ref: b906c98cd92b4661135e293fa270921fb389c246
dir: /src/pad.c/
/* libSoX effect: Pad With Silence (c) 2006 robs@users.sourceforge.net * * This library is free software; you can redistribute it and/or modify it * under the terms of the GNU Lesser General Public License as published by * the Free Software Foundation; either version 2.1 of the License, or (at * your option) any later version. * * This library is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser * General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with this library; if not, write to the Free Software Foundation, * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include "sox_i.h" typedef struct { unsigned npads; /* Number of pads requested */ struct { char * str; /* Command-line argument to parse for this pad */ size_t start; /* Start padding when in_pos equals this */ size_t pad; /* Number of samples to pad */ } * pads; size_t in_pos; /* Number of samples read from the input stream */ unsigned pads_pos; /* Number of pads completed so far */ size_t pad_pos; /* Number of samples through the current pad */ } priv_t; static int parse(sox_effect_t * effp, char * * argv, sox_rate_t rate) { priv_t * p = (priv_t *)effp->priv; char const * next; unsigned i; for (i = 0; i < p->npads; ++i) { if (argv) /* 1st parse only */ p->pads[i].str = lsx_strdup(argv[i]); next = lsx_parsesamples(rate, p->pads[i].str, &p->pads[i].pad, 't'); if (next == NULL) break; if (*next == '\0') p->pads[i].start = i? SOX_SIZE_MAX : 0; else { if (*next != '@') break; next = lsx_parsesamples(rate, next+1, &p->pads[i].start, 't'); if (next == NULL || *next != '\0') break; } if (i > 0 && p->pads[i].start <= p->pads[i-1].start) break; } if (i < p->npads) return lsx_usage(effp); return SOX_SUCCESS; } static int create(sox_effect_t * effp, int argc, char * * argv) { priv_t * p = (priv_t *)effp->priv; --argc, ++argv; p->pads = lsx_calloc(p->npads = argc, sizeof(*p->pads)); return parse(effp, argv, 1e5); /* No rate yet; parse with dummy */ } static int start(sox_effect_t * effp) { priv_t * p = (priv_t *)effp->priv; unsigned i; parse(effp, 0, effp->in_signal.rate); /* Re-parse now rate is known */ p->in_pos = p->pad_pos = p->pads_pos = 0; for (i = 0; i < p->npads; ++i) if (p->pads[i].pad) return SOX_SUCCESS; return SOX_EFF_NULL; } static int flow(sox_effect_t * effp, const sox_sample_t * ibuf, sox_sample_t * obuf, size_t * isamp, size_t * osamp) { priv_t * p = (priv_t *)effp->priv; size_t c, idone = 0, odone = 0; *isamp /= effp->in_signal.channels; *osamp /= effp->in_signal.channels; do { /* Copying: */ for (; idone < *isamp && odone < *osamp && !(p->pads_pos != p->npads && p->in_pos == p->pads[p->pads_pos].start); ++idone, ++odone, ++p->in_pos) for (c = 0; c < effp->in_signal.channels; ++c) *obuf++ = *ibuf++; /* Padding: */ if (p->pads_pos != p->npads && p->in_pos == p->pads[p->pads_pos].start) { for (; odone < *osamp && p->pad_pos < p->pads[p->pads_pos].pad; ++odone, ++p->pad_pos) for (c = 0; c < effp->in_signal.channels; ++c) *obuf++ = 0; if (p->pad_pos == p->pads[p->pads_pos].pad) { /* Move to next pad? */ ++p->pads_pos; p->pad_pos = 0; } } } while (idone < *isamp && odone < *osamp); *isamp = idone * effp->in_signal.channels; *osamp = odone * effp->in_signal.channels; return SOX_SUCCESS; } static int drain(sox_effect_t * effp, sox_sample_t * obuf, size_t * osamp) { priv_t * p = (priv_t *)effp->priv; static size_t isamp = 0; if (p->pads_pos != p->npads && p->in_pos != p->pads[p->pads_pos].start) p->in_pos = SOX_SIZE_MAX; /* Invoke the final pad (with no given start) */ return flow(effp, 0, obuf, &isamp, osamp); } static int stop(sox_effect_t * effp) { priv_t * p = (priv_t *)effp->priv; if (p->pads_pos != p->npads) lsx_warn("Input audio too short; pads not applied: %u", p->npads-p->pads_pos); return SOX_SUCCESS; } static int lsx_kill(sox_effect_t * effp) { priv_t * p = (priv_t *)effp->priv; unsigned i; for (i = 0; i < p->npads; ++i) free(p->pads[i].str); free(p->pads); return SOX_SUCCESS; } sox_effect_handler_t const * lsx_pad_effect_fn(void) { static sox_effect_handler_t handler = { "pad", "{length[@position]}", SOX_EFF_MCHAN|SOX_EFF_LENGTH|SOX_EFF_MODIFY, create, start, flow, drain, stop, lsx_kill, sizeof(priv_t) }; return &handler; }