MFPKEY_WMRESAMP_CHANNELMTX Property

Article
01/07/2021

Specifies the channel matrix, which is used to convert the source channels into the destination channels (for example, to convert 5.1 to stereo).

Constant for IPropertyBag

Available only by using IPropertyStore.

Data Type

VT_I4 | VT_ARRAY

Applies To

Audio Resampler DSP

Remarks

The value of the property is a matrix of Ns x Nd coefficients, where Ns is the number of source channels and Nd is the number of destination channels. Coefficients are specified in decibels using the following formula:

(int)(65536*20*log10(dB))

The matrix is stored as an array in row-major order where the row number is the source channel and the column number is the destination channel.

Thus, if the matrix is the following:

00       01       ...      0(Ns-1)
10       11       ...      1(Ns-1)
...      ...      ...      ...
(Nd-1)0 (Nd-1)1 ... (Nd-1)(Ns-1)

then you would specify the array as:

[ 00, 01, ..., 0(Ns-1), 10, 11, ..., 1(Ns-1), ..., (Nd-1)0, (Nd-1)1, ..., (Nd-1)(Ns-1) ]

Requirements

Requirement	Value
Minimum supported client	Windows XP [desktop apps only]
Minimum supported server	Windows Server 2003 [desktop apps only]
Header	Wmcodecdsp.h