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