#include <inttypes.h>
#include <sys/types.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 */
};
#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 */
struct pa_sample_spec {
- enum pa_sample_format format;
- uint32_t rate;
- uint8_t channels;
+ enum pa_sample_format format; /**< The sample format */
+ uint32_t rate; /**< The sample rate. (e.g. 44100) */
+ uint8_t channels; /**< Audio channels. (1 for mono, 2 for stereo, ...) */
};
+/** Return the amount of bytes playback of a second of audio with the speicified sample type takes */
size_t pa_bytes_per_second(const struct pa_sample_spec *spec);
-size_t pa_sample_size(const struct pa_sample_spec *spec);
-uint32_t pa_samples_usec(size_t length, 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);
+
+/** Calculate the time the specified bytes take to play with the specified sample type */
+uint32_t pa_bytes_to_usec(size_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);
-int pa_sample_spec_equal(const struct pa_sample_spec*a, const struct pa_sample_spec*b);
+/** 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);
+/** Maximum required string length for pa_sample_spec_snprint() */
#define PA_SAMPLE_SNPRINT_MAX_LENGTH 32
-void pa_sample_snprint(char *s, size_t l, const struct pa_sample_spec *spec);
+
+/** 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)
+
+/** 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);
+
+PA_C_DECL_END
#endif