Audio Mixer: Technical Specs

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[[Audio Mixer]] DirectShow specs.
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==[[Audio Mixer]] DirectShow specs==
  
 
Audio mixer is a standard DirectShow filter.
 
Audio mixer is a standard DirectShow filter.
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Parameters of format:
 
Parameters of format:
  
WAVEFORMATEX::nSamplesPerSec and WAVEFORMATEX::wBitsPerSample: the same for all inputs/outputs.
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WAVEFORMATEX::nSamplesPerSec: the same for all inputs and outputs.
  
 
WAVEFORMATEX::nChannels from 1 to 32. Can be different for different input/output pins.
 
WAVEFORMATEX::nChannels from 1 to 32. Can be different for different input/output pins.
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WAVEFORMATEX::wBitsPerSample: from 8 to 32. Can be different for different input/output pins.
  
 
Any channel(s) of any input pin(s) can be mixed with any other channel(s) of same or other input pin(s). Mixing coefficients can be changed in play time  
 
Any channel(s) of any input pin(s) can be mixed with any other channel(s) of same or other input pin(s). Mixing coefficients can be changed in play time  
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Notes:
 
Notes:
  
* All input frequencies and bits per mono samples should be identical (resampling not implemented in current version).
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* All input frequencies should be identical (resampling not implemented in current version).
 
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* Only 8 or 16 bits per mono audio sample supported in current version
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* After start of graph the media type of output pins cannot be changed.
 
* After start of graph the media type of output pins cannot be changed.
  
 
The filter has IMLAudioMixer interface and property page for set/get parameters of mixing (Input/channel -> Output/channel) and other parameters.
 
The filter has IMLAudioMixer interface and property page for set/get parameters of mixing (Input/channel -> Output/channel) and other parameters.
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[[Category: Technical Specs]]
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__NOTOC__

Latest revision as of 00:16, 27 September 2018

Audio Mixer DirectShow specs

Audio mixer is a standard DirectShow filter.

Number of input pins = 2 for stereo and mono modes and from 1 to 64 for custom mode (new pin will be added after connection of all free input pins).

Number of output pins = 1 for stereo and mono modes and from 1 to 64 for custom mode (new pin will be added after connection of all free output pins).

Number of bits per mono audio sample for any input or output: from 8 to 32

Input/output media type:

 majortype:
   MEDIATYPE_Audio
 subtype:
   MEDIASUBTYPE_PCM
 formattype:
   FORMAT_WaveFormatEx
 cbFormat, pbFormat:
   WAVEFORMATEX struct (wFormatTag = WAVE_FORMAT_PCM) for nChannels = 1 or 2 only
   WAVEFORMATEXTENSIBLE struct (Format.wFormatTag = WAVE_FORMAT_EXTENSIBLE)

Parameters of format:

WAVEFORMATEX::nSamplesPerSec: the same for all inputs and outputs.

WAVEFORMATEX::nChannels from 1 to 32. Can be different for different input/output pins.

WAVEFORMATEX::wBitsPerSample: from 8 to 32. Can be different for different input/output pins.

Any channel(s) of any input pin(s) can be mixed with any other channel(s) of same or other input pin(s). Mixing coefficients can be changed in play time also (without graph stop).

Notes:

  • All input frequencies should be identical (resampling not implemented in current version).
  • After start of graph the media type of output pins cannot be changed.

The filter has IMLAudioMixer interface and property page for set/get parameters of mixing (Input/channel -> Output/channel) and other parameters.

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