rockbox/apps/codecs/libspeex/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:
   
   - Redistributions of source code must retain the above copyright
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   - Neither the name of the Xiph.org Foundation nor the names of its
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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.h"
#include "speex_bits.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) */
};

/** Packet has been retrieved */
#define JITTER_BUFFER_OK 0
/** Packet is missing */
#define JITTER_BUFFER_MISSING 1
/** Packet is incomplete (does not cover the entive tick */
#define JITTER_BUFFER_INCOMPLETE 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_AVALIABLE_COUNT wouldn't make sense */
/** Get the amount of avaliable packets currently buffered */
#define JITTER_BUFFER_GET_AVALIABLE_COUNT 3

#define JITTER_BUFFER_ADJUST_INTERPOLATE -1
#define JITTER_BUFFER_ADJUST_OK 0
#define JITTER_BUFFER_ADJUST_DROP 1

/** Initialises jitter buffer 
 * 
 * @param tick Number of samples per "tick", i.e. the time period of the elements that will be retrieved
 * @return Newly created jitter buffer state
 */
JitterBuffer *jitter_buffer_init(int tick);

/** 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 current_timestamp Timestamp for the returned packet 
*/
int jitter_buffer_get(JitterBuffer *jitter, JitterBufferPacket *packet, spx_uint32_t *current_timestamp);

/** 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);

/** 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_uint32_t *start_offset);

/* @} */

/** @defgroup SpeexJitter SpeexJitter: Adaptive jitter buffer specifically for Speex
 *  This is the jitter buffer that reorders UDP/RTP packets and adjusts the buffer size
 * to maintain good quality and low latency. This is a simplified version that works only
 * with Speex, but is much easier to use.
 *  @{
*/

/** Speex jitter-buffer state. Never use it directly! */
typedef struct SpeexJitter {
   SpeexBits current_packet;         /**< Current Speex packet */
   int valid_bits;                   /**< True if Speex bits are valid */
   JitterBuffer *packets;            /**< Generic jitter buffer state */
   void *dec;                        /**< Pointer to Speex decoder */
   spx_int32_t frame_size;           /**< Frame size of Speex decoder */
} SpeexJitter;

/** Initialise jitter buffer 
 * 
 * @param jitter State of the Speex jitter buffer
 * @param decoder Speex decoder to call
 * @param sampling_rate Sampling rate used by the decoder
*/
void speex_jitter_init(SpeexJitter *jitter, void *decoder, int sampling_rate);

/** Destroy jitter buffer */
void speex_jitter_destroy(SpeexJitter *jitter);

/** Put one packet into the jitter buffer */
void speex_jitter_put(SpeexJitter *jitter, char *packet, int len, int timestamp);

/** Get one packet from the jitter buffer */
void speex_jitter_get(SpeexJitter *jitter, spx_int16_t *out, int *start_offset);

/** Get pointer timestamp of jitter buffer */
int speex_jitter_get_pointer_timestamp(SpeexJitter *jitter);

#ifdef __cplusplus
}
#endif

/* @} */
#endif