METHOD FOR GENERATING DOUBLE-SPEED IDR-UNIT FOR TRICK PLAY, AND TRICK PLAY SYSTEM AND METHOD USING THE SAME

• US 20080131078A1
• Filed: 12/03/2007
• Published: 06/05/2008
• Est. Priority Date: 12/04/2006
• Status: Active Grant

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: KIM, Jung-Koun, PARK, Choon-Soo, MIN, Ok-Goo, JEONG, Jin-Hwan, KIM, Hag-Young, Kim, Myung-Joon, LEE, Yong-Ju
• Granted Patent: US 8,483,551 B2
• Time in Patent Office: Days
• US Class Current: 386/68
• CPC Class Codes: H04N 5/783 Adaptations for reproducing at a rate different from the recording rate
• CPC Class Codes: H04N 9/8042 involving data reduction

Abstract

Provided are a method for generating an instantaneous decoding refresh (IDR) unit for trick play, and a trick play system and method using the same. The trick play system includes: a speed information input unit configured to receive a speed value; a transmission condition determining unit configured to determine instantaneous decoding refresh (IDR) transmission conditions based on the speed value inputted through the speed information input unit; a double-speed IDR-unit generating unit configured to generate a double-speed IDR-unit by adjusting the number and data size of video frames to be transmitted in accordance with the transmission conditions determined by the transmission condition determining unit; and a transmitting unit configured to transmit the generated double-speed IDR-unit to an external user terminal.

Claims

1. A trick play system, comprising:

a speed information input unit configured to receive a speed value;

a transmission condition determining unit configured to determine instantaneous decoding refresh (IDR) transmission conditions based on the speed value inputted through the speed information input unit;

a double-speed IDR-unit generating unit configured to generate a double-speed IDR-unit by adjusting the number and data size of video frames to be transmitted in accordance with the transmission conditions determined by the transmission condition determining unit; and

a transmitting unit configured to transmit the generated double-speed IDR-unit to an external user terminal.

2. The trick play system of claim 1, wherein the transmission condition determining unit determines transmission or skip of IDR-unit according to a value of (S/2−

1), where S represents the speed value.

3. The trick play system of claim 2, wherein the transmission condition determining unit determines to transmit the IDR-unit if the value of (S/2−

1) is equal to 0, and to skips as many as (S/2−

1) IDR-units after generation and transmission of the double-speed IDR-unit if the value of (S/2−

1) is not equal to 0.

4. The trick play system of claim 2, wherein the transmission condition determining unit determines to transmit the IDR-unit if the value of (S/2−

1) is equal to 0, and wherein the transmission condition determining unit subtracts “

1”

from the value of (S/2−

1) if the value of (S/2−

1) is not equal to 0, skips to a next IDR frame when the subtraction result value is not equal to 0, repeats the subtraction and the skip until the subtraction result value is equal to 0 and determines to transmit the IDR-unit.

5. The trick play system of claim 1, wherein the double-speed IDR-unit generating unit receives total frames ranging from an IDR frame start position to the last prediction frame before a next IDR frame start position, removes second half of prediction frames from the total frames, and generates the double-speed IDR-unit such that a sum of data sizes of the remaining first half of the prediction frames is less than a half of the data size of the total frames.

6. The trick play system of claim 5, wherein the double-speed IDR-unit generating unit uses a stack to remove the second half of the prediction frames in a reverse order.

7. A trick play method, comprising:

receiving a speed value;

determining instantaneous decoding refresh (IDR) transmission conditions based on the speed value;

generating a double-speed IDR-unit by adjusting the number and data size of video frames to be transmitted in accordance with the determined transmission conditions; and

transmitting the generated double-speed IDR-unit to a user terminal.

8. The trick play method of claim 7, wherein the determining the transmission conditions includes determining IDR-unit transmission or skip according to a value of (S/2−

1), where S represents the speed value.

9. The trick play method of claim 8, wherein the determining the transmission conditions includes:

determining to transmit the IDR-unit when the value of (S/2−

1) is equal to 0; and

skipping as many as (S/2−

1) IDR-units after generation and transmission of the double-speed IDR-unit if the value of (S/2−

1) is not equal to 0.

10. The trick play method of claim 8, wherein the determining the transmission conditions includes:

determining to transmit the IDR-unit when the value of (S/2−

1) is equal to 0;

subtracting “

1”

from the value of (S/2−

1) when the value of (S/2−

1) is not equal to 0;

skipping to a next IDR frame when the subtraction result value is not equal to 0; and

repeating the subtraction and the skip until the subtraction result value is equal to 0 and determining to transmit the IDR-unit.

11. The trick play method of claim 7, wherein the generating the double-speed IDR-unit includes:

removing second half of prediction frames from total frames ranging from a first IDR frame start position to the last prediction frame before a second IDR frame start position; and

generating the double-speed IDR-unit with the remaining frames when a data size of the remaining frames is less than a half of the data size of the total frames.

12. The trick play method of claim 11, further comprising:

removing frames referring to the removed second half of prediction frames from the remaining frames; and

returning to the step of generating the double-speed IDR-unit with the remaining frames.

13. The trick play method of claim 12, wherein the removing the second half of prediction frames includes:

removing the second half of the prediction frames in a reverse order based on a stack.

14. A method for generating a double-speed instantaneous decoding refresh (IDR)-unit for trick play, the method comprising:

removing second half of prediction frames from total frames ranging from a IDR frame start position to the last prediction frame before a next IDR frame position; and

generating the double-speed IDR-unit with the remaining frames when a data size of the remaining frames is less than a half of the data size of the total frames.

15. The method of claim 14, further comprising:

removing frames referring to the removed prediction frames from the remaining frames; and

returning to the step of generating the double-speed IDR-unit.

16. The method of claim 14, wherein the generating the double-speed IDR-unit includes:

determining if the data size of the remaining frames is less than a half of the data size of the total frames;

additionally removing second half of frames from the remaining frames when the data size of the remaining frames is equal to or greater than a half of the data size of the total frames; and

generating the double-speed IDR-unit with the remaining frames when the data size of the remaining frames is less than a half of the data size of the total frames.

17. The method of claim 16, wherein the removing the second half of the prediction frames in a reverse order based on a stack.