godot/drivers/speex/speex_jitter.h

/* Copyright (C) 2002 Jean-Marc Valin */
/**
   @file speex_jitter.h
   @brief Adaptive jitter buffer for Speex
*/
/*
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   are met:
   
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   this software without specific prior written permission.
   
   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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*/

#ifndef SPEEX_JITTER_H
#define SPEEX_JITTER_H
/** @defgroup JitterBuffer JitterBuffer: Adaptive jitter buffer
 *  This is the jitter buffer that reorders UDP/RTP packets and adjusts the buffer size
 * to maintain good quality and low latency.
 *  @{
 */

#include "speex/speex_types.h"

#ifdef __cplusplus
extern "C" {
#endif

/** Generic adaptive jitter buffer state */
struct JitterBuffer_;

/** Generic adaptive jitter buffer state */
typedef struct JitterBuffer_ JitterBuffer;

/** Definition of an incoming packet */
typedef struct _JitterBufferPacket JitterBufferPacket;

/** Definition of an incoming packet */
struct _JitterBufferPacket {
   char        *data;       /**< Data bytes contained in the packet */
   spx_uint32_t len;        /**< Length of the packet in bytes */
   spx_uint32_t timestamp;  /**< Timestamp for the packet */
   spx_uint32_t span;       /**< Time covered by the packet (same units as timestamp) */
   spx_uint16_t sequence;   /**< RTP Sequence number if available (0 otherwise) */
   spx_uint32_t user_data;  /**< Put whatever data you like here (it's ignored by the jitter buffer) */
};

/** Packet has been retrieved */
#define JITTER_BUFFER_OK 0
/** Packet is lost or is late */
#define JITTER_BUFFER_MISSING 1
/** A "fake" packet is meant to be inserted here to increase buffering */
#define JITTER_BUFFER_INSERTION 2
/** There was an error in the jitter buffer */
#define JITTER_BUFFER_INTERNAL_ERROR -1
/** Invalid argument */
#define JITTER_BUFFER_BAD_ARGUMENT -2


/** Set minimum amount of extra buffering required (margin) */
#define JITTER_BUFFER_SET_MARGIN 0
/** Get minimum amount of extra buffering required (margin) */
#define JITTER_BUFFER_GET_MARGIN 1
/* JITTER_BUFFER_SET_AVAILABLE_COUNT wouldn't make sense */

/** Get the amount of available packets currently buffered */
#define JITTER_BUFFER_GET_AVAILABLE_COUNT 3
/** Included because of an early misspelling (will remove in next release) */
#define JITTER_BUFFER_GET_AVALIABLE_COUNT 3

/** Assign a function to destroy unused packet. When setting that, the jitter 
    buffer no longer copies packet data. */
#define JITTER_BUFFER_SET_DESTROY_CALLBACK 4
/**  */
#define JITTER_BUFFER_GET_DESTROY_CALLBACK 5

/** Tell the jitter buffer to only adjust the delay in multiples of the step parameter provided */
#define JITTER_BUFFER_SET_DELAY_STEP 6
/**  */
#define JITTER_BUFFER_GET_DELAY_STEP 7

/** Tell the jitter buffer to only do concealment in multiples of the size parameter provided */
#define JITTER_BUFFER_SET_CONCEALMENT_SIZE 8
#define JITTER_BUFFER_GET_CONCEALMENT_SIZE 9

/** Absolute max amount of loss that can be tolerated regardless of the delay. Typical loss 
    should be half of that or less. */
#define JITTER_BUFFER_SET_MAX_LATE_RATE 10
#define JITTER_BUFFER_GET_MAX_LATE_RATE 11

/** Equivalent cost of one percent late packet in timestamp units */
#define JITTER_BUFFER_SET_LATE_COST 12
#define JITTER_BUFFER_GET_LATE_COST 13


/** Initialises jitter buffer 
 * 
 * @param step_size Starting value for the size of concleanment packets and delay 
       adjustment steps. Can be changed at any time using JITTER_BUFFER_SET_DELAY_STEP
       and JITTER_BUFFER_GET_CONCEALMENT_SIZE.
 * @return Newly created jitter buffer state
 */
JitterBuffer *jitter_buffer_init(int step_size);

/** Restores jitter buffer to its original state 
 * 
 * @param jitter Jitter buffer state
 */
void jitter_buffer_reset(JitterBuffer *jitter);

/** Destroys jitter buffer 
 * 
 * @param jitter Jitter buffer state
 */
void jitter_buffer_destroy(JitterBuffer *jitter);

/** Put one packet into the jitter buffer
 * 
 * @param jitter Jitter buffer state
 * @param packet Incoming packet
*/
void jitter_buffer_put(JitterBuffer *jitter, const JitterBufferPacket *packet);

/** Get one packet from the jitter buffer
 * 
 * @param jitter Jitter buffer state
 * @param packet Returned packet
 * @param desired_span Number of samples (or units) we wish to get from the buffer (no guarantee)
 * @param current_timestamp Timestamp for the returned packet 
*/
int jitter_buffer_get(JitterBuffer *jitter, JitterBufferPacket *packet, spx_int32_t desired_span, spx_int32_t *start_offset);

/** Used right after jitter_buffer_get() to obtain another packet that would have the same timestamp.
 * This is mainly useful for media where a single "frame" can be split into several packets.
 * 
 * @param jitter Jitter buffer state
 * @param packet Returned packet
 */
int jitter_buffer_get_another(JitterBuffer *jitter, JitterBufferPacket *packet);

/** Get pointer timestamp of jitter buffer
 * 
 * @param jitter Jitter buffer state
*/
int jitter_buffer_get_pointer_timestamp(JitterBuffer *jitter);

/** Advance by one tick
 * 
 * @param jitter Jitter buffer state
*/
void jitter_buffer_tick(JitterBuffer *jitter);

/** Telling the jitter buffer about the remaining data in the application buffer
 * @param jitter Jitter buffer state
 * @param rem Amount of data buffered by the application (timestamp units)
 */
void jitter_buffer_remaining_span(JitterBuffer *jitter, spx_uint32_t rem);

/** Used like the ioctl function to control the jitter buffer parameters
 * 
 * @param jitter Jitter buffer state
 * @param request ioctl-type request (one of the JITTER_BUFFER_* macros)
 * @param ptr Data exchanged to-from function
 * @return 0 if no error, -1 if request in unknown
*/
int jitter_buffer_ctl(JitterBuffer *jitter, int request, void *ptr);

int jitter_buffer_update_delay(JitterBuffer *jitter, JitterBufferPacket *packet, spx_int32_t *start_offset);

/* @} */

#ifdef __cplusplus
}
#endif

#endif