This file is part of polypaudio.
polypaudio is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published
+ 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.
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 General Public License
+ 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 "cdecl.h"
+/** \file
+ * Constants and routines for sample type handling */
+
PA_C_DECL_BEGIN
+/** Sample format */
enum pa_sample_format {
- PA_SAMPLE_U8,
- PA_SAMPLE_ALAW,
- PA_SAMPLE_ULAW,
- PA_SAMPLE_S16LE,
- PA_SAMPLE_S16BE,
- PA_SAMPLE_FLOAT32LE,
- PA_SAMPLE_FLOAT32BE,
- PA_SAMPLE_MAX
+ 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..1 */
+ PA_SAMPLE_FLOAT32BE, /**< 32 Bit IEEE floating point, big endian, range -1..1 */
+ PA_SAMPLE_MAX, /**< Upper limit of valid sample types */
+ PA_SAMPLE_INVALID = -1 /**< An invalid value */
};
#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
#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
#endif
+
+/** A Shortcut for PA_SAMPLE_FLOAT32NE */
#define PA_SAMPLE_FLOAT32 PA_SAMPLE_FLOAT32NE
/** A sample format and attribute specification */
uint8_t channels; /**< Audio channels. (1 for mono, 2 for stereo, ...) */
};
+/** 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 struct pa_sample_spec *spec);
+
+/** Return the size of a frame with the specific sample type */
size_t pa_frame_size(const struct pa_sample_spec *spec);
-uint32_t pa_bytes_to_usec(size_t length, const struct 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 struct pa_sample_spec *spec);
+
+/** Return non-zero when the sample type specification is valid */
int pa_sample_spec_valid(const struct pa_sample_spec *spec);
+
+/** Return non-zero when the two sample type specifications match */
int pa_sample_spec_equal(const struct pa_sample_spec*a, const struct pa_sample_spec*b);
-#define PA_SAMPLE_SNPRINT_MAX_LENGTH 32
-void pa_sample_snprint(char *s, size_t l, const struct pa_sample_spec *spec);
+/** 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 */
+void pa_sample_spec_snprint(char *s, size_t l, const struct pa_sample_spec *spec);
+/** Volume specification: 0: silence; < 256: diminished volume; 256: normal volume; > 256 amplified volume */
+typedef uint32_t pa_volume_t;
+
+/** Normal volume (100%) */
#define PA_VOLUME_NORM (0x100)
-#define PA_VOLUME_MUTE (0)
-uint32_t pa_volume_multiply(uint32_t a, uint32_t b);
+
+/** Muted volume (0%) */
+#define PA_VOLUME_MUTED (0)
+
+/** Multiply two volumes specifications, return the result. This uses PA_VOLUME_NORM as neutral element of multiplication. */
+pa_volume_t pa_volume_multiply(pa_volume_t a, pa_volume_t b);
+
+/** Convert volume from decibel to linear level. \since 0.4 */
+pa_volume_t pa_volume_from_dB(double f);
+
+/** Convert volume from linear level to decibel. \since 0.4 */
+double pa_volume_to_dB(pa_volume_t v);
+
+/** Convert volume to scaled value understandable by the user (between 0 and 1). \since 0.6 */
+double pa_volume_to_user(pa_volume_t v);
+
+/** Convert user volume to polypaudio volume. \since 0.6 */
+pa_volume_t pa_volume_from_user(double v);
+
+#ifdef INFINITY
+#define PA_DECIBEL_MININFTY (-INFINITY)
+#else
+/** This value is used as minus infinity when using pa_volume_{to,from}_dB(). \since 0.4 */
+#define PA_DECIBEL_MININFTY (-200)
+#endif
+
+/** Pretty print a byte size value. (i.e. "2.5 MB") */
+void pa_bytes_snprint(char *s, size_t l, unsigned v);
+
+/** Parse a sample format text */
+enum pa_sample_format pa_parse_sample_format(const char *format);
PA_C_DECL_END