The KSAC3_ALTERNATE_AUDIO structure specifies whether the two mono channels in an AC-3-encoded stream should be interpreted as a stereo pair or as two independent program channels.

typedef struct
{
  BOOL  fStereo;
  ULONG  DualMode;
} KSAC3_ALTERNATE_AUDIO, *PKSAC3_ALTERNATE_AUDIO;

Members

fStereo

Specifies whether the two mono channels should be interpreted as a stereo pair. If TRUE, the two mono channels are treated as a stereo pair. If FALSE, DualMode=0x03 causes the two mono channels to be mixed before being output by the decoder.

DualMode

When two independent channels of audio are encoded in the stream, this member specifies whether to use the audio track in channel 1, channel 2, or both. A value of 0x01 selects channel 1, 0x02 selects channel 2, and 0x03 selects both. Specify the value of this member as one of the following constants:

Constant name	Value
KSAC3_ALTERNATE_AUDIO_1	0x01
KSAC3_ALTERNATE_AUDIO_2	0x02
KSAC3_ALTERNATE_AUDIO_BOTH	0x03

Comments

This structure is used by the KSPROPERTY_AC3_ALTERNATE_AUDIO property.

For more information about the encoding of AC-3 program channels, see the AC-3 specification at the Dolby Laboratories Web site. The specification is titled Digital Audio Compression Standard (AC-3).

Requirements

Headers: Declared in Ksmedia.h. Include Ksmedia.h.

See Also

KSPROPERTY_AC3_ALTERNATE_AUDIO