edcd45df94
It may be desirable to change the range of integer volume levels (e.g. to 1024, which may utilize shifts instead of expensive integer divisions). Introduce the constant PCM_VOLUME_1 which describes the integer value for "100% volume". This is currently 1000.
73 lines
2.0 KiB
C
73 lines
2.0 KiB
C
/* the Music Player Daemon (MPD)
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* Copyright (C) 2003-2007 by Warren Dukes (warren.dukes@gmail.com)
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* This project's homepage is: 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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#ifndef MPD_PCM_UTILS_H
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#define MPD_PCM_UTILS_H
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#include "pcm_resample.h"
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#include "pcm_dither.h"
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#include <stdint.h>
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#include <stddef.h>
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struct audio_format;
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enum {
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/** this value means "100% volume" */
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PCM_VOLUME_1 = 1000,
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};
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struct pcm_convert_state {
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struct pcm_resample_state resample;
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struct pcm_dither_24 dither;
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/* Strict C99 doesn't allow empty structs */
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int error;
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};
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/**
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* Converts a float value (0.0 = silence, 1.0 = 100% volume) to an
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* integer volume value (1000 = 100%).
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*/
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static inline int
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pcm_float_to_volume(float volume)
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{
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return volume * PCM_VOLUME_1 + 0.5;
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}
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void pcm_volume(char *buffer, int bufferSize,
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const struct audio_format *format,
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int volume);
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void 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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void pcm_convert_init(struct pcm_convert_state *state);
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size_t pcm_convert(const struct audio_format *inFormat,
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const char *inBuffer, size_t inSize,
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const struct audio_format *outFormat,
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char *outBuffer,
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struct pcm_convert_state *convState);
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size_t pcm_convert_size(const struct audio_format *inFormat, size_t inSize,
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const struct audio_format *outFormat);
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#endif
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