Method and apparatus for determining encoding mode by using temporal and spatial complexity
A method and apparatus for deciding an encoding mode are disclosed. The encoding mode decision apparatus comprises a temporal complexity calculator to calculate a temporal complexity of a macroblock and a mode decider to elect the encoding mode utilizing the temporal complexity. The disclosure calculates the temporal and spatial complexes for the macroblocks more accurately as well as elects the optimal encoding mode using the same resulting in a reduction of the calculation complexity when applying the rate-distortion technique along with an improvement of its processing speed.
1. An encoding mode decision apparatus using a temporal complexity comprising:
a temporal complexity calculator to calculate a temporal complexity by using Hadamard transforming block residuals to obtain temporal block complexity in accordance with the following equation:
Temporal
Block
Complexity
=
(
∑
i
=
0
n
Block_Complexity
(
i
)
)
/
Q_step
where
n
is
a
number
>
zero
and
<
or
equal
to
15
;
with the temporal block complexity being divided by a quantization width; and further comprising a mode decider to decide the encoding mode utilizing the temporal complexity.
2. The encoding mode decision apparatus in claim 1 , wherein the mode decider elects an intra block mode as the encoding mode if the temporal complexity is greater than a predetermined temporal threshold.
3. The encoding mode decision apparatus in claim 1 , wherein the encoding mode decider decides an inter block mode as the encoding mode if the temporal complexity is less than or equal to a predetermined temporal threshold.
4. The encoding mode decision apparatus in claim 2 , wherein the temporal threshold is defined as a temporal complexity of a previous macroblock in a previous frame to a current frame with the previous macroblock being equally positioned to the macroblock contained in the current frame.
5. An encoding mode decision apparatus using a spatial complexity comprising:
a spatial complexity calculator to calculate a spatial complexity by dividing the sum of vertical and horizontal complexities of a macroblock by a quantization width in accordance with the following equation:
Spatial_Complexity
=
(
∑
i
=
0
n
Block_Complexity
(
i
)
16
)
/
Q_step
where n is a number > zero and < or equal to 255; and
a mode decider to decide the encoding mode utilizing the spatial complexity.
6. The encoding mode decision apparatus in claim 5 , wherein the mode decider elects a small block mode as the encoding mode if the spatial complexity is greater than a predetermined spatial threshold.
7. The encoding mode decision apparatus in claim 5 , wherein the mode decider elects a large block mode as the encoding mode if the spatial complexity is less than or equal to a predetermined spatial threshold.
8. The encoding mode decision apparatus in claim 6 , wherein the spatial threshold is defined as a spatial complexity of a previous macroblock in a previous frame to a current frame with the previous macroblock being equally positioned to the macroblock contained in the current frame.
9. The encoding mode decision apparatus in claim 5 , wherein the spatial complexity comprises a vertical and a horizontal complexity of the macroblock and wherein the mode decider decides a vertical block mode as the encoding mode if the vertical complexity is greater than the horizontal complexity.
10. The encoding mode decision apparatus in claim 5 , wherein the spatial complexity comprises vertical and horizontal complexities of the macroblock and wherein the mode decider decides a non-directional block mode as the encoding mode if the vertical complexity is equal to the horizontal complexity.
11. The encoding mode decision apparatus in claim 5 , wherein the spatial complexity comprises vertical and horizontal complexities of the macroblock and wherein the mode decider decides a horizontal block mode as the encoding mode if the vertical complexity is less than the horizontal complexity.
12. An encoding mode decision method using temporal and spatial complexities, the method comprising and performing through an encoding mode decision apparatus:
calculating a temporal complexity by Hadamard transforming block residuals to obtain temporal block complexity in accordance with the following equation:
Temporal
Block
Complexity
=
(
∑
i
=
0
n
Block_Complexity
(
i
)
)
/
Q_step
where
n
is
a
number
>
zero
and
<
or
equal
to
15
;
and
dividing the temporal block complexity by a quantization width;
calculating a spatial complexity by dividing the sum of vertical and horizontal complexities of a macroblock by a quantization width in accordance with the following equation:
Spatial_Complexity
=
(
∑
i
=
0
n
Block_Complexity
(
i
)
16
)
/
Q_step
where n is a number > zero and < or equal to 255;
electing an intra block mode as the encoding mode if the temporal complexity is greater than a predetermined temporal threshold; and
electing an inter block mode as the encoding mode if the temporal complexity is less than or equal to the temporal threshold.
13. The encoding mode decision method in claim 12 , further comprising, after the calculating of the spatial complexity:
deciding a small block mode as the encoding mode if the spatial complexity is greater than a predetermined spatial threshold; and
deciding a large block mode as the encoding mode if the spatial complexity is less than or equal to the spatial threshold.
14. The encoding mode decision method in claim 13 , further comprising, after the calculating of the spatial complexity:
comparing between vertical and horizontal complexities of the macroblock using the spatial complexity;
if a vertical complexity of the macroblock is greater than its horizontal complexity, electing a vertical block mode as the encoding mode;
if vertical complexity of the macroblock is equal to the horizontal complexity, electing a non-directional block mode as the encoding mode; and
if a vertical complexity of the macroblock is less than the horizontal complexity, electing a horizontal block mode as the encoding mode.
15. The encoding mode decision apparatus in claim 3 , wherein the temporal threshold is defined as a temporal complexity of a previous macroblock in a previous frame to a current frame with the previous macroblock being equally positioned to the macroblock contained in the current frame.
16. The encoding mode decision apparatus in claim 7 , wherein the spatial threshold is defined as a spatial complexity of a previous macroblock in a previous frame to a current frame with the previous macroblock being equally positioned to the macroblock contained in the current frame.