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 2.1 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
  30 #include <pulse/gccmacro.h>
  31 #include <pulse/cdecl.h>
  32 #include <pulse/version.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 individual 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  * See also \subpage sample
 110  */
 111
 112 PA_C_DECL_BEGIN
 113
 114 #if !defined(WORDS_BIGENDIAN)
 115 #if defined(__BYTE_ORDER)
 116 #if __BYTE_ORDER == __BIG_ENDIAN
 117 #define WORDS_BIGENDIAN
 118 #endif
 119 #endif
 120 #endif
 121
 122 /** Maximum number of allowed channels */
 123 #define PA_CHANNELS_MAX 32U
 124
 125 /** Maximum allowed sample rate */
 126 #define PA_RATE_MAX (48000U*4U)
 127
 128 /** Sample format */
 129 typedef enum pa_sample_format {
 130     PA_SAMPLE_U8,
 131     /**< Unsigned 8 Bit PCM */
 132
 133     PA_SAMPLE_ALAW,
 134     /**< 8 Bit a-Law */
 135
 136     PA_SAMPLE_ULAW,
 137     /**< 8 Bit mu-Law */
 138
 139     PA_SAMPLE_S16LE,
 140     /**< Signed 16 Bit PCM, little endian (PC) */
 141
 142     PA_SAMPLE_S16BE,
 143     /**< Signed 16 Bit PCM, big endian */
 144
 145     PA_SAMPLE_FLOAT32LE,
 146     /**< 32 Bit IEEE floating point, little endian (PC), range -1.0 to 1.0 */
 147
 148     PA_SAMPLE_FLOAT32BE,
 149     /**< 32 Bit IEEE floating point, big endian, range -1.0 to 1.0 */
 150
 151     PA_SAMPLE_S32LE,
 152     /**< Signed 32 Bit PCM, little endian (PC) */
 153
 154     PA_SAMPLE_S32BE,
 155     /**< Signed 32 Bit PCM, big endian */
 156
 157     PA_SAMPLE_S24LE,
 158     /**< Signed 24 Bit PCM packed, little endian (PC). \since 0.9.15 */
 159
 160     PA_SAMPLE_S24BE,
 161     /**< Signed 24 Bit PCM packed, big endian. \since 0.9.15 */
 162
 163     PA_SAMPLE_S24_32LE,
 164     /**< Signed 24 Bit PCM in LSB of 32 Bit words, little endian (PC). \since 0.9.15 */
 165
 166     PA_SAMPLE_S24_32BE,
 167     /**< Signed 24 Bit PCM in LSB of 32 Bit words, big endian. \since 0.9.15 */
 168
 169     PA_SAMPLE_MAX,
 170     /**< Upper limit of valid sample types */
 171
 172     PA_SAMPLE_INVALID = -1
 173     /**< An invalid value */
 174 } pa_sample_format_t;
 175
 176 #ifdef WORDS_BIGENDIAN
 177 /** Signed 16 Bit PCM, native endian */
 178 #define PA_SAMPLE_S16NE PA_SAMPLE_S16BE
 179 /** 32 Bit IEEE floating point, native endian */
 180 #define PA_SAMPLE_FLOAT32NE PA_SAMPLE_FLOAT32BE
 181 /** Signed 32 Bit PCM, native endian */
 182 #define PA_SAMPLE_S32NE PA_SAMPLE_S32BE
 183 /** Signed 24 Bit PCM packed, native endian. \since 0.9.15 */
 184 #define PA_SAMPLE_S24NE PA_SAMPLE_S24BE
 185 /** Signed 24 Bit PCM in LSB of 32 Bit words, native endian. \since 0.9.15 */
 186 #define PA_SAMPLE_S24_32NE PA_SAMPLE_S24_32BE
 187
 188 /** Signed 16 Bit PCM reverse endian */
 189 #define PA_SAMPLE_S16RE PA_SAMPLE_S16LE
 190 /** 32 Bit IEEE floating point, reverse endian */
 191 #define PA_SAMPLE_FLOAT32RE PA_SAMPLE_FLOAT32LE
 192 /** Signed 32 Bit PCM, reverse endian */
 193 #define PA_SAMPLE_S32RE PA_SAMPLE_S32LE
 194 /** Signed 24 Bit PCM, packed reverse endian. \since 0.9.15 */
 195 #define PA_SAMPLE_S24RE PA_SAMPLE_S24LE
 196 /** Signed 24 Bit PCM, in LSB of 32 Bit words, reverse endian. \since 0.9.15 */
 197 #define PA_SAMPLE_S24_32RE PA_SAMPLE_S24_32LE
 198 #else
 199 /** Signed 16 Bit PCM, native endian */
 200 #define PA_SAMPLE_S16NE PA_SAMPLE_S16LE
 201 /** 32 Bit IEEE floating point, native endian */
 202 #define PA_SAMPLE_FLOAT32NE PA_SAMPLE_FLOAT32LE
 203 /** Signed 32 Bit PCM, native endian */
 204 #define PA_SAMPLE_S32NE PA_SAMPLE_S32LE
 205 /** Signed 24 Bit PCM packed, native endian. \since 0.9.15 */
 206 #define PA_SAMPLE_S24NE PA_SAMPLE_S24LE
 207 /** Signed 24 Bit PCM in LSB of 32 Bit words, native endian. \since 0.9.15 */
 208 #define PA_SAMPLE_S24_32NE PA_SAMPLE_S24_32LE
 209
 210 /** Signed 16 Bit PCM, reverse endian */
 211 #define PA_SAMPLE_S16RE PA_SAMPLE_S16BE
 212 /** 32 Bit IEEE floating point, reverse endian */
 213 #define PA_SAMPLE_FLOAT32RE PA_SAMPLE_FLOAT32BE
 214 /** Signed 32 Bit PCM, reverse endian */
 215 #define PA_SAMPLE_S32RE PA_SAMPLE_S32BE
 216 /** Signed 24 Bit PCM, packed reverse endian. \since 0.9.15 */
 217 #define PA_SAMPLE_S24RE PA_SAMPLE_S24BE
 218 /** Signed 24 Bit PCM, in LSB of 32 Bit words, reverse endian. \since 0.9.15 */
 219 #define PA_SAMPLE_S24_32RE PA_SAMPLE_S24_32BE
 220 #endif
 221
 222 /** A Shortcut for PA_SAMPLE_FLOAT32NE */
 223 #define PA_SAMPLE_FLOAT32 PA_SAMPLE_FLOAT32NE
 224
 225 /** \cond fulldocs */
 226 /* Allow clients to check with #ifdef for these sample formats */
 227 #define PA_SAMPLE_U8 PA_SAMPLE_U8
 228 #define PA_SAMPLE_ALAW PA_SAMPLE_ALAW
 229 #define PA_SAMPLE_ULAW PA_SAMPLE_ULAW
 230 #define PA_SAMPLE_S16LE PA_SAMPLE_S16LE
 231 #define PA_SAMPLE_S16BE PA_SAMPLE_S16BE
 232 #define PA_SAMPLE_FLOAT32LE PA_SAMPLE_FLOAT32LE
 233 #define PA_SAMPLE_FLOAT32BE PA_SAMPLE_FLOAT32BE
 234 #define PA_SAMPLE_S32LE PA_SAMPLE_S32LE
 235 #define PA_SAMPLE_S32BE PA_SAMPLE_S32BE
 236 #define PA_SAMPLE_S24LE PA_SAMPLE_S24LE
 237 #define PA_SAMPLE_S24BE PA_SAMPLE_S24BE
 238 #define PA_SAMPLE_S24_32LE PA_SAMPLE_S24_32LE
 239 #define PA_SAMPLE_S24_32BE PA_SAMPLE_S24_32BE
 240 /** \endcond */
 241
 242 /** A sample format and attribute specification */
 243 typedef struct pa_sample_spec {
 244     pa_sample_format_t format;
 245     /**< The sample format */
 246
 247     uint32_t rate;
 248     /**< The sample rate. (e.g. 44100) */
 249
 250     uint8_t channels;
 251     /**< Audio channels. (1 for mono, 2 for stereo, ...) */
 252 } pa_sample_spec;
 253
 254 /** Type for usec specifications (unsigned). Always 64 bit. */
 255 typedef uint64_t pa_usec_t;
 256
 257 /** Return the amount of bytes playback of a second of audio with the specified sample type takes */
 258 size_t pa_bytes_per_second(const pa_sample_spec *spec) PA_GCC_PURE;
 259
 260 /** Return the size of a frame with the specific sample type */
 261 size_t pa_frame_size(const pa_sample_spec *spec) PA_GCC_PURE;
 262
 263 /** Return the size of a sample with the specific sample type */
 264 size_t pa_sample_size(const pa_sample_spec *spec) PA_GCC_PURE;
 265
 266 /** Similar to pa_sample_size() but take a sample format instead of a
 267  * full sample spec. \since 0.9.15 */
 268 size_t pa_sample_size_of_format(pa_sample_format_t f) PA_GCC_PURE;
 269
 270 /** Calculate the time the specified bytes take to play with the
 271  * specified sample type. The return value will always be rounded
 272  * down for non-integral return values. */
 273 pa_usec_t pa_bytes_to_usec(uint64_t length, const pa_sample_spec *spec) PA_GCC_PURE;
 274
 275 /** Calculates the number of bytes that are required for the specified
 276  * time. The return value will always be rounded down for non-integral
 277  * return values. \since 0.9 */
 278 size_t pa_usec_to_bytes(pa_usec_t t, const pa_sample_spec *spec) PA_GCC_PURE;
 279
 280 /** Initialize the specified sample spec and return a pointer to
 281  * it. The sample spec will have a defined state but
 282  * pa_sample_spec_valid() will fail for it. \since 0.9.13 */
 283 pa_sample_spec* pa_sample_spec_init(pa_sample_spec *spec);
 284
 285 /** Return non-zero when the sample type specification is valid */
 286 int pa_sample_spec_valid(const pa_sample_spec *spec) PA_GCC_PURE;
 287
 288 /** Return non-zero when the two sample type specifications match */
 289 int pa_sample_spec_equal(const pa_sample_spec*a, const pa_sample_spec*b) PA_GCC_PURE;
 290
 291 /** Return a descriptive string for the specified sample format. \since 0.8 */
 292 const char *pa_sample_format_to_string(pa_sample_format_t f) PA_GCC_PURE;
 293
 294 /** Parse a sample format text. Inverse of pa_sample_format_to_string() */
 295 pa_sample_format_t pa_parse_sample_format(const char *format) PA_GCC_PURE;
 296
 297 /** Maximum required string length for
 298  * pa_sample_spec_snprint(). Please note that this value can change
 299  * with any release without warning and without being considered API
 300  * or ABI breakage. You should not use this definition anywhere where
 301  * it might become part of an ABI. */
 302 #define PA_SAMPLE_SPEC_SNPRINT_MAX 32
 303
 304 /** Pretty print a sample type specification to a string */
 305 char* pa_sample_spec_snprint(char *s, size_t l, const pa_sample_spec *spec);
 306
 307 /** Maximum required string length for pa_bytes_snprint(). Please note
 308  * that this value can change with any release without warning and
 309  * without being considered API or ABI breakage. You should not use
 310  * this definition anywhere where it might become part of an
 311  * ABI. \since 0.9.16 */
 312 #define PA_BYTES_SNPRINT_MAX 11
 313
 314 /** Pretty print a byte size value. (i.e. "2.5 MiB") */
 315 char* pa_bytes_snprint(char *s, size_t l, unsigned v);
 316
 317 /** Return 1 when the specified format is little endian, return -1
 318  * when endianess does not apply to this format. \since 0.9.16 */
 319 int pa_sample_format_is_le(pa_sample_format_t f) PA_GCC_PURE;
 320
 321 /** Return 1 when the specified format is big endian, return -1 when
 322  * endianess does not apply to this format. \since 0.9.16 */
 323 int pa_sample_format_is_be(pa_sample_format_t f) PA_GCC_PURE;
 324
 325 #ifdef WORDS_BIGENDIAN
 326 #define pa_sample_format_is_ne(f) pa_sample_format_is_be(f)
 327 #define pa_sample_format_is_re(f) pa_sample_format_is_le(f)
 328 #else
 329 /** Return 1 when the specified format is native endian, return -1
 330  * when endianess does not apply to this format. \since 0.9.16 */
 331 #define pa_sample_format_is_ne(f) pa_sample_format_is_le(f)
 332 /** Return 1 when the specified format is reverse endian, return -1
 333  * when endianess does not apply to this format. \since 0.9.16 */
 334 #define pa_sample_format_is_re(f) pa_sample_format_is_be(f)
 335 #endif
 336
 337 PA_C_DECL_END
 338
 339 #endif