CODECAPI_AVEncVideoEncodeFrameTypeQP property
Specifies the frame types (I, P, or B) that the quantization parameter (QP) is applied to.
Data type
ULONGULONG (VT_UI8)
Property GUID
CODECAPI_AVEncVideoEncodeFrameTypeQP
Remarks
For encoders which support setting a quantization parameter (QP) for different frame types (I, P, B), they shall expose this API in addition to CODECAPI_AVEncVideoEncodeQP. If an encoder supports only a single QP for all frame types, they shall support only CODECAPI_AVEncVideoEncodeQP.
This is a dynamic encoding property meaning that a new value can be set any time during the encoding session.
H.264/AVC encoders:
Encoder shall support GetValue, SetValue, and GetParameterRange.
A set of four 16-bit fields are used to specify the frame QPs in fixed-QP encoding. The fields are:
- Bits 0-15: QP used for I frames, valid range [0, 51].
- Bits 16-31: QP used for P frames, valid range [0, 51].
- Bits 32-47: QP used for B frames, valid range [0, 51]
- Bits 48-63: reserved
When this CodecAPI is supported, encoders shall support QP setting on frame type of I, P, and B.
Default value shall be 0x0000001a001a001a. QP equal to 26 for I, P and B.
When CODECAPI_AVEncVideoSelectLayer selects a specific temporal layer, SetValue of CODECAPI_AVEncVideoEncodeFrameTypeQP shall set QP for I, P, and B frames on that temporal layer. By default, it sets QP for I, P, and B frames on base temporal layer temporal layer 0.
CODECAPI_AVEncVideoMaxQP and CODECAPI_AVEncVideoMinQP shall be used to define and limit the QP range for QPs of all picture types, I, P and B.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client |
Windows 8.1 [desktop apps | UWP apps] |
| Minimum supported server |
Windows Server 2012 R2 [desktop apps | UWP apps] |
| Header |
|