Subtype | Description | Header |
---|---|---|
MFAudioFormat_AAC | Raw AAC or ADTS AAC. For this subtype, the media type gives the sample rate and number of channels prior to the application of spectral band replication (SBR) and parametric stereo (PS) tools, if present. The effect of the SBR tool is to double the decoded sample rate relative to the core AAC-LC sample rate. The effect of the PS tool is to decode stereo from a mono-channel core AAC-LC stream. This subtype is equivalent to MEDIASUBTYPE_MPEG_HEAAC, defined in wmcodecdsp.h. See Audio Subtype GUIDs. The MPEG-4 File Source and the ADTS Parser output this subtype. | mfapi.h |
MEDIASUBTYPE_RAW_AAC1 | Raw AAC. This subtype is used for AAC contained in an AVI file with the audio format tag equal to WAVE_FORMAT_RAW_AAC1 (0x00FF). For this subtype, the media type gives the sample rate and number of channels after the SBR and PS tools are applied, if present. | wmcodecdsp.h |
Attribute | Description | Remarks |
---|---|---|
MF_MT_MAJOR_TYPE | Major type. | Must be MFMediaType_Audio. |
MF_MT_SUBTYPE | Audio subtype. | Refer to the previous description for details. |
MF_MT_AAC_AUDIO_PROFILE_LEVEL_INDICATION | Audio profile and level. | Optional. Applies only to MFAudioFormat_AAC. The value of this attribute is the audioProfileLevelIndication field, as defined by ISO/IEC 14496-3. If unknown, set to zero or 0xFE ('no audio profile specified'). |
MF_MT_AAC_PAYLOAD_TYPE | Payload type. | Applies only to MFAudioFormat_AAC. The decoder supports the following payload types:
|
MF_MT_AUDIO_BITS_PER_SAMPLE | Desired bit depth of the decoded PCM audio. | |
MF_MT_AUDIO_CHANNEL_MASK | Specifies the assignment of audio channels to speaker positions. | Optional. For more information, see Format Constraints. |
MF_MT_AUDIO_NUM_CHANNELS | Number of channels, including the low frequency (LFE) channel, if present. | The interpretation of this value depends on the media subtype, as described previously. |
MF_MT_AUDIO_SAMPLES_PER_SECOND | Sample rate, in samples per second. | The interpretation of this value depends on the media subtype, as described previously. |
MF_MT_USER_DATA | Additional format information. | The value of this attribute depends on the subtype.
The value of audioObjectType as defined in AudioSpecificConfig() must be 2, indicating AAC-LC. The value of extensionAudioObjectType must be 5 for SBR or 29 for PS. |
Subtype | Description |
---|---|
MFAudioFormat_Float | IEEE floating-point audio. |
MFAudioFormat_PCM | 16-bit PCM audio. |
MFAudioFormat_AAC | Requires Windows 8. This output type can be used to convert an AAC stream in the LOAS/LATM format to ADTS format. To convert an LOAS/LATM stream to an ADTS stream, set the input type to MFAudioFormat_AAC with payload type 3 (LOAS). Then set the output type to MFAudioFormat_AAC with payload type 1 (ADTS). The decoder will reformat the conainter without decoding the bitstream. [!Note] |
Configuration | Channel Mask | AAC Syntactic Elements |
---|---|---|
Mono | SPEAKER_FRONT_CENTER | |
Stereo or dual mono | SPEAKER_FRONT_LEFT | SPEAKER_FRONT_RIGHT | |
2/1 | SPEAKER_FRONT_LEFT | SPEAKER_FRONT_RIGHT | SPEAKER_BACK_CENTER | |
2/2 | SPEAKER_FRONT_LEFT | SPEAKER_FRONT_RIGHT | SPEAKER_BACK_LEFT | SPEAKER_BACK_RIGHT | |
3/0 | SPEAKER_FRONT_LEFT | SPEAKER_FRONT_RIGHT | SPEAKER_FRONT_CENTER | |
3/1 | SPEAKER_FRONT_LEFT | SPEAKER_FRONT_RIGHT | SPEAKER_FRONT_CENTER | SPEAKER_BACK_CENTER | |
3/2 | SPEAKER_FRONT_LEFT | SPEAKER_FRONT_RIGHT | SPEAKER_FRONT_CENTER | SPEAKER_BACK_LEFT | SPEAKER_BACK_RIGHT | |
3/2 + LFE | SPEAKER_FRONT_LEFT | SPEAKER_FRONT_RIGHT | SPEAKER_FRONT_CENTER | SPEAKER_LOW_FREQUENCY | SPEAKER_BACK_LEFT | SPEAKER_BACK_RIGHT |
Attribute | Description |
---|---|
CODECAPI_AVDecAudioDualMono | Specifies whether 2-channel audio is encoded as stereo or dual mono. Treat as read-only. |
CODECAPI_AVDecAudioDualMonoReproMode | Specifies how the decoder reproduces dual mono audio. The default value is eAVDecAudioDualMonoReproMode_LEFT_MONO: Output Ch1 to the left and right speakers. Applications can set this property to change the default behavior. |
MFT_SUPPORT_DYNAMIC_FORMAT_CHANGE | The AAC decoder does not handle dynamic format changes, and must be flushed or drained before a new input media type is set. Treat this attribute as read-only. [!Note] In Windows 7, the decoder incorrectly reports a value of TRUE for this attribute. In Windows 8, the decoder reports FALSE, which is the correct value |
Attribute | Value |
---|---|
MF_MT_MAJOR_TYPE | MFMediaType_Audio |
MF_MT_SUBTYPE | MFAudioFormat_AAC |
MF_MT_AUDIO_SAMPLES_PER_SECOND | 48000 |
MF_MT_AUDIO_NUM_CHANNELS | 6 |
MF_MT_AAC_PAYLOAD_TYPE | 0 |
MF_MT_USER_DATA | {0x00, 0x00, 0x2a, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x11, 0xb0} |
MF_MT_AAC_AUDIO_PROFILE_LEVEL_INDICATION | 0x2a (optional) |
Attribute | Value |
---|---|
MF_MT_MAJOR_TYPE | MFMediaType_Audio |
MF_MT_SUBTYPE | MFAudioFormat_Float |
MF_MT_AUDIO_BITS_PER_SAMPLE | 32 |
MF_MT_AUDIO_SAMPLES_PER_SECOND | 48000 |
MF_MT_AUDIO_NUM_CHANNELS | 6 |
MF_MT_AUDIO_AVG_BYTES_PER_SECOND | 1152000 (optional) |
MF_MT_AUDIO_BLOCK_ALIGNMENT | 24 (optional) |
MF_MT_AUDIO_CHANNEL_MASK | 0x3f (optional) |
Minimum supported client | Windows 7 [desktop apps only] |
Minimum supported server | Windows Server 2008 R2 [desktop apps only] |
DLL |
|
Code Memory (KiB) | Constant Data Tables (KiB) | Data RAM (KiB) | MIPS | |||
2-Ch | 6-Ch | 2-Ch | 6-Ch | |||
AAC-LC | 44.59 | 30.50 | 68.95 | 87.95 | 6.4 | 21.8 |
HE-AAC v2 | 110.75 | 46.91 | 101.20 | 180.82 | 15.8 | 41.2 |