1 #ifndef foosamplehfoo 2 #define foosamplehfoo 3 4 /* $Id: sample.h 2157 2008-03-27 23:25:08Z lennart $ */ 5 6 /*** 7 This file is part of PulseAudio. 8 9 Copyright 2004-2006 Lennart Poettering 10 Copyright 2006 Pierre Ossman <ossman (at) cendio.se> for Cendio AB 11 12 PulseAudio is free software; you can redistribute it and/or modify 13 it under the terms of the GNU Lesser General Public License as published 14 by the Free Software Foundation; either version 2 of the License, 15 or (at your option) any later version. 16 17 PulseAudio is distributed in the hope that it will be useful, but 18 WITHOUT ANY WARRANTY; without even the implied warranty of 19 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 20 General Public License for more details. 21 22 You should have received a copy of the GNU Lesser General Public License 23 along with PulseAudio; if not, write to the Free Software 24 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 25 USA. 26 ***/ 27 28 #include <inttypes.h> 29 #include <sys/types.h> 30 #include <sys/param.h> 31 #include <math.h> 32 33 #include <pulse/cdecl.h> 34 35 /** \page sample Sample Format Specifications 36 * 37 * \section overv_sec Overview 38 * 39 * PulseAudio is capable of handling a multitude of sample formats, rates 40 * and channels, transparently converting and mixing them as needed. 41 * 42 * \section format_sec Sample Format 43 * 44 * PulseAudio supports the following sample formats: 45 * 46 * \li PA_SAMPLE_U8 - Unsigned 8 bit integer PCM. 47 * \li PA_SAMPLE_S16LE - Signed 16 integer bit PCM, little endian. 48 * \li PA_SAMPLE_S16BE - Signed 16 integer bit PCM, big endian. 49 * \li PA_SAMPLE_FLOAT32LE - 32 bit IEEE floating point PCM, little endian. 50 * \li PA_SAMPLE_FLOAT32BE - 32 bit IEEE floating point PCM, big endian. 51 * \li PA_SAMPLE_ALAW - 8 bit a-Law. 52 * \li PA_SAMPLE_ULAW - 8 bit mu-Law. 53 * \li PA_SAMPLE_S32LE - Signed 32 bit integer PCM, little endian. 54 * \li PA_SAMPLE_S32BE - Signed 32 bit integer PCM, big endian. 55 * 56 * The floating point sample formats have the range from -1 to 1. 57 * 58 * The sample formats that are sensitive to endianness have convenience 59 * macros for native endian (NE), and reverse endian (RE). 60 * 61 * \section rate_sec Sample Rates 62 * 63 * PulseAudio supports any sample rate between 1 Hz and 4 GHz. There is no 64 * point trying to exceed the sample rate of the output device though as the 65 * signal will only get downsampled, consuming CPU on the machine running the 66 * server. 67 * 68 * \section chan_sec Channels 69 * 70 * PulseAudio supports up to 16 individiual channels. The order of the 71 * channels is up to the application, but they must be continous. To map 72 * channels to speakers, see \ref channelmap. 73 * 74 * \section calc_sec Calculations 75 * 76 * The PulseAudio library contains a number of convenience functions to do 77 * calculations on sample formats: 78 * 79 * \li pa_bytes_per_second() - The number of bytes one second of audio will 80 * take given a sample format. 81 * \li pa_frame_size() - The size, in bytes, of one frame (i.e. one set of 82 * samples, one for each channel). 83 * \li pa_sample_size() - The size, in bytes, of one sample. 84 * \li pa_bytes_to_usec() - Calculate the time it would take to play a buffer 85 * of a certain size. 86 * 87 * \section util_sec Convenience Functions 88 * 89 * The library also contains a couple of other convenience functions: 90 * 91 * \li pa_sample_spec_valid() - Tests if a sample format specification is 92 * valid. 93 * \li pa_sample_spec_equal() - Tests if the sample format specifications are 94 * identical. 95 * \li pa_sample_format_to_string() - Return a textual description of a 96 * sample format. 97 * \li pa_parse_sample_format() - Parse a text string into a sample format. 98 * \li pa_sample_spec_snprint() - Create a textual description of a complete 99 * sample format specification. 100 * \li pa_bytes_snprint() - Pretty print a byte value (e.g. 2.5 MiB). 101 */ 102 103 /** \file 104 * Constants and routines for sample type handling */ 105 106 PA_C_DECL_BEGIN 107 108 #if !defined(WORDS_BIGENDIAN) 109 #if defined(__BYTE_ORDER) 110 #if __BYTE_ORDER == __BIG_ENDIAN 111 #define WORDS_BIGENDIAN 112 #endif 113 #endif 114 #endif 115 116 /** Maximum number of allowed channels */ 117 #define PA_CHANNELS_MAX 32 118 119 /** Maximum allowed sample rate */ 120 #define PA_RATE_MAX (48000*4) 121 122 /** Sample format */ 123 typedef enum pa_sample_format { 124 PA_SAMPLE_U8, /**< Unsigned 8 Bit PCM */ 125 PA_SAMPLE_ALAW, /**< 8 Bit a-Law */ 126 PA_SAMPLE_ULAW, /**< 8 Bit mu-Law */ 127 PA_SAMPLE_S16LE, /**< Signed 16 Bit PCM, little endian (PC) */ 128 PA_SAMPLE_S16BE, /**< Signed 16 Bit PCM, big endian */ 129 PA_SAMPLE_FLOAT32LE, /**< 32 Bit IEEE floating point, little endian, range -1 to 1 */ 130 PA_SAMPLE_FLOAT32BE, /**< 32 Bit IEEE floating point, big endian, range -1 to 1 */ 131 PA_SAMPLE_S32LE, /**< Signed 32 Bit PCM, little endian (PC) */ 132 PA_SAMPLE_S32BE, /**< Signed 32 Bit PCM, big endian (PC) */ 133 PA_SAMPLE_MAX, /**< Upper limit of valid sample types */ 134 PA_SAMPLE_INVALID = -1 /**< An invalid value */ 135 } pa_sample_format_t; 136 137 #ifdef WORDS_BIGENDIAN 138 /** Signed 16 Bit PCM, native endian */ 139 #define PA_SAMPLE_S16NE PA_SAMPLE_S16BE 140 /** 32 Bit IEEE floating point, native endian */ 141 #define PA_SAMPLE_FLOAT32NE PA_SAMPLE_FLOAT32BE 142 /** Signed 32 Bit PCM, native endian */ 143 #define PA_SAMPLE_S32NE PA_SAMPLE_S32BE 144 /** Signed 16 Bit PCM reverse endian */ 145 #define PA_SAMPLE_S16RE PA_SAMPLE_S16LE 146 /** 32 Bit IEEE floating point, reverse endian */ 147 #define PA_SAMPLE_FLOAT32RE PA_SAMPLE_FLOAT32LE 148 /** Signed 32 Bit PCM reverse endian */ 149 #define PA_SAMPLE_S32RE PA_SAMPLE_S32LE 150 #else 151 /** Signed 16 Bit PCM, native endian */ 152 #define PA_SAMPLE_S16NE PA_SAMPLE_S16LE 153 /** 32 Bit IEEE floating point, native endian */ 154 #define PA_SAMPLE_FLOAT32NE PA_SAMPLE_FLOAT32LE 155 /** Signed 32 Bit PCM, native endian */ 156 #define PA_SAMPLE_S32NE PA_SAMPLE_S32LE 157 /** Signed 16 Bit PCM reverse endian */ 158 #define PA_SAMPLE_S16RE PA_SAMPLE_S16BE 159 /** 32 Bit IEEE floating point, reverse endian */ 160 #define PA_SAMPLE_FLOAT32RE PA_SAMPLE_FLOAT32BE 161 /** Signed 32 Bit PCM reverse endian */ 162 #define PA_SAMPLE_S32RE PA_SAMPLE_S32BE 163 #endif 164 165 /** A Shortcut for PA_SAMPLE_FLOAT32NE */ 166 #define PA_SAMPLE_FLOAT32 PA_SAMPLE_FLOAT32NE 167 168 /** A sample format and attribute specification */ 169 typedef struct pa_sample_spec { 170 pa_sample_format_t format; /**< The sample format */ 171 uint32_t rate; /**< The sample rate. (e.g. 44100) */ 172 uint8_t channels; /**< Audio channels. (1 for mono, 2 for stereo, ...) */ 173 } pa_sample_spec; 174 175 /** Type for usec specifications (unsigned). May be either 32 or 64 bit, depending on the architecture */ 176 typedef uint64_t pa_usec_t; 177 178 /** Return the amount of bytes playback of a second of audio with the specified sample type takes */ 179 size_t pa_bytes_per_second(const pa_sample_spec *spec) PA_GCC_PURE; 180 181 /** Return the size of a frame with the specific sample type */ 182 size_t pa_frame_size(const pa_sample_spec *spec) PA_GCC_PURE; 183 184 /** Return the size of a sample with the specific sample type */ 185 size_t pa_sample_size(const pa_sample_spec *spec) PA_GCC_PURE; 186 187 /** Calculate the time the specified bytes take to play with the specified sample type */ 188 pa_usec_t pa_bytes_to_usec(uint64_t length, const pa_sample_spec *spec) PA_GCC_PURE; 189 190 /** Calculates the number of bytes that are required for the specified time. \since 0.9 */ 191 size_t pa_usec_to_bytes(pa_usec_t t, const pa_sample_spec *spec) PA_GCC_PURE; 192 193 /** Return non-zero when the sample type specification is valid */ 194 int pa_sample_spec_valid(const pa_sample_spec *spec) PA_GCC_PURE; 195 196 /** Return non-zero when the two sample type specifications match */ 197 int pa_sample_spec_equal(const pa_sample_spec*a, const pa_sample_spec*b) PA_GCC_PURE; 198 199 /** Return a descriptive string for the specified sample format. \since 0.8 */ 200 const char *pa_sample_format_to_string(pa_sample_format_t f) PA_GCC_PURE; 201 202 /** Parse a sample format text. Inverse of pa_sample_format_to_string() */ 203 pa_sample_format_t pa_parse_sample_format(const char *format) PA_GCC_PURE; 204 205 /** Maximum required string length for pa_sample_spec_snprint() */ 206 #define PA_SAMPLE_SPEC_SNPRINT_MAX 32 207 208 /** Pretty print a sample type specification to a string */ 209 char* pa_sample_spec_snprint(char *s, size_t l, const pa_sample_spec *spec); 210 211 /** Pretty print a byte size value. (i.e. "2.5 MiB") */ 212 char* pa_bytes_snprint(char *s, size_t l, unsigned v); 213 214 PA_C_DECL_END 215 216 #endif 217
