mirror of
https://github.com/cookiengineer/audacity
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405 lines
12 KiB
C
405 lines
12 KiB
C
/* downsample.c -- linear interpolation to a lower sample rate */
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/* CHANGE LOG
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* --------------------------------------------------------------------
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* 28Apr03 dm changes for portability and fix compiler warnings
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*/
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#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 "downsample.h"
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void down_free();
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typedef struct down_susp_struct {
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snd_susp_node susp;
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boolean started;
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long terminate_cnt;
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boolean logically_stopped;
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sound_type s;
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long s_cnt;
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sample_block_values_type s_ptr;
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/* support for interpolation of s */
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sample_type s_x1_sample;
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double s_pHaSe;
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double s_pHaSe_iNcR;
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/* support for ramp between samples of s */
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double output_per_s;
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long s_n;
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} down_susp_node, *down_susp_type;
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void down_n_fetch(susp, snd_list)
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register down_susp_type susp;
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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 = 0;
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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 sample_block_values_type s_ptr_reg;
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falloc_sample_block(out, "down_n_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 the s input sample block: */
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susp_check_term_log_samples(s, s_ptr, s_cnt);
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togo = MIN(togo, susp->s_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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/* don't run past logical stop time */
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if (!susp->logically_stopped && susp->susp.log_stop_cnt != UNKNOWN) {
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int to_stop = susp->susp.log_stop_cnt - (susp->susp.current + cnt);
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if (to_stop < togo && ((togo = to_stop) == 0)) break;
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}
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n = togo;
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s_ptr_reg = susp->s_ptr;
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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++ = *s_ptr_reg++;
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} while (--n); /* inner loop */
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/* using s_ptr_reg is a bad idea on RS/6000: */
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susp->s_ptr += togo;
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out_ptr += togo;
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susp_took(s_cnt, 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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/* test for logical stop */
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if (susp->logically_stopped) {
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snd_list->logically_stopped = true;
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} else if (susp->susp.log_stop_cnt == susp->susp.current) {
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susp->logically_stopped = true;
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}
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} /* down_n_fetch */
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void down_s_fetch(susp, snd_list)
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register down_susp_type susp;
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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 = 0;
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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 sample_type s_scale_reg = susp->s->scale;
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register sample_block_values_type s_ptr_reg;
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falloc_sample_block(out, "down_s_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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/* don't run past logical stop time */
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if (!susp->logically_stopped && susp->susp.log_stop_cnt != UNKNOWN) {
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int to_stop = susp->susp.log_stop_cnt - (susp->susp.current + cnt);
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if (to_stop < togo && ((togo = to_stop) == 0)) break;
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}
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n = togo;
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s_ptr_reg = susp->s_ptr;
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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++ = (s_scale_reg * *s_ptr_reg++);
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} while (--n); /* inner loop */
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susp->s_ptr = s_ptr_reg;
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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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/* test for logical stop */
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if (susp->logically_stopped) {
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snd_list->logically_stopped = true;
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} else if (susp->susp.log_stop_cnt == susp->susp.current) {
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susp->logically_stopped = true;
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}
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} /* down_s_fetch */
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void down_i_fetch(susp, snd_list)
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register down_susp_type susp;
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snd_list_type snd_list;
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{
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int cnt = 0; /* how many samples computed */
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sample_type s_x2_sample;
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int togo = 0;
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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 sample_type s_pHaSe_iNcR_rEg = (sample_type) susp->s_pHaSe_iNcR;
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register double s_pHaSe_ReG;
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register sample_type s_x1_sample_reg;
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falloc_sample_block(out, "down_i_fetch");
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out_ptr = out->samples;
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snd_list->block = out;
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/* make sure sounds are primed with first values */
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if (!susp->started) {
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susp->started = true;
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susp_check_term_log_samples(s, s_ptr, s_cnt);
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susp->s_x1_sample = susp_fetch_sample(s, s_ptr, s_cnt);
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}
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susp_check_term_log_samples(s, s_ptr, s_cnt);
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s_x2_sample = susp_current_sample(s, s_ptr);
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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) {
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togo = 0;
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break;
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}
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}
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/* don't run past logical stop time */
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if (!susp->logically_stopped && susp->susp.log_stop_cnt != UNKNOWN) {
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int to_stop = susp->susp.log_stop_cnt - (susp->susp.current + cnt);
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if (to_stop < togo && ((togo = to_stop) <= 0)) {
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togo = 0;
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break;
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}
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}
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n = togo;
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s_pHaSe_ReG = susp->s_pHaSe;
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s_x1_sample_reg = susp->s_x1_sample;
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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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while (s_pHaSe_ReG >= 1.0) {
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s_x1_sample_reg = s_x2_sample;
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/* pick up next sample as s_x2_sample: */
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susp->s_ptr++;
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susp_took(s_cnt, 1);
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s_pHaSe_ReG -= 1.0;
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/* derived from susp_check_term_log_samples_break, but with
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a goto instead of a break */
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if (susp->s_cnt == 0) {
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susp_get_samples(s, s_ptr, s_cnt);
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terminate_test(s_ptr, s, susp->s_cnt);
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/* see if newly discovered logical stop time: */
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logical_stop_test(s, susp->s_cnt);
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if ((susp->terminate_cnt != UNKNOWN &&
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susp->terminate_cnt <
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susp->susp.current + cnt + togo) ||
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(!susp->logically_stopped &&
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susp->susp.log_stop_cnt != UNKNOWN &&
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susp->susp.log_stop_cnt <
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susp->susp.current + cnt + togo)) {
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goto breakout;
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}
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}
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s_x2_sample = susp_current_sample(s, s_ptr);
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}
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*out_ptr_reg++ = (sample_type)
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(s_x1_sample_reg * (1 - s_pHaSe_ReG) +
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s_x2_sample * s_pHaSe_ReG);
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s_pHaSe_ReG += s_pHaSe_iNcR_rEg;
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} while (--n); /* inner loop */
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breakout:
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togo -= n;
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susp->s_pHaSe = s_pHaSe_ReG;
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susp->s_x1_sample = s_x1_sample_reg;
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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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/* test for logical stop */
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if (susp->logically_stopped) {
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snd_list->logically_stopped = true;
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} else if (susp->susp.log_stop_cnt == susp->susp.current) {
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susp->logically_stopped = true;
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}
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} /* down_i_fetch */
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void down_toss_fetch(snd_list)
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snd_list_type snd_list;
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{
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register down_susp_type susp = (down_susp_type) snd_list->u.susp;
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long final_count = MIN(susp->susp.current + max_sample_block_len,
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susp->susp.toss_cnt);
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time_type final_time = susp->susp.t0 + final_count / susp->susp.sr;
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long n;
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/* fetch samples from s up to final_time for this block of zeros */
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while (((long) ((final_time - susp->s->t0) * susp->s->sr + 0.5)) >=
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susp->s->current)
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susp_get_samples(s, s_ptr, s_cnt);
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/* convert to normal processing when we hit final_count */
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/* we want each signal positioned at final_time */
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if (final_count == susp->susp.toss_cnt) {
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n = ROUND((final_time - susp->s->t0) * susp->s->sr -
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(susp->s->current - susp->s_cnt));
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susp->s_ptr += n;
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susp_took(s_cnt, n);
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susp->susp.fetch = susp->susp.keep_fetch;
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}
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snd_list->block_len = (short) (final_count - susp->susp.current);
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susp->susp.current = final_count;
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snd_list->u.next = snd_list_create((snd_susp_type) susp);
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snd_list->block = internal_zero_block;
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}
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void down_mark(down_susp_type susp)
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{
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sound_xlmark(susp->s);
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}
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void down_free(down_susp_type susp)
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{
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sound_unref(susp->s);
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ffree_generic(susp, sizeof(down_susp_node), "down_free");
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}
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void down_print_tree(down_susp_type susp, int n)
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{
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indent(n);
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stdputstr("s:");
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sound_print_tree_1(susp->s, n);
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}
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sound_type snd_make_down(sr, s)
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rate_type sr;
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sound_type s;
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{
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register down_susp_type susp;
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/* sr specified as input parameter */
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time_type t0 = s->t0;
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sample_type scale_factor = 1.0F;
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time_type t0_min = t0;
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if (s->sr < sr) {
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sound_unref(s);
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xlfail("snd-down: output sample rate must be lower than input");
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}
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falloc_generic(susp, down_susp_node, "snd_make_down");
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/* select a susp fn based on sample rates */
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if (s->sr == sr) {
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susp->susp.fetch = ((s->scale == 1.0) ?
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down_n_fetch : down_s_fetch);
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} else {
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susp->susp.fetch = down_i_fetch;
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}
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susp->terminate_cnt = UNKNOWN;
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/* handle unequal start times, if any */
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if (t0 < s->t0) sound_prepend_zeros(s, t0);
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/* minimum start time over all inputs: */
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t0_min = MIN(s->t0, t0);
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/* how many samples to toss before t0: */
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susp->susp.toss_cnt = ROUND((t0 - t0_min) * sr);
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if (susp->susp.toss_cnt > 0) {
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susp->susp.keep_fetch = susp->susp.fetch;
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susp->susp.fetch = down_toss_fetch;
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t0 = t0_min;
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}
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/* initialize susp state */
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susp->susp.free = down_free;
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susp->susp.sr = sr;
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susp->susp.t0 = t0;
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susp->susp.mark = down_mark;
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susp->susp.print_tree = down_print_tree;
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susp->susp.name = "down";
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susp->logically_stopped = false;
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susp->susp.log_stop_cnt = logical_stop_cnt_cvt(s);
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susp->started = false;
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susp->susp.current = 0;
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susp->s = s;
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susp->s_cnt = 0;
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susp->s_pHaSe = 0.0;
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susp->s_pHaSe_iNcR = s->sr / sr;
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susp->s_n = 0;
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susp->output_per_s = sr / s->sr;
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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_down(sr, s)
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rate_type sr;
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sound_type s;
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{
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sound_type s_copy = sound_copy(s);
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return snd_make_down(sr, s_copy);
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}
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