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.
  
Number of input pins >= 1 (new pin will be added after connection of all  
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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).
 
free input pins).
  
Number of output pins >= 1 (new pin will be added after connection of all  
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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).
 
free output pins).
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Number of bits per mono audio sample for any input or output: from 8 to 32
  
 
Input/output media type:
 
Input/output media type:
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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.
  
Each input channel can be mixed with second channel of the same pin (for
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WAVEFORMATEX::wBitsPerSample: from 8 to 32. Can be different for different input/output pins.
stereo inputs) or with any channel of another input pin (or several input
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pins). Input channels can be switched on another output pin in play time  
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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).
 
also (without graph stop).
  
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* All input frequencies should be identical (resampling not implemented in current version).
 
* 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 (mono to stereo and vice versa).
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* After start of graph the media type of output pins cannot be changed.
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The filter has IMLAudioMixer interface and property page for set/get parameters of mixing (Input/channel -> Output/channel) and other parameters.
  
The filter will have a COM interface and property page for set/get parameters of mixing (Input/channel -> Output/channel).
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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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