Read/write.įor Dolby Digital (AC-3) streams, specifies the bit rate of the input stream in bits per second. The application can set this property at any time. The default value is eAVDecAudioDualMonoReproMode_LEFT_MONO. Specifies how the decoder reproduces dual-mono audio. After decoding begins, the value reflects the most recent Dolby frame. Before the first Dolby frame is decoded, the value is eAVDecAudioDualMono_UnSpecified. Specifies whether a 2-channel Dolby audio stream is encoded as stereo or dual-mono. The application can use this method to get or set the following attributes. The Dolby audio decoder implements the IMFTransform::GetAttributes method. Not needed for the digital output subtypes. If set, the value must be identical to MF_MT_AUDIO_BITS_PER_SAMPLE. Number of valid bits of audio data in each audio sample. The value must be 32 for MFAudioFormat_Float, and 16 for MFAudioFormat_PCM. Required for PCM output if the number of channels is greater than 2. If the input type is mono, stereo, or dual-mono (all without LFE channel), the only valid value is 2, for stereo output. The decoder cannot change the sampling rate of the stream. The output sample rate must be identical to the input sample rate. The following table lists the required and optional attributes for the output media type. IEEE 32-bit floating-point PCM audio Windows 10: stereo, 5.1, 7.1 Previous versions: stereo, 5.1ġ6-bit PCM audio Windows 10: stereo, 5.1, 7.1 Previous versions: stereo, 5.1 KSDATAFORMAT_SUBTYPE_IEC61937_DOLBY_DIGITAL_PLUSĭolby Digital Plus audio formatted for HDMI digital output. Subtypeĭolby AC-3 audio formatted for S/PDIF digital output. The Dolby audio decoder supports the following output subtypes. In addition, channel configurations 1/0, 2/0, 3/0, 2/1, 3/1, and 2/2 may also appear with an LFE channel. SPEAKER_BACK_RIGHT) or 0圆0F ( SPEAKER_FRONT_LEFTģ/2/2 + LFE Dolby Digital Plus only. SPEAKER_BACK_RIGHT) or 0圆07 ( SPEAKER_FRONT_LEFT SPEAKER_BACK_RIGHT) or 0圆03 ( SPEAKER_FRONT_LEFT The following table lists the supported Dolby channel configurations. If the attribute is not set, the decoder uses a default channel mask, based on the number of channels. If specified, the value must be consistent with the number of audio channels. Specifies the assignment of audio channels to speaker positions. If this attribute is not set, the default value is 2 (stereo). Valid values are in the range 1 (mono) to 8 (7.1 channel configuration). Number of channels, including the low frequency (LFE) channel, if present. Dolby AC-3 streams are limited to the three highest rates in this list. If this attribute is not set, the default value is 48000. The following table lists the requires and optional attributes for the input media type. This subtype can be used interchangeably with MEDIASUBTYPE_DOLBY_AC3. Subtypeĭolby Digital audio see Audio Subtypes. The Dolby audio decoder supports the following input subtypes. The class identifier (CLSID) of the Dolby audio decoder is CLSID_CMSDDPlusDecMFT, defined in the header file wmcodecdsp.h. The decoder can also convert a Dolby Digital Plus stream to Dolby Digital format for AC-3 S/PIDF output, or format a Dolby Digital Plus stream for HDMI digital output. For versions of Windows prior to Windows 8, the Microsoft implementation of the Dolby Digital technology is restricted under terms of the Dolby Digital licensing program to use by Microsoft applications.įor more information about these formats, refer to Advanced Television Systems Committee (ATSC) document Digital Audio Compression Standard (AC-3, E-AC-3) Revision B.
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |