AVICOMPRESSOPTIONS

Article
12/10/2007

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).

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;

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:

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

**  Windows NT/2000/XP:** Included in Windows NT 3.1 and later.
**  Windows 95/98/Me:** Included in Windows 95 and later.
**  Header:** Declared in Vfw.h.

AVICOMPRESSOPTIONS

Additional resources