| Microsoft DirectX 9.0 |
The DVD_MUA_Coeff structure defines the mixing coefficients for one channel in a multichannel audio stream. The DVD_MultichannelAudioAttributes structure contains an array of eight DVD_MUA_Coeff structures, one for each channel in the stream.
Syntax
typedef struct tagDVD_MUA_Coeff {
double log2_alpha;
double log2_beta;
} DVD_MUA_Coeff;
Members
log2_alpha
Variable of type double indicating the mixing coefficient for this channel to channel 0.
log2_beta
Variable of type double indicating the mixing coefficient for this channel to channel 1.
Remarks
The information contained in this structure reflects the mixing coefficients as authored on the digital video disc (DVD). An application cannot modify these values or otherwise use them unless it is also decoding the audio. In the typical DVD filter graph, the DVD Navigator filter does not send this information to the decoder.
The alpha coefficient is used to mix to audio channel 0 and the beta coefficient is used to mix to audio channel 1. In general, the following formula calculates the mixing coefficients.
Audio channel 0 = coeff[0].alpha * value[0] + coeff[1].alpha * value[1] + ...
Audio channel 1 = coeff[0].beta * value[0] + coeff[1].beta * value[1] + ...
See Also