This filter decodes the following audio formats:
- MPEG-1 audio layers I and II.
- Backward-compatible MPEG-2 audio, layers I and II (ISO/IEC 13818-3), mono and stereo only.
- Advanced Audio Coding (AAC) Low Complexity (LC) profile.
- High-Efficiency AAC (HE-AAC) version 1 and version 2.
- Pass-through Digital Theater Systems (DTS) for digital output.
- LPCM, mono and stereo only, with or without PES headers.
- Dolby Digital.
- Dolby Digital Plus, including conversion from Dolby Digital Plus to Dolby Digital for digital output.
Note The Microsoft implementation of the Dolby Digital technology is restricted under terms of the Dolby Digital licensing program to use by Microsoft applications.
Decoding of Dolby Digital Plus, AAC, and HE-AAC formats requires Windows 7.
Note This filter is not supported on IA-64-based platforms.
In the registry, the friendly name of this filter is "Microsoft DTV-DVD Audio Decoder".
| Filter Information |
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| Filter Interfaces |
IBaseFilter
ICodecAPI
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| Input Pin Media Types |
In Windows Vista and later, the filter supports the following input types:
- MEDIATYPE_Audio, MEDIASUBTYPE_DOLBY_AC31
- MEDIATYPE_Audio, MEDIASUBTYPE_MPEG1Audio
- MEDIATYPE_Audio, MEDIASUBTYPE_MPEG1Payload
- MEDIATYPE_Audio, MEDIASUBTYPE_MPEG2_AUDIO
- MEDIATYPE_DVD_ENCRYPTED_PACK, MEDIASUBTYPE_DOLBY_AC31
- MEDIATYPE_DVD_ENCRYPTED_PACK, MEDIASUBTYPE_DTS2
- MEDIATYPE_DVD_ENCRYPTED_PACK, MEDIASUBTYPE_DVD_LPCM_AUDIO
- MEDIATYPE_DVD_ENCRYPTED_PACK, MEDIASUBTYPE_MPEG2_AUDIO
- MEDIATYPE_MPEG2_PES, MEDIASUBTYPE_DOLBY_AC31
- MEDIATYPE_MPEG2_PES, MEDIASUBTYPE_DTS2
- MEDIATYPE_MPEG2_PES, MEDIASUBTYPE_DVD_LPCM_AUDIO
- MEDIATYPE_MPEG2_PES, MEDIASUBTYPE_MPEG2_AUDIO
- MEDIATYPE_Stream, MEDIASUBTYPE_DOLBY_AC31
- MEDIATYPE_Stream, MEDIASUBTYPE_MPEG1Audio
- MEDIATYPE_Stream, MEDIASUBTYPE_MPEG2_AUDIO
Starting in Windows 7, the filter also supports the following input types:
- MEDIATYPE_Audio, MEDIASUBTYPE_DOLBY_DDPLUS1
- MEDIATYPE_Audio, MEDIASUBTYPE_DTS22
- MEDIATYPE_Audio, MEDIASUBTYPE_DVD_LPCM_AUDIO
- MEDIATYPE_Audio, MEDIASUBTYPE_DVM1
- MEDIATYPE_Audio, MEDIASUBTYPE_MPEG_ADTS_AAC
- MEDIATYPE_Audio, MEDIASUBTYPE_MPEG_LOAS
- MEDIATYPE_Audio, MEDIASUBTYPE_MPEG1AudioPayload
- MEDIATYPE_Audio, MEDIASUBTYPE_RAW_AAC1
- MEDIATYPE_Stream, MEDIASUBTYPE_DOLBY_DDPLUS1
- MEDIATYPE_Stream, MEDIASUBTYPE_MPEG_ADTS_AAC
- MEDIATYPE_Stream, MEDIASUBTYPE_MPEG_LOAS
The input type can change dynamically during streaming.
For more information about these media types, see Audio Subtypes.
Note 1. The Microsoft implementation of the Dolby Digital technology is restricted under terms of the Dolby Digital licensing program to use by Microsoft applications.
Note 2. For Digital Theater Systems (DTS) input, only S/PDIF output is supported (Dolby AC-3 over S/PDIF). Audio decoding is not supported.
|
| Input Pin Interfaces |
ICodecAPI
IKsPropertySet
IMemInputPin
IPin
IQualityControl
|
| Output Pin Media Types |
In Windows Vista and later, the filter supports the following output types:
- MEDIATYPE_Audio, MEDIASUBTYPE_DOLBY_AC3_SPDIF (same as KSDATAFORMAT_SUBTYPE_IEC61937_DOLBY_DIGITAL)
- MEDIATYPE_Audio, MEDIASUBTYPE_PCM
Starting in Windows 7, the filter also supports the following output types:
- MEDIATYPE_Audio, KSDATAFORMAT_SUBTYPE_IEC61937_DTS
- MEDIATYPE_Audio, MEDIASUBTYPE_IEEE_FLOAT
|
| Output Pin Interfaces |
IMediaSeeking
IPin
IQualityControl
|
| Filter CLSID | CLSID_CMPEG2AudDecoderDS (declared in wmcodecdsp.h) |
| Executable | msmpeg2adec.dll |
| Merit | MERIT_NORMAL - 1 |
| Filter Category | CLSID_LegacyAmFilterCategory |
Note An earlier version of the documentation stated that this filter can decoder "MPEG-2 audio." The filter decodes only backward-compatible MPEG-2 audio.
Remarks
Mono streams are always decoded to stereo.
For streams with a channel configuration of two or more speakers, the decoder does one of the following:
- Up-mixes to six channels, using the common 5.1 speaker configuration.
- Downmixes to stereo.
To select between these two options, use the ICodecAPI interface to set the AVDecCommonOutputFormat property, before connecting the pins. Alternatively, when the application builds the filter graph, it can set the desired media type on the output pin.
For AAC, the decoder has the same format constraints as the Media Foundation AAC Decoder.
Property Sets
The decoder's input pin supports the following property sets through IKsPropertySet:
Note Starting in Windows 7, the decoder supports trick mode through the rate-change property set. It supports playback rates in the range [0.501 – 2.0], where 1.0 is normal playback rate, and 2.0 is twice the normal rate.
Codec Properties
The decoder's input pin supports the following properties through ICodecAPI:
The filter supports the following properties through ICodecAPI:
Note 1. The AVDecCommonOutputFormat property must be set before the decoder's output pin is connected. Otherwise, the change has no effect.
Requirements
| Minimum supported client | Windows Vista Home Premium, Windows Vista Ultimate, Windows 7 Home Premium, Windows 7 Business, Windows 7 Enterprise, Windows 7 Ultimate |
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| Minimum supported server | None supported |
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| Header | Wmcodecdsp.h |
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See Also
- Audio Subtypes
- DirectShow Filters
- DVD Media Types
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Build date: 10/19/2009