MULTICAST-BASED CONTENT TRANSMITTING SYSTEM AND METHOD, AND DEVICE AND METHOD FOR ESTIMATING HIGH-SPEED MOVEMENT

• US 20140143824A1
• Filed: 05/02/2012
• Published: 05/22/2014
• Est. Priority Date: 07/06/2011
• Status: Active Grant

• Current Assignee: SK Planet Co., Ltd. (SK Telecom Co., Ltd.)
• Original Assignee: SK Planet Co., Ltd. (SK Telecom Co., Ltd.)
• Inventors: Bae, Tae Meon
• Granted Patent: US 9,769,511 B2
• Time in Patent Office: Days
• US Class Current: 725/116
• CPC Class Codes: H04N 19/51 Motion estimation or motion compensation
• CPC Class Codes: H04N 19/513 Processing of motion vectors
• CPC Class Codes: H04N 19/89 involving methods or arrangements for detection of transmission errors at the decoder
• CPC Class Codes: H04N 21/23439 for generating different versions
• CPC Class Codes: H04N 21/26275 for distributing content or additional data in a staggered manner, e.g. repeating movies on different channels in a time-staggered manner in a near video on demand system
• CPC Class Codes: H04N 21/4382 Demodulation or channel decoding, e.g. QPSK demodulation analog front ends or means for connecting modulators, demodulators or transceivers to a transmission line H04L27/0002
• CPC Class Codes: H04N 21/44209 Monitoring of downstream path of the transmission network originating from a server, e.g. bandwidth variations of a wireless network arrangements for maintenance or administration in data switching networks involving bandwidth and capacity management H04L41/0896
• CPC Class Codes: H04N 21/6405 Multicasting data broadcast and multicast in packet switching networks H04L12/18
• CPC Class Codes: H04N 21/64776 for requesting retransmission, e.g. of data packets lost or corrupted during transmission from server ARQ protocols H04L1/18; implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP] H04L69/16
• CPC Class Codes: H04N 21/6581 Reference data, e.g. a movie identifier for ordering a movie or a product identifier in a home shopping application

Abstract

The present invention relates to a multicast-based content transmitting system and method, and a device and method for estimating high-speed movement. Included are: a content providing device for generating N×M multicast stream channels having different transmission start times and transmission rates, providing N×M multicast stream channel lists, and transmitting content through one channel of N×M multicast stream channels; and a user terminal for selecting one channel of the N×M multicast stream channel lists provided from the content providing device and receiving content through the selected multicast stream channel.

Claims

1. A multicast-based contents transmission system comprising:

a contents providing apparatus for creating N×

M multicast stream channels respectively having a different transmission start time and a different transmission rate, providing an N×

M multicast stream channel list, and transmitting contents through a channel among the N×

M multicast stream channels; and

a user terminal for selecting a channel from the N×

M multicast stream channel list provided by the content providing apparatus and receiving the content through the selected multicast stream channel.

2. A contents providing apparatus comprising:

a channel creation unit for creating N×

M multicast stream channels;

a channel list creation unit for creating an N×

M multicast stream channel list including information on the N×

M multicast stream channels; and

a communication unit for providing the N×

M multicast stream channel list created by the channel list creation unit and transmitting contents through a channel among the N×

M multicast stream channels created by the channel creation unit.

3. The apparatus according to claim 2, wherein the channel creation unit creates the N×

M multicast stream channels configured of N multicast stream channels having transmission start times arranged at time intervals of T and M multicast stream channels of different transmission rates configured in each of the N multicast stream channels.

4. The apparatus according to claim 2, wherein the N×

M multicast stream channel information includes information on contents to be transmitted, a transmission start time and a transmission rate of each channel.

5. The apparatus according to claim 2, further comprising a channel preparation unit for creating the contents to be transmitted on the N×

M multicast stream channels in the form of a packet.

6. A user terminal comprising:

a communication unit for receiving an N×

M multicast stream channel list, transmitting a channel selection signal for selecting a multicast stream channel from the N×

M multicast stream channel list, and receiving contents through a multicast stream channel corresponding to the channel selection signal; and

a channel selection unit for confirming an available transmission rate of a network and selecting an available multicast stream channel from the N×

M multicast stream channel list received from the communication unit using the available transmission rate and a contents transmission request time.

7. The user terminal according to claim 6, wherein the N×

M multicast stream channel list includes multicast stream channel information configured of information on contents to be transmitted, a transmission start time and a transmission rate of each channel.

8. The user terminal according to claim 7, wherein the channel selection unit selects a multicast stream channel having a transmission rate lower than the available transmission rate from the provided N×

M multicast stream channel list as a candidate multicast stream channel, and selects a multicast stream channel having a transmission start time closest to the contents transmission request time in the N×

M multicast stream channel list among the candidate multicast stream channels.

9. The user terminal according to claim 7, further comprising a contents reception unit for storing the transmitted contents, wherein the contents reception unit restores and stores lost packets using a Forward Error Correction method if the number of lost packets is smaller than a reference value and requests retransmission of the contents after deleting packets of the transmitted contents if the number of lost packets exceeds the reference value.

10. The user terminal according to claim 9, wherein if retransmission of the contents is requested, the channel selection unit selects a candidate multicast stream channel list by comparing an available transmission rate of the user terminal at the time of requesting retransmission of the contents with transmission rates of the N×

M multicast stream channel list and select a multicast stream channel by comparing a contents retransmission request time with the transmission start time.

11. The user terminal according to claim 7, wherein the channel selection unit selects a multicast stream channel having a transmission start time later than the contents transmission request time in the N×

M multicast stream channel list from the provided N×

M multicast stream channel list as a candidate multicast stream channel and selects a multicast stream channel having a transmission rate lower than the available transmission rate and highest among the candidate multicast stream channels.

12. A multicast-based contents transmission method comprising the steps of:

creating, by a contents providing apparatus, N×

M multicast stream channels and an N×

M multicast stream channel list including information on the multicast stream channels;

transmitting, by the contents providing apparatus, the N×

M multicast stream channel list to a user terminal;

transmitting, by the user terminal, a channel selection signal for selecting a multicast stream channel for transmitting contents using the multicast stream channel information of the transmitted N×

M multicast stream channel list to the contents providing apparatus; and

transmitting, by the contents providing apparatus, the contents to the user terminal using a multicast stream channel corresponding to the channel selection signal.

13. A multicast-based contents transmission method of a contents providing apparatus, the method comprising the steps of:

(a) creating, by the contents providing apparatus, N×

M multicast stream channels respectively having a different transmission start time and a different transmission rate;

(b) creating and providing, by the contents providing apparatus, an N×

M multicast stream channel list including information on the N×

M multicast stream channels; and

(c) receiving, by the contents providing apparatus, a channel selection signal and transmitting contents using a multicast stream channel corresponding to the channel selection signal.

14. The method according to claim 13, wherein step (a) includes the steps of:

(a-1) creating the N multicast stream channels having transmission start times arranged at time intervals of T; and

(a-2) creating the N×

M multicast stream channels by creating M multicast stream channels of different transmission rates configured in each of the N multicast stream channels.

15. A multicast-based contents reception method of a user terminal, the method comprising the steps of:

(a) receiving, by the user terminal, an N×

M multicast stream channel list including information on multicast stream channels configured of contents information, a transmission start time and a transmission rate;

(b) selecting, by the user terminal, a multicast stream channel by comparing the transmission start time, the transmission rate and the contents information of the transmitted N×

M multicast stream channel list with an available transmission rate of a network measured by the user terminal, a contents transmission request time and information on contents to be received;

(c) transmitting, by the user terminal, a channel selection signal for selecting the multicast stream channel; and

(d) receiving, by the user terminal, contents using the selected multicast stream channel.

16. The method according to claim 15, wherein step (b) includes the steps of:

(b-1) selecting a multicast stream channel having a transmission rate lower than the available transmission rate from the transmitted N×

M multicast stream channel list as a candidate multicast stream channel; and

(b-2) selecting a multicast stream channel having a transmission start time closest to the contents transmission request time in the N×

M multicast stream channel list among the candidate multicast stream channels.

17. The method according to claim 15, wherein step (b) includes the steps of:

(b-1) selecting a multicast stream channel having a transmission start time later than the contents transmission request time in the N×

M multicast stream channel list from the transmitted N×

M multicast stream channel list as a candidate multicast stream channel; and

(b-2) selecting a multicast stream channel having a highest transmission rate among the candidate multicast stream channels.

18. The method according to claim 15, further comprising, after step (d), the step of (e) comparing, by the user terminal, the number of lost packets of the transmitted contents with a reference value and restoring the lost packets using a Forward Error Correction method or requesting retransmission of the contents after deleting packets of the transmitted contents.

19. A motion estimation apparatus comprising:

an n-th image creation unit for creating an n-th compared image and an n-th reference image having a value obtained by multiplying a pixel value by n times as an n-th pixel value of a pixel for each pixel of the compared image and the reference image;

an n-th integral image creation unit for creating an n-th integral compared image and an n-th integral reference image by calculating pixel values up to set pixel coordinates for the n-th compared image and the n-th reference image;

an n-th momentum calculation unit for calculating an n-th momentum of the compared image and an n-th momentum of the reference image for a set block using the n-th integral compared image and the n-th integral reference image; and

a motion vector estimation unit for calculating a block matching error using the n-th momentum of the compared image and the n-th momentum of the reference image and estimating a coordinate difference between a compared image block and a reference image block having a smallest block matching error as a motion vector.

20. The method according to claim 19, wherein the n-th image creation unit creates the n-th compared image and the n-th reference image using a following mathematical expression:

[Mathematical expression] O_n(x,y)=i(x,y)*O_n-1(x,y), wherein i(x,y) expresses an original image of the compared image or the reference image, O_n(x,y) expresses the n-th compared image or the n-th reference image, and (x,y) expresses the pixel coordinates.

21. The method according to claim 19, wherein the n-th integral image creation unit creates the n-th integral compared image and the n-th integral reference image using a following mathematical expression:

[Mathematical expression] I_n(X,Y)=Σ

^YΣ

^XO_n(x,y), wherein I_n(x,y) expresses the n-th integral compared image or the n-th integral reference image, O_n(x,y) expresses the n-th compared image or the n-th reference image, and (x,y) expresses the pixel coordinates.

22. The method according to claim 19, wherein the n-th momentum calculation unit calculates the n-th momentum of four blocks including a set block for the compared image and the reference image using a following mathematical expression:

[Mathematical expression] M_n=I_n(x_e,y_e)+I_n(x_e−

1,y_e−

1)[I_n(x_e−

1,y_e)+I_n(x_e,y_e−

1)], wherein I_n(x, y) expresses the n-th integral compared image or the n-th integral reference image of a pixel or a block (x_e, y_e), and (x_e, y_e), (x_e−

1, y_e−

1), (x_e−

1, y_e) and (x_e, y_e−

1) express the pixel coordinates or block coordinates.

23. The method according to claim 19, wherein the motion vector estimation unit calculates at least one of SAD and SSD as the block matching error using a following mathematical expression:

[Mathematical expressions] SAD=[Σ

α

_n|M_n,ref−

M_n,curr|]xγ and

SSD=[Σ

β

_n|M_n,ref−

M_n,curr|²]xγ

, wherein M_n,ref denotes the n-th momentum for the set block of the reference image, M_n,curr curr denotes the n-th momentum for the set block of the compared image, α

_n and β

_n denote weighting factors of the n-th momentums, and γ

denotes a constant.

24. An image encoding apparatus for estimating a motion at a high speed, the apparatus comprising:

a motion estimation unit for creating an n-th compared image and an n-th reference image for a compared image and a reference image, creating an n-th integral compared image and an n-th integral reference image by calculating pixel values up to set pixel coordinates for the n-th compared image and the n-th reference image, calculating an n-th momentum of the compared image and an n-th momentum of the reference image for a set block using the n-th integral compared image and the n-th integral reference image, calculating a block matching error using an n-th momentum difference, and estimating a coordinate difference between a compared image block and a reference image block having a smallest block matching error as a motion vector;

a motion compensation unit for creating an estimated image for the compared image from the reference image using the estimated motion vector;

a subtractor for creating a difference image of the compared image and the reference image; and

an encoding unit for encoding the created difference image.

25. A method of estimating a motion at a high speed, the method comprising the steps of:

creating an n-th compared image and an n-th reference image having a value obtained by multiplying a pixel value by n times as an n-th pixel value of a pixel for each pixel of the compared image and the reference image;

creating an n-th integral compared image and an n-th integral reference image by calculating pixel values up to set pixel coordinates for the n-th compared image and the n-th reference image;

calculating an n-th momentum of the compared image and an n-th momentum of the reference image for a set block using the n-th integral compared image and the n-th integral reference image;

calculating a block matching error using a difference between the n-th momentum of the compared image and the n-th momentum of the reference image; and

estimating a coordinate difference between a compared image block and a reference image block having a smallest block matching error as a motion vector.