This conformant component accepts raw PCM audio samples, and can
encode them using a number of formats to produce compressed audio
frames. This component will buffer a small number of PCM samples to
allow re-packetisation depending on the frame size of the encoded
format. It also buffers encoded frames to allow for latency in the
multiplexer file writing.
| Port | Index | Notes
|
| 160 | OMX_IndexParamPortDefinition
| Query / set the port parameter. Must be set to PCM audio.
|
| OMX_IndexParamAudioPcm
| Query / set the port PCM format for the input port.
nChannels must be 1, 2, 4, or 8. 5.1 audio can be carried
inside 8 channels, with the last two channels advertise as blank.
nBitPerSample must be 16 or 32.
eNumData must be OMX_NumericalDataSigned.
eEndian must be OMX_EndianLittle.
bInterleaved must be OMX_TRUE.
ePCMMode must be OMX_AUDIO_PCMModeLinear.
|
| 161 | OMX_IndexParamPortDefinition
| Query / set the port parameter. The encoder to be used is specified by
setting the format.audio.eEncoding field. When encoding
starts, if the maximum size of encoded frame is larger than the
nBufferSize value then the nBufferSize is increased to
this value and an OMX_EventPortSettingsChanged event is
signalled.
|
| OMX_IndexParamAudioMp3
| Query / set the MP3 parameters for the encoded bitstream. Only the
nBitRate and nChannels (must be 1 or 2) fields are
considered; other parameters are copied through from the PCM input
port.
|
| OMX_IndexParamAudioAac
| Query / set the AAC parameters for the encoded bitstream. The fields
nBitRate, eAACStreamFormat, nSampleRate and
nChannels (must be 1 or 2) are respected; other parameters
are copied through from the PCM input port. Stream formats supported
are the default value of MP2ADTS, and RAW.
|
| OMX_IndexParamAudioAmr
| Query / set the AMR parameters for the encoded bitstream.
The field nChannels must be 1 (mono).
|
| OMX_IndexParamCodecConfig
| Query for codec-specific information.
|
| OMX_IndexParamBrcmDataUnit
| Query the type of data delivery for the encoded data. This port emits
OMX_DataUnitCodedPicture format data.
|
| 160 161 | OMX_IndexParamAudioPortFormat
| Query / set the audio port format used on this port. The input port
supports PCM only, the output port supports a number of encoded audio
formats.
|
| OMX_IndexParamILFifoConfig
| Set the internal fifo size for both input and output ports. The input
port fifo is used to buffer enough PCM audio samples for the encoder
to consume a whole frame. The output fifo needs to buffer enough
encoded frames to cope with variations of writing speed through the
filesystem. Both input and output fifos will default to a sensible
size if this index is not set, the primary use for this index is in
testing.
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