DXVAHD_STREAM_DATA structure (dxvahd.h)

Article
04/02/2021

Contains per-stream data for the IDXVAHD_VideoProcessor::VideoProcessBltHD method.

Syntax

typedef struct _DXVAHD_STREAM_DATA {
  BOOL              Enable;
  UINT              OutputIndex;
  UINT              InputFrameOrField;
  UINT              PastFrames;
  UINT              FutureFrames;
  IDirect3DSurface9 **ppPastSurfaces;
  IDirect3DSurface9 *pInputSurface;
  IDirect3DSurface9 **ppFutureSurfaces;
} DXVAHD_STREAM_DATA;

Members

Enable

Specifies whether this input stream is enabled. If the value is TRUE, the VideoProcessBltHD method blits this stream to the output surface. Otherwise, the stream is not blitted. The maximum number of streams that can be enabled at one time is given in the MaxInputStreams member of the DXVAHD_VPDEVCAPS structure.

OutputIndex

The zero-based index number of the output frame. See Remarks.

InputFrameOrField

The zero-based index number of the input frame or field. See Remarks.

PastFrames

The number of past reference frames. This value must be less than or equal to the value of the PastFrames member of the DXVAHD_VPCAPS structure.

FutureFrames

The number of future reference frames. This value must be less than or equal to the value of the FutureFrames member of the DXVAHD_VPCAPS structure.

ppPastSurfaces

A pointer to an array of IDirect3DSurface9 pointers, allocated by the caller. This array contains the past reference frames for the video processing operation. The number of elements in the array is equal to the value of the PastFrames member.

pInputSurface

A pointer to the IDirect3DSurface9 interface of a Microsoft Direct3D surface that contains the current input frame.

ppFutureSurfaces

A pointer to an array of IDirect3DSurface9 pointers, allocated by the caller. This array contains the future reference frames for the video processing operation. The number of elements in the array is equal to the value of the FutureFrames member.

Remarks

Input Surfaces

The Direct3D surfaces must be allocated in the memory pool specified by the InputPool member of the DXVAHD_VPDEVCAPS structure. The following surface types can be used:

A video surface of type DXVAHD_SURFACE_TYPE_VIDEO_INPUT or DXVAHD_SURFACE_TYPE_VIDEO_INPUT_PRIVATE. See IDXVAHD_Device::CreateVideoSurface.
A decoder render-target surface of type DXVA2_VideoDecoderRenderTarget. See IDirectXVideoAccelerationService::CreateSurface.
An off-screen plain surface.

The past and future reference frames must be placed in the arrays in temporal order, from oldest to newest. For example, if T is the current input frame, the arrays would be ordered as follows:

ppPastSurfaces: { …, T-3, T-2, T-1 }
ppInputSurface: T
ppFutureSurfaces: { T+1, T+2, T+3, … }

The DXVAHD_VPCAPS structure specifies the number of reference frames required to get the best deinterlacing quality. If the application provides fewer reference frames, the device will fall back to simpler deinterlacing algorithms. If no reference frames are provided, the device can use bob deinterlacing. Here are some cases where an application might provide fewer reference frames:

At the beginning or end of the video sequence
With progressive input
During a transition between progressive and interlaced input
For a substream that does not require high deinterlacing quality
While dropping frames

Input and Output Indexes

The OutputIndex and InputFrameOrField members are used to correlate input frames or fields with output frames. The value of the OutputIndex member is cyclic and resets to zero after each cycle.

Here are some example patterns:

Progressive video at normal rate. Each input frame produces one output frame.
- Output index: 0, 0, 0, 0, …
- Input index: 0, 1, 2, 3, …
Interlaced video at normal rate. Each interlaced frame (two fields) produces two output frames.
- Output index: 0, 1, 0, 1, …
- Input index: 0, 1, 2, 3, …
Progressive video at 2/1 output rate. Each input frame produces one output frame.
- Output index: 0, 1, 0, 1, …
- Input index: 0, 1, 2, 3, …
Interlaced video at 1/2 output rate. Each interlaced frame produces one output frame. (The two fields are blended to create one frame.)
- Output index: 0, 0, 0, 0, …
- Input index: 0, 2, 4, 6, …

Requirements

Requirement	Value
Minimum supported client	Windows 7 [desktop apps only]
Minimum supported server	Windows Server 2008 R2 [desktop apps only]
Header	dxvahd.h

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