cubeb.h

/*
 * Copyright © 2011 Mozilla Foundation
 *
 * This program is made available under an ISC-style license.  See the
 * accompanying file LICENSE for details.
 */
#if !defined(CUBEB_c2f983e9_c96f_e71c_72c3_bbf62992a382)
#define CUBEB_c2f983e9_c96f_e71c_72c3_bbf62992a382

#include <cubeb/cubeb-stdint.h>

#if defined(__cplusplus)
extern "C" {
#endif

/** @mainpage

    @section intro Introduction

    This is the documentation for the <tt>libcubeb</tt> C API.
    <tt>libcubeb</tt> is a callback-based audio API library allowing the
    authoring of portable multiplatform audio playback.

    @section example Example code

    @code
    cubeb * app_ctx;
    cubeb_init(&app_ctx, "Example Application");

    cubeb_stream_params params;
    params.format = CUBEB_SAMPLE_S16NE;
    params.rate = 48000;
    params.channels = 2;

    unsigned int latency_ms = 250;

    cubeb_stream * stm;
    cubeb_stream_init(app_ctx, &stm, "Example Stream 1", params,
                      latency_ms, data_cb, state_cb, NULL);

    cubeb_stream_start(stm);
    for (;;) {
      cubeb_stream_get_position(stm, &ts);
      printf("time=%llu\n", ts);
      sleep(1);
    }
    cubeb_stream_stop(stm);

    cubeb_stream_destroy(stm);
    cubeb_destroy(app_ctx);
    @endcode

    @code
    long data_cb(cubeb_stream * stm, void * user, void * buffer, long nframes)
    {
      short * buf = buffer;
      for (i = 0; i < nframes; ++i) {
        for (c = 0; c < params.channels; ++c) {
          buf[i][c] = 0;
        }
      }
      return nframes;
    }
    @endcode

    @code
    void state_cb(cubeb_stream * stm, void * user, cubeb_state state)
    {
      printf("state=%d\n", state);
    }
    @endcode
*/

/** @file
    The <tt>libcubeb</tt> C API. */

typedef struct cubeb cubeb;               /**< Opaque handle referencing the application state. */
typedef struct cubeb_stream cubeb_stream; /**< Opaque handle referencing the stream state. */

/** Sample format enumeration. */
typedef enum {
  /**< Little endian 16-bit signed PCM. */
  CUBEB_SAMPLE_S16LE,
  /**< Big endian 16-bit signed PCM. */
  CUBEB_SAMPLE_S16BE,
  /**< Little endian 32-bit IEEE floating point PCM. */
  CUBEB_SAMPLE_FLOAT32LE,
  /**< Big endian 32-bit IEEE floating point PCM. */
  CUBEB_SAMPLE_FLOAT32BE,
#if defined(WORDS_BIGENDIAN) || defined(__BIG_ENDIAN__)
  /**< Native endian 16-bit signed PCM. */
  CUBEB_SAMPLE_S16NE = CUBEB_SAMPLE_S16BE,
  /**< Native endian 32-bit IEEE floating point PCM. */
  CUBEB_SAMPLE_FLOAT32NE = CUBEB_SAMPLE_FLOAT32BE
#else
  /**< Native endian 16-bit signed PCM. */
  CUBEB_SAMPLE_S16NE = CUBEB_SAMPLE_S16LE,
  /**< Native endian 32-bit IEEE floating point PCM. */
  CUBEB_SAMPLE_FLOAT32NE = CUBEB_SAMPLE_FLOAT32LE
#endif
} cubeb_sample_format;

#if defined(__ANDROID__)
typedef enum {
    CUBEB_STREAM_TYPE_VOICE_CALL = 0,
    CUBEB_STREAM_TYPE_SYSTEM = 1,
    CUBEB_STREAM_TYPE_RING = 2,
    CUBEB_STREAM_TYPE_MUSIC = 3,
    CUBEB_STREAM_TYPE_ALARM = 4,
    CUBEB_STREAM_TYPE_NOTIFICATION = 5,
    CUBEB_STREAM_TYPE_BLUETOOTH_SCO = 6,
    CUBEB_STREAM_TYPE_SYSTEM_ENFORCED = 7,
    CUBEB_STREAM_TYPE_DTMF = 8,
    CUBEB_STREAM_TYPE_TTS = 9,
    CUBEB_STREAM_TYPE_FM = 10,

    CUBEB_STREAM_TYPE_MAX
} cubeb_stream_type;
#endif

typedef void * cubeb_devid;

/** Stream format initialization parameters. */
typedef struct {
  cubeb_sample_format format; /**< Requested sample format.  One of
                                   #cubeb_sample_format. */
  unsigned int rate;          /**< Requested sample rate.  Valid range is [1000, 192000]. */
  unsigned int channels;      /**< Requested channel count.  Valid range is [1, 8]. */
#if defined(__ANDROID__)
  cubeb_stream_type stream_type; /**< Used to map Android audio stream types */
#endif
  cubeb_devid devid;
} cubeb_stream_params;

/** Output device description */
typedef struct {
  char * output_name; /**< The name of the output device */
  char * input_name; /**< The name of the input device */
} cubeb_device;

/** Stream states signaled via state_callback. */
typedef enum {
  CUBEB_STATE_STARTED, /**< Stream started. */
  CUBEB_STATE_STOPPED, /**< Stream stopped. */
  CUBEB_STATE_DRAINED, /**< Stream drained. */
  CUBEB_STATE_ERROR    /**< Stream disabled due to error. */
} cubeb_state;

/** Result code enumeration. */
enum {
  CUBEB_OK = 0,                       /**< Success. */
  CUBEB_ERROR = -1,                   /**< Unclassified error. */
  CUBEB_ERROR_INVALID_FORMAT = -2,    /**< Unsupported #cubeb_stream_params requested. */
  CUBEB_ERROR_INVALID_PARAMETER = -3, /**< Invalid parameter specified. */
  CUBEB_ERROR_NOT_SUPPORTED = -4      /**< Optional function not implemented in current backend. */
};

/**
 * Whether a particular device is an input device (e.g. a microphone), or an
 * output device (e.g. headphones). */
typedef enum {
  CUBEB_DEVICE_TYPE_UNKNOWN,
  CUBEB_DEVICE_TYPE_INPUT,
  CUBEB_DEVICE_TYPE_OUTPUT
} cubeb_device_type;

/**
 * The state of a device.
 */
typedef enum {
  CUBEB_DEVICE_STATE_DISABLED, /**< The device has been disabled at the system level. */
  CUBEB_DEVICE_STATE_UNPLUGGED, /**< The device is enabled, but nothing is plugged into it. */
  CUBEB_DEVICE_STATE_ENABLED /**< The device is enabled. */
} cubeb_device_state;

/** An opaque handle used to refer a particular input or output device
 *  accross calls. */
/**
 * Architecture specific sample type.
 */
typedef enum {
  CUBEB_DEVICE_FMT_S16LE          = 0x0010, /**< 16-bit integers, Little Endian. */
  CUBEB_DEVICE_FMT_S16BE          = 0x0020, /**< 16-bit integers, Big Endian. */
  CUBEB_DEVICE_FMT_F32LE          = 0x1000, /**< 32-bit floating point, Little Endian. */
  CUBEB_DEVICE_FMT_F32BE          = 0x2000  /**< 32-bit floating point, Big Endian. */
} cubeb_device_fmt;

#if defined(WORDS_BIGENDIAN) || defined(__BIG_ENDIAN__)
/** 16-bit integers, native endianess, when on a Big Endian environment. */
#define CUBEB_DEVICE_FMT_S16NE     CUBEB_DEVICE_FMT_S16BE
/** 32-bit floating points, native endianess, when on a Big Endian environment. */
#define CUBEB_DEVICE_FMT_F32NE     CUBEB_DEVICE_FMT_F32BE
#else
/** 16-bit integers, native endianess, when on a Little Endian environment. */
#define CUBEB_DEVICE_FMT_S16NE     CUBEB_DEVICE_FMT_S16LE
/** 32-bit floating points, native endianess, when on a Little Endian
 *  environment. */
#define CUBEB_DEVICE_FMT_F32NE     CUBEB_DEVICE_FMT_F32LE
#endif
/** All the 16-bit integers types. */
#define CUBEB_DEVICE_FMT_S16_MASK  (CUBEB_DEVICE_FMT_S16LE | CUBEB_DEVICE_FMT_S16BE)
/** All the 32-bit floating points types. */
#define CUBEB_DEVICE_FMT_F32_MASK  (CUBEB_DEVICE_FMT_F32LE | CUBEB_DEVICE_FMT_F32BE)
/** All the device formats types. */
#define CUBEB_DEVICE_FMT_ALL       (CUBEB_DEVICE_FMT_S16_MASK | CUBEB_DEVICE_FMT_F32_MASK)

/** Channel type for a `cubeb_stream`. Depending on the backend and platform
 * used, this can control inter-stream interruption, ducking, and volume
 * control.
 */
typedef enum {
  CUBEB_DEVICE_PREF_NONE          = 0x00,
  CUBEB_DEVICE_PREF_MULTIMEDIA    = 0x01,
  CUBEB_DEVICE_PREF_VOICE         = 0x02,
  CUBEB_DEVICE_PREF_NOTIFICATION  = 0x04,
  CUBEB_DEVICE_PREF_ALL           = 0x0F
} cubeb_device_pref;

/** This structure holds the characteristics
 *  of an input or output audio device. It can be obtained using
 *  `cubeb_enumerate_devices`, and must be destroyed using
 *  `cubeb_device_info_destroy`. */
typedef struct {
  cubeb_devid devid;          /**< Device identifier handle. */
  char * device_id;           /**< Device identifier which might be presented in a UI. */
  char * friendly_name;       /**< Friendly device name which might be presented in a UI. */
  char * group_id;            /**< Two devices have the same group identifier if they belong to the same physical device; for example a headset and microphone. */
  char * vendor_name;         /**< Optional vendor name, may be NULL. */

  cubeb_device_type type;     /**< Type of device (Input/Output). */
  cubeb_device_state state;   /**< State of device disabled/enabled/unplugged. */
  cubeb_device_pref preferred;/**< Preferred device. */

  cubeb_device_fmt format;    /**< Sample format supported. */
  cubeb_device_fmt default_format; /**< The default sample format for this device. */
  unsigned int max_channels;  /**< Channels. */
  unsigned int default_rate;  /**< Default/Preferred sample rate. */
  unsigned int max_rate;      /**< Maximum sample rate supported. */
  unsigned int min_rate;      /**< Minimum sample rate supported. */

  unsigned int latency_lo_ms; /**< Lowest possible latency in milliseconds. */
  unsigned int latency_hi_ms; /**< Higest possible latency in milliseconds. */
} cubeb_device_info;

/** Device collection. */
typedef struct {
  uint32_t count;                 /**< Device count in collection. */
  cubeb_device_info * device[1];   /**< Array of pointers to device info. */
} cubeb_device_collection;

/** User supplied data callback.
    @param stream The stream for which this callback fired
    @param user_ptr The pointer passed to cubeb_stream_create
    @param input_buffer A pointer containing the input data, or nullptr
                        if this is an output-only stream.
    @param output_buffer A pointer containing the output data, or nullptr
                         if this is an input -only stream.
    @param nframes The number of frames of the two buffer.
    @retval Number of frames written to the output buffer, which must equal
            nframes except at end of stream.
    @retval CUBEB_ERROR on error, in which case the data callback will stop
            and the stream will enter a shutdown state. */
typedef long (* cubeb_data_callback)(cubeb_stream * stream,
                                     void * user_ptr,
                                     void * input_buffer,
                                     void * output_buffer,
                                     long nframes);

/** User supplied state callback.
    @param stream
    @param user_ptr
    @param state */
typedef void (* cubeb_state_callback)(cubeb_stream * stream,
                                      void * user_ptr,
                                      cubeb_state state);

/**
 * User supplied callback called when the underlying device changed.
 * @param user */
typedef void (* cubeb_device_changed_callback)(void * user_ptr);

/**
 * User supplied callback called when the underlying device collection changed.
 * @param context
 * @param user_ptr */
typedef void (* cubeb_device_collection_changed_callback)(cubeb * context, void * user_ptr);

/** Initialize an application context.  This will perform any library or
    application scoped initialization.
    @param context
    @param context_name
    @retval CUBEB_OK
    @retval CUBEB_ERROR */
int cubeb_init(cubeb ** context, char const * context_name);

/** Get a read-only string identifying this context's current backend.
    @param context
    @retval Read-only string identifying current backend. */
char const * cubeb_get_backend_id(cubeb * context);

/** Get the maximum possible number of channels.
    @param context
    @param max_channels The maximum number of channels.
    @retval CUBEB_OK
    @retval CUBEB_ERROR_INVALID_PARAMETER
    @retval CUBEB_ERROR_NOT_SUPPORTED
    @retval CUBEB_ERROR */
int cubeb_get_max_channel_count(cubeb * context, uint32_t * max_channels);

/** Get the minimal latency value, in milliseconds, that is guaranteed to work
    when creating a stream for the specified sample rate. This is platform and
    backend dependant.
    @param context
    @param params On some backends, the minimum achievable latency depends on
                  the characteristics of the stream.
    @param latency_ms The latency value, in ms, to pass to cubeb_stream_init.
    @retval CUBEB_OK
    @retval CUBEB_ERROR_INVALID_PARAMETER
    @retval CUBEB_ERROR_NOT_SUPPORTED */
int cubeb_get_min_latency(cubeb * context,
                          cubeb_stream_params params,
                          uint32_t * latency_ms);

/** Get the preferred sample rate for this backend: this is hardware and
    platform dependant, and can avoid resampling, and/or trigger fastpaths.
    @param context
    @param rate The samplerate (in Hz) the current configuration prefers.
    @retval CUBEB_OK
    @retval CUBEB_ERROR_INVALID_PARAMETER
    @retval CUBEB_ERROR_NOT_SUPPORTED */
int cubeb_get_preferred_sample_rate(cubeb * context, uint32_t * rate);

/** Destroy an application context.
    @param context */
void cubeb_destroy(cubeb * context);

/** Initialize a stream associated with the supplied application context.
    @param context
    @param stream
    @param stream_name
    @param input_stream_params Parameters for the input side of the stream, or
                               NULL if this stream is output only.
    @param output_stream_params Parameters for the output side of the stream, or
                                NULL if this stream is input only.
    @param latency Approximate stream latency in milliseconds.  Valid range
                   is [1, 2000].
    @param data_callback Will be called to preroll data before playback is
                         started by cubeb_stream_start.
    @param state_callback
    @param user_ptr
    @retval CUBEB_OK
    @retval CUBEB_ERROR
    @retval CUBEB_ERROR_INVALID_FORMAT */
int cubeb_stream_init(cubeb * context,
                      cubeb_stream ** stream,
                      char const * stream_name,
                      cubeb_stream_params * input_stream_params,
                      cubeb_stream_params * output_stream_params,
                      unsigned int latency,
                      cubeb_data_callback data_callback,
                      cubeb_state_callback state_callback,
                      void * user_ptr);

/** Destroy a stream.
    @param stream */
void cubeb_stream_destroy(cubeb_stream * stream);

/** Start playback.
    @param stream
    @retval CUBEB_OK
    @retval CUBEB_ERROR */
int cubeb_stream_start(cubeb_stream * stream);

/** Stop playback.
    @param stream
    @retval CUBEB_OK
    @retval CUBEB_ERROR */
int cubeb_stream_stop(cubeb_stream * stream);

/** Get the current stream playback position.
    @param stream
    @param position Playback position in frames.
    @retval CUBEB_OK
    @retval CUBEB_ERROR */
int cubeb_stream_get_position(cubeb_stream * stream, uint64_t * position);

/** Get the latency for this stream, in frames. This is the number of frames
    between the time cubeb acquires the data in the callback and the listener
    can hear the sound.
    @param stream
    @param latency Current approximate stream latency in frames.
    @retval CUBEB_OK
    @retval CUBEB_ERROR_NOT_SUPPORTED
    @retval CUBEB_ERROR */
int cubeb_stream_get_latency(cubeb_stream * stream, uint32_t * latency);

/** Set the volume for a stream.
    @param stream the stream for which to adjust the volume.
    @param volume a float between 0.0 (muted) and 1.0 (maximum volume)
    @retval CUBEB_OK
    @retval CUBEB_ERROR_INVALID_PARAMETER volume is outside [0.0, 1.0] or
            stream is an invalid pointer
    @retval CUBEB_ERROR_NOT_SUPPORTED */
int cubeb_stream_set_volume(cubeb_stream * stream, float volume);

/** If the stream is stereo, set the left/right panning. If the stream is mono,
    this has no effect.
    @param stream the stream for which to change the panning
    @param panning a number from -1.0 to 1.0. -1.0 means that the stream is
           fully mixed in the left channel, 1.0 means the stream is fully
           mixed in the right channel. 0.0 is equal power in the right and
           left channel (default).
    @retval CUBEB_OK
    @retval CUBEB_ERROR_INVALID_PARAMETER if stream is null or if panning is
            outside the [-1.0, 1.0] range.
    @retval CUBEB_ERROR_NOT_SUPPORTED
    @retval CUBEB_ERROR stream is not mono nor stereo */
int cubeb_stream_set_panning(cubeb_stream * stream, float panning);

/** Get the current output device for this stream.
    @param stm the stream for which to query the current output device
    @param device a pointer in which the current output device will be stored.
    @retval CUBEB_OK in case of success
    @retval CUBEB_ERROR_INVALID_PARAMETER if either stm, device or count are
            invalid pointers
    @retval CUBEB_ERROR_NOT_SUPPORTED */
int cubeb_stream_get_current_device(cubeb_stream * stm,
                                    cubeb_device ** const device);

/** Destroy a cubeb_device structure.
    @param stream the stream passed in cubeb_stream_get_current_device
    @param devices the devices to destroy
    @retval CUBEB_OK in case of success
    @retval CUBEB_ERROR_INVALID_PARAMETER if devices is an invalid pointer
    @retval CUBEB_ERROR_NOT_SUPPORTED */
int cubeb_stream_device_destroy(cubeb_stream * stream,
                                cubeb_device * devices);

/** Set a callback to be notified when the output device changes.
    @param stream the stream for which to set the callback.
    @param device_changed_callback a function called whenever the device has
           changed. Passing NULL allow to unregister a function
    @retval CUBEB_OK
    @retval CUBEB_ERROR_INVALID_PARAMETER if either stream or
            device_changed_callback are invalid pointers.
    @retval CUBEB_ERROR_NOT_SUPPORTED */
int cubeb_stream_register_device_changed_callback(cubeb_stream * stream,
                                                  cubeb_device_changed_callback  device_changed_callback);

/** Returns enumerated devices.
    @param context
    @param devtype device type to include
    @param collection output collection. Must be destroyed with cubeb_device_collection_destroy
    @retval CUBEB_OK in case of success
    @retval CUBEB_ERROR_INVALID_PARAMETER if collection is an invalid pointer
    @retval CUBEB_ERROR_NOT_SUPPORTED */
int cubeb_enumerate_devices(cubeb * context,
                            cubeb_device_type devtype,
                            cubeb_device_collection ** collection);

/** Destroy a cubeb_device_collection, and its `cubeb_device_info`.
    @param collection collection to destroy
    @retval CUBEB_OK
    @retval CUBEB_ERROR_INVALID_PARAMETER if collection is an invalid pointer */
int cubeb_device_collection_destroy(cubeb_device_collection * collection);

/** Destroy a cubeb_device_info structure.
    @param info pointer to device info structure
    @retval CUBEB_OK
    @retval CUBEB_ERROR_INVALID_PARAMETER if info is an invalid pointer */
int cubeb_device_info_destroy(cubeb_device_info * info);

/** Registers a callback which is called when the system detects
    a new device or a device is removed.
    @param context
    @param callback a function called whenever the system device list changes.
           Passing NULL allow to unregister a function
    @param user_ptr pointer to user specified data which will be present in
           subsequent callbacks.
    @retval CUBEB_ERROR_NOT_SUPPORTED */
int cubeb_register_device_collection_changed(cubeb * context,
                                       cubeb_device_collection_changed_callback callback,
                                       void * user_ptr);

#if defined(__cplusplus)
}
#endif

#endif /* CUBEB_c2f983e9_c96f_e71c_72c3_bbf62992a382 */