7. A medium as recited in claim 1, wherein the inserting further comprises adjusting a delivery deadline schedule so that the portion of the new stream is given as much reserved bit-rate as possible for delivery via the network given the one or more chokepoints in the network and the preexisting delivery deadlines and bit-rates that are already scheduled.

8. A medium as recited in claim 1, wherein the inserting further comprises assigning delivery deadlines for the portion of the new stream as late into a deadline delivery schedule as possible while still avoiding underflow of the portion of the new stream at the presentation device.

9. A medium as recited in claim 1, wherein the generating further comprises generating a profile for the media-stream presentation device including at least a number of packets that the media-stream presentation device needs to receive before presenting the portion of the new media stream.

10. A medium as recited in claim 1, wherein the network is, at least partially, unicast.

11. A computing device comprising a medium as recited in claim 1.

12. A medium as recited in claim 1, wherein the portion of the new stream is a highest priority portion of the new stream.

13. A medium as recited in claim 1, wherein the portion of the new stream is a video stream.

14. A scheduling system comprising:

a request receiver configured to receive a request to start a new media stream from a media-stream presentation device on a media-stream network having one or more bandwidth-limiting chokepoints therein;

a calculator configured to determine an available data-rate reservation through the network to the presentation device using a portion of the new media stream, wherein the available data-rate is limited by the one or more chokepoints in the network;

an inserter configured to modify a schedule of outgoing media streams being sent via the network by inserting data associated with the portion of the new media stream into the schedule; and

a profile configured to be generated, wherein the profile indicates the conditions under which the presentation device should start presenting the portion of the new media stream.

15. A scheduling system as recited in claim 14, wherein the inserter further modifies the schedule by inserting scheduling data which is not proximate the start of the new stream to be delivered before designated decode time(s) of that data.

16. A scheduling system as recited in claim 14, wherein the profile is generated by determining a number of packets by identifying a value representing how much extra data would be required before startup in order to avoid underflow due to playback of a particular frame at a particular time.

17. A scheduling system as recited in claim 16, wherein when the profile is generated, a start time that would be required to cause the particular frame to play at the particular time is determined.

18. A scheduling system as recited in claim 14, wherein the network is, at least partially, unicast.

19. A scheduling system as recited in claim 14, wherein the portion of the new stream is a highest priority portion of the new stream.

20. A scheduling system as recited in claim 14, wherein the portion of the new stream is a video stream.

21. A scheduling system as recited in claim 14, further comprising a message that is configured to be transmitted to the presentation device, the message being generated by an analyzer, which analyzes the profile in order to generate the message.