79 lines
2.5 KiB
C
79 lines
2.5 KiB
C
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/*-
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* Copyright (c) 2005 Ariff Abdullah
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* <skywizard@MyBSD.org.my> All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* feeder_volume, a long 'Lost Technology' rather than a new feature.
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*/
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#include <dev/sound/pcm/sound.h>
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#include "feeder_if.h"
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SND_DECLARE_FILE("$FreeBSD$");
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static int
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feed_volume_s16(struct pcm_feeder *f, struct pcm_channel *c, uint8_t *b,
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uint32_t count, void *source)
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{
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int i, j, k, vol[2];
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int16_t *buf;
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k = FEEDER_FEED(f->source, c, b, count & ~1, source);
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if (k < 2) {
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#if 0
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device_printf(c->dev, "%s: Not enough data (Got: %d bytes)\n",
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__func__, k);
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#endif
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return 0;
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}
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#if 0
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if (k & 1)
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device_printf(c->dev, "%s: Bytes not 16bit aligned.\n", __func__);
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#endif
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k &= ~1;
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i = k >> 1;
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buf = (int16_t *)b;
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vol[0] = c->volume & 0x7f;
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vol[1] = (c->volume >> 8) & 0x7f;
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while (i > 0) {
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i--;
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j = (vol[i & 1] * buf[i]) / 100;
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if (j > 32767)
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j = 32767;
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if (j < -32768)
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j = -32768;
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buf[i] = j;
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}
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return k;
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}
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static struct pcm_feederdesc feeder_volume_s16_desc[] = {
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{FEEDER_VOLUME, AFMT_S16_LE|AFMT_STEREO, AFMT_S16_LE|AFMT_STEREO, 0},
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{0, 0, 0, 0},
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};
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static kobj_method_t feeder_volume_s16_methods[] = {
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KOBJMETHOD(feeder_feed, feed_volume_s16),
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{0, 0}
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};
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FEEDER_DECLARE(feeder_volume_s16, 2, NULL);
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