Texas Instruments DM365, User Manual

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API Reference
4-29
For example, consider you have to check if the following values are
supported for level 2.0:
‰
maxHeight
= 480
‰
maxWidth
= 720
The supported
maxFrameSizeinMbs
value for level 2.0 as per Table A.1
– Level Limits is 396.
Compute the expression as:
maxFrameSizeinMbs >= (480*720) / 256
The value of
maxFrameSizeinMbs
is 1350 and hence the condition is
not true. Therefore, the above values of
maxHeight
and
maxWidth
are
not supported for level 2.0.
The maximum value for
maxFrameRate
and
maxBitRate
is 120
(120000) and 50000000 respectively.
Use the following expression to check the supported
maxFrameRate
values for each level:
maxFrameRate
<=
maxMbsPerSecond
/
FrameSizeinMbs
;
See Table A.1 – Level Limits in ISO/IEC 14496-10 for the supported
values of
maxMbsPerSecond
.
Use the following expression to calculate
FrameSizeinMbs
:
FrameSizeinMbs
=
(inputWidth * inputHeight) / 256
;
See Table A.1 – Level Limits in ISO/IEC 14496-10 for the supported
values of Max Video bit-rate.
During creation time, these values are checked against the maximum
values defined for the encoder. If the specified values exceed or do not
match the limit supported by encoder, the encoder continues to encode
with the next higher supported level. Since the actual height and width
are specified later using control operation with dynamic parameters, the
level based checking is done during the control operation.