Adaptive video switching for variable network conditions

Patent metadata

Field	Value
Publication number	US-9420347-B2
Application number	US-201213727332-A
Country	US
Kind code	B2
Filing date	Dec 26, 2012
Priority date	Jun 27, 2008
Publication date	Aug 16, 2016
Grant date	Aug 16, 2016

Abstract

A method for video playback switching in response to changing network conditions. The method includes accessing a server to retrieve respective index files for a low bit rate version and a high bit rate version of the video file, and instantiating a low bit rate media player and a high bit rate media. Playback of the video file is begun by the high bit rate media player streaming the high bit rate version from the server. Upon an indication of impeded network conditions, a transition point is selected, wherein the transition point indicates where downloading of the high bit rate version stops and where downloading of the low bit rate version begins. The low bit rate media player is then positioned to begin playback at the transition point. Playback of the video file is then switched to the low bit rate player upon encountering the transition point.

First claim

What is claimed is:

1. A system for video playback switching, comprising:
a client computing device comprising:
a memory device configured to store a plurality of programmed instructions and a plurality of index files of a low bit rate version and a high bit rate version of a video file received from a remote server;
a processor configured to instantiate a low bit rate media player application and a high bit rate media player application for streaming respective versions of the video file, to detect an indication of impeded playback conditions, to select a first transition point in the high bit rate version based on the impeded playback conditions, to position the low bit rate media player for playback of the low bit rate version beginning at a position in the low bit version corresponding to the first transition point while the high bit rate version is streaming, and to switch between the high bit rate media player and the low bit rate media player when the first transition point is reached,

wherein the playback conditions comprise current network and local hardware conditions corresponding to the client device.

2. The system according to claim 1 , wherein the first transition point is indicative of where streaming of the high bit rate version stops and streaming of the low bit rate version begins.

3. The system according to claim 1 , wherein, the client device is further configured to select a second transition point upon an indication of improved playback conditions, the second transition point being comprised within the low bit rate version.

4. The system according to claim 3 , wherein the second transition point indicates where a downloading of the low bit rate version stops and where a downloading of the high bit rate version begins.

5. The system according to claim 3 , wherein the high bit rate media player is further configured to begin playback at the second transition point.

6. The system according to claim 5 , wherein a playback of the video file is switched from the low bit rate player to the high bit rate player upon encountering the second transition point, where after the high bit rate player resumes streaming the high bit rate version from the server.

7. The system of claim 1 , wherein the server further comprises a plurality of different versions of the video file with each of the plurality of versions having a respective different bit rate, and wherein the client device is configured to instantiate a corresponding plurality of respective different media players to enable switching playback of the video file between the plurality of different versions to dynamically adapt to changing playback conditions.

8. The system of claim 1 , wherein the high bit rate media player comprises a playback buffer, and wherein the indication of impeded playback conditions comprises a drainage state of the playback buffer within the high bit rate media player indicating the streaming is being impeded by the playback conditions.

9. The system of claim 1 , further comprising a player arbiter coupled to the low bit rate media player and the high bit rate media player, wherein a switching of the playback of the video file is controlled by the player arbiter.

10. The system of claim 1 , wherein a switch between the high bit rate media player and the low bit rate media player appears seamless to a user of the client device.

11. The system of claim 1 , wherein a switch between the low bit rate media player and the high bit rate media player appears seamless to a user of the client device.

12. The system of claim 1 , wherein the low bit rate version of the video file is independently playable from the high bit rate version of the video file.

13. The system of claim 1 , wherein the high bit rate version of the video file is independently playable from the low bit rate version of the video file.

14. The system of claim 1 , wherein the first transition point is located at a keyframe to facilitate a switch to the low bit rate player.

15. The system of claim 14 , wherein the first transition point is located a number of frames away from a keyframe, and wherein the number of frames and the keyframe are downloaded in the client device to position the low bit rate media player to begin playback at the transition point.

16. The system of claim 15 , wherein the number of frames and the keyframe are downloaded in the background and the low bit rate media player is positioned to begin playback at the first transition point in the background.

17. The system of claim 1 , wherein the low bit rate version comprises a different file format from the high bit rate version.

18. The system of claim 1 , wherein the network conditions comprises a network transmission bandwidth.

19. The system of claim 18 , wherein the indication of impeded playback conditions comprises a decrease in network transmission bandwidth.

20. The system of claim 1 , wherein the client device comprises a processor, and wherein the local hardware conditions comprises a processor availability for video playback.

Assignees

• Microsoft Corp

Inventors

• Khouzam Gilles
• Karlov Donald
• Zhang Wenbo
• Schliemann Federico
• George Sam
• Harsh Mike

Classifications

• H04N21/64769

  for rate control (flow control in packet networks H04L47/10) · CPC title

• H04N21/4621

  Controlling the complexity of the content stream or additional data, e.g. lowering the resolution or bit-rate of the video stream for a mobile client with a small screen (arrangements for using the results of monitoring on user's side in broadcast systems H04H60/65; flow control in packet networks H04L47/10) · CPC title

• H04N21/64738 Primary

  Monitoring network characteristics, e.g. bandwidth, congestion level (data switched network analysis H04L41/14; monitoring functioning in data switched networks H04L43/0817; flow control in packet networks H04L47/10) · CPC title

• H04N21/6373

  for rate control {, e.g. request to the server to modify its transmission rate (flow control in packet networks H04L47/10)} · CPC title

• H04N21/234381

  by altering the temporal resolution, e.g. decreasing the frame rate by frame skipping · CPC title