1 /*- 2 * Copyright (c) 2005 Ariff Abdullah <ariff@FreeBSD.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * feeder_volume, a long 'Lost Technology' rather than a new feature. 27 */ 28 29 #include <dev/sound/pcm/sound.h> 30 #include "feeder_if.h" 31 32 SND_DECLARE_FILE("$FreeBSD$"); 33 34 static int 35 feed_volume_s16(struct pcm_feeder *f, struct pcm_channel *c, uint8_t *b, 36 uint32_t count, void *source) 37 { 38 int i, j, k, vol[2]; 39 int16_t *buf; 40 41 k = FEEDER_FEED(f->source, c, b, count & ~1, source); 42 if (k < 2) { 43 #if 0 44 device_printf(c->dev, "%s: Not enough data (Got: %d bytes)\n", 45 __func__, k); 46 #endif 47 return 0; 48 } 49 #if 0 50 if (k & 1) 51 device_printf(c->dev, "%s: Bytes not 16bit aligned.\n", __func__); 52 #endif 53 k &= ~1; 54 i = k >> 1; 55 buf = (int16_t *)b; 56 vol[0] = c->volume & 0x7f; 57 vol[1] = (c->volume >> 8) & 0x7f; 58 while (i > 0) { 59 i--; 60 j = (vol[i & 1] * buf[i]) / 100; 61 if (j > 32767) 62 j = 32767; 63 if (j < -32768) 64 j = -32768; 65 buf[i] = j; 66 } 67 return k; 68 } 69 70 static struct pcm_feederdesc feeder_volume_s16_desc[] = { 71 {FEEDER_VOLUME, AFMT_S16_LE|AFMT_STEREO, AFMT_S16_LE|AFMT_STEREO, 0}, 72 {0, 0, 0, 0}, 73 }; 74 static kobj_method_t feeder_volume_s16_methods[] = { 75 KOBJMETHOD(feeder_feed, feed_volume_s16), 76 {0, 0} 77 }; 78 FEEDER_DECLARE(feeder_volume_s16, 2, NULL); 79