code.delx.au - pulseaudio/blob - polyp/sample.h

   1 #ifndef foosamplehfoo
   2 #define foosamplehfoo
   3
   4 /* $Id$ */
   5
   6 /***
   7   This file is part of polypaudio.
   8
   9   polypaudio is free software; you can redistribute it and/or modify
  10   it under the terms of the GNU General Public License as published
  11   by the Free Software Foundation; either version 2 of the License,
  12   or (at your option) any later version.
  13
  14   polypaudio is distributed in the hope that it will be useful, but
  15   WITHOUT ANY WARRANTY; without even the implied warranty of
  16   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  17   General Public License for more details.
  18
  19   You should have received a copy of the GNU General Public License
  20   along with polypaudio; if not, write to the Free Software
  21   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  22   USA.
  23 ***/
  24
  25 #include <inttypes.h>
  26 #include <sys/types.h>
  27 #include <math.h>
  28
  29 #include "cdecl.h"
  30
  31 /** \file
  32  * Constants and routines for sample type handling */
  33
  34 PA_C_DECL_BEGIN
  35
  36 /** Sample format */
  37 enum pa_sample_format {
  38     PA_SAMPLE_U8,              /**< Unsigned 8 Bit PCM */
  39     PA_SAMPLE_ALAW,            /**< 8 Bit a-Law */
  40     PA_SAMPLE_ULAW,            /**< 8 Bit mu-Law */
  41     PA_SAMPLE_S16LE,           /**< Signed 16 Bit PCM, little endian (PC) */
  42     PA_SAMPLE_S16BE,           /**< Signed 16 Bit PCM, big endian */
  43     PA_SAMPLE_FLOAT32LE,       /**< 32 Bit IEEE floating point, little endian, range -1..1 */
  44     PA_SAMPLE_FLOAT32BE,       /**< 32 Bit IEEE floating point, big endian, range -1..1 */
  45     PA_SAMPLE_MAX              /**< Upper limit of valid sample types */
  46 };
  47
  48 #ifdef WORDS_BIGENDIAN
  49 /** Signed 16 Bit PCM, native endian */
  50 #define PA_SAMPLE_S16NE PA_SAMPLE_S16BE
  51 /** 32 Bit IEEE floating point, native endian */
  52 #define PA_SAMPLE_FLOAT32NE PA_SAMPLE_FLOAT32BE
  53 #else
  54 /** Signed 16 Bit PCM, native endian */
  55 #define PA_SAMPLE_S16NE PA_SAMPLE_S16LE
  56 /** 32 Bit IEEE floating point, native endian */
  57 #define PA_SAMPLE_FLOAT32NE PA_SAMPLE_FLOAT32LE
  58 #endif
  59
  60 /** A Shortcut for PA_SAMPLE_FLOAT32NE */
  61 #define PA_SAMPLE_FLOAT32 PA_SAMPLE_FLOAT32NE
  62
  63 /** A sample format and attribute specification */
  64 struct pa_sample_spec {
  65     enum pa_sample_format format;  /**< The sample format */
  66     uint32_t rate;                 /**< The sample rate. (e.g. 44100) */
  67     uint8_t channels;              /**< Audio channels. (1 for mono, 2 for stereo, ...) */
  68 };
  69
  70 /** Type for usec specifications */
  71 typedef uint32_t pa_usec_t;
  72
  73 /** Return the amount of bytes playback of a second of audio with the speicified sample type takes */
  74 size_t pa_bytes_per_second(const struct pa_sample_spec *spec);
  75
  76 /** Return the size of a frame with the specific sample type */
  77 size_t pa_frame_size(const struct pa_sample_spec *spec);
  78
  79 /** Calculate the time the specified bytes take to play with the specified sample type */
  80 pa_usec_t pa_bytes_to_usec(size_t length, const struct pa_sample_spec *spec);
  81
  82 /** Return non-zero when the sample type specification is valid */
  83 int pa_sample_spec_valid(const struct pa_sample_spec *spec);
  84
  85 /** Return non-zero when the two sample type specifications match */
  86 int pa_sample_spec_equal(const struct pa_sample_spec*a, const struct pa_sample_spec*b);
  87
  88 /** Maximum required string length for pa_sample_spec_snprint() */
  89 #define PA_SAMPLE_SNPRINT_MAX_LENGTH 32
  90
  91 /** Pretty print a sample type specification to a string */
  92 void pa_sample_spec_snprint(char *s, size_t l, const struct pa_sample_spec *spec);
  93
  94 /** Volume specification: 0: silence; < 256: diminished volume; 256: normal volume; > 256 amplified volume */
  95 typedef uint32_t pa_volume_t;
  96
  97 /** Normal volume (100%) */
  98 #define PA_VOLUME_NORM (0x100)
  99
 100 /** Muted volume (0%) */
 101 #define PA_VOLUME_MUTED (0)
 102
 103 /** Multiply two volumes specifications, return the result. This uses PA_VOLUME_NORM as neutral element of multiplication. */
 104 pa_volume_t pa_volume_multiply(pa_volume_t a, pa_volume_t b);
 105
 106 /** Convert volume from decibel to linear level. \since 0.4 */
 107 pa_volume_t pa_volume_from_dB(double f);
 108
 109 /** Convert volume from linear level to decibel.  \since 0.4 */
 110 double pa_volume_to_dB(pa_volume_t v);
 111
 112 #ifdef INFINITY
 113 #define PA_DECIBEL_MININFTY (-INFINITY)
 114 #else
 115 /** This value is used as minus infinity when using pa_volume_{to,from}_dB(). \since 0.4 */
 116 #define PA_DECIBEL_MININFTY (-200)
 117 #endif
 118
 119 /** Pretty print a byte size value. (i.e. "2.5 MB") */
 120 void pa_bytes_snprint(char *s, size_t l, off_t v);
 121
 122 PA_C_DECL_END
 123
 124 #endif