119 lines
3.0 KiB
C
119 lines
3.0 KiB
C
/*
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* Copyright (C) 2003-2009 The Music Player Daemon Project
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* http://www.musicpd.org
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include "pcm_mix.h"
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#include "pcm_volume.h"
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#include "pcm_utils.h"
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#include "audio_format.h"
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#include <glib.h>
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#include <math.h>
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#undef G_LOG_DOMAIN
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#define G_LOG_DOMAIN "pcm"
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static void
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pcm_add_8(int8_t *buffer1, const int8_t *buffer2,
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unsigned num_samples, int volume1, int volume2)
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{
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while (num_samples > 0) {
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int32_t sample1 = *buffer1;
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int32_t sample2 = *buffer2++;
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sample1 = ((sample1 * volume1 + sample2 * volume2) +
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pcm_dither() + PCM_VOLUME_1 / 2) / PCM_VOLUME_1;
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*buffer1++ = pcm_range(sample1, 8);
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--num_samples;
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}
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}
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static void
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pcm_add_16(int16_t *buffer1, const int16_t *buffer2,
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unsigned num_samples, int volume1, int volume2)
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{
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while (num_samples > 0) {
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int32_t sample1 = *buffer1;
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int32_t sample2 = *buffer2++;
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sample1 = ((sample1 * volume1 + sample2 * volume2) +
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pcm_dither() + PCM_VOLUME_1 / 2) / PCM_VOLUME_1;
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*buffer1++ = pcm_range(sample1, 16);
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--num_samples;
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}
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}
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static void
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pcm_add_24(int32_t *buffer1, const int32_t *buffer2,
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unsigned num_samples, unsigned volume1, unsigned volume2)
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{
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while (num_samples > 0) {
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int64_t sample1 = *buffer1;
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int64_t sample2 = *buffer2++;
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sample1 = ((sample1 * volume1 + sample2 * volume2) +
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pcm_dither() + PCM_VOLUME_1 / 2) / PCM_VOLUME_1;
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*buffer1++ = pcm_range(sample1, 24);
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--num_samples;
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}
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}
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static void
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pcm_add(char *buffer1, const char *buffer2, size_t size,
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int vol1, int vol2,
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const struct audio_format *format)
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{
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switch (format->bits) {
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case 8:
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pcm_add_8((int8_t *)buffer1, (const int8_t *)buffer2,
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size, vol1, vol2);
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break;
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case 16:
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pcm_add_16((int16_t *)buffer1, (const int16_t *)buffer2,
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size / 2, vol1, vol2);
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break;
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case 24:
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pcm_add_24((int32_t*)buffer1,
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(const int32_t*)buffer2,
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size / 4, vol1, vol2);
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break;
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default:
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g_error("%u bits not supported by pcm_add!\n", format->bits);
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}
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}
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void
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pcm_mix(char *buffer1, const char *buffer2, size_t size,
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const struct audio_format *format, float portion1)
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{
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int vol1;
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float s = sin(M_PI_2 * portion1);
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s *= s;
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vol1 = s * PCM_VOLUME_1 + 0.5;
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vol1 = vol1 > PCM_VOLUME_1 ? PCM_VOLUME_1 : (vol1 < 0 ? 0 : vol1);
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pcm_add(buffer1, buffer2, size, vol1, PCM_VOLUME_1 - vol1, format);
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}
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