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

@@ -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 <inttypes.h>
+#include <sys/types.h>
+#include <math.h>
+
+#include <pulse/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