IWMEncAudioSource::get_PreProcessPass

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The get_PreProcessPass method retrieves the preprocess pass count.

Syntax

HRESULT get_PreProcessPass(
  short*  piPassesCount
);

Parameters

piPassesCount

[out]  Pointer to a short that indicates the number of passes to make (0 or 1) for preprocessing.

Return Values

If the method succeeds, it returns S_OK. If it fails, it supports the IErrorInfo interface and returns an HRESULT error code.

Return code Number Description
E_POINTER 0x80004003 The pointer to the preprocess pass count is NULL.

Remarks

During one-pass encoding (where the get_PreProcessPass method is 0), audio content is analyzed and compressed at the same time.

During two-pass encoding (where the get_PreProcessPass method is 1), audio content is analyzed in the first pass, and then the best combinations of bit rate, frame rate, buffer size, and image quality are applied during the second pass. Two-pass encoding produces a better-quality result but the process takes longer. To use two-pass encoding, the input cannot be a live source and the output cannot be a broadcast.

Requirements

Header: wmencode.h

Library: wmenc.exe

See Also