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