AVIFILEINFOW structure (vfw.h)

The AVIFILEINFO structure contains global information for an entire AVI file.

Syntax

typedef struct _AVIFILEINFOW {
  DWORD dwMaxBytesPerSec;
  DWORD dwFlags;
  DWORD dwCaps;
  DWORD dwStreams;
  DWORD dwSuggestedBufferSize;
  DWORD dwWidth;
  DWORD dwHeight;
  DWORD dwScale;
  DWORD dwRate;
  DWORD dwLength;
  DWORD dwEditCount;
  WCHAR szFileType[64];
} AVIFILEINFOW, *LPAVIFILEINFOW;

Members

dwMaxBytesPerSec

Approximate maximum data rate of the AVI file.

dwFlags

A bitwise OR of zero or more flags. The following flags are defined:

Name	Description
AVIFILEINFO_HASINDEX	The AVI file has an index at the end of the file. For good performance, all AVI files should contain an index.
AVIFILEINFO_MUSTUSEINDEX	The file index contains the playback order for the chunks in the file. Use the index rather than the physical ordering of the chunks when playing back the data. This could be used for creating a list of frames for editing.
AVIFILEINFO_ISINTERLEAVED	The AVI file is interleaved.
AVIFILEINFO_WASCAPTUREFILE	The AVI file is a specially allocated file used for capturing real-time video. Applications should warn the user before writing over a file with this flag set because the user probably defragmented this file.
AVIFILEINFO_COPYRIGHTED	The AVI file contains copyrighted data and software. When this flag is used, software should not permit the data to be duplicated.

dwCaps

Capability flags. The following flags are defined:

Name	Description
AVIFILECAPS_CANREAD	An application can open the AVI file with the read privilege.
AVIFILECAPS_CANWRITE	An application can open the AVI file with the write privilege.
AVIFILECAPS_ALLKEYFRAMES	Every frame in the AVI file is a key frame.
AVIFILECAPS_NOCOMPRESSION	The AVI file does not use a compression method.

dwStreams

Number of streams in the file. For example, a file with audio and video has at least two streams.

dwSuggestedBufferSize

Suggested buffer size, in bytes, for reading the file. Generally, this size should be large enough to contain the largest chunk in the file. For an interleaved file, this size should be large enough to read an entire record, not just a chunk.

If the buffer size is too small or is set to zero, the playback software will have to reallocate memory during playback, reducing performance.

dwWidth

Width, in pixels, of the AVI file.

dwHeight

Height, in pixels, of the AVI file.

dwScale

Time scale applicable for the entire file. Dividing dwRate by dwScale gives the number of samples per second.

Any stream can define its own time scale to supersede the file time scale.

dwRate

Rate in an integer format. To obtain the rate in samples per second, divide this value by the value in dwScale.

dwLength

Length of the AVI file. The units are defined by dwRate and dwScale.

dwEditCount

Number of streams that have been added to or deleted from the AVI file.

szFileType[64]

Null-terminated string containing descriptive information for the file type.

Remarks

Note

The vfw.h header defines AVIFILEINFO as an alias that automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that is not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see Conventions for Function Prototypes.

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