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_S24LE - Signed 24 bit integer PCM packed, little endian.
  55  * \li PA_SAMPLE_S24BE - Signed 24 bit integer PCM packed, big endian.
  56  * \li PA_SAMPLE_S24_32LE - Signed 24 bit integer PCM in LSB of 32 bit words, little endian.
  57  * \li PA_SAMPLE_S24_32BE - Signed 24 bit integer PCM in LSB of 32 bit words, big endian.
  58  *
  59  * The floating point sample formats have the range from -1.0 to 1.0.
  60  *
  61  * The sample formats that are sensitive to endianness have convenience
  62  * macros for native endian (NE), and reverse endian (RE).
  63  *
  64  * \section rate_sec Sample Rates
  65  *
  66  * PulseAudio supports any sample rate between 1 Hz and 192000 Hz. There is no
  67  * point trying to exceed the sample rate of the output device though as the
  68  * signal will only get downsampled, consuming CPU on the machine running the
  69  * server.
  70  *
  71  * \section chan_sec Channels
  72  *
  73  * PulseAudio supports up to 32 individiual channels. The order of the
  74  * channels is up to the application, but they must be continous. To map
  75  * channels to speakers, see \ref channelmap.
  76  *
  77  * \section calc_sec Calculations
  78  *
  79  * The PulseAudio library contains a number of convenience functions to do
  80  * calculations on sample formats:
  81  *
  82  * \li pa_bytes_per_second() - The number of bytes one second of audio will
  83  *                             take given a sample format.
  84  * \li pa_frame_size() - The size, in bytes, of one frame (i.e. one set of
  85  *                       samples, one for each channel).
  86  * \li pa_sample_size() - The size, in bytes, of one sample.
  87  * \li pa_bytes_to_usec() - Calculate the time it would take to play a buffer
  88  *                          of a certain size.
  89  *
  90  * \section util_sec Convenience Functions
  91  *
  92  * The library also contains a couple of other convenience functions:
  93  *
  94  * \li pa_sample_spec_valid() - Tests if a sample format specification is
  95  *                              valid.
  96  * \li pa_sample_spec_equal() - Tests if the sample format specifications are
  97  *                              identical.
  98  * \li pa_sample_format_to_string() - Return a textual description of a
  99  *                                    sample format.
 100  * \li pa_parse_sample_format() - Parse a text string into a sample format.
 101  * \li pa_sample_spec_snprint() - Create a textual description of a complete
 102  *                                 sample format specification.
 103  * \li pa_bytes_snprint() - Pretty print a byte value (e.g. 2.5 MiB).
 104  */
 105
 106 /** \file
 107  * Constants and routines for sample type handling */
 108
 109 PA_C_DECL_BEGIN
 110
 111 #if !defined(WORDS_BIGENDIAN)
 112 #if defined(__BYTE_ORDER)
 113 #if __BYTE_ORDER == __BIG_ENDIAN
 114 #define WORDS_BIGENDIAN
 115 #endif
 116 #endif
 117 #endif
 118
 119 /** Maximum number of allowed channels */
 120 #define PA_CHANNELS_MAX 32U
 121
 122 /** Maximum allowed sample rate */
 123 #define PA_RATE_MAX (48000U*4U)
 124
 125 /** Sample format */
 126 typedef enum pa_sample_format {
 127     PA_SAMPLE_U8,
 128     /**< Unsigned 8 Bit PCM */
 129
 130     PA_SAMPLE_ALAW,
 131     /**< 8 Bit a-Law */
 132
 133     PA_SAMPLE_ULAW,
 134     /**< 8 Bit mu-Law */
 135
 136     PA_SAMPLE_S16LE,
 137     /**< Signed 16 Bit PCM, little endian (PC) */
 138
 139     PA_SAMPLE_S16BE,
 140     /**< Signed 16 Bit PCM, big endian */
 141
 142     PA_SAMPLE_FLOAT32LE,
 143     /**< 32 Bit IEEE floating point, little endian (PC), range -1.0 to 1.0 */
 144
 145     PA_SAMPLE_FLOAT32BE,
 146     /**< 32 Bit IEEE floating point, big endian, range -1.0 to 1.0 */
 147
 148     PA_SAMPLE_S32LE,
 149     /**< Signed 32 Bit PCM, little endian (PC) */
 150
 151     PA_SAMPLE_S32BE,
 152     /**< Signed 32 Bit PCM, big endian */
 153
 154     PA_SAMPLE_S24LE,
 155     /**< Signed 24 Bit PCM packed, little endian (PC). \since 0.9.15 */
 156
 157     PA_SAMPLE_S24BE,
 158     /**< Signed 24 Bit PCM packed, big endian. \since 0.9.15 */
 159
 160     PA_SAMPLE_S24_32LE,
 161     /**< Signed 24 Bit PCM in LSB of 32 Bit words, little endian (PC). \since 0.9.15 */
 162
 163     PA_SAMPLE_S24_32BE,
 164     /**< Signed 24 Bit PCM in LSB of 32 Bit words, big endian. \since 0.9.15 */
 165
 166     PA_SAMPLE_MAX,
 167     /**< Upper limit of valid sample types */
 168
 169     PA_SAMPLE_INVALID = -1
 170     /**< An invalid value */
 171 } pa_sample_format_t;
 172
 173 #ifdef WORDS_BIGENDIAN
 174 /** Signed 16 Bit PCM, native endian */
 175 #define PA_SAMPLE_S16NE PA_SAMPLE_S16BE
 176 /** 32 Bit IEEE floating point, native endian */
 177 #define PA_SAMPLE_FLOAT32NE PA_SAMPLE_FLOAT32BE
 178 /** Signed 32 Bit PCM, native endian */
 179 #define PA_SAMPLE_S32NE PA_SAMPLE_S32BE
 180 /** Signed 24 Bit PCM packed, native endian. \since 0.9.15 */
 181 #define PA_SAMPLE_S24NE PA_SAMPLE_S24BE
 182 /** Signed 24 Bit PCM in LSB of 32 Bit words, native endian. \since 0.9.15 */
 183 #define PA_SAMPLE_S24_32NE PA_SAMPLE_S24_32BE
 184
 185 /** Signed 16 Bit PCM reverse endian */
 186 #define PA_SAMPLE_S16RE PA_SAMPLE_S16LE
 187 /** 32 Bit IEEE floating point, reverse endian */
 188 #define PA_SAMPLE_FLOAT32RE PA_SAMPLE_FLOAT32LE
 189 /** Signed 32 Bit PCM, reverse endian */
 190 #define PA_SAMPLE_S32RE PA_SAMPLE_S32LE
 191 /** Signed 24 Bit PCM, packed reverse endian. \since 0.9.15 */
 192 #define PA_SAMPLE_S24RE PA_SAMPLE_S24LE
 193 /** Signed 24 Bit PCM, in LSB of 32 Bit words, reverse endian. \since 0.9.15 */
 194 #define PA_SAMPLE_S24_32RE PA_SAMPLE_S24_32LE
 195 #else
 196 /** Signed 16 Bit PCM, native endian */
 197 #define PA_SAMPLE_S16NE PA_SAMPLE_S16LE
 198 /** 32 Bit IEEE floating point, native endian */
 199 #define PA_SAMPLE_FLOAT32NE PA_SAMPLE_FLOAT32LE
 200 /** Signed 32 Bit PCM, native endian */
 201 #define PA_SAMPLE_S32NE PA_SAMPLE_S32LE
 202 /** Signed 24 Bit PCM packed, native endian. \since 0.9.15 */
 203 #define PA_SAMPLE_S24NE PA_SAMPLE_S24LE
 204 /** Signed 24 Bit PCM in LSB of 32 Bit words, native endian. \since 0.9.15 */
 205 #define PA_SAMPLE_S24_32NE PA_SAMPLE_S24_32LE
 206
 207 /** Signed 16 Bit PCM, reverse endian */
 208 #define PA_SAMPLE_S16RE PA_SAMPLE_S16BE
 209 /** 32 Bit IEEE floating point, reverse endian */
 210 #define PA_SAMPLE_FLOAT32RE PA_SAMPLE_FLOAT32BE
 211 /** Signed 32 Bit PCM, reverse endian */
 212 #define PA_SAMPLE_S32RE PA_SAMPLE_S32BE
 213 /** Signed 24 Bit PCM, packed reverse endian. \since 0.9.15 */
 214 #define PA_SAMPLE_S24RE PA_SAMPLE_S24BE
 215 /** Signed 24 Bit PCM, in LSB of 32 Bit words, reverse endian. \since 0.9.15 */
 216 #define PA_SAMPLE_S24_32RE PA_SAMPLE_S24_32BE
 217 #endif
 218
 219 /** A Shortcut for PA_SAMPLE_FLOAT32NE */
 220 #define PA_SAMPLE_FLOAT32 PA_SAMPLE_FLOAT32NE
 221
 222 /** \cond fulldocs */
 223 /* Allow clients to check with #ifdef for thse sample formats */
 224 #define PA_SAMPLE_U8 PA_SAMPLE_U8
 225 #define PA_SAMPLE_ALAW PA_SAMPLE_ALAW
 226 #define PA_SAMPLE_ULAW PA_SAMPLE_ULAW
 227 #define PA_SAMPLE_S16LE PA_SAMPLE_S16LE
 228 #define PA_SAMPLE_S16BE PA_SAMPLE_S16BE
 229 #define PA_SAMPLE_FLOAT32LE PA_SAMPLE_FLOAT32LE
 230 #define PA_SAMPLE_FLOAT32BE PA_SAMPLE_FLOAT32BE
 231 #define PA_SAMPLE_S32LE PA_SAMPLE_S32LE
 232 #define PA_SAMPLE_S32BE PA_SAMPLE_S32BE
 233 #define PA_SAMPLE_S24LE PA_SAMPLE_S24LE
 234 #define PA_SAMPLE_S24BE PA_SAMPLE_S24BE
 235 #define PA_SAMPLE_S24_32LE PA_SAMPLE_S24_32LE
 236 #define PA_SAMPLE_S24_32BE PA_SAMPLE_S24_32BE
 237 /** \endcond */
 238
 239 /** A sample format and attribute specification */
 240 typedef struct pa_sample_spec {
 241     pa_sample_format_t format;
 242     /**< The sample format */
 243
 244     uint32_t rate;
 245     /**< The sample rate. (e.g. 44100) */
 246
 247     uint8_t channels;
 248     /**< Audio channels. (1 for mono, 2 for stereo, ...) */
 249 } pa_sample_spec;
 250
 251 /** Type for usec specifications (unsigned). Always 64 bit. */
 252 typedef uint64_t pa_usec_t;
 253
 254 /** Return the amount of bytes playback of a second of audio with the specified sample type takes */
 255 size_t pa_bytes_per_second(const pa_sample_spec *spec) PA_GCC_PURE;
 256
 257 /** Return the size of a frame with the specific sample type */
 258 size_t pa_frame_size(const pa_sample_spec *spec) PA_GCC_PURE;
 259
 260 /** Return the size of a sample with the specific sample type */
 261 size_t pa_sample_size(const pa_sample_spec *spec) PA_GCC_PURE;
 262
 263 /** Calculate the time the specified bytes take to play with the
 264  * specified sample type. The return value will always be rounded
 265  * down for non-integral return values. */
 266 pa_usec_t pa_bytes_to_usec(uint64_t length, const pa_sample_spec *spec) PA_GCC_PURE;
 267
 268 /** Calculates the number of bytes that are required for the specified
 269  * time. The return value will always be rounded down for non-integral
 270  * return values. \since 0.9 */
 271 size_t pa_usec_to_bytes(pa_usec_t t, const pa_sample_spec *spec) PA_GCC_PURE;
 272
 273 /** Initialize the specified sample spec and return a pointer to
 274  * it. The sample spec will have a defined state but
 275  * pa_sample_spec_valid() will fail for it. \since 0.9.13 */
 276 pa_sample_spec* pa_sample_spec_init(pa_sample_spec *spec);
 277
 278 /** Return non-zero when the sample type specification is valid */
 279 int pa_sample_spec_valid(const pa_sample_spec *spec) PA_GCC_PURE;
 280
 281 /** Return non-zero when the two sample type specifications match */
 282 int pa_sample_spec_equal(const pa_sample_spec*a, const pa_sample_spec*b) PA_GCC_PURE;
 283
 284 /** Return a descriptive string for the specified sample format. \since 0.8 */
 285 const char *pa_sample_format_to_string(pa_sample_format_t f) PA_GCC_PURE;
 286
 287 /** Parse a sample format text. Inverse of pa_sample_format_to_string() */
 288 pa_sample_format_t pa_parse_sample_format(const char *format) PA_GCC_PURE;
 289
 290 /** Maximum required string length for
 291  * pa_sample_spec_snprint(). Please note that this value can change
 292  * with any release without warning and without being considered API
 293  * or ABI breakage. You should not use this definition anywhere where
 294  * it might become part of an ABI. */
 295 #define PA_SAMPLE_SPEC_SNPRINT_MAX 32
 296
 297 /** Pretty print a sample type specification to a string */
 298 char* pa_sample_spec_snprint(char *s, size_t l, const pa_sample_spec *spec);
 299
 300 /** Pretty print a byte size value. (i.e. "2.5 MiB") */
 301 char* pa_bytes_snprint(char *s, size_t l, unsigned v);
 302
 303 PA_C_DECL_END
 304
 305 #endif