audio_capture

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Custom Index Metadata
| # OMX.broadcom.audio_capture
181
| audio_capture |
180
This component interacts with platform-specific audio input devices to emit raw PCM samples. It can provide a media reference time to a clock component if connected. If used in this mode, the component will not output data when the clock is stopped, and will send media time updates to the clock by default. Time stamps will only reset once the component is transitioned to loaded. If the audio output port is executing with the capturing enabled when a connected clock is transitioned to stop, the component will stop recording data and transmit its next packet with no data but with the EOS flag set.
Port | Index | Notes
180 | `OMX_IndexParamPortDefinition` | Query / set the port parameters for the audio output stream. The audio format must not be encoded. `nBufferSize` must be a multiple of 4 and equal to or larger than 32 (the maximum buffer size is limited by the platform-specific audio input device, but may be 16384). `nBufferAlignment` must be equal to or larger than 32.
`OMX_IndexParamAudioPcm` | Query / set the PCM format used. `nChannels` will be 2. `eNumData` will be `OMX_NumericalDataSigned`. `eEndian` will be `OMX_EndianLittle`. `bInterleaved` will be `OMX_TRUE`. `nBitPerSample` will be 16. `ePCMMode` will be `OMX_AUDIO_PCMModeLinear`. `nSamplingRate` can be set and defaults to 32000.
`OMX_IndexConfigBrcmAudioSource` | Query / set the audio platform-specific source for audio input. Currently only supported when the component is not capturing audio.
`OMX_IndexConfigAudioVolume` | Query / set the volume to be applying using a software scaling after the audio samples have been initially read.
`OMX_IndexConfigAudioMute` | Query / set whether the audio is muted.
`OMX_IndexParamAudioPortFormat` | Query / set the audio port format used on this port. The port supports PCM only.
182 | `OMX_IndexParamPortDefinition` | Query / set the port parameter to support connecting to a clock component output port.
`OMX_IndexParamOtherPortFormat` | Query / set the other port format used on this port. The port supports time format only.
| `OMX_IndexConfigCapturing` | Query / set whether we are actively capturing audio data, subject to the restrictions given about when connected to a clock component. N.B. Port 181 is used for audio events. It is defined as an audio port (so that MMAL does not misclassify it as a clock port) although it is really just a generic data port used to send data of type AUDIOPLUS_EVENT_T.