MF_PD_ASF_METADATA_LEAKY_BUCKET_PAIRS attribute

Specifies a list of bit rates and corresponding buffer windows for a variable bit rate (VBR) Advanced Systems Format (ASF) file.

Data type

Byte array

Remarks

This attribute applies to presentation descriptors for ASF content.

The IMFASFContentInfo::GeneratePresentationDescriptor method generates this attribute that applies to the presentation descriptor for ASF content.

The value of the attribute has the following format:

struct {
    WORD wReserved;
    WM_LEAKY_BUCKET_PAIR bucket[2];
};

The WM_LEAKY_BUCKET_PAIR structure is defined as follows:

typedef struct _WMLeakyBucketPair {
  DWORD  dwBitrate;
  DWORD  msBufferWindow;
} WM_LEAKY_BUCKET_PAIR;

For each bit rate, the msBufferWindow member indicates how much content is buffered before playback begins, in milliseconds. The size of the buffer in bytes equals msBufferWinow x dwBitrate / 8000.

Requirements

See also

Alphabetical List of Media Foundation Attributes

IMFAttributes::GetBlob

IMFAttributes::SetBlob

IMFPresentationDescriptor

Presentation Descriptor Attributes

ASF Header Object

Presentation Descriptors