mirror of
https://github.com/cookiengineer/audacity
synced 2025-05-05 14:18:53 +02:00
127 lines
3.1 KiB
C
127 lines
3.1 KiB
C
#include "stdio.h"
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#ifndef mips
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#include "stdlib.h"
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#endif
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#include "xlisp.h"
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#include "sound.h"
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#include "falloc.h"
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#include "cext.h"
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#include "sine.h"
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void sine_free();
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typedef struct sine_susp_struct {
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snd_susp_node susp;
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long terminate_cnt;
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long phase;
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long ph_incr;
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} sine_susp_node, *sine_susp_type;
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sample_type sine_table[SINE_TABLE_LEN + 1];
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void sine_init()
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{
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int i;
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for (i = 0; i <= SINE_TABLE_LEN; i++)
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sine_table[i] = (sample_type) (sin((PI * 2 * i) / SINE_TABLE_LEN));
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}
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void sine__fetch(register sine_susp_type susp, snd_list_type snd_list)
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{
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int cnt = 0; /* how many samples computed */
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int togo;
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int n;
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sample_block_type out;
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register sample_block_values_type out_ptr;
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register sample_block_values_type out_ptr_reg;
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register long phase_reg;
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register long ph_incr_reg;
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falloc_sample_block(out, "sine__fetch");
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out_ptr = out->samples;
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snd_list->block = out;
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while (cnt < max_sample_block_len) { /* outer loop */
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/* first compute how many samples to generate in inner loop: */
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/* don't overflow the output sample block: */
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togo = max_sample_block_len - cnt;
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/* don't run past terminate time */
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if (susp->terminate_cnt != UNKNOWN &&
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susp->terminate_cnt <= susp->susp.current + cnt + togo) {
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togo = susp->terminate_cnt - (susp->susp.current + cnt);
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if (togo == 0) break;
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}
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n = togo;
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phase_reg = susp->phase;
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ph_incr_reg = susp->ph_incr;
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out_ptr_reg = out_ptr;
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if (n) do { /* the inner sample computation loop */
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*out_ptr_reg++ = sine_table[phase_reg >> SINE_TABLE_SHIFT];
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phase_reg += ph_incr_reg;
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phase_reg &= SINE_TABLE_MASK;;
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} while (--n); /* inner loop */
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susp->phase = (susp->phase + susp->ph_incr * togo) & SINE_TABLE_MASK;
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out_ptr += togo;
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cnt += togo;
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} /* outer loop */
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/* test for termination */
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if (togo == 0 && cnt == 0) {
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snd_list_terminate(snd_list);
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} else {
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snd_list->block_len = cnt;
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susp->susp.current += cnt;
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}
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} /* sine__fetch */
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void sine_free(sine_susp_type susp)
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{
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ffree_generic(susp, sizeof(sine_susp_node), "sine_free");
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}
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void sine_print_tree(sine_susp_type susp, int n)
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{
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}
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sound_type snd_make_sine(time_type t0, double hz, rate_type sr, time_type d)
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{
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register sine_susp_type susp;
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/* sr specified as input parameter */
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/* t0 specified as input parameter */
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sample_type scale_factor = 1.0F;
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falloc_generic(susp, sine_susp_node, "snd_make_sine");
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susp->phase = 0;
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susp->ph_incr = round(((hz * SINE_TABLE_LEN) * (1 << SINE_TABLE_SHIFT) / sr));
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susp->susp.fetch = sine__fetch;
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susp->terminate_cnt = round((d) * sr);
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/* initialize susp state */
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susp->susp.free = sine_free;
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susp->susp.sr = sr;
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susp->susp.t0 = t0;
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susp->susp.mark = NULL;
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susp->susp.print_tree = sine_print_tree;
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susp->susp.name = "sine";
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susp->susp.log_stop_cnt = UNKNOWN;
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susp->susp.current = 0;
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return sound_create((snd_susp_type)susp, t0, sr, scale_factor);
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}
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sound_type snd_sine(time_type t0, double hz, rate_type sr, time_type d)
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{
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return snd_make_sine(t0, hz, sr, d);
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}
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