toxcore/other/apidsl/toxav.in.h

%{
/* toxav.h
 * 
 * Copyright (C) 2013-2015 Tox project All Rights Reserved.
 *
 * This file is part of Tox.
 *
 * Tox is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Tox 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 General Public License
 * along with Tox. If not, see <http://www.gnu.org/licenses/>.
 * 
 */

#ifndef TOXAV_H
#define TOXAV_H

#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>

#ifdef __cplusplus
extern "C" {
#endif
%}

/** \page av Public audio/video API for Tox clients.
 * 
 * This API can handle multiple calls. Each call has its state, in very rare
 * occasions the library can change the state of the call without apps knowledge.
 * 
 */

/** \subsection events Events and callbacks
 *
 * As in Core API, events are handled by callbacks. One callback can be 
 * registered per event. All events have a callback function type named 
 * `toxav_{event}_cb` and a function to register it named `tox_callback_{event}`. 
 * Passing a NULL callback will result in no callback being registered for that 
 * event. Only one callback per event can be registered, so if a client needs 
 * multiple event listeners, it needs to implement the dispatch functionality 
 * itself. Unlike Core API, lack of some event handlers will cause the the 
 * library to drop calls before they are started. Hanging up call from a 
 * callback causes undefined behaviour.
 * 
 */

/** \subsection threading Threading implications
 *
 * Unlike the Core API, this API is fully thread-safe. The library will ensure
 * the proper synchronization of parallel calls. 
 * 
 * A common way to run ToxAV (multiple or single instance) is to have a thread,
 * separate from tox instance thread, running a simple ${toxAV.iterate} loop, 
 * sleeping for ${toxAV.iteration_interval} * milliseconds on each iteration.
 *
 * An important thing to note is that events are triggered from both tox and
 * toxav thread (see above). audio and video receive frame events are triggered
 * from toxav thread while all the other events are triggered from tox thread.
 * 
 * Tox thread has priority with mutex mechanisms. Any api function can
 * fail if mutexes are held by tox thread in which case they will set SYNC
 * error code.
 */

/**
 * External Tox type.
 */
class tox {
  struct this;
}

/**
 * ToxAV.
 */
class toxAV {

/**
 * The ToxAV instance type. Each ToxAV instance can be bound to only one Tox
 * instance, and Tox instance can have only one ToxAV instance. One must make
 * sure to close ToxAV instance prior closing Tox instance otherwise undefined
 * behaviour occurs. Upon closing of ToxAV instance, all active calls will be 
 * forcibly terminated without notifying peers.
 * 
 */
struct this;
/*******************************************************************************
 *
 * :: API version
 *
 ******************************************************************************/
/**
 * The major version number. Incremented when the API or ABI changes in an
 * incompatible way.
 */
#define TOXAV_VERSION_MAJOR               0u
/**
 * The minor version number. Incremented when functionality is added without
 * breaking the API or ABI. Set to 0 when the major version number is
 * incremented.
 */
#define TOXAV_VERSION_MINOR               0u
/**
 * The patch or revision number. Incremented when bugfixes are applied without
 * changing any functionality or API or ABI.
 */
#define TOXAV_VERSION_PATCH               0u

/**
 * A macro to check at preprocessing time whether the client code is compatible
 * with the installed version of ToxAV.
 */
#define TOXAV_VERSION_IS_API_COMPATIBLE(MAJOR, MINOR, PATCH)        \
  (TOXAV_VERSION_MAJOR == MAJOR &&                                \
   (TOXAV_VERSION_MINOR > MINOR ||                                \
    (TOXAV_VERSION_MINOR == MINOR &&                              \
     TOXAV_VERSION_PATCH >= PATCH)))

/**
 * A macro to make compilation fail if the client code is not compatible with
 * the installed version of ToxAV.
 */
#define TOXAV_VERSION_REQUIRE(MAJOR, MINOR, PATCH)                \
  typedef char toxav_required_version[TOXAV_IS_COMPATIBLE(MAJOR, MINOR, PATCH) ? 1 : -1]

/**
 * A convenience macro to call ${version.is_compatible} with the currently
 * compiling API version.
 */
#define TOXAV_VERSION_IS_ABI_COMPATIBLE()                         \
  toxav_version_is_compatible(TOXAV_VERSION_MAJOR, TOXAV_VERSION_MINOR, TOXAV_VERSION_PATCH)


static namespace version {

  /**
   * Return the major version number of the library. Can be used to display the
   * ToxAV library version or to check whether the client is compatible with the
   * dynamically linked version of ToxAV.
   */
  uint32_t major();

  /**
   * Return the minor version number of the library.
   */
  uint32_t minor();

  /**
   * Return the patch number of the library.
   */
  uint32_t patch();

  /**
   * Return whether the compiled library version is compatible with the passed
   * version numbers.
   */
  bool is_compatible(uint32_t major, uint32_t minor, uint32_t patch);

}
/*******************************************************************************
 * 
 * :: Creation and destruction
 *
 ******************************************************************************/
/**
 * Start new A/V session. There can only be only one session per Tox instance.
 */
static this new (tox::this *tox) {
  NULL,
  /**
   * Memory allocation failure while trying to allocate structures required for
   * the A/V session.
   */
  MALLOC,
  /**
   * Attempted to create a second session for the same Tox instance.
   */
  MULTIPLE,
}
/**
 * Releases all resources associated with the A/V session.
 *
 * If any calls were ongoing, these will be forcibly terminated without
 * notifying peers. After calling this function, no other functions may be
 * called and the av pointer becomes invalid.
 */
void kill();
/**
 * Returns the Tox instance the A/V object was created for.
 */
tox::this *tox { get(); }
/*******************************************************************************
 * 
 * :: A/V event loop
 *
 ******************************************************************************/
/**
 * Returns the interval in milliseconds when the next toxav_iterate call should
 * be. If no call is active at the moment, this function returns 200.
 */
const uint32_t iteration_interval();
/**
 * Main loop for the session. This function needs to be called in intervals of
 * toxav_iteration_interval() milliseconds. It is best called in the separate 
 * thread from tox_iterate.
 */
void iterate();
/*******************************************************************************
 * 
 * :: Call setup
 *
 ******************************************************************************/
/**
 * Call a friend. This will start ringing the friend.
 *
 * It is the client's responsibility to stop ringing after a certain timeout,
 * if such behaviour is desired. If the client does not stop ringing, the
 * library will not stop until the friend is disconnected. Audio and video 
 * receiving are both enabled by default.
 *
 * @param friend_number The friend number of the friend that should be called.
 * @param audio_bit_rate Audio bit rate in Kb/sec. Set this to 0 to disable
 * audio sending.
 * @param video_bit_rate Video bit rate in Kb/sec. Set this to 0 to disable
 * video sending.
 */
bool call(uint32_t friend_number, uint32_t audio_bit_rate, uint32_t video_bit_rate) {
  /**
   * A resource allocation error occurred while trying to create the structures
   * required for the call.
   */
  MALLOC,
  /**
   * Synchronization error occurred.
   */
  SYNC,
  /**
   * The friend number did not designate a valid friend.
   */
  FRIEND_NOT_FOUND,
  /**
   * The friend was valid, but not currently connected.
   */
  FRIEND_NOT_CONNECTED,
  /**
   * Attempted to call a friend while already in an audio or video call with
   * them.
   */
  FRIEND_ALREADY_IN_CALL,
  /**
   * Audio or video bit rate is invalid.
   */
  INVALID_BIT_RATE,
}
event call {
  /**
   * The function type for the ${event call} callback.
   * 
   * @param friend_number The friend number from which the call is incoming.
   * @param audio_enabled True if friend is sending audio.
   * @param video_enabled True if friend is sending video.
   */
  typedef void(uint32_t friend_number, bool audio_enabled, bool video_enabled);
}
/**
 * Accept an incoming call.
 *
 * If answering fails for any reason, the call will still be pending and it is
 * possible to try and answer it later. Audio and video receiving are both
 * enabled by default.
 *
 * @param friend_number The friend number of the friend that is calling.
 * @param audio_bit_rate Audio bit rate in Kb/sec. Set this to 0 to disable
 * audio sending.
 * @param video_bit_rate Video bit rate in Kb/sec. Set this to 0 to disable
 * video sending.
 */
bool answer(uint32_t friend_number, uint32_t audio_bit_rate, uint32_t video_bit_rate) {
  /**
   * Synchronization error occurred.
   */
  SYNC,
  /**
   * Failed to initialize codecs for call session. Note that codec initiation
   * will fail if there is no receive callback registered for either audio or
   * video.
   */
  CODEC_INITIALIZATION,
  /**
   * The friend number did not designate a valid friend.
   */
  FRIEND_NOT_FOUND,
  /**
   * The friend was valid, but they are not currently trying to initiate a call.
   * This is also returned if this client is already in a call with the friend.
   */
  FRIEND_NOT_CALLING,
  /**
   * Audio or video bit rate is invalid.
   */
  INVALID_BIT_RATE,
}
/*******************************************************************************
 * 
 * :: Call state graph
 *
 ******************************************************************************/
bitmask FRIEND_CALL_STATE {
  /**
   * Set by the AV core if an error occurred on the remote end or if friend 
   * timed out. This is the final state after which no more state
   * transitions can occur for the call. This call state will never be triggered
   * in combination with other call states.
   */
  ERROR,
  /**
   * The call has finished. This is the final state after which no more state
   * transitions can occur for the call. This call state will never be 
   * triggered in combination with other call states.
   */
  FINISHED,
  /**
   * The flag that marks that friend is sending audio.
   */
  SENDING_A,
  /**
   * The flag that marks that friend is sending video.
   */
  SENDING_V,
  /**
   * The flag that marks that friend is receiving audio.
   */
  ACCEPTING_A,
  /**
   * The flag that marks that friend is receiving video.
   */
  ACCEPTING_V,
}
event call_state {
 /**
  * The function type for the ${event call_state} callback.
  *
  * @param friend_number The friend number for which the call state changed.
  * @param state The bitmask of the new call state which is guaranteed to be
  * different than the previous state. The state is set to 0 when the call is
  * paused. The bitmask represents all the activities currently performed by the
  * friend.
  */
  typedef void(uint32_t friend_number, uint32_t state);
}
/*******************************************************************************
 * 
 * :: Call control
 *
 ******************************************************************************/
enum class CALL_CONTROL {
    /**
     * Resume a previously paused call. Only valid if the pause was caused by this
     * client, if not, this control is ignored. Not valid before the call is accepted.
     */
    RESUME,
    /**
     * Put a call on hold. Not valid before the call is accepted.
     */
    PAUSE,
    /**
     * Reject a call if it was not answered, yet. Cancel a call after it was
     * answered.
     */
    CANCEL,
    /**
     * Request that the friend stops sending audio. Regardless of the friend's
     * compliance, this will cause the ${event audio.receive_frame} event to stop being
     * triggered on receiving an audio frame from the friend.
     */
    MUTE_AUDIO,
    /**
     * Calling this control will notify client to start sending audio again.
     */
    UNMUTE_AUDIO,
    /**
     * Request that the friend stops sending video. Regardless of the friend's
     * compliance, this will cause the ${event video.receive_frame} event to stop being
     * triggered on receiving a video frame from the friend.
     */
    HIDE_VIDEO,
    /**
     * Calling this control will notify client to start sending video again.
     */
    SHOW_VIDEO,
}
/**
 * Sends a call control command to a friend.
 *
 * @param friend_number The friend number of the friend this client is in a call
 * with.
 * @param control The control command to send.
 *
 * @return true on success.
 */
bool call_control (uint32_t friend_number, CALL_CONTROL control) {
  /**
   * Synchronization error occurred.
   */
  SYNC,
  /**
   * The friend_number passed did not designate a valid friend.
   */
  FRIEND_NOT_FOUND,
  /**
   * This client is currently not in a call with the friend. Before the call is
   * answered, only CANCEL is a valid control.
   */
  FRIEND_NOT_IN_CALL,
  /**
   * Happens if user tried to pause an already paused call or if trying to
   * resume a call that is not paused.
   */
  INVALID_TRANSITION,
}
/*******************************************************************************
 * 
 * :: Controlling bit rates
 *
 ******************************************************************************/
namespace bit_rate {
    /**
     * Set the audio bit rate to be used in subsequent audio/video frames.
     *
     * @param friend_number The friend number.
     * @param audio_bit_rate The new audio bit rate in Kb/sec. Set to 0 to disable
     * audio sending. Set to -1 to leave unchanged.
     * @param video_bit_rate The new video bit rate in Kb/sec. Set to 0 to disable
     * video sending. Set to -1 to leave unchanged.
     * 
     */
    bool set(uint32_t friend_number, int32_t audio_bit_rate, int32_t video_bit_rate) {
        /**
         * Synchronization error occurred.
         */
        SYNC,
        /**
         * The bit rate passed was not one of the supported values.
         */
        INVALID,
        /**
         * The friend_number passed did not designate a valid friend.
         */
        FRIEND_NOT_FOUND,
        /**
         * This client is currently not in a call with the friend.
         */
        FRIEND_NOT_IN_CALL,
    }
    event status {
        /**
         * The function type for the ${event status} callback. The event is triggered
         * when the network becomes too saturated for current bit rates at which 
         * point core suggests new bit rates.
         * 
         * @param friend_number The friend number.
         * @param audio_bit_rate Suggested maximum audio bit rate in Kb/sec.
         * @param video_bit_rate Suggested maximum video bit rate in Kb/sec.
         */
        typedef void(uint32_t friend_number, uint32_t audio_bit_rate, uint32_t video_bit_rate);
    }
}
/*******************************************************************************
 * 
 * :: A/V sending
 *
 ******************************************************************************/
error for send_frame {
  /**
   * In case of video, one of Y, U, or V was NULL. In case of audio, the samples
   * data pointer was NULL.
   */
  NULL,
  /**
   * The friend_number passed did not designate a valid friend.
   */
  FRIEND_NOT_FOUND,
  /**
   * This client is currently not in a call with the friend.
   */
  FRIEND_NOT_IN_CALL,
  /**
   * One of the frame parameters was invalid. E.g. the resolution may be too
   * small or too large, or the audio sampling rate may be unsupported.
   */
  INVALID,
  /**
   * Either friend turned off audio or video receiving or we turned off sending
   * for the said payload.
   */
  PAYLOAD_TYPE_DISABLED,
  /**
   * Failed to push frame through rtp interface.
   */
  RTP_FAILED,
}
namespace audio {
  /**
   * Send an audio frame to a friend.
   *
   * The expected format of the PCM data is: [s1c1][s1c2][...][s2c1][s2c2][...]...
   * Meaning: sample 1 for channel 1, sample 1 for channel 2, ...
   * For mono audio, this has no meaning, every sample is subsequent. For stereo,
   * this means the expected format is LRLRLR... with samples for left and right
   * alternating.
   *
   * @param friend_number The friend number of the friend to which to send an
   * audio frame.
   * @param pcm An array of audio samples. The size of this array must be
   * sample_count * channels.
   * @param sample_count Number of samples in this frame. Valid numbers here are
   * ((sample rate) * (audio length) / 1000), where audio length can be
   * 2.5, 5, 10, 20, 40 or 60 millseconds.
   * @param channels Number of audio channels. Supported values are 1 and 2.
   * @param sampling_rate Audio sampling rate used in this frame. Valid sampling
   * rates are 8000, 12000, 16000, 24000, or 48000.
   */
  bool send_frame(uint32_t friend_number, const int16_t *pcm, size_t sample_count, 
                  uint8_t channels, uint32_t sampling_rate) with error for send_frame;
}
namespace video {
  /**
   * Send a video frame to a friend.
   *
   * Y - plane should be of size: height * width
   * U - plane should be of size: (height/2) * (width/2)
   * V - plane should be of size: (height/2) * (width/2)
   *
   * @param friend_number The friend number of the friend to which to send a video
   * frame.
   * @param width Width of the frame in pixels.
   * @param height Height of the frame in pixels.
   * @param y Y (Luminance) plane data.
   * @param u U (Chroma) plane data.
   * @param v V (Chroma) plane data.
   */
  bool send_frame(uint32_t friend_number, uint16_t width, uint16_t height,
                  const uint8_t *y, const uint8_t *u, const uint8_t *v) with error for send_frame;
}
/*******************************************************************************
 * 
 * :: A/V receiving
 *
 ******************************************************************************/
namespace audio {
  event receive_frame {
    /**
     * The function type for the ${event receive_frame} callback. The callback can be
     * called multiple times per single iteration depending on the amount of queued
     * frames in the buffer. The received format is the same as in send function.
     * 
     * @param friend_number The friend number of the friend who sent an audio frame.
     * @param pcm An array of audio samples (sample_count * channels elements).
     * @param sample_count The number of audio samples per channel in the PCM array.
     * @param channels Number of audio channels.
     * @param sampling_rate Sampling rate used in this frame.
     *
     */
    typedef void(uint32_t friend_number, const int16_t *pcm, size_t sample_count,
                 uint8_t channels, uint32_t sampling_rate);
  }
}
namespace video {
  event receive_frame {
    /**
     * The function type for the ${event receive_frame} callback.
     *
     * @param friend_number The friend number of the friend who sent a video frame.
     * @param width Width of the frame in pixels.
     * @param height Height of the frame in pixels.
     * @param y 
     * @param u 
     * @param v Plane data.
     *          The size of plane data is derived from width and height where
     *          Y = MAX(width, abs(ystride)) * height, 
     *          U = MAX(width/2, abs(ustride)) * (height/2) and 
     *          V = MAX(width/2, abs(vstride)) * (height/2).
     * @param ystride
     * @param ustride
     * @param vstride Strides data. Strides represent padding for each plane
     *                that may or may not be present. You must handle strides in
     *                your image processing code. Strides are negative if the 
     *                image is bottom-up hence why you MUST abs() it when
     *                calculating plane buffer size.
     */
    typedef void(uint32_t friend_number, uint16_t width, uint16_t height,
                 const uint8_t *y, const uint8_t *u, const uint8_t *v,
                 int32_t ystride, int32_t ustride, int32_t vstride);
  }
}

}
%{
#ifdef __cplusplus
}
#endif
#endif /* TOXAV_H */
%}