Managed degradation of a video stream

• US 20060193380A1
• Filed: 01/31/2006
• Published: 08/31/2006
• Est. Priority Date: 03/30/2001
• Status: Active Grant

• Current Assignee: Pixelworks Incorporated
• Original Assignee: VIXS Systems Incorporated (Pixelworks Incorporated)
• Inventors: Laksono, Indra
• Granted Patent: US 9,826,259 B2
• Time in Patent Office: Days
• US Class Current: 375/240.01
• 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 21/234354 by altering signal-to-noise ratio parameters, e.g. requantization
• CPC Class Codes: H04N 21/234363 by altering the spatial resolution, e.g. for clients with a lower screen resolution
• 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 21/25808 Management of client data terminal profiles in network data switching protocols H04L67/303
• CPC Class Codes: H04N 21/25825 involving client display capabilities, e.g. screen resolution of a mobile phone optimising the visualisation of content during browsing in the Internet G06F16/9577; processing of terminal status or physical abilities in wireless networks H04W8/22; authentication in wireless network security H04W12/06
• CPC Class Codes: H04N 21/26233 involving content or additional data duration or size, e.g. length of a movie, size of an executable file
• 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 21/4363 Adapting the video stream to a specific local network, e.g. a Bluetooth® network

Abstract

A system and a method for simultaneous transmission of multiple media streams in a fixed bandwidth network are disclosed herein. The system is comprised of a central gateway media server and a plurality of client receiver units. The input media streams arrive from an external source and are then transmitted to the client receiver units in a compressed format. A state machine on the gateway media server detects if the network bandwidth is close to saturation. In one embodiment, the potential bandwidth saturation is measured by matching the time when the start of unit of media for each stream against the estimated transmission time for that unit. When any one actual transmission time exceeds its estimated transmission time by a predetermined threshold value, the network is deemed to be close to saturation, or already saturated, and the state machine executes a process of selecting at least one stream as a target for lowering total bandwidth usage. Once the target stream associated with a client receiver unit is chosen, the amount of data transmitted by the target stream is reduced, which could result in a lower data transmission rate. In one embodiment, the amount of data is reduced by a gradual degradation of the precision of the data, resulting in a greater potential for data compression, and/or by gradually reducing the resolution of the data of the target stream.

Claims

1. A method comprising:

determining if a first portion of a display stream is transmissible via a transmission link in a manner permitting real time display; and

compressing the first portion of the display stream in a first compression manner to produce a first compressed display stream portion when it is determined that the first portion of the display stream data is not transmissible over the transmission link in a manner permitting real time display.

2. The method of claim 1, wherein the first portion of the display stream is determined to be transmissible in a manner permitting real time display when an expected time of transmission of a second portion of the display stream via the transmission link is within a predetermined tolerance of an actual time of transmission of the second portion of the display stream via the transmission link.

3. The method of claim 2, wherein the predetermined tolerance is determined based on an expected buffer fullness of a buffer of a receiving device connected to the transmission link.

4. The method of claim 2, wherein:

the display stream represents a series of display frames;

the first portion of the display stream represents a first sequence of one or more display frames of the series of display frames; and

the second portion of the display stream represents a second sequence of one or more display frames of the series of display frames prior to the first sequence.

5. The method of claim 1, wherein the first portion of the display stream includes data compressed in a second compression manner different than the first compression manner, wherein the first compression manner represents a higher degree of data compression than the second compression manner.

6. The method of claim 5, wherein the first compression manner includes a first compression technique and the second compression manner includes a second compression technique different than the first compression technique.

7. The method of claim 5, wherein the first compression manner includes a compression technique and a first set of compression parameters and the second compression manner includes the compression technique and a second set of compression parameters different than the first set of compression parameters.

8. The method of claim 1, further comprising:

transmitting the first compressed display stream portion via the transmission link;

determining whether a second portion of the display stream is transmissible via the transmission link in a manner permitting real time display based on the transmission of the first compressed display stream portion via the transmission link; and

compressing the second portion of the display stream in a second compression manner to produce a second compressed display stream portion when it is determined that the second portion of the display stream is not transmissible via the transmission link in a manner permitting real time display, wherein the second compression manner represents a higher degree of data compression than the first compression manner.

9. The method of claim 8, wherein the second portion of the display stream is determined to be transmissible in a manner permitting real time display when an expected time of the transmission of the first compressed display stream portion via the transmission link is within a predetermined tolerance of an actual time of the transmission of the first compressed display stream portion via the transmission link.

10. The method of claim 1, further comprising:

transmitting the first portion of the display stream when it is determined that the first portion of the display stream data is transmissible over the transmission link in a manner permitting real time display.

11. The method of claim 1, wherein the transmission link comprises a wireless link.

12. The method of claim 1, wherein the first compression manner comprises at least one of implementing increased encoding quantization factors, decreasing a video resolution, decreasing a frame size, or decreasing an audio resolution.

13. The method of claim 1, wherein the first portion of the display stream is compressed using a multimedia processor.

14. A method comprising:

receiving a first data stream representative of a series of display frames;

managing a degradation of the data stream based on a bandwidth of a transmission link to generate a second data stream representative of the series of display frames, wherein the second data stream comprises less data than the first data stream; and

transmitting the second data stream via the transmission link.

15. The method of claim 14, wherein the first compressed portion of the second display stream is determined to be transmissible in a manner permitting real time display when an expected time of transmission of a second compressed portion of the second display stream via the transmission link is within a predetermined tolerance of an actual time of transmission of the second compressed portion of the second display stream via the transmission link.

16. The method of claim 14, wherein a degree of degradation of the data stream is incremented for successive portions of the second data stream until a first compressed portion of the second data stream is determined to be transmissible in manner permitting real time display.

17. The method of claim 16, wherein the first display stream is degraded to generate the second display stream using a first compression technique and wherein the degree of degradation is incremented based on implementing different compression parameters for each of the successive portions of the data stream.

18. The method of claim 16, wherein the degree of degradation of the data stream is incremented based on implementing different compression techniques for each of the successive portions of the data stream.

19. The method of claim 14, wherein each portion of the successive portions of the second data stream comprises a different sequence of one or more display frames of the series of display frames.

20. The method of claim 14, wherein the transmission link comprises a wireless link.

21. A system comprising:

means for determining if a first portion of a display stream is transmissible via a transmission link in a manner permitting real time display; and

means for compressing the first portion of the display stream in a first compression manner to produce a first compressed display stream portion when it is determined that the first portion of the display stream data is not transmissible over the transmission link in a manner permitting real time display.

22. A computer readable medium embodying a computer program, the computer program comprising:

instructions to determine if a first portion of a display stream is transmissible via a transmission link in a manner permitting real time display; and

instructions to compress the first portion of the display stream in a first compression manner to produce a first compressed display stream portion when it is determined that the first portion of the display stream data is not transmissible over the transmission link in a manner permitting real time display.

23. A system comprising:

means for receiving a first data stream representative of a series of display frames;

means for managing a degradation of the data stream based on a bandwidth of a transmission link to generate a second data stream representative of the series of display frames, wherein the second data stream comprises less data than the first data stream; and

means for transmitting the second data stream via the transmission link.

24. A computer readable medium embodying a computer program, the computer program comprising:

instructions to receive a first data stream representative of a series of display frames;

instructions to manage a degradation of the data stream based on a bandwidth of a transmission link to generate a second data stream representative of the series of display frames, wherein the second data stream comprises less data than the first data stream; and

instructions to transmit the second data stream via the transmission link.