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121 lines
3.8 KiB
121 lines
3.8 KiB
/**********************************************************************
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resample.h
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Real-time library interface by Dominic Mazzoni
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Based on resample-1.7:
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http://www-ccrma.stanford.edu/~jos/resample/
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License: LGPL - see the file LICENSE.txt for more information
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**********************************************************************/
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/*!
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* \file
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* \brief libresample API
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* \author Dominic Mazzoni
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*/
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#ifndef LIBRESAMPLE_INCLUDED
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#define LIBRESAMPLE_INCLUDED
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#ifdef __cplusplus
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extern "C" {
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#endif /* __cplusplus */
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/*!
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* \brief Create a resampler
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*
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* \arg highQuality Set this argument to non-zero to enable higher quality
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* resampling.
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* \arg minFactor This is the minimum resampling factor that will be used for
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* this resampler. The resampling factor is calculated in the following
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* way: ( from sample rate / to sample rate ).
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* \arg maxFactor This is the maximum resampling factor that will be used for
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* this resampler.
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*
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* Use this function to create a new resampler that will maintain state
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* information about the stream of audio being resampled.
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*
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* \return A handle to a new resampler
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*/
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void *resample_open(int highQuality,
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double minFactor,
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double maxFactor);
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/*!
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* \brief Duplicate a resampler
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*
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* \arg handle the resampler to duplicate
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*
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* \return A new handle to a resampler, initialized with the same parameters
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* used to create the original resampler.
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*/
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void *resample_dup(const void *handle);
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/*!
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* \brief Get filter width for resampler
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*
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* \arg handle the resampler
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*
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* \return the filter width.
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*/
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int resample_get_filter_width(const void *handle);
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/*!
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* \brief Resample a chunk of audio
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*
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* \arg handle the resampler
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* \arg factor the resampling factor. This factor should be calculated as
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* ( from sample rate / to sample rate ). So, for converting from 8 kHz
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* to 16 kHz, this value would be 2.0.
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* \arg inBuffer the input buffer for audio to resample.
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* \arg inBufferLen the number of samples in the input buffer
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* \arg lastFlag Set this argument to non-zero if the data in the input buffer
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* is known to be the end of a stream. This would be used if you're
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* resampling a file, for example.
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* \arg inBufferUsed This is an output parameter that indicates how many
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* samples were consumed from the input buffer. Generally, this function
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* is called in a loop until you know that the entire input buffer has
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* been consumed, as it may take multiple calls to complete.
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* \arg outBuffer This is the output buffer. This function will write the
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* resampled audio into this buffer.
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* \arg outBufferLen This parameter specifies how many samples there is room
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* for in the output buffer.
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*
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* This is the main function used for resampling audio. It should be called
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* in a loop until all of the data from the input buffer is consumed, or the
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* output buffer has been filled.
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*
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* \return the number of samples written to the output buffer. If the return
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* value is equal to the value provided in the outBufferLen parameter,
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* then the output buffer has been filled.
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*/
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int resample_process(void *handle,
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double factor,
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float *inBuffer,
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int inBufferLen,
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int lastFlag,
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int *inBufferUsed,
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float *outBuffer,
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int outBufferLen);
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/*!
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* \brief Close a resampler
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*
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* \arg handle the resampler to close
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*
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* Use this function to release a handle to a resampler that was created using
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* either resample_open() or resample_dup().
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*
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* \return nothing.
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*/
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void resample_close(void *handle);
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#ifdef __cplusplus
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} /* extern "C" */
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#endif /* __cplusplus */
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#endif /* LIBRESAMPLE_INCLUDED */
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