Methods and Systems for Rate-Adaptive Transmission of Video

• US 20080181302A1
• Filed: 01/25/2007
• Published: 07/31/2008
• Est. Priority Date: 01/25/2007
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Deshpande, Sachin G., van Beek, Petrus J.L., Demircin, Mehmet Umut
• Granted Patent: US 8,243,789 B2
• Time in Patent Office: Days
• US Class Current: 375/240.06
• CPC Class Codes: H04N 19/152 by measuring the fullness of the transmission buffer
• CPC Class Codes: H04N 19/177 the unit being a group of pictures [GOP]
• CPC Class Codes: H04N 19/34 Scalability techniques involving progressive bit-plane based encoding of the enhancement layer, e.g. fine granular scalability [FGS]

Abstract

Embodiments of the present invention comprise methods and systems for adapting a video transmission rate.

Claims

1. A method for rate-adaptive transmission of scalable signals, said method comprising:

a. selecting a group of frames (GOF) comprising a current frame;

b. determining the initial size of said GOF, comprising all NAL units in said GOF;

c. determining a GOF bit budget for said GOF;

d. computing a current frame bit budget for said current frame wherein said current frame bit budget is proportional to the total size of all NAL units in said current frame multiplied by the ratio of the GOF bit budget to the initial size of said GOF;

e. computing the size of a current-frame base layer NAL unit and any current frame enhancement layer NAL units of said current frame;

f. allocating a portion of said current frame bit budget to said current frame base layer NAL unit thereby determining a current-frame bit budget remainder;

g. authorizing transmission of said current frame base layer NAL unit;

h. determining whether the size of a next most important layer NAL unit of said current frame is less than said current-frame bit budget remainder;

i. allocating a next portion of said current-frame bit budget remainder to said next most important layer NAL unit thereby determining an adjusted current-frame bit budget remainder if the size of said next most important layer NAL unit is less than said current-frame bit budget remainder;

j. authorizing transmission of said next most important layer NAL unit if the size of said next most important layer NAL unit is less than said current-frame bit budget remainder; and

k. repeating steps h-j for each successively more important enhancement layer NAL unit of said current frame until said adjusted current-frame bit budget remainder is smaller than a last most important layer NAL unit.

2. A method as described in claim 1 further comprising:

a. truncating said last most important layer NAL unit to fit in said adjusted current-frame bit budget remainder and transmitting said truncated last most important layer NAL unit when said scalable signal is encoded with Fine Grain Scalability (FGS); and

b. discarding said last most important layer NAL unit, when said scalable signal is not encoded with FGS.

3. A method as described in claim 1 further comprising:

a. analyzing an updated available transmission bandwidth after transmission of said current frame base layer NAL unit and any next most important layer NAL units thereby determining an updated bit budget;

b. determining eligible unsent NAL units and partially-unsent NAL units;

c. allocating said unsent/partially-unsent NAL units to said updated bit budget until said updated bit budget is expended; and

d. authorizing said allocated unsent/partially-unsent NAL units for transmission.

4. A method as described in claim 1 further comprising:

a. analyzing an updated available transmission bandwidth after transmission of said current frame base layer NAL unit and any next most important layer NAL units thereby determining an updated bit budget;

b. determining eligible unsent NAL units and partially-unsent NAL units;

c. determining a quality layer identification (QLID) for each of said unsent/partially-unsent NAL units;

d. allocating said unsent/partially-unsent NAL units to said updated bit budget in order of QLID until said updated bit budget is expended; and

e. authorizing said unsent/partially-unsent NAL units for transmission.

5. A method for rate-adaptive transmission of scalable signals, said method comprising:

a. selecting a group of frames (GOF) comprising a current frame;

b. determining a GOF bit budget for said GOF;

c. determining a GOF total base layer size for all base layer NAL units in said GOF;

d. when said GOF total base layer size is greater than said GOF bit budget—

i) assigning a temporal level to each of said base layer NAL units in said GOF,

ii) allocating base layer NAL units to said GOF bit budget in order of highest priority temporal level until said GOF bit budget is expended, and

iii) authorizing transmission of said allocated base layer NAL units.

6. A method as described in claim 5 further comprising transmitting all base layer NAL units in said GOF when said GOF total base layer size is less than said GOF bit budget.

7. A method as described in claim 5 further comprising:

a. analyzing an updated available transmission bandwidth after transmission of any of said base layer NAL units and any next most important layer NAL units thereby determining an updated bit budget;

b. determining eligible unsent NAL units;

c. allocating said unsent NAL units to said updated bit budget until said updated bit budget is expended; and

d. authorizing said allocated unsent NAL units for transmission.

8. A method as described in claim 5 further comprising:

a. analyzing an updated available transmission bandwidth after transmission of said base layer NAL units thereby determining an updated bit budget;

b. determining eligible unsent NAL units;

c. determining a quality layer identification (QLID) for each of said unsent NAL units;

d. allocating said unsent NAL units to said updated bit budget in order of QLID until said updated bit budget is expended; and

e. authorizing said unsent NAL units for transmission.

9. A method as described in claim 5 wherein said temporal level is related to the number of frames through which a frame is predicted.

10. A method for rate-adaptive transmission of scalable signals, said method comprising:

a. selecting a group of frames (GOF) comprising a current frame;

b. determining the initial size of all base layer NAL units in said GOF;

c. analyzing available transmission bandwidth to determine a GOF bit budget for said GOF;

d. allocating said base layer NAL units to said GOF budget, thereby calculating a first remaining GOF bit budget;

e. transmitting said base layer NAL units;

f. determining the size of all NAL units in a first enhancement layer;

g. determining whether the size of said first enhancement layer NAL units is less than said first remaining GOF bit budget;

h. allocating said first enhancement layer NAL units to said first remaining GOF bit budget thereby creating a second remaining GOF bit budget and transmitting a first enhancement layer NAL unit for said current frame when said size of said first enhancement layer NAL units is less than said first remaining GOF bit budget;

i. repeating step (h) for successive enhancement layers until the size of said first remaining GOF bit budget is less than the size of all NAL units in an enhancement layer; and

j. truncating a current frame enhancement layer NAL unit in proportion to the ratio of the first remaining GOF bit budget to the size of the first enhancement layer NAL units for said GOF and transmitting said truncated current frame enhancement layer NAL unit when the size of said first enhancement layer NAL units is less than said first remaining GOF bit budget and the signal is encoded with Fine Grain Scalability (FGS).

11. A method as described in claim 10 further comprising discarding said current frame enhancement layer NAL unit when the size of said enhancement layer NAL units is less than said first remaining GOF bit budget and said signal is not encoded with FGS.

12. A method as described in claim 10 further comprising:

a. analyzing an updated available transmission bandwidth after transmission of said current frame base layer NAL unit and any next most important layer NAL units thereby determining an updated bit budget;

b. determining eligible unsent NAL units and partially-unsent NAL units;

c. allocating said unsent/partially-unsent NAL units to said updated bit budget until said updated bit budget is expended; and

d. selecting said allocated unsent/partially-unsent NAL units for transmission.

13. A method as described in claim 10 further comprising:

a. analyzing an updated available transmission bandwidth after transmission of said current frame base layer NAL unit and any next most important layer NAL units thereby determining an updated bit budget;

b. determining eligible unsent NAL units and partially-unsent NAL units;

c. determining a quality layer identification (QLID) for each of said unsent/partially-unsent NAL units;

d. allocating said unsent/partially-unsent NAL units to said updated bit budget in order of QLID until said updated bit budget is expended; and

e. selecting said unsent/partially-unsent NAL units for transmission.

14. A method for rate-adaptive transmission of scalable signals, said method comprising:

a. selecting a group of frames (GOF) comprising a current frame, wherein each frame in said GOF comprises at least one NAL unit;

b. determining the initial total size of said GOF;

c. determining a GOF bit budget for said GOF;

d. assigning a quality layer identification (QLID) to each NAL unit in said GOF;

e. selecting a first threshold QLID value, that is assigned to a current frame NAL unit, wherein the total size of all NAL units in said GOF with QLID values more important than said first threshold QLID value is no larger than said GOF bit budget;

f. authorizing for transmission all current frame NAL units with QLIDs more important than said first threshold QLID value;

g. determining whether the total size of all NAL units in said GOF with QLID values at least as important as said first threshold QLID value is no larger than said GOF bit budget; and

h. authorizing for transmission all current frame NAL units with QLIDs at least as important as said first threshold QLID value when the total size of all NAL units in said GOF with QLID values at least as important as said first threshold QLID value is no larger than said GOF bit budget.

15. A method as described in claim 14 further comprising:

a. truncating a current frame NAL unit to fit in said GOF bit budget and transmitting said truncated current frame NAL unit when said scalable signal is encoded with Fine Grain Scalability (FGS) and when the total size of all NAL units in said GOF with QLID values at least as important as said first threshold QLID value is larger than said GOF bit budget; and

b. discarding said current frame NAL unit, when said scalable signal is not encoded with FGS and when the total size of all NAL units in said GOF with QLID values at least as important as said first threshold QLID value is larger than said GOF bit budget.

16. A method as described in claim 14 further comprising:

a. analyzing an updated available transmission bandwidth after transmission of said current frame NAL unit thereby determining an updated bit budget;

b. determining eligible unsent NAL units and partially-unsent NAL units;

c. allocating said unsent/partially-unsent NAL units to said updated bit budget until said updated bit budget is expended; and

d. authorizing said allocated unsent/partially-unsent NAL units for transmission.

17. A method as described in claim 14 further comprising:

a. analyzing an updated available transmission bandwidth after transmission of said current frame NAL unit thereby determining an updated bit budget;

b. determining eligible unsent NAL units and partially-unsent NAL units;

c. determining a quality layer identification (QLID) for each of said unsent/partially-unsent NAL units;

d. allocating said unsent/partially-unsent NAL units to said updated bit budget in order of QLID until said updated bit budget is expended; and

e. authorizing said unsent/partially-unsent NAL units for transmission.

18. A method as described in claim 15 wherein said truncating comprises truncating said current frame NAL unit in proportion to a ratio of a remaining bit budget to the total size of all NAL units with QLID equal to the QLID of the current NAL unit.

19. A method as described in claim 15 wherein said truncating comprises authorizing for transmission any portion of a current frame NAL unit that will fit in a remaining bit budget.

20. A method as described in claim 15 further comprising allocating any remaining GOF bit budget to other NAL units with a QLID equal to that of the current frame.