DVD_MUA_Coeff structure (strmif.h)

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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

The mixing coefficient for this channel to channel 0.

log2_beta

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.

C++
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] + ...

Requirements

Requirement	Value
Header	strmif.h (include Dshow.h)

See also

DVD_AudioAttributes

DVD_MUA_MixingInfo

DirectShow Structures