Audio Renderer


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Audio Renderer

The Audio Renderer filter is a generic audio rendering filter that you can connect to the output of any of the following filters, if they contain WAV audio: File Source (Async), File Source (URL), MPEG-1 Stream Splitter, AVI Splitter, WAVE Parser, or any audio transform filter. This filter does not check the audio stream's subtype; the WAVEFORMAT or WAVEFORMATEX structure passed in the format block contains the information needed to connect to this filter.
The filter's property sheet contains the following:

Tab Property Values

Audio Input Pin (rendered) Preferred Media Types Lists the major type, subtype, and format.

Audio Renderer wFormatTag Waveform-audio format type. Many compression algorithms have registered format tags; the Mmreg.h header file contains a complete list of these format tags.

nChannels Number of channels in the waveform-audio data. Monaural data uses one channel and stereo data uses two channels.

nSamplePerSec Rate, in samples per second (hertz), at which each channel should play or record. If wFormatTag is WAVE_FORMAT_PCM, then common values for nSamplePerSec are 8.0 kHz, 11.025 kHz, 22.05 kHz, and 44.1 kHz. For non-PCM formats, you must compute this member according to the manufacturer's format specification.

nAvgBytesPerSec Required average data-transfer rate, in bytes per second, for the format tag. If wFormatTag is WAVE_FORMAT_PCM, then nAvgBytesPerSec should equal the product of nSamplesPerSec and nBlockAlign. For formats other than pulse code modulation (PCM), you must compute this member according to the manufacturer's format specification. Playback and record software can estimate buffer sizes by using the nAvgBytesPerSec member.

nBlockAlign Block alignment, in bytes. The block alignment is the smallest unit of data for the wFormatTag format type. If wFormatTag is WAVE_FORMAT_PCM, then nBlockAlign should equal nChannels. For non-PCM formats, this member must be computed according to the manufacturer's format specification.
Playback and record software must process a multiple of nBlockAlign bytes of data at a time. Data written and read from a device must always start at the beginning of a block. For example, it is illegal to start playback of PCM data in the middle of a sample (that is, on a non-block-aligned boundary).

Rate Specifies the rendering rate for this file. This value acts as a multiplier; 1.0 represents the authored speed. Read-only.

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Tab	Property	Values
Audio Input Pin (rendered)	Preferred Media Types	Lists the major type, subtype, and format.
Audio Renderer	wFormatTag	Waveform-audio format type. Many compression algorithms have registered format tags; the Mmreg.h header file contains a complete list of these format tags.
	nChannels	Number of channels in the waveform-audio data. Monaural data uses one channel and stereo data uses two channels.
	nSamplePerSec	Rate, in samples per second (hertz), at which each channel should play or record. If wFormatTag is WAVE_FORMAT_PCM, then common values for nSamplePerSec are 8.0 kHz, 11.025 kHz, 22.05 kHz, and 44.1 kHz. For non-PCM formats, you must compute this member according to the manufacturer's format specification.
	nAvgBytesPerSec	Required average data-transfer rate, in bytes per second, for the format tag. If wFormatTag is WAVE_FORMAT_PCM, then nAvgBytesPerSec should equal the product of nSamplesPerSec and nBlockAlign. For formats other than pulse code modulation (PCM), you must compute this member according to the manufacturer's format specification. Playback and record software can estimate buffer sizes by using the nAvgBytesPerSec member.
	nBlockAlign	Block alignment, in bytes. The block alignment is the smallest unit of data for the wFormatTag format type. If wFormatTag is WAVE_FORMAT_PCM, then nBlockAlign should equal nChannels. For non-PCM formats, this member must be computed according to the manufacturer's format specification. Playback and record software must process a multiple of nBlockAlign bytes of data at a time. Data written and read from a device must always start at the beginning of a block. For example, it is illegal to start playback of PCM data in the middle of a sample (that is, on a non-block-aligned boundary).
	Rate	Specifies the rendering rate for this file. This value acts as a multiplier; 1.0 represents the authored speed. Read-only.