CHANNEL ADAPTIVE VIDEO TRANSMISSION METHOD, APPARATUS USING THE SAME, AND SYSTEM PROVIDING THE SAME

• US 20100262712A1
• Filed: 04/13/2010
• Published: 10/14/2010
• Est. Priority Date: 04/13/2009
• Status: Active Grant

• Current Assignee: Korea University Research and Business Foundation, Samsung Electronics Co. Ltd.
• Original Assignee: Korea University Research and Business Foundation, Samsung Electronics Co. Ltd.
• Inventors: NAM, Hyeong-Min, KIM, Sung-Kee, KO, Sung-Jae, PARK, Tae-Sung
• Granted Patent: US 8,700,794 B2
• Time in Patent Office: Days
• US Class Current: 709/231
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04N 19/132 Sampling, masking or truncation of coding units, e.g. adaptive resampling, frame skipping, frame interpolation or high-frequency transform coefficient masking
• CPC Class Codes: H04N 19/164 Feedback from the receiver or from the transmission channel
• CPC Class Codes: H04N 19/172 the region being a picture, frame or field
• CPC Class Codes: H04N 19/187 the unit being a scalable video layer
• CPC Class Codes: H04N 19/36 Scalability techniques involving formatting the layers as a function of picture distortion after decoding, e.g. signal-to-noise [SNR] scalability
• CPC Class Codes: H04N 19/587 involving temporal sub-sampling or interpolation, e.g. decimation or subsequent interpolation of pictures in a video sequence
• CPC Class Codes: H04N 21/234327 by decomposing into layers, e.g. base layer and one or more enhancement layers
• 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 21/25825 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 21/25833 involving client hardware characteristics, e.g. manufacturer, processing or storage capabilities allocation of resources considering hardware capabilities in multiprogramming arrangements G06F9/5044; allocation of resources considering software capabilities in multiprogramming arrangements G06F9/5055
• CPC Class Codes: H04N 21/6582 Data stored in the client, e.g. viewing habits, hardware capabilities, credit card number arrangements where receivers interact with the broadcast H04H20/38

Abstract

A video transmission method is provided, which includes receiving state information from at least one mobile terminal that intends to perform a video stream service through a wireless network, determining a size of an image by selecting a specified spatial layer bit stream on the basis of the state information of the mobile terminal from a plurality of spatial layer bit streams generated at different bit rates during encoding of the bit stream, selecting a specified time and an SNR layer bit stream by increasing or decreasing time of the image and a layer position of the SNR layer bit stream on the basis of network parameters included in the state information of the mobile terminal, and transmitting the bit stream generated by extracting the specified layer bit stream of the selected layer to the mobile terminal.

Claims

1. A channel adaptive video transmission method comprising:

receiving state information from at least one mobile terminal that intends to perform a video stream service through a wireless network;

determining a size of an image by selecting a specified spatial layer bit stream on the basis of the state information of the mobile terminal from a plurality of spatial layer bit streams generated at different bit rates during encoding of the bit stream;

selecting a specified time and a signal to noise ration (SNR) layer bit stream by increasing or decreasing a time of the image and a layer position of the SNR layer bit stream on the basis of network parameters included in the state information of the mobile terminal; and

transmitting the bit stream generated by extracting the specified spatial layer bit stream of the selected layer to the mobile terminal.

2. The video transmission method as claimed in claim 1, wherein the state information of the mobile terminal comprises CPU information of the mobile terminal, memory information, a size of a display screen, a resolution of the display screen, and network state information of the mobile terminal.

3. The video transmission method as claimed in claim 1, wherein the network parameters are buffer state of the mobile terminal and a round trip time (RTT) that indicates a round trip time of a packet through the network.

4. The video transmission method as claimed in claim 1, wherein the video stream encoding is a scalable video coding (SVC) type video coding that supports multi-dimensional scalability of time, space, and signal-to-noise ratio (SNR).

5. The video transmission method as claimed in claim 1, wherein the step of increasing or decreasing the time of the image and the layer position of the SNR layer bit stream comprises:

comparing a buffer state included in the network parameters of the mobile terminal with a predetermined buffer state threshold value and comparing a round trip time (RTT) value with a predetermined RTT threshold value;

discriminating the layer position of the SNR bit stream and decreasing the layer position of the temporal layer bit stream if the comparing the buffer state with the predetermined buffer state threshold value determines that the buffer state is smaller than the buffer state threshold value;

increasing a number of frames by calculating a current bit rate, discriminating the layer position of the SNR layer bit stream, and determining whether the layer position of the temporal layer bit stream is decreased if the RTT value is smaller than the RTT threshold value when the buffer state is smaller than the buffer state threshold value based on the comparing the buffer state and the buffer state threshold value;

maintaining the current bit stream if the RTT value is larger than the RTT threshold value in a state where the buffer state is larger than the buffer state threshold value based on the comparing of the buffer state and the buffer state threshold value; and

increasing the layer position of the SNR layer bit stream if the RTT value is smaller than the RTT threshold value in a state where the buffer state is larger than the buffer state threshold value based on the comparing of the buffer state and the buffer state threshold value.

6. The video transmission method as claimed in claim 5, wherein the step of increasing or decreasing the time of the image and the layer position of the SNR layer bit stream further comprises decreasing the layer position of the temporal layer bit stream if the layer position of the SNR layer bit stream is lowermost in the state where the buffer state is smaller than the buffer state threshold value and the RTT value is smaller than the RTT threshold value.

7. A channel adaptive video transmission apparatus comprising:

an encoder which encodes a high picture quality digital video stream, and outputs the video stream;

a wireless module which receives state information of at least one mobile terminal through a wireless network;

an image size determination unit which determines a size of an image by selecting a specified spatial layer bit stream based on the state information of the at least one mobile terminal output from the wireless module from spatial layer bit streams of the video streams output from the encoder; and

a control unit which selects a specified time and a signal to noise ratio (SNR) layer bit stream from the video stream of which the image size has been determined by increasing or decreasing time of the image and a layer position of the SNR layer bit stream based on network parameters included in the state information of the at least one mobile terminal, and transmits a bit stream generated by extracting the specified spatial layer bit stream of the selected SNR layer bit stream to the mobile terminal.

8. The video transmission apparatus as claimed in claim 7, wherein the encoder performs a scalable video coding (SVC) type video coding that supports multi-dimensional scalability of time, space, and signal-to-noise ratio (SNR).

9. The video transmission apparatus as claimed in claim 7, wherein the control unit comprises:

a first comparison unit which compares a buffer state included in the network parameters of the at least one mobile terminal with a predetermined buffer state threshold value, and if the predetermined buffer state threshold value is larger than the buffer state, outputs the buffer state to a second comparison unit, and if the predetermined buffer state threshold value is smaller than the buffer state, outputs the buffer state to a third comparison unit;

the second comparison unit compares a round trip time (RTT) value included in the network parameters of the at least one mobile terminal with a predetermined RTT threshold value, and if the RTT value is larger than the predetermined RTT threshold value, discriminates the layer position of the SNR layer bit stream, determines and outputs whether the layer position of the temporal layer bit stream is decreased according to the layer position, and if the RTT value is smaller than the predetermined RTT threshold value, increases a number of frames by calculating a current bit rate, discriminates the layer position of the SNR layer bit stream, determines and outputs whether the layer position of the temporal layer bit stream is decreased according to the layer position;

the third comparison unit compares the RTT value included in the network parameters of the mobile terminal with the predetermined RTT threshold value, and if the RTT value is larger than the predetermined RTT threshold value, maintains the current bit stream, while if the RTT value is smaller than the predetermined RTT threshold value, increases and outputs the layer position of the SNR layer bit stream; and

a scalable video coding (SVC) extraction unit which extracts specified layer bit streams output from the second and third comparison units and outputs one bit stream.

10. The video transmission apparatus as claimed in claim 9, wherein if the layer position of the SNR layer bit stream is lowermost, decreases the layer position of the temporal layer bit stream.

11. A system for providing a video transmission service comprising:

a server recognizing network situations and performance of a plurality of mobile terminals using state information received from the mobile terminals through a wireless network,

comparing the state information of the mobile terminals with a predetermined threshold value, selecting a specified layer bit stream by increasing or decreasing a layer position of the bit stream for at least one layer, extracting and transmitting the selected specified layer bit stream to the mobile terminals; and

the mobile terminals transmitting their own state information to the server through the wireless network.

12. The system as claimed in claim 11, wherein the state information of the mobile terminals comprises CPU information of the mobile terminal, memory information, a size of a display screen, a resolution of the display screen, and network state information including a buffer state of the mobile terminal and a round trip time (RTT) value.

13. A video transmission method comprising:

receiving state information from at least one mobile terminal that intends to perform a video stream service through a wireless network;

selecting optimum content from a plurality of content of which sizes of images and picture qualities discriminate from one another based on the state information of the at least one mobile terminal; and

transmitting a bit stream generated by extracting the bit stream from the selected content, to the mobile terminal.

14. The video transmission method as claimed in claim 13, wherein the state information of the mobile terminal comprises CPU information of the mobile terminal, memory information, a size of a display screen, a resolution of the display screen, and network state information of the mobile terminal.

15. The video transmission method as claimed in claim 13, wherein the step of selecting the optimum content comprises:

comparing a buffer state included in the network parameters of the mobile terminal with a predetermined buffer state threshold value and comparing a round trip time (RTT) value with a predetermined RTT threshold value;

discriminating a layer position of a signal to noise ratio (SNR) bit stream and determining whether the layer position of a temporal layer bit stream is decreased if the buffer state is smaller than the buffer state threshold value as a result of the comparing;

increasing a number of frames by calculating a current bit rate, discriminating the layer position of the SNR layer bit stream, and determining whether the layer position of the temporal layer bit stream is decreased according to if the RTT value is smaller than the RTT threshold value in a state where the buffer state is smaller than the buffer state threshold value as a result of the comparing; and

increasing the layer position of the SNR layer bit stream if the RTT value is smaller than the RTT threshold value in a state where the buffer state is larger than the buffer state threshold value as the result of the comparing.