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AVICOMPRESSOPTIONS structure (vfw.h)

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The AVICOMPRESSOPTIONS structure contains information about a stream and how it is compressed and saved. This structure passes data to the AVIMakeCompressedStream function (or the AVISave function, which uses AVIMakeCompressedStream).

Syntax

typedef struct {
  DWORD  fccType;
  DWORD  fccHandler;
  DWORD  dwKeyFrameEvery;
  DWORD  dwQuality;
  DWORD  dwBytesPerSecond;
  DWORD  dwFlags;
  LPVOID lpFormat;
  DWORD  cbFormat;
  LPVOID lpParms;
  DWORD  cbParms;
  DWORD  dwInterleaveEvery;
} AVICOMPRESSOPTIONS, *LPAVICOMPRESSOPTIONS;

Members

fccType

Four-character code indicating the stream type. The following constants have been defined for the data commonly found in AVI streams:

Constant Description
streamtypeAUDIO
 Indicates an audio stream.
streamtypeMIDI
 Indicates a MIDI stream.
streamtypeTEXT
 Indicates a text stream.
streamtypeVIDEO
 Indicates a video stream.

fccHandler

Four-character code for the compressor handler that will compress this video stream when it is saved (for example, mmioFOURCC ('M','S','V','C')). This member is not used for audio streams.

dwKeyFrameEvery

Maximum period between video key frames. This member is used only if the AVICOMPRESSF_KEYFRAMES flag is set; otherwise every video frame is a key frame.

dwQuality

Quality value passed to a video compressor. This member is not used for an audio compressor.

dwBytesPerSecond

Video compressor data rate. This member is used only if the AVICOMPRESSF_DATARATE flag is set.

dwFlags

Flags used for compression. The following values are defined:

Name Description
AVICOMPRESSF_DATARATE
 Compresses this video stream using the data rate specified in dwBytesPerSecond.
AVICOMPRESSF_INTERLEAVE
 Interleaves this stream every dwInterleaveEvery frames with respect to the first stream.
AVICOMPRESSF_KEYFRAMES
 Saves this video stream with key frames at least every dwKeyFrameEvery frames. By default, every frame will be a key frame.
AVICOMPRESSF_VALID
 Uses the data in this structure to set the default compression values for AVISaveOptions. If an empty structure is passed and this flag is not set, some defaults will be chosen.

lpFormat

Pointer to a structure defining the data format. For an audio stream, this is an LPWAVEFORMAT structure.

cbFormat

Size, in bytes, of the data referenced by lpFormat.

lpParms

Video-compressor-specific data; used internally.

cbParms

Size, in bytes, of the data referenced by lpParms

dwInterleaveEvery

Interleave factor for interspersing stream data with data from the first stream. Used only if the AVICOMPRESSF_INTERLEAVE flag is set.

Requirements

Requirement Value
Minimum supported client Windows 2000 Professional [desktop apps only]
Minimum supported server Windows 2000 Server [desktop apps only]
Header vfw.h

See also

AVIFile Functions and Macros

AVIFile Structures

AVIMakeCompressedStream

AVISave

AVISaveOptions

mmioFOURCC