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#ifndef foosamplehfoo
#define foosamplehfoo
/* $Id$ */
/***
This file is part of polypaudio.
polypaudio 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.
polypaudio 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 polypaudio; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
USA.
***/
#include <inttypes.h>
#include <sys/types.h>
#include <math.h>
#include <polyp/cdecl.h>
/** \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
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