Return to rate_template.h CVS log

Up to [Qemu by Fabrice Bellard] / qemu / audio

Annotation of qemu/audio/rate_template.h, revision 1.1.1.2

1.1       root        1: /*
                      2:  * QEMU Mixing engine
                      3:  *
                      4:  * Copyright (c) 2004-2005 Vassili Karpov (malc)
                      5:  * Copyright (c) 1998 Fabrice Bellard
                      6:  *
                      7:  * Permission is hereby granted, free of charge, to any person obtaining a copy
                      8:  * of this software and associated documentation files (the "Software"), to deal
                      9:  * in the Software without restriction, including without limitation the rights
                     10:  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
                     11:  * copies of the Software, and to permit persons to whom the Software is
                     12:  * furnished to do so, subject to the following conditions:
                     13:  *
                     14:  * The above copyright notice and this permission notice shall be included in
                     15:  * all copies or substantial portions of the Software.
                     16:  *
                     17:  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
                     18:  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
                     19:  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
                     20:  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
                     21:  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
                     22:  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
                     23:  * THE SOFTWARE.
                     24:  */
                     25: 
                     26: /*
                     27:  * Processed signed long samples from ibuf to obuf.
                     28:  * Return number of samples processed.
                     29:  */
                     30: void NAME (void *opaque, st_sample_t *ibuf, st_sample_t *obuf,
                     31:            int *isamp, int *osamp)
                     32: {
                     33:     struct rate *rate = opaque;
                     34:     st_sample_t *istart, *iend;
                     35:     st_sample_t *ostart, *oend;
                     36:     st_sample_t ilast, icur, out;
                     37: #ifdef FLOAT_MIXENG
                     38:     real_t t;
                     39: #else
                     40:     int64_t t;
                     41: #endif
                     42: 
                     43:     ilast = rate->ilast;
                     44: 
                     45:     istart = ibuf;
                     46:     iend = ibuf + *isamp;
                     47: 
                     48:     ostart = obuf;
                     49:     oend = obuf + *osamp;
                     50: 
                     51:     if (rate->opos_inc == (1ULL + UINT_MAX)) {
                     52:         int i, n = *isamp > *osamp ? *osamp : *isamp;
                     53:         for (i = 0; i < n; i++) {
1.1.1.2 ! root       54:             OP (obuf[i].l, ibuf[i].l);
1.1       root       55:             OP (obuf[i].r, ibuf[i].r);
                     56:         }
                     57:         *isamp = n;
                     58:         *osamp = n;
                     59:         return;
                     60:     }
                     61: 
                     62:     while (obuf < oend) {
                     63: 
                     64:         /* Safety catch to make sure we have input samples.  */
                     65:         if (ibuf >= iend) {
                     66:             break;
                     67:         }
                     68: 
                     69:         /* read as many input samples so that ipos > opos */
                     70: 
                     71:         while (rate->ipos <= (rate->opos >> 32)) {
                     72:             ilast = *ibuf++;
                     73:             rate->ipos++;
                     74:             /* See if we finished the input buffer yet */
                     75:             if (ibuf >= iend) {
                     76:                 goto the_end;
                     77:             }
                     78:         }
                     79: 
                     80:         icur = *ibuf;
                     81: 
                     82:         /* interpolate */
                     83: #ifdef FLOAT_MIXENG
                     84: #ifdef RECIPROCAL
                     85:         t = (rate->opos & UINT_MAX) * (1.f / UINT_MAX);
                     86: #else
                     87:         t = (rate->opos & UINT_MAX) / (real_t) UINT_MAX;
                     88: #endif
                     89:         out.l = (ilast.l * (1.0 - t)) + icur.l * t;
                     90:         out.r = (ilast.r * (1.0 - t)) + icur.r * t;
                     91: #else
                     92:         t = rate->opos & 0xffffffff;
                     93:         out.l = (ilast.l * ((int64_t) UINT_MAX - t) + icur.l * t) >> 32;
                     94:         out.r = (ilast.r * ((int64_t) UINT_MAX - t) + icur.r * t) >> 32;
                     95: #endif
                     96: 
                     97:         /* output sample & increment position */
                     98:         OP (obuf->l, out.l);
                     99:         OP (obuf->r, out.r);
                    100:         obuf += 1;
                    101:         rate->opos += rate->opos_inc;
                    102:     }
                    103: 
                    104: the_end:
                    105:     *isamp = ibuf - istart;
                    106:     *osamp = obuf - ostart;
                    107:     rate->ilast = ilast;
                    108: }
                    109: 
                    110: #undef NAME
                    111: #undef OP

This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.