82 lines
2.9 KiB
C
82 lines
2.9 KiB
C
/** \file
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Sample buffer that resamples from input clock rate to output sample rate */
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/* blip_buf $vers */
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#ifndef BLIP_BUF_H
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#define BLIP_BUF_H
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// MODIFIED by tildearrow:
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// - add option to disable high-pass filter
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#ifdef __cplusplus
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extern "C" {
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#endif
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/** First parameter of most functions is blip_t*, or const blip_t* if nothing
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is changed. */
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typedef struct blip_t blip_t;
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/** Creates new buffer that can hold at most sample_count samples. Sets rates
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so that there are blip_max_ratio clocks per sample. Returns pointer to new
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buffer, or NULL if insufficient memory. */
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blip_t* blip_new( int sample_count );
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/** (tildearrow) sets whether to enable high-pass filter. */
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void blip_set_dc( blip_t*, unsigned char enable );
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/** Sets approximate input clock rate and output sample rate. For every
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clock_rate input clocks, approximately sample_rate samples are generated. */
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void blip_set_rates( blip_t*, double clock_rate, double sample_rate );
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enum { /** Maximum clock_rate/sample_rate ratio. For a given sample_rate,
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clock_rate must not be greater than sample_rate*blip_max_ratio. */
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blip_max_ratio = 1 << 20 };
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/** Clears entire buffer. Afterwards, blip_samples_avail() == 0. */
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void blip_clear( blip_t* );
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/** (tildearrow) ability to change blip_add_delta at runtime */
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extern void (*blip_add_delta)( blip_t*, unsigned int, int );
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/** Adds positive/negative delta into buffer at specified clock time. */
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void blip_add_delta_slow( blip_t*, unsigned int clock_time, int delta );
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/** Same as blip_add_delta(), but uses faster, lower-quality synthesis. */
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void blip_add_delta_fast( blip_t*, unsigned int clock_time, int delta );
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/** Length of time frame, in clocks, needed to make sample_count additional
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samples available. */
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int blip_clocks_needed( const blip_t*, int sample_count );
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enum { /** Maximum number of samples that can be generated from one time frame. */
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blip_max_frame = 4000 };
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/** Makes input clocks before clock_duration available for reading as output
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samples. Also begins new time frame at clock_duration, so that clock time 0 in
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the new time frame specifies the same clock as clock_duration in the old time
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frame specified. Deltas can have been added slightly past clock_duration (up to
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however many clocks there are in two output samples). */
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void blip_end_frame( blip_t*, unsigned int clock_duration );
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/** Number of buffered samples available for reading. */
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int blip_samples_avail( const blip_t* );
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/** Reads and removes at most 'count' samples and writes them to 'out'. If
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'stereo' is true, writes output to every other element of 'out', allowing easy
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interleaving of two buffers into a stereo sample stream. Outputs 16-bit signed
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samples. Returns number of samples actually read. */
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int blip_read_samples( blip_t*, short out [], int count, int stereo );
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/** Frees buffer. No effect if NULL is passed. */
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void blip_delete( blip_t* );
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/* Deprecated */
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typedef blip_t blip_buffer_t;
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#ifdef __cplusplus
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}
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#endif
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#endif
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