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DVD_MUA_MixingInfo structure (strmif.h)

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[The feature associated with this page, DirectShow, is a legacy feature. It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation. Those features have been optimized for Windows 10 and Windows 11. Microsoft strongly recommends that new code use MediaPlayer, IMFMediaEngine and Audio/Video Capture in Media Foundation instead of DirectShow, when possible. Microsoft suggests that existing code that uses the legacy APIs be rewritten to use the new APIs if possible.]

The DVD_MUA_MixingInfo structure describes the surround sound mixing information for the channels in one audio stream in a specified title.

Syntax

typedef struct tagDVD_MUA_MixingInfo {
  BOOL  fMixTo0;
  BOOL  fMixTo1;
  BOOL  fMix0InPhase;
  BOOL  fMix1InPhase;
  DWORD dwSpeakerPosition;
} DVD_MUA_MixingInfo;

Members

fMixTo0

Variable of type BOOL; TRUE means the channel is mixed to channel 0.

fMixTo1

Variable of type BOOL; TRUE means the channel is mixed to channel 1.

fMix0InPhase

Variable of type BOOL; TRUE means the channel is mixed in phase to channel 0.

fMix1InPhase

Variable of type BOOL; TRUE means the channel is mixed in phase to channel 1.

dwSpeakerPosition

The speaker for which this channel is intended. See Remarks.

Remarks

Applications cannot use the information contained in this structure to change the mixing unless they have a way to communicate with a custom audio decoder that has been inserted manually into the filter graph. The default audio decoder handles Linear Pulse Code Modulated (LPCM) audio using the mixing information on the digital video disc (DVD), but applications have no way to instruct the decoder to modify the mixing values. This means that current DVD playback applications should have no need to access the multichannel-related data structures.

The DVD_MultichannelAudioAttributes structure contains information about one audio stream in a specified title. An array of up to eight DVD_MUA_MixingInfo structures will be populated in this structure, if the following conditions are true.

  • DVD_AudioAttributes.AppMode = DVD_AudioMode_Surround
  • DVD_AudioAttributes.AudioFormat = DVD_AudioFormat_LPCM
  • DVD_AudioAttributes.fHasMultichannelInfo = 1
Possible values for dwSpeakerPosition are defined in Ksmedia.h as follows:
Define Value
KSAUDIO_SPEAKER_LEFT 0x1
KSAUDIO_SPEAKER_RIGHT 0x2
KSAUDIO_SPEAKER_CENTER 0x4
KSAUDIO_SPEAKER_SURROUND_LEFT 0x8
KSAUDIO_SPEAKER_SURROUND_RIGHT 0x10
KSAUDIO_SPEAKER_SUBWOOFER 0x20
KSAUDIO_SPEAKER_LEFT_OF_CENTER 0x40
KSAUDIO_SPEAKER_RIGHT_OF_CENTER 0x80
KSAUDIO_SPEAKER_SURROUND_MONO 0x100
KSAUDIO_SPEAKER_SIDE_LEFT 0x200
KSAUDIO_SPEAKER_SIDE_RIGHT 0x400
KSAUDIO_SPEAKER_TOP 0x800

Requirements

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

See also

DVD_AudioAttributes

DirectShow Structures