AVIOLDINDEX structure (aviriff.h)

Article
4/26/2023

[The feature associated with this page, DirectShow, is a legacy feature. It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation. Those features have been optimized for Windows 10 and Windows 11. Microsoft strongly recommends that new code use MediaPlayer, IMFMediaEngine and Audio/Video Capture in Media Foundation instead of DirectShow, when possible. Microsoft suggests that existing code that uses the legacy APIs be rewritten to use the new APIs if possible.]

The AVIOLDINDEX structure describes an AVI 1.0 index ('idx1' format). New AVI files should use an AVI 2.0 index ('indx' format).

Syntax

typedef struct _avioldindex {
  FOURCC             fcc;
  DWORD              cb;
  struct {
    DWORD dwChunkId;
    DWORD dwFlags;
    DWORD dwOffset;
    DWORD dwSize;
  } _avioldindex_entry;
  _avioldindex_entry aIndex[];
} AVIOLDINDEX;

Members

fcc

Specifies a FOURCC code. The value must be 'idx1'.

cb

Specifies the size of the structure, not including the initial 8 bytes.

_avioldindex_entry

_avioldindex_entry.dwChunkId

_avioldindex_entry.dwFlags

_avioldindex_entry.dwOffset

_avioldindex_entry.dwSize

aIndex

Array of structures that contain the following members.

dwChunkId

Specifies a FOURCC that identifies a stream in the AVI file. The FOURCC must have the form 'xxyy' where xx is the stream number and yy is a two-character code that identifies the contents of the stream:

db (Uncompressed video frame)

dc (Compressed video frame)

pc (Palette change)

wb (Audio data)

dwFlags

Specifies a bitwise combination of zero or more of the following flags:

Value	Meaning
AVIIF_KEYFRAME	The data chunk is a key frame.
AVIIF_LIST	The data chunk is a 'rec ' list.
AVIIF_NO_TIME	The data chunk does not affect the timing of the stream. For example, this flag should be set for palette changes.

dwOffset

Specifies the location of the data chunk in the file. The value should be specified as an offset, in bytes, from the start of the 'movi' list; however, in some AVI files it is given as an offset from the start of the file.

dwSize

Specifies the size of the data chunk, in bytes.

Remarks

This structure consists of the initial RIFF chunk (the fcc and cb members) followed by one index entry for each data chunk in the 'movi' list.

Requirements

Requirement	Value
Header	aviriff.h

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