diff options
Diffstat (limited to 'tran/alpass.c')
| -rw-r--r-- | tran/alpass.c | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/tran/alpass.c b/tran/alpass.c new file mode 100644 index 0000000..cad43ef --- /dev/null +++ b/tran/alpass.c @@ -0,0 +1,193 @@ +#include "stdio.h" +#ifndef mips +#include "stdlib.h" +#endif +#include "xlisp.h" +#include "sound.h" + +#include "falloc.h" +#include "cext.h" +#include "alpass.h" + +void alpass_free(); + + +typedef struct alpass_susp_struct { + snd_susp_node susp; + long terminate_cnt; + sound_type input; + long input_cnt; + sample_block_values_type input_ptr; + + double feedback; + long delaylen; + sample_type *delaybuf; + sample_type *delayptr; + sample_type *endptr; +} alpass_susp_node, *alpass_susp_type; + + +void alpass_n_fetch(register alpass_susp_type susp, snd_list_type snd_list) +{ + 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 double feedback_reg; + register sample_type * delayptr_reg; + register sample_type * endptr_reg; + register sample_block_values_type input_ptr_reg; + falloc_sample_block(out, "alpass_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 input input sample block: */ + susp_check_term_samples(input, input_ptr, input_cnt); + togo = min(togo, susp->input_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; + } + + n = togo; + feedback_reg = susp->feedback; + delayptr_reg = susp->delayptr; + endptr_reg = susp->endptr; + input_ptr_reg = susp->input_ptr; + out_ptr_reg = out_ptr; + if (n) do { /* the inner sample computation loop */ +register sample_type y, z; + y = *delayptr_reg; + *delayptr_reg++ = z = (sample_type) (feedback_reg * y + *input_ptr_reg++); + *out_ptr_reg++ = (sample_type) (y - feedback_reg * z); + if (delayptr_reg >= endptr_reg) delayptr_reg = susp->delaybuf;; + } while (--n); /* inner loop */ + + susp->delayptr = delayptr_reg; + /* using input_ptr_reg is a bad idea on RS/6000: */ + susp->input_ptr += togo; + out_ptr += togo; + susp_took(input_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; + } +} /* alpass_n_fetch */ + + +void alpass_toss_fetch(susp, snd_list) + register alpass_susp_type susp; + snd_list_type snd_list; +{ + long final_count = susp->susp.toss_cnt; + time_type final_time = susp->susp.t0; + long n; + + /* fetch samples from input up to final_time for this block of zeros */ + while ((round((final_time - susp->input->t0) * susp->input->sr)) >= + susp->input->current) + susp_get_samples(input, input_ptr, input_cnt); + /* convert to normal processing when we hit final_count */ + /* we want each signal positioned at final_time */ + n = round((final_time - susp->input->t0) * susp->input->sr - + (susp->input->current - susp->input_cnt)); + susp->input_ptr += n; + susp_took(input_cnt, n); + susp->susp.fetch = susp->susp.keep_fetch; + (*(susp->susp.fetch))(susp, snd_list); +} + + +void alpass_mark(alpass_susp_type susp) +{ + sound_xlmark(susp->input); +} + + +void alpass_free(alpass_susp_type susp) +{ +free(susp->delaybuf); sound_unref(susp->input); + ffree_generic(susp, sizeof(alpass_susp_node), "alpass_free"); +} + + +void alpass_print_tree(alpass_susp_type susp, int n) +{ + indent(n); + stdputstr("input:"); + sound_print_tree_1(susp->input, n); +} + + +sound_type snd_make_alpass(sound_type input, time_type delay, double feedback) +{ + register alpass_susp_type susp; + rate_type sr = input->sr; + time_type t0 = input->t0; + int interp_desc = 0; + sample_type scale_factor = 1.0F; + time_type t0_min = t0; + /* combine scale factors of linear inputs (INPUT) */ + scale_factor *= input->scale; + input->scale = 1.0F; + + /* try to push scale_factor back to a low sr input */ + if (input->sr < sr) { input->scale = scale_factor; scale_factor = 1.0F; } + + falloc_generic(susp, alpass_susp_node, "snd_make_alpass"); + susp->feedback = feedback; + susp->delaylen = max(1, round(input->sr * delay)); + susp->delaybuf = (sample_type *) calloc (susp->delaylen, sizeof(sample_type)); + susp->delayptr = susp->delaybuf; + susp->endptr = susp->delaybuf + susp->delaylen; + susp->susp.fetch = alpass_n_fetch; + susp->terminate_cnt = UNKNOWN; + /* handle unequal start times, if any */ + if (t0 < input->t0) sound_prepend_zeros(input, t0); + /* minimum start time over all inputs: */ + t0_min = min(input->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 = alpass_toss_fetch; + } + + /* initialize susp state */ + susp->susp.free = alpass_free; + susp->susp.sr = sr; + susp->susp.t0 = t0; + susp->susp.mark = alpass_mark; + susp->susp.print_tree = alpass_print_tree; + susp->susp.name = "alpass"; + susp->susp.log_stop_cnt = UNKNOWN; + susp->susp.current = 0; + susp->input = input; + susp->input_cnt = 0; + return sound_create((snd_susp_type)susp, t0, sr, scale_factor); +} + + +sound_type snd_alpass(sound_type input, time_type delay, double feedback) +{ + sound_type input_copy = sound_copy(input); + return snd_make_alpass(input_copy, delay, feedback); +} |