Method and system for rate estimation in a video encoder
View Patent ↗Described herein is a method and system for rate estimation in a video encoder. The method and system use estimation metrics that can also be part of motion estimation and spatial prediction. A rate controller may utilize the system for rate estimation in two ways. The rate controller may supply a quantization parameter and receive a bit estimate from the rate estimator. Alternatively, the rate controller may supply a bit estimate and receive a quantization parameter from the rate estimator.
1. A method for rate estimation in a video encoder in a circuit, said method comprising:
determining a correlation between a first rate control metric and a second rate control metric in said circuit;
generating an estimation metric; and
estimating the first rate control metric from the second rate control metric and the estimation metric;
wherein determining, generating, and estimating occur while predicting a partition of a picture from an original another picture, wherein predicting is limited to integer offsets;
executing a first plurality of instructions stored in a non-transitory computer-readable medium for predicting the partition from the another picture, wherein predicting further comprises interpolating fractional sample resolutions, thereby resulting in a prediction error; and
executing a second plurality of instructions stored in a non-transitory computer-readable medium for quantizing the prediction error based at least in part on the first rate control metric.
2. The method of claim 1 , wherein the first rate control metric is an estimated amount of data for encoding a macroblock and the second rate control metric is a quantization parameter.
3. The method of claim 1 , wherein the first rate control metric is a quantization parameter and the second rate control metric is an estimated amount of data for encoding a macroblock.
4. The method of claim 1 , wherein the estimation metric is a sum of absolute difference between a current picture partition and a reference picture portion.
5. The method of claim 1 , wherein the estimation metric is based on a spatial prediction.
6. The method of claim 1 , wherein the estimation metric is based on a motion prediction.
7. The method of claim 1 , wherein the correlation between the first rate control metric and the second rate control metric is stored in a look-up table.
8. The method of claim 1 , further comprising:
predicting the partition from a reconstructed another picture, wherein the reconstructed picture represents the original another picture with lossy coding and decoding, thereby generating a prediction error;
quantizing the prediction error based at least in part on the first rate control metric.
9. A system for rate estimation in a video encoder, said system comprising:
a first plurality of instructions for correlating a first rate control metric and a second rate control metric;
a second plurality of instructions for generating an estimation metric; and
a third plurality of instructions for estimating the first rate control metric from the second rate control metric and the estimation metric;
wherein correlating, generating, and estimating occur while predicting a partition from a picture from another picture, wherein predicting is limited to integer offsets;
a fourth plurality of instructions for predicting the partition from the another picture, wherein predicting further comprises interpolating fractional sample resolutions, thereby resulting in a prediction error; and
a fifth plurality of instructions for quantizing the prediction error based at least in part on the first rate control metric.
10. The system of claim 9 , wherein the first rate control metric is a number of bits to code a macroblock and the second rate control metric is a quantization parameter.
11. The system of claim 9 , wherein the first rate control metric is a quantization parameter and the second rate control metric is a number of bits to code a macroblock.
12. The system of claim 9 , wherein the estimation metric is a sum of absolute difference between a current picture portion and a reference picture portion.
13. The system of claim 9 , wherein the picture estimator further comprises: a spatial estimator for generating a spatial estimation metric; a motion estimator for generating a motion estimation metric; and a selector for selecting the estimation metric from the spatial estimation metric and the motion estimation metric.
14. The system of claim 9 , wherein the metric engine comprises a look-up table.
15. A system comprising:
an integrated circuit comprising:
a first circuit for determining a correlation between a first rate control metric and a second rate control metric;
a second circuit for generating an estimation metric; and
a third circuit for estimating the first rate control metric from the second rate control metric and the estimation metric;
wherein determining, generating, and estimating occur while predicting a partition of a picture from an original another picture, wherein predicting is limited to integer offsets; and
a fourth circuit for predicting the partition from a reconstructed another picture, wherein the reconstructed picture represents the original another picture with lossy coding and decoding, wherein predicting further comprises interpolating fractional sample resolutions, thereby resulting in a prediction error; and
a fifth circuit for quantizing the prediction error based at least in part on the first rate control metric.
16. The system of claim 15 , wherein the first rate control metric is a number of bits to code a macroblock and the second rate control metric is a quantization parameter.
17. The system of claim 15 , wherein the first rate control metric is a quantization parameter and the second rate control metric is a number of bits to code a macroblock.
18. The system of claim 15 , wherein the estimation metric is a sum of absolute difference between a current picture portion and a reference picture portion.
19. The system of claim 15 , wherein the estimation metric is based on a spatial prediction.
20. The system of claim 15 , wherein the estimation metric is based on a motion prediction.
21. The system of claim 15 , wherein the correlation between the first rate control metric and the second rate control metric is stored in a memory.
22. A system comprising:
an integrated circuit comprising:
a first circuit for determining a correlation between a first rate control metric and a second rate control metric;
a second circuit for generating an estimation metric; and
a third circuit for estimating the first rate control metric from the second rate control metric and the estimation metric;
wherein correlating, generating, and estimating occur while predicting a partition from a picture from another picture, wherein predicting is limited to integer offsets;
a non-transitory computer-readable medium storing:
a first plurality of instructions for predicting the partition from the another picture, wherein predicting further comprises interpolating fractional sample resolutions, thereby resulting in a prediction error; and
a second plurality of instructions for quantizing the prediction error based at least in part on the first rate control metric.
23. The system of claim 22 , wherein the first rate control metric is a number of bits to code a macroblock and the second rate control metric is a quantization parameter.
24. The system of claim 22 , wherein the first rate control metric is a quantization parameter and the second rate control metric is a number of bits to code a macroblock.
25. The system of claim 22 , wherein the estimation metric is a sum of absolute difference between a current picture portion and a reference picture portion.
26. The system of claim 22 , wherein the estimation metric is based on a spatial prediction.
27. The system of claim 22 , wherein the estimation metric is based on a motion prediction.
28. The system of claim 22 , wherein the correlation between the first rate control metric and the second rate control metric is stored in a memory.