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
  28 #include "cdecl.h"
  29
  30 /** \file
  31  * Constants and routines for sample type handling */
  32
  33 PA_C_DECL_BEGIN
  34
  35 /** Sample format */
  36 enum pa_sample_format {
  37     PA_SAMPLE_U8,              /**< Unsigned 8 Bit PCM */
  38     PA_SAMPLE_ALAW,            /**< 8 Bit a-Law */
  39     PA_SAMPLE_ULAW,            /**< 8 Bit mu-Law */
  40     PA_SAMPLE_S16LE,           /**< Signed 16 Bit PCM, little endian (PC) */
  41     PA_SAMPLE_S16BE,           /**< Signed 16 Bit PCM, big endian */
  42     PA_SAMPLE_FLOAT32LE,       /**< 32 Bit IEEE floating point, little endian, range -1..1 */
  43     PA_SAMPLE_FLOAT32BE,       /**< 32 Bit IEEE floating point, big endian, range -1..1 */
  44     PA_SAMPLE_MAX              /**< Upper limit of valid sample types */
  45 };
  46
  47 #ifdef WORDS_BIGENDIAN
  48 /** Signed 16 Bit PCM, native endian */
  49 #define PA_SAMPLE_S16NE PA_SAMPLE_S16BE
  50 /** 32 Bit IEEE floating point, native endian */
  51 #define PA_SAMPLE_FLOAT32NE PA_SAMPLE_FLOAT32BE
  52 #else
  53 /** Signed 16 Bit PCM, native endian */
  54 #define PA_SAMPLE_S16NE PA_SAMPLE_S16LE
  55 /** 32 Bit IEEE floating point, native endian */
  56 #define PA_SAMPLE_FLOAT32NE PA_SAMPLE_FLOAT32LE
  57 #endif
  58
  59 /** A Shortcut for PA_SAMPLE_FLOAT32NE */
  60 #define PA_SAMPLE_FLOAT32 PA_SAMPLE_FLOAT32NE
  61
  62 /** A sample format and attribute specification */
  63 struct pa_sample_spec {
  64     enum pa_sample_format format;  /**< The sample format */
  65     uint32_t rate;                 /**< The sample rate. (e.g. 44100) */
  66     uint8_t channels;              /**< Audio channels. (1 for mono, 2 for stereo, ...) */
  67 };
  68
  69 /** Type for usec specifications */
  70 typedef uint32_t pa_usec_t;
  71
  72 /** Return the amount of bytes playback of a second of audio with the speicified sample type takes */
  73 size_t pa_bytes_per_second(const struct pa_sample_spec *spec);
  74
  75 /** Return the size of a frame with the specific sample type */
  76 size_t pa_frame_size(const struct pa_sample_spec *spec);
  77
  78 /** Calculate the time the specified bytes take to play with the specified sample type */
  79 pa_usec_t pa_bytes_to_usec(size_t length, const struct pa_sample_spec *spec);
  80
  81 /** Return non-zero when the sample type specification is valid */
  82 int pa_sample_spec_valid(const struct pa_sample_spec *spec);
  83
  84 /** Return non-zero when the two sample type specifications match */
  85 int pa_sample_spec_equal(const struct pa_sample_spec*a, const struct pa_sample_spec*b);
  86
  87 /** Maximum required string length for pa_sample_spec_snprint() */
  88 #define PA_SAMPLE_SNPRINT_MAX_LENGTH 32
  89
  90 /** Pretty print a sample type specification to a string */
  91 void pa_sample_spec_snprint(char *s, size_t l, const struct pa_sample_spec *spec);
  92
  93 /** Volume specification: 0: silence; < 256: diminished volume; 256: normal volume; > 256 amplified volume */
  94 typedef uint32_t pa_volume_t;
  95
  96 /** Normal volume (100%) */
  97 #define PA_VOLUME_NORM (0x100)
  98
  99 /** Muted volume (0%) */
 100 #define PA_VOLUME_MUTED (0)
 101
 102 /** Multiply two volumes specifications, return the result. This uses PA_VOLUME_NORM as neutral element of multiplication. */
 103 pa_volume_t pa_volume_multiply(pa_volume_t a, pa_volume_t b);
 104
 105 PA_C_DECL_END
 106
 107 #endif