Microsoft DirectX 8.0

ACM Wrapper Filter

The ACM Wrapper filter enables codecs that use the Audio Compression Manager (ACM) to join a Microsoft® DirectShow® filter graph. Decompression is only to PCM audio. When wrapping a compressor, this filter appears in the audio compressor category and can support additional interfaces. There should never be any need to add it manually to a graph; it is pulled in automatically by the filter graph manager. It is used only for playback or sample rate conversion.

Filter interfaces IBaseFilter, IPersistPropertyBag
Input pin media types MEDIATYPE_Audio, MEDIASUBTYPE_NULL, FORMAT_WaveFormatEx
Input pin interfaces IMemInputPin, IPin, IQualityControl
Output pin media types MEDIATYPE_Audio, MEDIASUBTYPE_PCM, FORMAT_WaveFormatEx.

Any combination of the following are possible.

  • Samples per second (kHz): 44.1, 22.05, 11.025, or 8.0.
  • Channels: Stereo or mono.
  • Bits per sample: 8 or 16.
Output pin interfaces IAMStreamConfig, IMediaPosition, IMediaSeeking, IPin, IQualityControl
Filter CLSID CLSID_ACMWrapper
Property Page CLSID No property page.
Executable Quartz.dll
Merit MERIT_NORMAL
Category CLSID_AudioCompressorCategory