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 Lesser 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 Lesser 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 <polyp/cdecl.h>
  30
  31 /** \file
  32  * Constants and routines for sample type handling */
  33
  34 PA_C_DECL_BEGIN
  35
  36 /* Maximum allowed channels */
  37 #define PA_CHANNELS_MAX 16
  38
  39 /** Sample format */
  40 typedef enum pa_sample_format {
  41     PA_SAMPLE_U8,              /**< Unsigned 8 Bit PCM */
  42     PA_SAMPLE_ALAW,            /**< 8 Bit a-Law */
  43     PA_SAMPLE_ULAW,            /**< 8 Bit mu-Law */
  44     PA_SAMPLE_S16LE,           /**< Signed 16 Bit PCM, little endian (PC) */
  45     PA_SAMPLE_S16BE,           /**< Signed 16 Bit PCM, big endian */
  46     PA_SAMPLE_FLOAT32LE,       /**< 32 Bit IEEE floating point, little endian, range -1..1 */
  47     PA_SAMPLE_FLOAT32BE,       /**< 32 Bit IEEE floating point, big endian, range -1..1 */
  48     PA_SAMPLE_MAX,             /**< Upper limit of valid sample types */
  49     PA_SAMPLE_INVALID = -1     /**< An invalid value */
  50 } pa_sample_format_t;
  51
  52 #ifdef WORDS_BIGENDIAN
  53 /** Signed 16 Bit PCM, native endian */
  54 #define PA_SAMPLE_S16NE PA_SAMPLE_S16BE
  55 /** 32 Bit IEEE floating point, native endian */
  56 #define PA_SAMPLE_FLOAT32NE PA_SAMPLE_FLOAT32BE
  57 /** Signed 16 Bit PCM reverse endian */
  58 #define PA_SAMPLE_S16RE PA_SAMPLE_S16LE
  59 /** 32 Bit IEEE floating point, reverse endian */
  60 #define PA_SAMPLE_FLOAT32RE PA_SAMPLE_FLOAT32LE
  61 #else
  62 /** Signed 16 Bit PCM, native endian */
  63 #define PA_SAMPLE_S16NE PA_SAMPLE_S16LE
  64 /** 32 Bit IEEE floating point, native endian */
  65 #define PA_SAMPLE_FLOAT32NE PA_SAMPLE_FLOAT32LE
  66 /** Signed 16 Bit PCM reverse endian */
  67 #define PA_SAMPLE_S16RE PA_SAMPLE_S16BE
  68 /** 32 Bit IEEE floating point, reverse endian */
  69 #define PA_SAMPLE_FLOAT32RE PA_SAMPLE_FLOAT32BE
  70 #endif
  71
  72 /** A Shortcut for PA_SAMPLE_FLOAT32NE */
  73 #define PA_SAMPLE_FLOAT32 PA_SAMPLE_FLOAT32NE
  74
  75 /** A sample format and attribute specification */
  76 typedef struct pa_sample_spec {
  77     pa_sample_format_t format;     /**< The sample format */
  78     uint32_t rate;                 /**< The sample rate. (e.g. 44100) */
  79     uint8_t channels;              /**< Audio channels. (1 for mono, 2 for stereo, ...) */
  80 } pa_sample_spec;
  81
  82 /** Type for usec specifications (unsigned). May be either 32 or 64 bit, depending on the architecture */
  83 typedef uint64_t pa_usec_t;
  84
  85 /** Return the amount of bytes playback of a second of audio with the specified sample type takes */
  86 size_t pa_bytes_per_second(const pa_sample_spec *spec);
  87
  88 /** Return the size of a frame with the specific sample type */
  89 size_t pa_frame_size(const pa_sample_spec *spec);
  90
  91 /** Return the size of a sample with the specific sample type */
  92 size_t pa_sample_size(const pa_sample_spec *spec);
  93
  94 /** Calculate the time the specified bytes take to play with the specified sample type */
  95 pa_usec_t pa_bytes_to_usec(uint64_t length, const pa_sample_spec *spec);
  96
  97 /** Return non-zero when the sample type specification is valid */
  98 int pa_sample_spec_valid(const pa_sample_spec *spec);
  99
 100 /** Return non-zero when the two sample type specifications match */
 101 int pa_sample_spec_equal(const pa_sample_spec*a, const pa_sample_spec*b);
 102
 103 /* Return a descriptive string for the specified sample format. \since 0.8 */
 104 const char *pa_sample_format_to_string(pa_sample_format_t f);
 105
 106 /** Parse a sample format text. Inverse of pa_sample_format_to_string() */
 107 pa_sample_format_t pa_parse_sample_format(const char *format);
 108
 109 /** Maximum required string length for pa_sample_spec_snprint() */
 110 #define PA_SAMPLE_SPEC_SNPRINT_MAX 32
 111
 112 /** Pretty print a sample type specification to a string */
 113 char* pa_sample_spec_snprint(char *s, size_t l, const pa_sample_spec *spec);
 114
 115 /** Pretty print a byte size value. (i.e. "2.5 MB") */
 116 void pa_bytes_snprint(char *s, size_t l, unsigned v);
 117
 118 PA_C_DECL_END
 119
 120 #endif