1 files changed, 652 insertions, 204 deletions

diff --git a/toxav/toxav.h b/toxav/toxav.h
index 7285f45c..c75f8bff 100644
--- a/toxav/toxav.h
+++ b/toxav/toxav.h
@@ -1,329 +1,777 @@
-/**  toxav.h
+/* toxav.h
+ * 
+ * Copyright (C) 2013-2015 Tox project All Rights Reserved.
  *
- *   Copyright (C) 2013 Tox project All Rights Reserved.
+ * This file is part of Tox.
  *
- *   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 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/>.
+ * 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
 
-#ifndef __TOXAV
-#define __TOXAV
-#include <inttypes.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-typedef struct _ToxAv ToxAv;
-
-/* vpx_image_t */
-#include <vpx/vpx_image.h>
-
-typedef void ( *ToxAVCallback ) ( void *agent, int32_t call_idx, void *arg );
-typedef void ( *ToxAvAudioCallback ) (void *agent, int32_t call_idx, const int16_t *PCM, uint16_t size, void *data);
-typedef void ( *ToxAvVideoCallback ) (void *agent, int32_t call_idx, const vpx_image_t *img, void *data);
-
+/** \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 synchronisation 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.
+ *
+ */
+/**
+ * External Tox type.
+ */
 #ifndef TOX_DEFINED
 #define TOX_DEFINED
 typedef struct Tox Tox;
-#endif
-
-#define RTP_PAYLOAD_SIZE 65535
-
+#endif /* TOX_DEFINED */
 
 /**
- * Callbacks ids that handle the call states.
+ * ToxAV.
  */
-typedef enum {
-    av_OnInvite, /* Incoming call */
-    av_OnRinging, /* When peer is ready to accept/reject the call */
-    av_OnStart, /* Call (RTP transmission) started */
-    av_OnCancel, /* The side that initiated call canceled invite */
-    av_OnReject, /* The side that was invited rejected the call */
-    av_OnEnd, /* Call that was active ended */
-    av_OnRequestTimeout, /* When the requested action didn't get response in specified time */
-    av_OnPeerTimeout, /* Peer timed out; stop the call */
-    av_OnPeerCSChange, /* Peer changing Csettings. Prepare for changed AV */
-    av_OnSelfCSChange /* Csettings change confirmation. Once triggered peer is ready to recv changed AV */
-} ToxAvCallbackID;
-
-
 /**
- * Call type identifier.
+ * 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.
+ * 
  */
-typedef enum {
-    av_TypeAudio = 192,
-    av_TypeVideo
-} ToxAvCallType;
+#ifndef TOXAV_DEFINED
+#define TOXAV_DEFINED
+typedef struct ToxAV ToxAV;
+#endif /* TOXAV_DEFINED */
 
 
-typedef enum {
-    av_CallNonExistent = -1,
-    av_CallInviting, /* when sending call invite */
-    av_CallStarting, /* when getting call invite */
-    av_CallActive,
-    av_CallHold,
-    av_CallHungUp
-} ToxAvCallState;
+/*******************************************************************************
+ *
+ * :: API version
+ *
+ ******************************************************************************/
 
-/**
- * Error indicators. Values under -20 are reserved for toxcore.
- */
-typedef enum {
-    av_ErrorNone = 0,
-    av_ErrorUnknown = -1, /* Unknown error */
-    av_ErrorNoCall = -20, /* Trying to perform call action while not in a call */
-    av_ErrorInvalidState = -21, /* Trying to perform call action while in invalid state*/
-    av_ErrorAlreadyInCallWithPeer = -22, /* Trying to call peer when already in a call with peer */
-    av_ErrorReachedCallLimit = -23, /* Cannot handle more calls */
-    av_ErrorInitializingCodecs = -30, /* Failed creating CSSession */
-    av_ErrorSettingVideoResolution = -31, /* Error setting resolution */
-    av_ErrorSettingVideoBitrate = -32, /* Error setting bitrate */
-    av_ErrorSplittingVideoPayload = -33, /* Error splitting video payload */
-    av_ErrorEncodingVideo = -34, /* vpx_codec_encode failed */
-    av_ErrorEncodingAudio = -35, /* opus_encode failed */
-    av_ErrorSendingPayload = -40, /* Sending lossy packet failed */
-    av_ErrorCreatingRtpSessions = -41, /* One of the rtp sessions failed to initialize */
-    av_ErrorNoRtpSession = -50, /* Trying to perform rtp action on invalid session */
-    av_ErrorInvalidCodecState = -51, /* Codec state not initialized */
-    av_ErrorPacketTooLarge = -52, /* Split packet exceeds it's limit */
-} ToxAvError;
 
 
 /**
- * Locally supported capabilities.
+ * The major version number. Incremented when the API or ABI changes in an
+ * incompatible way.
  */
-typedef enum {
-    av_AudioEncoding = 1 << 0,
-    av_AudioDecoding = 1 << 1,
-    av_VideoEncoding = 1 << 2,
-    av_VideoDecoding = 1 << 3
-} ToxAvCapabilities;
-
+#define TOXAV_VERSION_MAJOR               0u
 
 /**
- * Encoding settings.
+ * 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.
  */
-typedef struct _ToxAvCSettings {
-    ToxAvCallType call_type;
-
-    uint32_t video_bitrate; /* In kbits/s */
-    uint16_t max_video_width; /* In px */
-    uint16_t max_video_height; /* In px */
-
-    uint32_t audio_bitrate; /* In bits/s */
-    uint16_t audio_frame_duration; /* In ms */
-    uint32_t audio_sample_rate; /* In Hz */
-    uint32_t audio_channels;
-} ToxAvCSettings;
-
-extern const ToxAvCSettings av_DefaultSettings;
+#define TOXAV_VERSION_MINOR               0u
 
 /**
- * Start new A/V session. There can only be one session at the time.
+ * The patch or revision number. Incremented when bugfixes are applied without
+ * changing any functionality or API or ABI.
  */
-ToxAv *toxav_new(Tox *messenger, int32_t max_calls);
+#define TOXAV_VERSION_PATCH               0u
 
 /**
- * Remove A/V session.
+ * A macro to check at preprocessing time whether the client code is compatible
+ * with the installed version of ToxAV.
  */
-void toxav_kill(ToxAv *av);
+#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)))
 
 /**
- * Returns the interval in milliseconds when the next toxav_do() should be called.
- * If no call is active at the moment returns 200.
+ * A macro to make compilation fail if the client code is not compatible with
+ * the installed version of ToxAV.
  */
-uint32_t toxav_do_interval(ToxAv *av);
+#define TOXAV_VERSION_REQUIRE(MAJOR, MINOR, PATCH)                \
+  typedef char toxav_required_version[TOXAV_IS_COMPATIBLE(MAJOR, MINOR, PATCH) ? 1 : -1]
 
 /**
- * Main loop for the session. Best called right after tox_do();
+ * A convenience macro to call toxav_version_is_compatible with the currently
+ * compiling API version.
  */
-void toxav_do(ToxAv *av);
+#define TOXAV_VERSION_IS_ABI_COMPATIBLE()                         \
+  toxav_version_is_compatible(TOXAV_VERSION_MAJOR, TOXAV_VERSION_MINOR, TOXAV_VERSION_PATCH)
 
 /**
- * Register callback for call state.
+ * 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.
  */
-void toxav_register_callstate_callback (ToxAv *av, ToxAVCallback cb, ToxAvCallbackID id, void *userdata);
+uint32_t toxav_version_major(void);
 
 /**
- * Register callback for audio data.
+ * Return the minor version number of the library.
  */
-void toxav_register_audio_callback (ToxAv *av, ToxAvAudioCallback cb, void *userdata);
+uint32_t toxav_version_minor(void);
 
 /**
- * Register callback for video data.
+ * Return the patch number of the library.
  */
-void toxav_register_video_callback (ToxAv *av, ToxAvVideoCallback cb, void *userdata);
+uint32_t toxav_version_patch(void);
 
 /**
- * Call user. Use its friend_id.
+ * Return whether the compiled library version is compatible with the passed
+ * version numbers.
  */
-int toxav_call(ToxAv *av,
-               int32_t *call_index,
-               int friend_id,
-               const ToxAvCSettings *csettings,
-               int ringing_seconds);
+bool toxav_version_is_compatible(uint32_t major, uint32_t minor, uint32_t patch);
+
+
+/*******************************************************************************
+ * 
+ * :: Creation and destruction
+ *
+ ******************************************************************************/
+
+
+
+typedef enum TOXAV_ERR_NEW {
+
+  /**
+   * The function returned successfully.
+   */
+  TOXAV_ERR_NEW_OK,
+  
+  /**
+   * One of the arguments to the function was NULL when it was not expected.
+   */
+  TOXAV_ERR_NEW_NULL,
+  
+  /**
+   * Memory allocation failure while trying to allocate structures required for
+   * the A/V session.
+   */
+  TOXAV_ERR_NEW_MALLOC,
+  
+  /**
+   * Attempted to create a second session for the same Tox instance.
+   */
+  TOXAV_ERR_NEW_MULTIPLE,
+  
+} TOXAV_ERR_NEW;
+
 
 /**
- * Hangup active call.
+ * Start new A/V session. There can only be only one session per Tox instance.
  */
-int toxav_hangup(ToxAv *av, int32_t call_index);
+ToxAV *toxav_new(Tox *tox, TOXAV_ERR_NEW *error);
 
 /**
- * Answer incoming call. Pass the csettings that you will use.
+ * 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.
  */
-int toxav_answer(ToxAv *av, int32_t call_index, const ToxAvCSettings *csettings );
+void toxav_kill(ToxAV *toxAV);
 
 /**
- * Reject incoming call.
+ * Returns the Tox instance the A/V object was created for.
  */
-int toxav_reject(ToxAv *av, int32_t call_index, const char *reason);
+Tox *toxav_get_tox(const ToxAV *toxAV);
+
+
+/*******************************************************************************
+ * 
+ * :: A/V event loop
+ *
+ ******************************************************************************/
+
+
 
 /**
- * Cancel outgoing request.
+ * 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.
  */
-int toxav_cancel(ToxAv *av, int32_t call_index, int peer_id, const char *reason);
+uint32_t toxav_iteration_interval(const ToxAV *toxAV);
 
 /**
- * Notify peer that we are changing codec settings.
+ * 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.
  */
-int toxav_change_settings(ToxAv *av, int32_t call_index, const ToxAvCSettings *csettings);
+void toxav_iterate(ToxAV *toxAV);
+
+
+/*******************************************************************************
+ * 
+ * :: Call setup
+ *
+ ******************************************************************************/
+
+
+
+typedef enum TOXAV_ERR_CALL {
+
+  /**
+   * The function returned successfully.
+   */
+  TOXAV_ERR_CALL_OK,
+  
+  /**
+   * A resource allocation error occurred while trying to create the structures
+   * required for the call.
+   */
+  TOXAV_ERR_CALL_MALLOC,
+  
+  /**
+   * The friend number did not designate a valid friend.
+   */
+  TOXAV_ERR_CALL_FRIEND_NOT_FOUND,
+  
+  /**
+   * The friend was valid, but not currently connected.
+   */
+  TOXAV_ERR_CALL_FRIEND_NOT_CONNECTED,
+  
+  /**
+   * Attempted to call a friend while already in an audio or video call with
+   * them.
+   */
+  TOXAV_ERR_CALL_FRIEND_ALREADY_IN_CALL,
+  
+  /**
+   * Audio or video bit rate is invalid.
+   */
+  TOXAV_ERR_CALL_INVALID_BIT_RATE,
+  
+} TOXAV_ERR_CALL;
+
 
 /**
- * Terminate transmission. Note that transmission will be
- * terminated without informing remote peer. Usually called when we can't inform peer.
+ * 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.
+ *
+ * @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.
  */
-int toxav_stop_call(ToxAv *av, int32_t call_index);
+bool toxav_call(ToxAV *toxAV, uint32_t friend_number, uint32_t audio_bit_rate, uint32_t video_bit_rate, TOXAV_ERR_CALL *error);
 
 /**
- * Allocates transmission data. Must be call before calling toxav_prepare_* and toxav_send_*.
- * Also, it must be called when call is started
+ * The function type for the 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.
  */
-int toxav_prepare_transmission(ToxAv *av, int32_t call_index, int support_video);
+typedef void toxav_call_cb(ToxAV *toxAV, uint32_t friend_number, bool audio_enabled, bool video_enabled, void *user_data);
+
 
 /**
- * Clears transmission data. Call this at the end of the transmission.
+ * Set the callback for the `call` event. Pass NULL to unset.
+ *
  */
-int toxav_kill_transmission(ToxAv *av, int32_t call_index);
+void toxav_callback_call(ToxAV *toxAV, toxav_call_cb *callback, void *user_data);
+
+typedef enum TOXAV_ERR_ANSWER {
+
+  /**
+   * The function returned successfully.
+   */
+  TOXAV_ERR_ANSWER_OK,
+  
+  /**
+   * 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.
+   */
+  TOXAV_ERR_ANSWER_CODEC_INITIALIZATION,
+  
+  /**
+   * The friend number did not designate a valid friend.
+   */
+  TOXAV_ERR_ANSWER_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.
+   */
+  TOXAV_ERR_ANSWER_FRIEND_NOT_CALLING,
+  
+  /**
+   * Audio or video bit rate is invalid.
+   */
+  TOXAV_ERR_ANSWER_INVALID_BIT_RATE,
+  
+} TOXAV_ERR_ANSWER;
+
 
 /**
- * Encode video frame.
+ * 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.
+ *
+ * @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.
  */
-int toxav_prepare_video_frame ( ToxAv *av,
-                                int32_t call_index,
-                                uint8_t *dest,
-                                int dest_max,
-                                vpx_image_t *input);
+bool toxav_answer(ToxAV *toxAV, uint32_t friend_number, uint32_t audio_bit_rate, uint32_t video_bit_rate, TOXAV_ERR_ANSWER *error);
+
+
+/*******************************************************************************
+ * 
+ * :: Call state graph
+ *
+ ******************************************************************************/
+
+
+
+enum TOXAV_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.
+   */
+  TOXAV_CALL_STATE_ERROR = 1,
+  
+  /**
+   * 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.
+   */
+  TOXAV_CALL_STATE_FINISHED = 2,
+  
+  /**
+   * The flag that marks that friend is sending audio.
+   */
+  TOXAV_CALL_STATE_SENDING_A = 4,
+  
+  /**
+   * The flag that marks that friend is sending video.
+   */
+  TOXAV_CALL_STATE_SENDING_V = 8,
+  
+  /**
+   * The flag that marks that friend is receiving audio.
+   */
+  TOXAV_CALL_STATE_RECEIVING_A = 16,
+  
+  /**
+   * The flag that marks that friend is receiving video.
+   */
+  TOXAV_CALL_STATE_RECEIVING_V = 32,
+  
+};
+
 
 /**
- * Send encoded video packet.
+ * The function type for the call_state callback.
+ *
+ * @param friend_number The friend number for which the call state changed.
+ * @param state 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.
  */
-int toxav_send_video ( ToxAv *av, int32_t call_index, const uint8_t *frame, uint32_t frame_size);
+typedef void toxav_call_state_cb(ToxAV *toxAV, uint32_t friend_number, uint32_t state, void *user_data);
+
 
 /**
- * Encode audio frame.
+ * Set the callback for the `call_state` event. Pass NULL to unset.
+ *
  */
-int toxav_prepare_audio_frame ( ToxAv *av,
-                                int32_t call_index,
-                                uint8_t *dest,
-                                int dest_max,
-                                const int16_t *frame,
-                                int frame_size);
+void toxav_callback_call_state(ToxAV *toxAV, toxav_call_state_cb *callback, void *user_data);
+
+
+/*******************************************************************************
+ * 
+ * :: Call control
+ *
+ ******************************************************************************/
+
+
+
+typedef enum TOXAV_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.
+   */
+  TOXAV_CALL_CONTROL_RESUME,
+  
+  /**
+   * Put a call on hold. Not valid before the call is accepted.
+   */
+  TOXAV_CALL_CONTROL_PAUSE,
+  
+  /**
+   * Reject a call if it was not answered, yet. Cancel a call after it was
+   * answered.
+   */
+  TOXAV_CALL_CONTROL_CANCEL,
+  
+  /**
+   * Request that the friend stops sending audio. Regardless of the friend's
+   * compliance, this will cause the audio_receive_frame event to stop being
+   * triggered on receiving an audio frame from the friend.
+   */
+  TOXAV_CALL_CONTROL_MUTE_AUDIO,
+  
+  /**
+   * Calling this control will notify client to start sending audio again.
+   */
+  TOXAV_CALL_CONTROL_UNMUTE_AUDIO,
+  
+  /**
+   * Request that the friend stops sending video. Regardless of the friend's
+   * compliance, this will cause the video_receive_frame event to stop being
+   * triggered on receiving an video frame from the friend.
+   */
+  TOXAV_CALL_CONTROL_HIDE_VIDEO,
+  
+  /**
+   * Calling this control will notify client to start sending video again.
+   */
+  TOXAV_CALL_CONTROL_SHOW_VIDEO,
+  
+} TOXAV_CALL_CONTROL;
+
+
+typedef enum TOXAV_ERR_CALL_CONTROL {
+
+  /**
+   * The function returned successfully.
+   */
+  TOXAV_ERR_CALL_CONTROL_OK,
+  
+  /**
+   * The friend_number passed did not designate a valid friend.
+   */
+  TOXAV_ERR_CALL_CONTROL_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.
+   */
+  TOXAV_ERR_CALL_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.
+   */
+  TOXAV_ERR_CALL_CONTROL_INVALID_TRANSITION,
+  
+} TOXAV_ERR_CALL_CONTROL;
+
 
 /**
- * Send encoded audio frame.
+ * 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.
  */
-int toxav_send_audio ( ToxAv *av, int32_t call_index, const uint8_t *frame, unsigned int size);
+bool toxav_call_control(ToxAV *toxAV, uint32_t friend_number, TOXAV_CALL_CONTROL control, TOXAV_ERR_CALL_CONTROL *error);
+
+
+/*******************************************************************************
+ * 
+ * :: Controlling bit rates
+ *
+ ******************************************************************************/
+
+
+
+typedef enum TOXAV_ERR_SET_BIT_RATE {
+
+  /**
+   * The function returned successfully.
+   */
+  TOXAV_ERR_SET_BIT_RATE_OK,
+  
+  /**
+   * The bit rate passed was not one of the supported values.
+   */
+  TOXAV_ERR_SET_BIT_RATE_INVALID,
+  
+  /**
+   * The friend_number passed did not designate a valid friend.
+   */
+  TOXAV_ERR_SET_BIT_RATE_FRIEND_NOT_FOUND,
+  
+  /**
+   * This client is currently not in a call with the friend.
+   */
+  TOXAV_ERR_SET_BIT_RATE_FRIEND_NOT_IN_CALL,
+  
+} TOXAV_ERR_SET_BIT_RATE;
+
 
 /**
- * Get codec settings from the peer. These were exchanged during call initialization
- * or when peer send us new csettings.
+ * The function type for the audio_bit_rate_status callback.
+ * 
+ * @param friend_number The friend number of the friend for which to set the
+ * audio bit rate.
+ * @param stable Is the stream stable enough to keep the bit rate. 
+ * Upon successful, non forceful, bit rate change, this is set to 
+ * true and 'bit_rate' is set to new bit rate.
+ * The stable is set to false with bit_rate set to the unstable
+ * bit rate when either current stream is unstable with said bit rate
+ * or the non forceful change failed.
+ * @param bit_rate The bit rate in Kb/sec.
  */
-int toxav_get_peer_csettings ( ToxAv *av, int32_t call_index, int peer, ToxAvCSettings *dest );
+typedef void toxav_audio_bit_rate_status_cb(ToxAV *toxAV, uint32_t friend_number, bool stable, uint32_t bit_rate, void *user_data);
+
 
 /**
- * Get friend id of peer participating in conversation.
+ * Set the callback for the `audio_bit_rate_status` event. Pass NULL to unset.
+ *
  */
-int toxav_get_peer_id ( ToxAv *av, int32_t call_index, int peer );
+void toxav_callback_audio_bit_rate_status(ToxAV *toxAV, toxav_audio_bit_rate_status_cb *callback, void *user_data);
 
 /**
- * Get current call state.
+ * Set the audio bit rate to be used in subsequent audio frames. If the passed 
+ * bit rate is the same as the current bit rate this function will return true 
+ * without calling a callback. If there is an active non forceful setup with the
+ * passed audio bit rate and the new set request is forceful, the bit rate is 
+ * forcefully set and the previous non forceful request is cancelled. The active
+ * non forceful setup will be canceled in favour of new non forceful setup.
+ *
+ * @param friend_number The friend number of the friend for which to set the
+ * audio bit rate.
+ * @param audio_bit_rate The new audio bit rate in Kb/sec. Set to 0 to disable
+ * audio sending.
+ * @param force True if the bit rate change is forceful.
+ * 
  */
-ToxAvCallState toxav_get_call_state ( ToxAv *av, int32_t call_index );
+bool toxav_audio_bit_rate_set(ToxAV *toxAV, uint32_t friend_number, uint32_t audio_bit_rate, bool force, TOXAV_ERR_SET_BIT_RATE *error);
 
 /**
- * Is certain capability supported. Used to determine if encoding/decoding is ready.
+ * The function type for the video_bit_rate_status callback.
+ * 
+ * @param friend_number The friend number of the friend for which to set the
+ * video bit rate.
+ * @param stable Is the stream stable enough to keep the bit rate. 
+ * Upon successful, non forceful, bit rate change, this is set to 
+ * true and 'bit_rate' is set to new bit rate.
+ * The stable is set to false with bit_rate set to the unstable
+ * bit rate when either current stream is unstable with said bit rate
+ * or the non forceful change failed.
+ * @param bit_rate The bit rate in Kb/sec.
  */
-int toxav_capability_supported ( ToxAv *av, int32_t call_index, ToxAvCapabilities capability );
+typedef void toxav_video_bit_rate_status_cb(ToxAV *toxAV, uint32_t friend_number, bool stable, uint32_t bit_rate, void *user_data);
+
 
 /**
- * Returns tox reference.
+ * Set the callback for the `video_bit_rate_status` event. Pass NULL to unset.
+ *
  */
-Tox *toxav_get_tox (ToxAv *av);
+void toxav_callback_video_bit_rate_status(ToxAV *toxAV, toxav_video_bit_rate_status_cb *callback, void *user_data);
 
 /**
- * Returns number of active calls or -1 on error.
+ * Set the video bit rate to be used in subsequent video frames. If the passed 
+ * bit rate is the same as the current bit rate this function will return true 
+ * without calling a callback. If there is an active non forceful setup with the
+ * passed video bit rate and the new set request is forceful, the bit rate is 
+ * forcefully set and the previous non forceful request is cancelled. The active
+ * non forceful setup will be canceled in favour of new non forceful setup.
+ *
+ * @param friend_number The friend number of the friend for which to set the
+ * video bit rate.
+ * @param audio_bit_rate The new video bit rate in Kb/sec. Set to 0 to disable
+ * video sending.
+ * @param force True if the bit rate change is forceful.
+ * 
  */
-int toxav_get_active_count (ToxAv *av);
+bool toxav_video_bit_rate_set(ToxAV *toxAV, uint32_t friend_number, uint32_t audio_bit_rate, bool force, TOXAV_ERR_SET_BIT_RATE *error);
+
 
-/* Create a new toxav group.
+/*******************************************************************************
+ * 
+ * :: A/V sending
  *
- * return group number on success.
- * return -1 on failure.
+ ******************************************************************************/
+
+
+
+typedef enum TOXAV_ERR_SEND_FRAME {
+
+  /**
+   * The function returned successfully.
+   */
+  TOXAV_ERR_SEND_FRAME_OK,
+  
+  /**
+   * In case of video, one of Y, U, or V was NULL. In case of audio, the samples
+   * data pointer was NULL.
+   */
+  TOXAV_ERR_SEND_FRAME_NULL,
+  
+  /**
+   * The friend_number passed did not designate a valid friend.
+   */
+  TOXAV_ERR_SEND_FRAME_FRIEND_NOT_FOUND,
+  
+  /**
+   * This client is currently not in a call with the friend.
+   */
+  TOXAV_ERR_SEND_FRAME_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.
+   */
+  TOXAV_ERR_SEND_FRAME_INVALID,
+  
+  /**
+   * Failed to push frame through rtp interface.
+   */
+  TOXAV_ERR_SEND_FRAME_RTP_FAILED,
+  
+} TOXAV_ERR_SEND_FRAME;
+
+
+/**
+ * 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 toxav_audio_send_frame(ToxAV *toxAV, uint32_t friend_number, const int16_t *pcm, size_t sample_count, uint8_t channels, uint32_t sampling_rate, TOXAV_ERR_SEND_FRAME *error);
+
+/**
+ * Send a video frame to a friend.
  *
- * Audio data callback format:
- *   audio_callback(Tox *tox, int groupnumber, int peernumber, const int16_t *pcm, unsigned int samples, uint8_t channels, unsigned int sample_rate, void *userdata)
+ * 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)
  *
- * Note that total size of pcm in bytes is equal to (samples * channels * sizeof(int16_t)).
+ * @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.
+ * @param a A (Alpha) plane data.
  */
-int toxav_add_av_groupchat(Tox *tox, void (*audio_callback)(Tox *, int, int, const int16_t *, unsigned int, uint8_t,
-                           unsigned int, void *), void *userdata);
+bool toxav_video_send_frame(ToxAV *toxAV, uint32_t friend_number, uint16_t width, uint16_t height, const uint8_t *y, const uint8_t *u, const uint8_t *v, const uint8_t *a, TOXAV_ERR_SEND_FRAME *error);
+
 
-/* Join a AV group (you need to have been invited first.)
+/*******************************************************************************
+ * 
+ * :: A/V receiving
  *
- * returns group number on success
- * returns -1 on failure.
+ ******************************************************************************/
+
+
+
+/**
+ * The function type for the audio_receive_frame callback.
  *
- * Audio data callback format (same as the one for toxav_add_av_groupchat()):
- *   audio_callback(Tox *tox, int groupnumber, int peernumber, const int16_t *pcm, unsigned int samples, uint8_t channels, unsigned int sample_rate, void *userdata)
+ * @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.
  *
- * Note that total size of pcm in bytes is equal to (samples * channels * sizeof(int16_t)).
  */
-int toxav_join_av_groupchat(Tox *tox, int32_t friendnumber, const uint8_t *data, uint16_t length,
-                            void (*audio_callback)(Tox *, int, int, const int16_t *, unsigned int, uint8_t, unsigned int, void *), void *userdata);
+typedef void toxav_audio_receive_frame_cb(ToxAV *toxAV, uint32_t friend_number, const int16_t *pcm, size_t sample_count, uint8_t channels, uint32_t sampling_rate, void *user_data);
 
-/* Send audio to the group chat.
- *
- * return 0 on success.
- * return -1 on failure.
+
+/**
+ * Set the callback for the `audio_receive_frame` event. Pass NULL to unset.
  *
- * Note that total size of pcm in bytes is equal to (samples * channels * sizeof(int16_t)).
+ */
+void toxav_callback_audio_receive_frame(ToxAV *toxAV, toxav_audio_receive_frame_cb *callback, void *user_data);
+
+/**
+ * The function type for the video_receive_frame callback.
  *
- * Valid number of samples are ((sample rate) * (audio length (Valid ones are: 2.5, 5, 10, 20, 40 or 60 ms)) / 1000)
- * Valid number of channels are 1 or 2.
- * Valid sample rates are 8000, 12000, 16000, 24000, or 48000.
+ * @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).
+ *          A = MAX(width, abs(astride)) * height.
+ * @param ystride
+ * @param ustride
+ * @param vstride
+ * @param astride 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 toxav_video_receive_frame_cb(ToxAV *toxAV, uint32_t friend_number, uint16_t width, uint16_t height, const uint8_t *y, const uint8_t *u, const uint8_t *v, const uint8_t *a, int32_t ystride, int32_t ustride, int32_t vstride, int32_t astride, void *user_data);
+
+
+/**
+ * Set the callback for the `video_receive_frame` event. Pass NULL to unset.
  *
- * Recommended values are: samples = 960, channels = 1, sample_rate = 48000
  */
-int toxav_group_send_audio(Tox *tox, int groupnumber, const int16_t *pcm, unsigned int samples, uint8_t channels,
-                           unsigned int sample_rate);
+void toxav_callback_video_receive_frame(ToxAV *toxAV, toxav_video_receive_frame_cb *callback, void *user_data);
 
-#ifdef __cplusplus
-}
 #endif
-
-#endif /* __TOXAV */