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 * $FreeBSD: src/sys/dev/sound/pcm/feeder_volume.c,v 1.2.2.1 2005/12/30 19:55:54 netchild Exp $ 27 * 28 * feeder_volume, a long 'Lost Technology' rather than a new feature. 29 */ 30 31 #include <dev/sound/pcm/sound.h> 32 #include "feeder_if.h" 33 34 SND_DECLARE_FILE("$DragonFly: src/sys/dev/sound/pcm/feeder_volume.c,v 1.1 2007/01/04 21:47:03 corecode Exp $"); 35 36 static int 37 feed_volume_s16(struct pcm_feeder *f, struct pcm_channel *c, uint8_t *b, 38 uint32_t count, void *source) 39 { 40 int i, j, k, vol[2]; 41 int16_t *buf; 42 43 k = FEEDER_FEED(f->source, c, b, count & ~1, source); 44 if (k < 2) { 45 #if 0 46 device_printf(c->dev, "%s: Not enough data (Got: %d bytes)\n", 47 __func__, k); 48 #endif 49 return 0; 50 } 51 #if 0 52 if (k & 1) 53 device_printf(c->dev, "%s: Bytes not 16bit aligned.\n", __func__); 54 #endif 55 k &= ~1; 56 i = k >> 1; 57 buf = (int16_t *)b; 58 vol[0] = c->volume & 0x7f; 59 vol[1] = (c->volume >> 8) & 0x7f; 60 while (i > 0) { 61 i--; 62 j = (vol[i & 1] * buf[i]) / 100; 63 if (j > 32767) 64 j = 32767; 65 if (j < -32768) 66 j = -32768; 67 buf[i] = j; 68 } 69 return k; 70 } 71 72 static struct pcm_feederdesc feeder_volume_s16_desc[] = { 73 {FEEDER_VOLUME, AFMT_S16_LE|AFMT_STEREO, AFMT_S16_LE|AFMT_STEREO, 0}, 74 {0, 0, 0, 0}, 75 }; 76 static kobj_method_t feeder_volume_s16_methods[] = { 77 KOBJMETHOD(feeder_feed, feed_volume_s16), 78 KOBJMETHOD_END 79 }; 80 FEEDER_DECLARE(feeder_volume_s16, 2, NULL); 81