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