Method for tuning coding rate and applying unequal error protection for adaptive video transmission, and video transmission/reception apparatus using the method

• US 8,654,834 B2
• Filed: 01/05/2010
• Issued: 02/18/2014
• Est. Priority Date: 01/06/2009
• Status: Active Grant

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Cho, Yong Ju, Hong, Jin Woo, Lee, Han Kyu
• Primary Examiner(s): SENFI, BEHROOZ M
• Application Number:
  US12/652,123
• Publication Number:
  US 20100171882A1
• Time in Patent Office: 1,505 Days
• Field of Search: 348/14.01, 348/14.02, 348/14.12, 348/420, 348/390.1, 37524001-24026, 386/67, 386/68, 386/109, 386/111, 386/112, 386/27, 386/33, 386/69, 386/37, 386/110
• US Class Current: 375/240.01
• CPC Class Codes: H04N 19/67 involving unequal error protection [UEP], i.e. providing protection according to the importance of the data

Abstract

Provided are a method of tuning a coding rate and applying an unequal error protection for an adaptive video transmission, and a video transmission/reception apparatus using the method. The video transmission apparatus may include: a coding rate tuner to predict, as a channel capacity of a subsequent channel interval, an estimated channel capacity value fed back from the video reception apparatus, and to tune video and channel coding rates within the predicted channel capacity; a video encoder to perform video encoding of video frames at the tuned video coding rate, and to generate a video packet; and a forward error correction (FEC) encoder to apply the unequal error protection based on a length of the video packet and a type of the video frames included in the video packet, and to perform channel encoding of the video packet at the tuned channel coding rate to generate a bitstream.

Claims

1. A method of tuning a coding rate and applying an unequal error protection for an adaptive video transmission, the method comprising:

predicting, as a channel capacity of a subsequent channel interval, an estimated channel capacity value that is fed back from a video reception apparatus;

tuning a video coding rate and a channel coding rate within the predicted channel capacity, wherein tuning comprises;

calculating the video coding rate using a rate distortion function and a screen quality distortion function of a video within the predicted channel capacity such that the screen quality distortion function Q′

(x) of the video is expressed by the following equation;

Q′

(x)=ax^b+c, 0≦

x≦

0.12, wherein x denotes an element of the screen quality distortion function of the video, and a, b, and c denote values determined based on an experiment; and

calculating the channel coding rate using the video coding rate;

performing video encoding of video frames at the tuned video coding rate to generate the video frames as a video packet;

applying the unequal error protection based on a length of the video packet and a type of the video frames included in the video packet; and

performing channel encoding of the unequal error protected video packet at the tuned channel coding rate to generate the video packet as a bitstream.

2. The method of claim 1, wherein the tuned video coding rate indicates a value at which a peak signal to noise ratio (PSNR) value of a video being transmitted is optimal during a corresponding channel interval.

3. The method of claim 1, wherein screen quality distortion function x denotes a difference between a coding rate to be predicted and a channel capacity expressed by the following equation:

4. The method of claim 1, wherein the rate distortion function of the video indicates a function that is obtained when encoding the video.

5. The method of claim 1, wherein the estimated channel capacity value, {tilde over (C)}_n^CLDS is expressed by the following equation:

6. The method of claim 1, wherein the applying comprises applying the unequal error protection so that the video packet including an intra-coded frame (I-frame) is relatively robust against an error compared to a video packet not including the I-frame, when the I-frame is included in the video packet.

7. A method of receiving an adaptive video having a tuned coding rate and where an unequal error protection is applied, the method comprising:

receiving an unequal error protected video stream;

estimating a bit error rate using side information associated with a channel status of the unequal error protected video stream;

estimating a channel capacity value using the estimated bit error rate in accordance to the following equation;

8. The method of claim 7, further comprising:

performing channel decoding of the video stream based on the unequal error protection.

9. The method of claim 7, wherein the unequal error protection is applied so that a video packet including an I-frame is relatively robust against an error compared to a video packet not including the I-frame when the I-frame is included in the video packet.

10. A video transmission apparatus of tuning a coding rate and applying an unequal error protection for an adaptive video transmission, the video transmission apparatus comprising:

a coding rate tuner to predict, as a channel capacity of a subsequent channel interval, an estimated channel capacity value that is fed back from a video reception apparatus, and to tune a video coding rate and a channel coding rate within the predicted channel capacity,

wherein the coding rate tuner calculates the video coding rate using a rate distortion function and a screen quality distortion function of a video within the predicted channel capacity, and calculates the channel coding rate using the video coding rate,

wherein the screen quality distortion function Q′

(x) of the video indicates a distortion of a screen quality of the video over a surplus of the channel capacity, and is expressed by the following equation;

Q′

(x)=ax^b+c , 0≦

x≦

0.12, wherein x denotes an element of the screen quality distortion function of the video, and a, b, and c denote values determined based on an experiment;

a video encoder to perform video encoding of video frames at the tuned video coding rate, and to generate the video frames as a video packet; and

a forward error correction (FEC) encoder to apply the unequal error protection based on a length of the video packet and a type of the video frames included in the video packet, and to perform channel encoding of the unequal error protected video packet at the tuned channel coding rate to generate the video packet as a bitstream.

11. The video transmission apparatus of claim 10, wherein the tuned video coding rate indicates a value at which a PSNR value of a video being transmitted is optimal during a corresponding channel interval.

12. The video transmission apparatus of claim 10, wherein x of the screen quality distortion function Q′

(x) of the video denotes a difference between a coding rate to be predicted and a channel capacity expressed by the following equation;

13. The video transmission apparatus of claim 10, wherein the rate distortion function of the video indicates a function that is obtained when encoding the video.

14. The video transmission apparatus of claim 10, wherein the estimated channel capacity value is in accordance to the following equation:

15. The video transmission apparatus of claim 10, wherein, when an I-frame is included in the video packet, the FEC encoder applies the unequal error protection so that the video packet including the I-frame is relatively robust against an error compared to a video packet not including the I-frame.

16. A video reception apparatus of receiving an adaptive video having a tuned coding rate and where an unequal error protection is applied, the video reception apparatus comprising:

a channel capacity estimator to estimate a bit error rate using side information associated with a channel status of an unequal error protected video stream when the unequal error protected video stream is received, to estimate a channel capacity value using the estimated bit error rate, and to feed back the estimated channel capacity value to a video transmission apparatus, wherein the estimated channel capacity value is in accordance to the following equation;

17. The video reception apparatus of claim 16, further comprising:

a FEC decoder to perform channel decoding of the video stream based on the unequal error protection.

18. The video reception apparatus of claim 16, wherein the unequal error protection is applied so that a video packet including an I-frame is relatively robust against an error compared to a video packet not including the I-frame when the I-frame is included in the video packet.

19. The video reception apparatus of claim 16, wherein the side information comprises a checksum.

20. The video reception apparatus of claim 16, wherein the side information comprises a signal to silence ratio (SSR).