From f44ba092651aa75055e109e04b4164ea92ae7fdc Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Mon, 19 Jun 2006 21:53:48 +0000 Subject: big s/polyp/pulse/g git-svn-id: file:///home/lennart/svn/public/pulseaudio/trunk@1033 fefdeb5f-60dc-0310-8127-8f9354f1896f --- src/pulse/sample.h | 189 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 189 insertions(+) create mode 100644 src/pulse/sample.h (limited to 'src/pulse/sample.h') diff --git a/src/pulse/sample.h b/src/pulse/sample.h new file mode 100644 index 00000000..848fd16d --- /dev/null +++ b/src/pulse/sample.h @@ -0,0 +1,189 @@ +#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 -- cgit