KSPROCESSPIN structure (ks.h)

The KSPROCESSPIN structure describes the process state of a specific pin.

Syntax

typedef struct _KSPROCESSPIN {
  PKSPIN            Pin;
  PKSSTREAM_POINTER StreamPointer;
  PKSPROCESSPIN     InPlaceCounterpart;
  PKSPROCESSPIN     DelegateBranch;
  PKSPROCESSPIN     CopySource;
  PVOID             Data;
  ULONG             BytesAvailable;
  ULONG             BytesUsed;
  ULONG             Flags;
  BOOLEAN           Terminate;
} KSPROCESSPIN, *PKSPROCESSPIN;

Members

Pin

A pointer to a KSPIN structure that the KSPROCESSPIN structure is describing. Everything in the structure refers to this KSPIN.

StreamPointer

A pointer to a KSSTREAM_POINTER structure that points into the input stream at the current input location or into the output stream at the current output location. This can be used, for example, by output pins to stamp information onto the associated KSSTREAM_HEADER (ProcessPin->StreamPointer->StreamHeader->Flags=...).

InPlaceCounterpart

A pointer to a KSPROCESSPIN structure. If this KSPROCESSPIN is not part of an inplace transform, AVStream sets InPlaceCounterpart to NULL. If this KSPROCESSPIN is the input to an inplace transform, InPlaceCounterpart points to the output process pin for the transform. If this KSPROCESSPIN is the output of an inplace transform, InPlaceCounterpart points to the input process pin for the transform.

DelegateBranch

A pointer to a KSPROCESSPIN structure. If frames coming out of this KSPROCESSPIN are being split and sent to multiple sink pins, and the split does not cause a data copy (that is, the split sends the frames in a read-only manner and all of the split pin instances are in the same pipe), DelegateBranch points to the first instance of the process pin. The splitter automatically handles any process pin that has a non-NULLDelegateBranch.

CopySource

A pointer to a KSPROCESSPIN structure. If frames coming out of this process pin are being split and sent to multiple sink pins in a manner that causes a data copy (that is, one of the downstream filters is modifying the data frame by using an in-place transform), CopySource points to the process pin from which the frame was copied. The splitter automatically handles any process pin that has a non-NULLCopySource.

Data

A pointer to a buffer. If the pin described by this process entry is an input pin, Data points to the next available byte of data to be input. If the pin described by this process entry is an output pin, Data points to an output buffer in which processed data is placed.

BytesAvailable

This member specifies how many bytes of data are available in Data.

BytesUsed

This member specifies how many bytes of this data frame have been used by the process function. AVStream drivers should set this member to update how much they have read or written.

Flags

This member contains a copy of the flags from the relevant KSSTREAM_HEADER structure, if this KSPROCESSPIN is an input pin.

Terminate

This member indicates whether the current data frame should be sent downstream after the process dispatch finishes. If TRUE, the frame is sent downstream even if all data has not been consumed. If FALSE, the frame is not released until all data is consumed.

Remarks

The KSPROCESSPIN structure is used in the filter-centric processing model. You can use this structure to access data on a specific input pin or to write out processed data to an output pin.

Only filter-centric clients use process pins. Further, process pins that have a non-NULLDelegateBranch or a non-NULLCopySource typically are not of concern to the client. The splitter automatically handles process pins with these pointers.

Most clients are concerned with the members Pin, Data, BytesAvailable, BytesUsed, Flags, and Terminate. Data can be read from the stream or written into the stream through the Data member; BytesAvailable tells the client how many bytes of data are available in the current data frame (buffer) that Data points to. As the client minidriver reads from or writes to the stream, BytesUsed should be updated to reflect how many bytes of data have been consumed. The Terminate flag can be set if the minidriver is done with the current frame despite the fact that BytesUsed is not equal to BytesAvailable. After the minidriver exits the processing dispatch, pointers are advanced, and frames are completed as appropriate.

Requirements

Requirement	Value
Minimum supported client	Available in Microsoft Windows XP and later operating systems and in Microsoft DirectX 8.0 and later versions.
Header	ks.h (include Ks.h)

See also

KSPIN

KSPROCESSPIN_INDEXENTRY

KSSTREAM_HEADER

KSSTREAM_POINTER