code.delx.au - pulseaudio/blob - src/pulse/sample.h

   1 #ifndef foosamplehfoo
   2 #define foosamplehfoo
   3
   4 /***
   5   This file is part of PulseAudio.
   6
   7   Copyright 2004-2006 Lennart Poettering
   8   Copyright 2006 Pierre Ossman <ossman@cendio.se> for Cendio AB
   9
  10   PulseAudio is free software; you can redistribute it and/or modify
  11   it under the terms of the GNU Lesser General Public License as published
  12   by the Free Software Foundation; either version 2 of the License,
  13   or (at your option) any later version.
  14
  15   PulseAudio is distributed in the hope that it will be useful, but
  16   WITHOUT ANY WARRANTY; without even the implied warranty of
  17   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  18   General Public License for more details.
  19
  20   You should have received a copy of the GNU Lesser General Public License
  21   along with PulseAudio; if not, write to the Free Software
  22   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  23   USA.
  24 ***/
  25
  26 #include <inttypes.h>
  27 #include <sys/types.h>
  28 #include <sys/param.h>
  29 #include <math.h>
  30
  31 #include <pulse/gccmacro.h>
  32 #include <pulse/cdecl.h>
  33
  34 /** \page sample Sample Format Specifications
  35  *
  36  * \section overv_sec Overview
  37  *
  38  * PulseAudio is capable of handling a multitude of sample formats, rates
  39  * and channels, transparently converting and mixing them as needed.
  40  *
  41  * \section format_sec Sample Format
  42  *
  43  * PulseAudio supports the following sample formats:
  44  *
  45  * \li PA_SAMPLE_U8 - Unsigned 8 bit integer PCM.
  46  * \li PA_SAMPLE_S16LE - Signed 16 integer bit PCM, little endian.
  47  * \li PA_SAMPLE_S16BE - Signed 16 integer bit PCM, big endian.
  48  * \li PA_SAMPLE_FLOAT32LE - 32 bit IEEE floating point PCM, little endian.
  49  * \li PA_SAMPLE_FLOAT32BE - 32 bit IEEE floating point PCM, big endian.
  50  * \li PA_SAMPLE_ALAW - 8 bit a-Law.
  51  * \li PA_SAMPLE_ULAW - 8 bit mu-Law.
  52  * \li PA_SAMPLE_S32LE - Signed 32 bit integer PCM, little endian.
  53  * \li PA_SAMPLE_S32BE - Signed 32 bit integer PCM, big endian.
  54  * \li PA_SAMPLE_242LE - Signed 24 bit integer PCM packed, little endian.
  55  * \li PA_SAMPLE_242BE - Signed 24 bit integer PCM packed, big endian.
  56  *
  57  * The floating point sample formats have the range from -1.0 to 1.0.
  58  *
  59  * The sample formats that are sensitive to endianness have convenience
  60  * macros for native endian (NE), and reverse endian (RE).
  61  *
  62  * \section rate_sec Sample Rates
  63  *
  64  * PulseAudio supports any sample rate between 1 Hz and 4 GHz. There is no
  65  * point trying to exceed the sample rate of the output device though as the
  66  * signal will only get downsampled, consuming CPU on the machine running the
  67  * server.
  68  *
  69  * \section chan_sec Channels
  70  *
  71  * PulseAudio supports up to 16 individiual channels. The order of the
  72  * channels is up to the application, but they must be continous. To map
  73  * channels to speakers, see \ref channelmap.
  74  *
  75  * \section calc_sec Calculations
  76  *
  77  * The PulseAudio library contains a number of convenience functions to do
  78  * calculations on sample formats:
  79  *
  80  * \li pa_bytes_per_second() - The number of bytes one second of audio will
  81  *                             take given a sample format.
  82  * \li pa_frame_size() - The size, in bytes, of one frame (i.e. one set of
  83  *                       samples, one for each channel).
  84  * \li pa_sample_size() - The size, in bytes, of one sample.
  85  * \li pa_bytes_to_usec() - Calculate the time it would take to play a buffer
  86  *                          of a certain size.
  87  *
  88  * \section util_sec Convenience Functions
  89  *
  90  * The library also contains a couple of other convenience functions:
  91  *
  92  * \li pa_sample_spec_valid() - Tests if a sample format specification is
  93  *                              valid.
  94  * \li pa_sample_spec_equal() - Tests if the sample format specifications are
  95  *                              identical.
  96  * \li pa_sample_format_to_string() - Return a textual description of a
  97  *                                    sample format.
  98  * \li pa_parse_sample_format() - Parse a text string into a sample format.
  99  * \li pa_sample_spec_snprint() - Create a textual description of a complete
 100  *                                 sample format specification.
 101  * \li pa_bytes_snprint() - Pretty print a byte value (e.g. 2.5 MiB).
 102  */
 103
 104 /** \file
 105  * Constants and routines for sample type handling */
 106
 107 PA_C_DECL_BEGIN
 108
 109 #if !defined(WORDS_BIGENDIAN)
 110 #if defined(__BYTE_ORDER)
 111 #if __BYTE_ORDER == __BIG_ENDIAN
 112 #define WORDS_BIGENDIAN
 113 #endif
 114 #endif
 115 #endif
 116
 117 /** Maximum number of allowed channels */
 118 #define PA_CHANNELS_MAX 32U
 119
 120 /** Maximum allowed sample rate */
 121 #define PA_RATE_MAX (48000U*4U)
 122
 123 /** Sample format */
 124 typedef enum pa_sample_format {
 125     PA_SAMPLE_U8,
 126     /**< Unsigned 8 Bit PCM */
 127
 128     PA_SAMPLE_ALAW,
 129     /**< 8 Bit a-Law */
 130
 131     PA_SAMPLE_ULAW,
 132     /**< 8 Bit mu-Law */
 133
 134     PA_SAMPLE_S16LE,
 135     /**< Signed 16 Bit PCM, little endian (PC) */
 136
 137     PA_SAMPLE_S16BE,
 138     /**< Signed 16 Bit PCM, big endian */
 139
 140     PA_SAMPLE_FLOAT32LE,
 141     /**< 32 Bit IEEE floating point, little endian, range -1 to 1 */
 142
 143     PA_SAMPLE_FLOAT32BE,
 144     /**< 32 Bit IEEE floating point, big endian, range -1 to 1 */
 145
 146     PA_SAMPLE_S32LE,
 147     /**< Signed 32 Bit PCM, little endian (PC) */
 148
 149     PA_SAMPLE_S32BE,
 150     /**< Signed 32 Bit PCM, big endian */
 151
 152     PA_SAMPLE_S24LE,
 153     /**< Signed 24 Bit PCM packed, little endian (PC) */
 154
 155     PA_SAMPLE_S24BE,
 156     /**< Signed 24 Bit PCM packed, big endian */
 157
 158     PA_SAMPLE_MAX,
 159     /**< Upper limit of valid sample types */
 160
 161     PA_SAMPLE_INVALID = -1
 162     /**< An invalid value */
 163 } pa_sample_format_t;
 164
 165 #ifdef WORDS_BIGENDIAN
 166 /** Signed 16 Bit PCM, native endian */
 167 #define PA_SAMPLE_S16NE PA_SAMPLE_S16BE
 168 /** 32 Bit IEEE floating point, native endian */
 169 #define PA_SAMPLE_FLOAT32NE PA_SAMPLE_FLOAT32BE
 170 /** Signed 32 Bit PCM, native endian */
 171 #define PA_SAMPLE_S32NE PA_SAMPLE_S32BE
 172 /** Signed 24 Bit PCM packed, native endian */
 173 #define PA_SAMPLE_S24NE PA_SAMPLE_S24BE
 174 /** Signed 16 Bit PCM reverse endian */
 175 #define PA_SAMPLE_S16RE PA_SAMPLE_S16LE
 176 /** 32 Bit IEEE floating point, reverse endian */
 177 #define PA_SAMPLE_FLOAT32RE PA_SAMPLE_FLOAT32LE
 178 /** Signed 32 Bit PCM, reverse endian */
 179 #define PA_SAMPLE_S32RE PA_SAMPLE_S32LE
 180 /** Signed 24 Bit PCM, packed reverse endian */
 181 #define PA_SAMPLE_S24RE PA_SAMPLE_242LE
 182 #else
 183 /** Signed 16 Bit PCM, native endian */
 184 #define PA_SAMPLE_S16NE PA_SAMPLE_S16LE
 185 /** 32 Bit IEEE floating point, native endian */
 186 #define PA_SAMPLE_FLOAT32NE PA_SAMPLE_FLOAT32LE
 187 /** Signed 32 Bit PCM, native endian */
 188 #define PA_SAMPLE_S32NE PA_SAMPLE_S32LE
 189 /** Signed 24 Bit PCM packed, native endian */
 190 #define PA_SAMPLE_S24NE PA_SAMPLE_S24LE
 191 /** Signed 16 Bit PCM, reverse endian */
 192 #define PA_SAMPLE_S16RE PA_SAMPLE_S16BE
 193 /** 32 Bit IEEE floating point, reverse endian */
 194 #define PA_SAMPLE_FLOAT32RE PA_SAMPLE_FLOAT32BE
 195 /** Signed 32 Bit PCM, reverse endian */
 196 #define PA_SAMPLE_S32RE PA_SAMPLE_S32BE
 197 /** Signed 24 Bit PCM packed, reverse endian */
 198 #define PA_SAMPLE_S24RE PA_SAMPLE_S24BE
 199 #endif
 200
 201 /** A Shortcut for PA_SAMPLE_FLOAT32NE */
 202 #define PA_SAMPLE_FLOAT32 PA_SAMPLE_FLOAT32NE
 203
 204 /** \cond fulldocs */
 205 /* Allow clients to check with #ifdef for thse sample formats */
 206 #define PA_SAMPLE_U8 PA_SAMPLE_U8
 207 #define PA_SAMPLE_ALAW PA_SAMPLE_ALAW
 208 #define PA_SAMPLE_ULAW PA_SAMPLE_ULAW
 209 #define PA_SAMPLE_S16LE PA_SAMPLE_S16LE
 210 #define PA_SAMPLE_S16BE PA_SAMPLE_S16BE
 211 #define PA_SAMPLE_FLOAT32LE PA_SAMPLE_FLOAT32LE
 212 #define PA_SAMPLE_FLOAT32BE PA_SAMPLE_FLOAT32BE
 213 #define PA_SAMPLE_S32LE PA_SAMPLE_S32LE
 214 #define PA_SAMPLE_S32BE PA_SAMPLE_S32BE
 215 #define PA_SAMPLE_S24LE PA_SAMPLE_S24LE
 216 #define PA_SAMPLE_S24BE PA_SAMPLE_S24BE
 217 /** \endcond */
 218
 219 /** A sample format and attribute specification */
 220 typedef struct pa_sample_spec {
 221     pa_sample_format_t format;
 222     /**< The sample format */
 223
 224     uint32_t rate;
 225     /**< The sample rate. (e.g. 44100) */
 226
 227     uint8_t channels;
 228     /**< Audio channels. (1 for mono, 2 for stereo, ...) */
 229 } pa_sample_spec;
 230
 231 /** Type for usec specifications (unsigned). Always 64 bit. */
 232 typedef uint64_t pa_usec_t;
 233
 234 /** Return the amount of bytes playback of a second of audio with the specified sample type takes */
 235 size_t pa_bytes_per_second(const pa_sample_spec *spec) PA_GCC_PURE;
 236
 237 /** Return the size of a frame with the specific sample type */
 238 size_t pa_frame_size(const pa_sample_spec *spec) PA_GCC_PURE;
 239
 240 /** Return the size of a sample with the specific sample type */
 241 size_t pa_sample_size(const pa_sample_spec *spec) PA_GCC_PURE;
 242
 243 /** Calculate the time the specified bytes take to play with the
 244  * specified sample type. The return value will always be rounded
 245  * down for non-integral return values. */
 246 pa_usec_t pa_bytes_to_usec(uint64_t length, const pa_sample_spec *spec) PA_GCC_PURE;
 247
 248 /** Calculates the number of bytes that are required for the specified
 249  * time. The return value will always be rounded down for non-integral
 250  * return values. \since 0.9 */
 251 size_t pa_usec_to_bytes(pa_usec_t t, const pa_sample_spec *spec) PA_GCC_PURE;
 252
 253 /** Initialize the specified sample spec and return a pointer to
 254  * it. The sample spec will have a defined state but
 255  * pa_sample_spec_valid() will fail for it. \since 0.9.13 */
 256 pa_sample_spec* pa_sample_spec_init(pa_sample_spec *spec);
 257
 258 /** Return non-zero when the sample type specification is valid */
 259 int pa_sample_spec_valid(const pa_sample_spec *spec) PA_GCC_PURE;
 260
 261 /** Return non-zero when the two sample type specifications match */
 262 int pa_sample_spec_equal(const pa_sample_spec*a, const pa_sample_spec*b) PA_GCC_PURE;
 263
 264 /** Return a descriptive string for the specified sample format. \since 0.8 */
 265 const char *pa_sample_format_to_string(pa_sample_format_t f) PA_GCC_PURE;
 266
 267 /** Parse a sample format text. Inverse of pa_sample_format_to_string() */
 268 pa_sample_format_t pa_parse_sample_format(const char *format) PA_GCC_PURE;
 269
 270 /** Maximum required string length for
 271  * pa_sample_spec_snprint(). Please note that this value can change
 272  * with any release without warning and without being considered API
 273  * or ABI breakage. You should not use this definition anywhere where
 274  * it might become part of an ABI. */
 275 #define PA_SAMPLE_SPEC_SNPRINT_MAX 32
 276
 277 /** Pretty print a sample type specification to a string */
 278 char* pa_sample_spec_snprint(char *s, size_t l, const pa_sample_spec *spec);
 279
 280 /** Pretty print a byte size value. (i.e. "2.5 MiB") */
 281 char* pa_bytes_snprint(char *s, size_t l, unsigned v);
 282
 283 PA_C_DECL_END
 284
 285 #endif