Windows Media Video 9 Encoder

Makale
03/22/2021

The Windows Media Video 9 encoder encodes video streams. The encoder supports the following four categories of encoded output.

Windows Media Video 9 Simple Profile
Windows Media Video 9 Main Profile
Windows Media Video 9 Advanced Profile
Windows Media Video 9.1 Image

Class Identifier

The class identifier (CLSID) for the Windows Media Video encoder is represented by the constant CLSID_CWMV9EncMediaObject. You can create an instance of the video encoder by calling CoCreateInstance.

Interfaces

A video encoder object exposes the IMediaObject interface so that the object can be used as a DirectX Media Object (DMO), and it exposes the IMFTransform interface so that the object can be used as a Media Foundation Transform (MFT).

A video encoder behaves as a DMO or an MFT depending on which interfaces you obtain and which version of Windows is running. The following table shows the conditions under which a video encoder behaves as a DMO or an MFT.

Operating system	Encoder behavior
Windows XP	A Windows Media video encoder always behaves as a DMO.
Windows Vista and Windows 7	By default, a Windows Media video encoder behaves as a DMO. If you obtain an IMFTransform interface on a video encoder, it behaves as an MFT.

Input Formats

The Windows Media Video encoder supports the following input media subtypes when it is acting as a DMO.

MEDIASUBTYPE_IYUV
MEDIASUBTYPE_I420
MEDIASUBTYPE_YV12
MEDIASUBTYPE_NV11
MEDIASUBTYPE_NV12
MEDIASUBTYPE_YUY2
MEDIASUBTYPE_UYVY
MEDIASUBTYPE_YVYU
MEDIASUBTYPE_RGB32
MEDIASUBTYPE_RGB24
MEDIASUBTYPE_RGB565
MEDIASUBTYPE_RGB555
MEDIASUBTYPE_RGB8
MEDIASUBTYPE_PHOTOMOTION

The Windows Media Video encoder supports the following input media subtypes when it is acting as an MFT.

MFVideoFormat_IYUV
MFVideoFormat_I420
MFVideoFormat_YV12
MFVideoFormat_NV11
MFVideoFormat_NV12
MFVideoFormat_YUY2
MFVideoFormat_UYVY
MFVideoFormat_YVYU
MFVideoFormat_RGB32
MFVideoFormat_RGB24
MFVideoFormat_RGB565
MFVideoFormat_RGB555
MFVideoFormat_RGB8
MEDIASUBTYPE_PHOTOMOTION

Output Formats

The following table shows the four-character codes (FOURCCs) that correspond to the categories of encoded output.

Category	FOURCC
Windows Media Video 9 Simple Profile	"WMV3"
Windows Media Video 9 Main Profile	"WMV3"
Windows Media Video 9 Advanced Profile	"WVC1"
Windows Media Video 9.1 Image	"WMVP" for 9.1, "WVP2" for 9.1 version 2

To distinguish between Simple Profile and Main Profile, set the MFPKEY_DECODERCOMPLEXITYREQUESTED property.

Properties

The Windows Media Video 9 encoder supports the following properties.

Property	Description
MFPKEY_ASFOVERHEADPERFRAME	Specifies the overhead, in bytes per packet, required for the container used to store the compressed content. Windows XP and later. Simple Profile, Main Profile, Advanced Profile, Image. Write-only.
MFPKEY_AVGFRAMERATE	Specifies the average frame rate of video content, in frames per second. Windows XP and later. Simple Profile, Main Profile, Advanced Profile, Image. Read-only.
MFPKEY_BAVG	Specifies the buffer window, in milliseconds, of a constrained variable-bit-rate (VBR) stream at its average bit rate (specified by MFPKEY_RAVG). Windows XP and later. Simple Profile, Main Profile, Advanced Profile. Read/write.
MFPKEY_BDELTAQP	Specifies the delta increase between the picture quantizer of the anchor frame and the picture quantizer of the B-frame. Windows XP and later. Main Profile, Advanced Profile. Write-only.
MFPKEY_BMAX	Specifies the buffer window, in milliseconds, of a constrained variable-bit-rate (VBR) stream at its peak bit rate (specified by MFPKEY_RMAX). Windows XP and later. Simple Profile, Main Profile, Advanced Profile, Image. Read/write.
MFPKEY_BUFFERFULLNESSINFIRSTBYTE	Specifies whether the encoded video bit stream contains a buffer fullness value with every key frame. Windows XP and later. Simple Profile, Main Profile, Advanced Profile. Read-only.
MFPKEY_CLOSEDENTRYPOINT	Specifies the encoding pattern to use at the beginning of a group of pictures. Windows Vista and later. Simple Profile, Main Profile, Advanced Profile, Image. Write-only.
MFPKEY_CODEDFRAMES	Specifies the number of video frames encoded by the codec. Windows XP and later. Simple Profile, Main Profile, Advanced Profile. Read-only.
MFPKEY_CODEDNONZEROFRAMES	Specifies the number of video frames encoded by the codec that actually contain data. Windows XP and later. Simple Profile, Main Profile, Advanced Profile. Read-only.
MFPKEY_COMPLEXITY	This property is superseded by MFPKEY_COMPLEXITYEX.
MFPKEY_COMPLEXITYEX	Specifies the complexity of the encoder algorithm. Windows Vista and later. Simple Profile, Main Profile. Advanced Profile. Write-only.
MFPKEY_COMPRESSIONOPTIMIZATIONTYPE	Specifies the type of optimization to use for the Windows Media Video 9 Advanced Profile codec. Windows XP and later. Simple Profile, Main Profile, Advanced Profile. Write.
MFPKEY_CRISP	Specifies a numeric representation of the tradeoff between motion smoothness and image quality in codec output. Windows XP and later. Simple Profile, Main Profile, Advanced Profile. Write-only.
MFPKEY_DATARATE	Not used.
MFPKEY_DECODERCOMPLEXITYPROFILE	Specifies the device conformance template to which the encoded content conforms. Windows XP and later. Simple Profile, Main Profile, Advanced Profile, Image. Read-only.
MFPKEY_DECODERCOMPLEXITYREQUESTED	Specifies the device conformance template that you want to use for video encoding. Windows XP and later. Simple Profile, Main Profile, Advanced Profile. Write-only.
MFPKEY_DELTAMVRANGEINDEX	Specifies the method used to encode the motion vector information. Windows XP and later. Simple Profile, Main Profile, Advanced Profile. Write-only.
MFPKEY_DENOISEOPTION	Specifies whether the codec will use the noise filter when encoding. Windows XP and later. Simple Profile, Main Profile, Advanced Profile. Write-only.
MFPKEY_DESIRED_VBRQUALITY	Specifies the desired quality level for quality based (1-pass) variable-bit-rate (VBR) encoding. Windows Vista and later. Simple Profile, Main Profile, Advanced Profile, Image. Write-only.
MFPKEY_DROPPEDFRAMES	Specifies the number of video frames dropped during encoding. Windows XP and later. Simple Profile, Main Profile, Advanced Profile. Read-only.
MFPKEY_ENDOFPASS	Specifies the end of an encoding pass. Windows XP and later. Simple Profile, Main Profile, Advanced Profile. Write-only.
MFPKEY_FORCEFRAMEHEIGHT	Specifies an intermediate frame height for encoded video. Windows XP and later. Advanced Profile. Write-only.
MFPKEY_FORCEFRAMEWIDTH	Specifies an intermediate frame width for encoded video. Windows XP and later. Advanced Profile. Write-only.
MFPKEY_FORCEMEDIANSETTING	Specifies whether the codec should use median filtering during encoding. Windows XP and later. Simple Profile, Main Profile, Advanced Profile. Write-only.
MFPKEY_FOURCC	Specifies the FOURCC that identifies the encoder you want to use. Windows XP and later. Simple Profile, Main Profile, Advanced Profile, Image. Write-only.
MFPKEY_FRAMECOUNT	Obsolete.
MFPKEY_FULLFRAMERATE	Specifies whether the encoder is allowed to drop frames. Windows XP and later. Simple Profile, Main Profile, Advanced Profile, Image. Write-only.
MFPKEY_INTERLACEDCODINGENABLED	Specifies whether the codec output will be interlaced. Windows XP and later. Advanced Profile. Write-only.
MFPKEY_KEYDIST	Specifies the maximum time, in milliseconds, between key frames in the codec output. Windows XP and later. Simple Profile, Main Profile, Advanced Profile, Image. Write-only.
MFPKEY_LIVEENCODE	Not used.
MFPKEY_LOOKAHEAD	Specifies the number of frames after the current frame that the codec will evaluate before encoding the current frame. Windows XP and later. Simple Profile, Main Profile, Advanced Profile. Write-only.
MFPKEY_LOOPFILTER	Specifies whether the codec should use the in-loop deblocking filter during encoding. Windows XP and later. Main Profile, Advanced Profile. Write-only.
MFPKEY_MACROBLOCKMODECOSTMETHOD	Specifies the cost method used by the codec to determine which macroblock mode to use. Windows XP and later. Simple Profile, Main Profile, Advanced Profile. Write-only.
MFPKEY_MOTIONMATCHMETHOD	Specifies the method to use for motion matching. Windows XP and later. Simple Profile, Main Profile, Advanced Profile. Write-only.
MFPKEY_MOTIONSEARCHLEVEL	Specifies the types of video information that are used in motion search operations. Windows XP and later. Simple Profile, Main Profile, Advanced Profile. Write-only.
MFPKEY_MOTIONSEARCHRANGE	Specifies the range used in motion searches. Windows XP and later. Main Profile, Advanced Profile. Write-only.
MFPKEY_NOISEEDGEREMOVAL	Specifies whether the codec should attempt to detect noisy frame edges and remove them. Windows XP and later. Simple Profile, Main Profile, Advanced Profile. Write-only.
MFPKEY_NUMBFRAMES	Specifies the number of bidirectional predictive frames (B-frames). Windows XP and later. Main Profile, Advanced Profile. Write-only.
MFPKEY_NUMTHREADS	Specifies the number of threads that the codec will use for encoding. Windows XP and later. Simple Profile, Main Profile, Advanced Profile. Write-only.
MFPKEY_PASSESRECOMMENDED	Specifies the maximum number of passes supported by the codec. Windows XP and later. Simple Profile, Main Profile, Advanced Profile, Image. Read-only.
MFPKEY_PASSESUSED	Specifies the number of passes that the codec will use to encode the content. Windows XP and later. Simple Profile, Main Profile, Advanced Profile, Image. Read/write.
MFPKEY_PERCEPTUALOPTLEVEL	Specifies whether the codec should use conservative perceptual optimization when encoding. Windows XP and later. Main Profile, Advanced Profile. Write-only.
MFPKEY_PRODUCEDUMMYFRAMES	Specifies whether the encoder produces dummy frame entries in the bit stream for duplicate frames. Windows XP and later. Simple Profile, Main Profile, Advanced Profile. Write-only.
MFPKEY_QPPERFRAME	Specifies QP. Windows Vista and later. Simple Profile, Main Profile, Advanced Profile, Image. Write-only.
MFPKEY_RANGEREDUX	Specifies the degree to which the codec should reduce the effective color range of the video. Windows XP and later. Advanced Profile. Write-only.
MFPKEY_RAVG	Specifies the average bit rate, in bits per second, used for 2-pass variable-bit-rate (VBR) encoding. Windows XP and later. Simple Profile, Main Profile, Advanced Profile. Read/write.
MFPKEY_RDSUBPIXELSEARCH	Specifies whether the encoder uses RD-based sub-pixel MV search. Windows XP and later. Simple Profile, Main Profile, Advanced Profile, Image. Write-only.
MFPKEY_REENCENDBUFFERSIZE	For segment re-encoding, specifies the buffer size. Windows Vista and later. Simple Profile, Main Profile, Advanced Profile, Image. Write-only.
MFPKEY_REENCDURATION	For segment re-encoding, specifies the duration of the segment to be re-encoded. Windows Vista and later. Simple Profile, Main Profile, Advanced Profile, Image. Write-only.
MFPKEY_REENCQPREF	For segment re-encoding, specifies the quantizer of the frame prior to the starting segment. Windows Vista and later. Simple Profile, Main Profile, Advanced Profile, Image. Write-only.
MFPKEY_REENCSTARTBUFFERSIZE	For segment re-encoding, specifies the starting buffer fullness. Windows Vista and later. Simple Profile, Main Profile, Advanced Profile, Image. Write-only.
MFPKEY_RMAX	Specifies the peak bit rate, in bits per second, used for constrained 2-pass variable-bit-rate (VBR). Windows XP and later. Simple Profile, Main Profile, Advanced Profile. Read/write.
MFPKEY_TOTALFRAMES	Specifies the number of video frames passed to the encoder during the encoding process. Windows XP and later. Simple Profile, Main Profile, Advanced Profile, Image. Read-only.
MFPKEY_VBRENABLED	Specifies whether the codec will use variable-bit-rate (VBR) encoding. Windows XP and later. Simple Profile, Main Profile, Advanced Profile, Image. Read/write.
MFPKEY_VBRQUALITY	Specifies the actual quality level for quality based (1-pass) variable-bit-rate (VBR) encoding. Windows XP and later. Simple Profile, Main Profile, Advanced Profile. Write-only.
MFPKEY_VIDEOSCALING	Specifies whether the codec will use video scaling optimization. Windows XP and later. Simple Profile, Main Profile, Advanced Profile. Write-only.
MFPKEY_VIDEOWINDOW	Specifies the amount of content, in milliseconds, that can fit into the model buffer. Windows XP and later. Advanced Profile. Write-only.
MFPKEY_VOLHEADERFORREENCODE	For segment re-encoding, specifies the codec private data of the file that is being re-encoded. Windows Vista and later. Simple Profile, Main Profile, Advanced Profile, Image. Write-only.
MFPKEY_VTYPE	Specifies the type of logic that the codec will use to detect interlaced source video. Windows XP and later. Advanced Profile. Write-only.
MFPKEY_ZEROBYTEFRAMES	Specifies the number of video frames that were skipped because they were duplicates of previous frames. Windows XP and later. Simple Profile, Main Profile, Advanced Profile. Read-only

Requirements

Requirement	Value
Client	Windows XP, Windows Vista or Windows 7
Header	Wmcodecdsp.h
DLL	Wmvencod.dll

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