Microsoft AC-3 Encoder

[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 It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation.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 Microsoft AC-3 Encoder filter encodes stereo PCM audio to a Dolby Digital bitstream.

Note

The Microsoft implementation of the Dolby Digital technology is restricted under terms of the Dolby Digital licensing program to use by Microsoft applications.

 

Note

This filter is not supported on IA-64-based platforms.

 

Filter Information

Filter Interfaces

IBaseFilter

Input Pin Media Types

MEDIATYPE_Audio, MEDIASUBTYPE_PCM
The input type must be 48-kHz stereo, 16 bits per sample.

Input Pin Interfaces

IMemInputPin
IPin
IQualityControl

Output Pin Media Types

MEDIATYPE_Audio, MEDIASUBTYPE_DOLBY_AC3
MEDIATYPE_Stream, MEDIASUBTYPE_DOLBY_AC3

Output Pin Interfaces

IMediaSeeking
IPin
IQualityControl

Filter CLSID

CLSID_CMSAC3Enc (declared in wmcodecdsp.h)

Executable

msac3enc.dll

Merit

MERIT_DO_NOT_USE

Filter Category

CLSID_LegacyAmFilterCategory

 

Remarks

This filter is not available for use by third-party applications.

Requirements

Requirement Value
Minimum supported client
Windows Vista Home Premium, Windows Vista Ultimate, Windows 7 Home Premium, Windows 7 Professional, Windows 7 Enterprise, Windows 7 Ultimate [desktop apps only]
Minimum supported server
None supported
Header
Wmcodecdsp.h

See also

DirectShow Filters