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doubango/tinyDAV/src/audio/tdav_jitterbuffer.c

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/* File from: http://cms.speakup.nl/tech/opensource/jitterbuffer/verslag-20051209.pdf/ */
/*******************************************************
* jitterbuffer:
* an application-independent jitterbuffer, which tries
* to achieve the maximum user perception during a call.
* For more information look at:
* http://www.speakup.nl/opensource/jitterbuffer/
*
* Copyright on this file is held by:
* - Jesse Kaijen <jesse@speakup.nl>
* - SpeakUp <info@speakup.nl>
*
* Contributors:
* Jesse Kaijen <jesse@speakup.nl>
*
* This program is free software, distributed under the terms of:
* - the GNU Lesser (Library) General Public License
* - the Mozilla Public License
*
* if you are interested in an different licence type, please contact us.
*
* How to use the jitterbuffer, please look at the comments
* in the headerfile.
*
* Further details on specific implementations,
* please look at the comments in the code file.
*/
#include "tinydav/audio/tdav_jitterbuffer.h"
#if !(HAVE_SPEEX_DSP && HAVE_SPEEX_JB)
#include "tsk_memory.h"
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#define jb_warn(...) (warnf ? warnf(__VA_ARGS__) : (void)0)
#define jb_err(...) (errf ? errf(__VA_ARGS__) : (void)0)
#define jb_dbg(...) (dbgf ? dbgf(__VA_ARGS__) : (void)0)
//public functions
jitterbuffer *jb_new();
void jb_reset(jitterbuffer *jb);
void jb_reset_all(jitterbuffer *jb);
void jb_destroy(jitterbuffer *jb);
void jb_set_settings(jitterbuffer *jb, jb_settings *settings);
void jb_get_info(jitterbuffer *jb, jb_info *stats);
void jb_get_settings(jitterbuffer *jb, jb_settings *settings);
float jb_guess_mos(float p, long d, int codec);
int jb_has_frames(jitterbuffer *jb);
void jb_put(jitterbuffer *jb, void *data, int type, long ms, long ts, long now, int codec);
int jb_get(jitterbuffer *jb, void **data, long now, long interpl);
//private functions
static void set_default_settings(jitterbuffer *jb);
static void reset(jitterbuffer *jb);
static long find_pointer(long *array, long max_index, long value);
static void frame_free(jb_frame *frame);
static void put_control(jitterbuffer *jb, void *data, int type, long ts);
static void put_voice(jitterbuffer *jb, void *data, int type, long ms, long ts, int codec);
static void put_history(jitterbuffer *jb, long ts, long now, long ms, int codec);
static void calculate_info(jitterbuffer *jb, long ts, long now, int codec);
static int get_control(jitterbuffer *jb, void **data);
static int get_voice(jitterbuffer *jb, void **data, long now, long interpl);
static int get_voicecase(jitterbuffer *jb, void **data, long now, long interpl, long diff);
static int get_next_frametype(jitterbuffer *jb, long ts);
static long get_next_framets(jitterbuffer *jb);
static jb_frame *get_frame(jitterbuffer *jb, long ts);
static jb_frame *get_all_frames(jitterbuffer *jb);
//debug...
static jb_output_function_t warnf, errf, dbgf;
void jb_setoutput(jb_output_function_t warn, jb_output_function_t err, jb_output_function_t dbg)
{
warnf = warn;
errf = err;
dbgf = dbg;
}
/***********
* create a new jitterbuffer
* return NULL if malloc doesn't work
* else return jb with default_settings.
*/
jitterbuffer *jb_new()
{
jitterbuffer *jb;
jb_dbg("N");
jb = tsk_calloc(1, sizeof(jitterbuffer));
if (!jb) {
jb_err("cannot allocate jitterbuffer\n");
return NULL;
}
set_default_settings(jb);
reset(jb);
return jb;
}
/***********
* empty voice messages
* reset statistics
* keep the settings
*/
void jb_reset(jitterbuffer *jb)
{
jb_frame *frame;
jb_dbg("R");
if (jb == NULL) {
jb_err("no jitterbuffer in jb_reset()\n");
return;
}
//free voice
while(jb->voiceframes) {
frame = get_all_frames(jb);
frame_free(frame);
}
//reset stats
memset(&(jb->info),0,sizeof(jb_info) );
// set default settings
reset(jb);
}
/***********
* empty nonvoice messages
* empty voice messages
* reset statistics
* reset settings to default
*/
void jb_reset_all(jitterbuffer *jb)
{
jb_frame *frame;
jb_dbg("r");
if (jb == NULL) {
jb_err("no jitterbuffer in jb_reset_all()\n");
return;
}
// free nonvoice
while(jb->controlframes) {
frame = jb->controlframes;
jb->controlframes = frame->next;
frame_free(frame);
}
// free voice and reset statistics is done by jb_reset
jb_reset(jb);
set_default_settings(jb);
}
/***********
* destroy the jitterbuffer
* free all the [non]voice frames with reset_all
* free the jitterbuffer
*/
void jb_destroy(jitterbuffer *jb)
{
jb_dbg("D");
if (jb == NULL) {
jb_err("no jitterbuffer in jb_destroy()\n");
return;
}
jb_reset_all(jb);
free(jb);
}
/***********
* Set settings for the jitterbuffer.
* Only if a setting is defined it will be written
* in the jb->settings.
* This means that no setting can be set to zero
*/
void jb_set_settings(jitterbuffer *jb, jb_settings *settings)
{
jb_dbg("S");
if (jb == NULL) {
jb_err("no jitterbuffer in jb_set_settings()\n");
return;
}
if (settings->min_jb) {
jb->settings.min_jb = settings->min_jb;
}
if (settings->max_jb) {
jb->settings.max_jb = settings->max_jb;
}
if (settings->max_successive_interp) {
jb->settings.max_successive_interp = settings->max_successive_interp;
}
if (settings->extra_delay) {
jb->settings.extra_delay = settings->extra_delay;
}
if (settings->wait_grow) {
jb->settings.wait_grow = settings->wait_grow;
}
if (settings->wait_shrink) {
jb->settings.wait_shrink = settings->wait_shrink;
}
if (settings->max_diff) {
jb->settings.max_diff = settings->max_diff;
}
}
/***********
* validates the statistics
* the losspct due the jitterbuffer will be calculated.
* delay and delay_target will be calculated
* *stats = info
*/
void jb_get_info(jitterbuffer *jb, jb_info *stats)
{
long max_index, pointer;
jb_dbg("I");
if (jb == NULL) {
jb_err("no jitterbuffer in jb_get_info()\n");
return;
}
jb->info.delay = jb->current - jb->min;
jb->info.delay_target = jb->target - jb->min;
//calculate the losspct...
max_index = (jb->hist_pointer < JB_HISTORY_SIZE) ?
jb->hist_pointer : JB_HISTORY_SIZE-1;
if (max_index>1) {
pointer = find_pointer(&jb->hist_sorted_delay[0], max_index,
jb->current);
jb->info.losspct = ((max_index - pointer)*100/max_index);
if (jb->info.losspct < 0) {
jb->info.losspct = 0;
}
}
else {
jb->info.losspct = 0;
}
*stats = jb->info;
}
/***********
* gives the settings for this jitterbuffer
* *settings = settings
*/
void jb_get_settings(jitterbuffer *jb, jb_settings *settings)
{
jb_dbg("S");
if (jb == NULL) {
jb_err("no jitterbuffer in jb_get_settings()\n");
return;
}
*settings = jb->settings;
}
/***********
* returns an estimate on the MOS with given loss, delay and codec
* if the formula is not present the default will be used
* please use the JB_CODEC_OTHER if you want to define your own formula
*
*/
float jb_guess_mos(float p, long d, int codec)
{
float result;
switch (codec) {
case JB_CODEC_GSM_EFR:
result = (4.31f - 0.23f*p - 0.0071f*d);
break;
case JB_CODEC_G723_1:
result = (3.99f - 0.16f*p - 0.0071f*d);
break;
case JB_CODEC_G729:
case JB_CODEC_G729A:
result = (4.13f - 0.14f*p - 0.0071f*d);
break;
case JB_CODEC_G711x_PLC:
result = (4.42f - 0.087f*p - 0.0071f*d);
break;
case JB_CODEC_G711x:
result = (4.42f - 0.63f*p - 0.0071f*d);
break;
case JB_CODEC_OTHER:
default:
result = (4.42f - 0.63f*p - 0.0071f*d);
}
return result;
}
/***********
* if there are any frames left in JB returns JB_OK, otherwise returns JB_EMPTY
*/
int jb_has_frames(jitterbuffer *jb)
{
jb_dbg("H");
if (jb == NULL) {
jb_err("no jitterbuffer in jb_has_frames()\n");
return JB_NOJB;
}
if(jb->controlframes || jb->voiceframes) {
return JB_OK;
}
else {
return JB_EMPTY;
}
}
/***********
* Put a packet into the jitterbuffers
* Only the timestamps of voicepackets are put in the history
* this because the jitterbuffer only works for voicepackets
* don't put packets twice in history and queue (e.g. transmitting every frame twice)
* keep track of statistics
*/
void jb_put(jitterbuffer *jb, void *data, int type, long ms, long ts, long now, int codec)
{
long pointer, max_index;
if (jb == NULL) {
jb_err("no jitterbuffer in jb_put()\n");
return;
}
jb->info.frames_received++;
if (type == JB_TYPE_CONTROL) {
//put the packet into the contol-queue of the jitterbuffer
jb_dbg("pC");
put_control(jb,data,type,ts);
}
else if (type == JB_TYPE_VOICE) {
// only add voice that aren't already in the buffer
max_index = (jb->hist_pointer < JB_HISTORY_SIZE) ? jb->hist_pointer : JB_HISTORY_SIZE-1;
pointer = find_pointer(&jb->hist_sorted_timestamp[0], max_index, ts);
if (jb->hist_sorted_timestamp[pointer]==ts) { //timestamp already in queue
jb_dbg("pT");
free(data);
jb->info.frames_dropped_twice++;
}
else { //add
jb_dbg("pV");
/* add voicepacket to history */
put_history(jb,ts,now,ms,codec);
/*calculate jitterbuffer size*/
calculate_info(jb, ts, now, codec);
/*put the packet into the queue of the jitterbuffer*/
put_voice(jb,data,type,ms,ts,codec);
}
}
else if (type == JB_TYPE_SILENCE) { //silence
jb_dbg("pS");
put_voice(jb,data,type,ms,ts,codec);
}
else { //should NEVER happen
jb_err("jb_put(): type not known\n");
free(data);
}
}
/***********
* control frames have a higher priority then voice frames
* returns JB_OK if a frame is available and *data points to the packet
* returns JB_NOFRAME if it's no time to play voice and no control available
* returns JB_INTERP if interpolating is required
* returns JB_EMPTY if no voice frame is in the jitterbuffer (only during silence)
*/
int jb_get(jitterbuffer *jb, void **data, long now, long interpl)
{
int result;
jb_dbg("A");
if (jb == NULL) {
jb_err("no jitterbuffer in jb_get()\n");
return JB_NOJB;
}
result = get_control(jb, data);
if (result != JB_OK ) { //no control message available maybe there is voice...
result = get_voice(jb, data, now, interpl);
}
return result;
}
/***********
* set all the settings to default
*/
static void set_default_settings(jitterbuffer *jb)
{
jb->settings.min_jb = JB_MIN_SIZE;
jb->settings.max_jb = JB_MAX_SIZE;
jb->settings.max_successive_interp = JB_MAX_SUCCESSIVE_INTERP;
jb->settings.extra_delay = JB_ALLOW_EXTRA_DELAY;
jb->settings.wait_grow = JB_WAIT_GROW;
jb->settings.wait_shrink = JB_WAIT_SHRINK;
jb->settings.max_diff = JB_MAX_DIFF;
}
/***********
* reset the jitterbuffer so we can start in silence and
* we start with a new history
*/
static void reset(jitterbuffer *jb)
{
jb->hist_pointer = 0; //start over
jb->silence_begin_ts = 0; //no begin_ts defined
jb->info.silence =1; //we always start in silence
}
/***********
* Search algorithm
* @REQUIRE max_index is within array
*
* Find the position of value in hist_sorted_delay
* if value doesn't exist return first pointer where array[low]>value
* int low; //the lowest index being examined
* int max_index; //the highest index being examined
* int mid; //the middle index between low and max_index.
* mid ==(low+max_index)/2
* at the end low is the position of value or where array[low]>value
*/
static long find_pointer(long *array, long max_index, long value)
{
register long low, mid, high;
low = 0;
high = max_index;
while (low<=high) {
mid= (low+high)/2;
if (array[mid] < value) {
low = mid+1;
}
else {
high = mid-1;
}
}
while(low < max_index && (array[low]==array[(low+1)]) ) {
low++;
}
return low;
}
/***********
* free the given frame, afterwards the framepointer is undefined
*/
static void frame_free(jb_frame *frame)
{
if (frame->data) {
free(frame->data);
}
free(frame);
}
/***********
* put a nonvoice frame into the nonvoice queue
*/
static void put_control(jitterbuffer *jb, void *data, int type, long ts)
{
jb_frame *frame, *p;
frame = malloc(sizeof(jb_frame));
if(!frame) {
jb_err("cannot allocate frame\n");
return;
}
frame->data = data;
frame->ts = ts;
frame->type = type;
frame->next = NULL;
data = NULL;//to avoid stealing memory
p = jb->controlframes;
if (p) { //there are already control messages
if (ts < p->ts) {
jb->controlframes = frame;
frame->next = p;
}
else {
while (p->next && (ts >=p->next->ts)) {//sort on timestamps! so find place to put...
p = p->next;
}
if (p->next) {
frame->next = p->next;
}
p->next = frame;
}
}
else {
jb->controlframes = frame;
}
}
/***********
* put a voice or silence frame into the jitterbuffer
*/
static void put_voice(jitterbuffer *jb, void *data, int type, long ms, long ts, int codec)
{
jb_frame *frame, *p;
frame = malloc(sizeof(jb_frame));
if(!frame) {
jb_err("cannot allocate frame\n");
return;
}
frame->data = data;
frame->ts = ts;
frame->ms = ms;
frame->type = type;
frame->codec = codec;
data = NULL; //to avoid stealing the memory location
/*
* frames are a circular list, jb->voiceframes points to to the lowest ts,
* jb->voiceframes->prev points to the highest ts
*/
if(!jb->voiceframes) { /* queue is empty */
jb->voiceframes = frame;
frame->next = frame;
frame->prev = frame;
}
else {
p = jb->voiceframes;
if(ts < p->prev->ts) { //frame is out of order
jb->info.frames_ooo++;
}
if (ts < p->ts) { //frame is lowest, let voiceframes point to it!
jb->voiceframes = frame;
}
else {
while(ts < p->prev->ts ) {
p = p->prev;
}
}
frame->next = p;
frame->prev = p->prev;
frame->next->prev = frame;
frame->prev->next = frame;
}
}
/***********
* puts the timestamps of a received packet in the history of *jb
* for later calculations of the size of jitterbuffer *jb.
*
* summary of function:
* - calculate delay difference
* - delete old value from hist & sorted_history_delay & sorted_history_timestamp if needed
* - add new value to history & sorted_history_delay & sorted_history_timestamp
* - we keep sorted_history_delay for calculations
* - we keep sorted_history_timestamp for ensuring each timestamp isn't put twice in the buffer.
*/
static void put_history(jitterbuffer *jb, long ts, long now, long ms, int codec)
{
jb_hist_element out, in;
long max_index, pointer, location;
// max_index is the highest possible index
max_index = (jb->hist_pointer < JB_HISTORY_SIZE) ? jb->hist_pointer : JB_HISTORY_SIZE-1;
location = (jb->hist_pointer % JB_HISTORY_SIZE);
// we want to delete a value from the jitterbuffer
// only when we are through the history.
if (jb->hist_pointer > JB_HISTORY_SIZE-1) {
/* the value we need to delete from sorted histories */
out = jb->hist[location];
//delete delay from hist_sorted_delay
pointer = find_pointer(&jb->hist_sorted_delay[0], max_index, out.delay);
/* move over pointer is the position of kicked*/
if (pointer<max_index) { //only move if we have something to move
memmove( &(jb->hist_sorted_delay[pointer]),
&(jb->hist_sorted_delay[pointer+1]),
((JB_HISTORY_SIZE-(pointer+1)) * sizeof(long)) );
}
//delete timestamp from hist_sorted_timestamp
pointer = find_pointer(&jb->hist_sorted_timestamp[0], max_index, out.ts);
/* move over pointer is the position of kicked*/
if (pointer<max_index) { //only move if we have something to move
memmove( &(jb->hist_sorted_timestamp[pointer]),
&(jb->hist_sorted_timestamp[pointer+1]),
((JB_HISTORY_SIZE-(pointer+1)) * sizeof(long)) );
}
}
in.delay = now - ts; //delay of current packet
in.ts = ts; //timestamp of current packet
in.ms = ms; //length of current packet
in.codec = codec; //codec of current packet
/* adding the new delay to the sorted history
* first special cases:
* - delay is the first history stamp
* - delay > highest history stamp
*/
if (max_index==0 || in.delay >= jb->hist_sorted_delay[max_index-1]) {
jb->hist_sorted_delay[max_index] = in.delay;
}
else {
pointer = find_pointer(&jb->hist_sorted_delay[0], (max_index-1), in.delay);
/* move over and add delay */
memmove( &(jb->hist_sorted_delay[pointer+1]),
&(jb->hist_sorted_delay[pointer]),
((JB_HISTORY_SIZE-(pointer+1)) * sizeof(long)) );
jb->hist_sorted_delay[pointer] = in.delay;
}
/* adding the new timestamp to the sorted history
* first special cases:
* - timestamp is the first history stamp
* - timestamp > highest history stamp
*/
if (max_index==0 || in.ts >= jb->hist_sorted_timestamp[max_index-1]) {
jb->hist_sorted_timestamp[max_index] = in.ts;
}
else {
pointer = find_pointer(&jb->hist_sorted_timestamp[0], (max_index-1), in.ts);
/* move over and add timestamp */
memmove( &(jb->hist_sorted_timestamp[pointer+1]),
&(jb->hist_sorted_timestamp[pointer]),
((JB_HISTORY_SIZE-(pointer+1)) * sizeof(long)) );
jb->hist_sorted_timestamp[pointer] = in.ts;
}
/* put the jb_hist_element in the history
* then increase hist_pointer for next time
*/
jb->hist[location] = in;
jb->hist_pointer++;
}
/***********
* this tries to make a jitterbuffer that behaves like
* the jitterbuffer proposed in this article:
* Adaptive Playout Buffer Algorithm for Enhancing Perceived Quality of Streaming Applications
* by: Kouhei Fujimoto & Shingo Ata & Masayuki Murata
* http://www.nal.ics.es.osaka-u.ac.jp/achievements/web2002/pdf/journal/k-fujimo02TSJ-AdaptivePlayoutBuffer.pdf
*
* it calculates jitter and minimum delay
* get the best delay for the specified codec
*/
static void calculate_info(jitterbuffer *jb, long ts, long now, int codec)
{
long diff, size, max_index, d, d1, d2, n;
float p, p1, p2, A, B;
//size = how many items there in the history
size = (jb->hist_pointer < JB_HISTORY_SIZE) ? jb->hist_pointer : JB_HISTORY_SIZE;
max_index = size-1;
/*
* the Inter-Quartile Range can be used for estimating jitter
* http://www.slac.stanford.edu/comp/net/wan-mon/tutorial.html#variable
* just take the square root of the iqr for jitter
*/
jb->info.iqr = jb->hist_sorted_delay[max_index*3/4] - jb->hist_sorted_delay[max_index/4];
/*
* The RTP way of calculating jitter.
* This one is used at the moment, although it is not correct.
* But in this way the other side understands us.
*/
diff = now - ts - jb->last_delay;
if (!jb->last_delay) {
diff = 0; //this to make sure we won't get odd jitter due first ts.
}
jb->last_delay = now - ts;
if (diff <0) {
diff = -diff;
}
jb->info.jitter = jb->info.jitter + (diff - jb->info.jitter)/16;
/* jb->min is minimum delay in hist_sorted_delay, we don't look at the lowest 2% */
/* because sometimes there are odd delays in there */
jb->min = jb->hist_sorted_delay[(max_index*2/100)];
/*
* calculating the preferred size of the jitterbuffer:
* instead of calculating the optimum delay using the Pareto equation
* I use look at the array of sorted delays and choose my optimum from there
* always walk trough a percentage of the history this because imagine following tail:
* [...., 12, 300, 301 ,302]
* her we want to discard last three but that won't happen if we won't walk the array
* the number of frames we walk depends on how scattered the sorted delays are.
* For that we look at the iqr. The dependencies of the iqr are based on
* tests we've done here in the lab. But are not optimized.
*/
//init:
//the higest delay..
d = d1= d2 = jb->hist_sorted_delay[max_index]- jb->min;
A=B=LONG_MIN;
p = p2 =0;
n=0;
p1 = 5; //always look at the top 5%
if (jb->info.iqr >200) { //with more jitter look at more delays
p1=25;
}
else if (jb->info.iqr >100) {
p1=20;
}
else if (jb->info.iqr >50) {
p1=11;
}
//find the optimum delay..
while(max_index>10 && (B > A ||p2<p1)) { // By MDI: from ">=" to ">"
//the packetloss with this delay
p2 =(n*100.0f/size);
// estimate MOS-value
B = jb_guess_mos(p2,d2,codec);
if (B > A) {
p = p2;
d = d2;
A = B;
}
d1 = d2;
//find next delay != delay so the same delay isn't calculated twice
//don't look further if we have seen half of the history
while((d2>=d1) && ((n*2)<max_index) ) {
n++;
d2 = jb->hist_sorted_delay[(max_index-n)] - jb->min;
}
}
//the targeted size of the jitterbuffer
if (jb->settings.min_jb && (jb->settings.min_jb > d) ) {
jb->target = jb->min + jb->settings.min_jb;
}
else if (jb->settings.max_jb && (jb->settings.max_jb > d) ) {
jb->target = jb->min + jb->settings.max_jb;
}
else {
jb->target = jb->min + d;
}
}
/***********
* if there is a nonvoice frame it will be returned [*data] and the frame
* will be made free
*/
static int get_control(jitterbuffer *jb, void **data)
{
jb_frame *frame;
int result;
frame = jb->controlframes;
if (frame) {
jb_dbg("gC");
*data = frame->data;
frame->data = NULL;
jb->controlframes = frame->next;
frame_free(frame);
result = JB_OK;
}
else {
result = JB_NOFRAME;
}
return result;
}
/***********
* returns JB_OK if a frame is available and *data points to the packet
* returns JB_NOFRAME if it's no time to play voice and or no frame available
* returns JB_INTERP if interpolating is required
* returns JB_EMPTY if no voice frame is in the jitterbuffer (only during silence)
*
* if the next frame is a silence frame we will go in silence-mode
* each new instance of the jitterbuffer will start in silence mode
* in silence mode we will set the jitterbuffer to the size we want
* when we are not in silence mode get_voicecase will handle the rest.
*/
static int get_voice(jitterbuffer *jb, void **data, long now, long interpl)
{
jb_frame *frame;
long diff;
int result;
diff = jb->target - jb->current;
//if the next frame is a silence frame, go in silence mode...
if((get_next_frametype(jb, now - jb->current) == JB_TYPE_SILENCE) ) {
jb_dbg("gs");
frame = get_frame(jb, now - jb->current);
*data = frame->data;
frame->data = NULL;
jb->info.silence =1;
jb->silence_begin_ts = frame->ts;
frame_free(frame);
result = JB_OK;
}
else {
if(jb->info.silence) { // we are in silence
/*
* During silence we can set the jitterbuffer size to the size
* we want...
*/
if (diff) {
jb->current = jb->target;
}
frame = get_frame(jb, now - jb->current);
if (frame) {
if (jb->silence_begin_ts && frame->ts < jb->silence_begin_ts) {
jb_dbg("gL");
/* voice frame is late, next!*/
jb->info.frames_late++;
frame_free(frame);
result = get_voice(jb, data, now, interpl);
}
else {
jb_dbg("gP");
/* voice frame */
jb->info.silence = 0;
jb->silence_begin_ts = 0;
jb->next_voice_time = frame->ts + frame->ms;
jb->info.last_voice_ms = frame->ms;
*data = frame->data;
frame->data = NULL;
frame_free(frame);
result = JB_OK;
}
}
else { //no frame
jb_dbg("gS");
result = JB_EMPTY;
}
}
else { //voice case
result = get_voicecase(jb,data,now,interpl,diff);
}
}
return result;
}
/***********
* The voicecase has four 'options'
* - difference is way off, reset
* - diff > 0, we may need to grow
* - diff < 0, we may need to shrink
* - everything else
*/
static int get_voicecase(jitterbuffer *jb, void **data, long now, long interpl, long diff)
{
jb_frame *frame;
int result;
// * - difference is way off, reset
if (diff > jb->settings.max_diff || -diff > jb->settings.max_diff) {
jb_err("wakko diff in get_voicecase\n");
reset(jb); //reset hist because the timestamps are wakko.
result = JB_NOFRAME;
//- diff > 0, we may need to grow
}
else if ((diff > 0) &&
(now > (jb->last_adjustment + jb->settings.wait_grow)
|| (now + jb->current + interpl) < get_next_framets(jb) ) ) { //grow
/* first try to grow */
if (diff<interpl/2) {
jb_dbg("ag");
jb->current +=diff;
}
else {
jb_dbg("aG");
/* grow by interp frame len */
jb->current += interpl;
}
jb->last_adjustment = now;
result = get_voice(jb, data, now, interpl);
//- diff < 0, we may need to shrink
}
else if ( (diff < 0)
&& (now > (jb->last_adjustment + jb->settings.wait_shrink))
&& ((-diff) > jb->settings.extra_delay) ) {
/* now try to shrink
* if there is a frame shrink by frame length
* otherwise shrink by interpl
*/
jb->last_adjustment = now;
frame = get_frame(jb, now - jb->current);
if(frame) {
jb_dbg("as");
/* shrink by frame size we're throwing out */
jb->info.frames_dropped++;
jb->current -= frame->ms;
frame_free(frame);
}
else {
jb_dbg("aS");
/* shrink by interpl */
jb->current -= interpl;
}
result = get_voice(jb, data, now, interpl);
}
else {
/* if it is not the time to play a result = JB_NOFRAME
* else We try to play a frame if a frame is available
* and not late it is played otherwise
* if available it is dropped and the next is tried
* last option is interpolating
*/
if (now - jb->current < jb->next_voice_time) {
jb_dbg("aN");
result = JB_NOFRAME;
}
else {
frame = get_frame(jb, now - jb->current);
if (frame) { //there is a frame
/* voice frame is late */
if(frame->ts < jb->next_voice_time) { //late
jb_dbg("aL");
jb->info.frames_late++;
frame_free(frame);
result = get_voice(jb, data, now, interpl);
}
else {
jb_dbg("aP");
/* normal case; return the frame, increment stuff */
*data = frame->data;
frame->data = NULL;
jb->next_voice_time = frame->ts + frame->ms;
jb->cnt_successive_interp = 0;
frame_free(frame);
result = JB_OK;
}
}
else { // no frame, thus interpolate
jb->cnt_successive_interp++;
/* assume silence instead of continuing to interpolate */
if (jb->settings.max_successive_interp && jb->cnt_successive_interp >= jb->settings.max_successive_interp) {
jb->info.silence = 1;
jb->silence_begin_ts = jb->next_voice_time;
}
jb_dbg("aI");
jb->next_voice_time += interpl;
result = JB_INTERP;
}
}
}
return result;
}
/***********
* if there are frames and next frame->ts is smaller or equal ts
* return type of next frame.
* else return 0
*/
static int get_next_frametype(jitterbuffer *jb, long ts)
{
jb_frame *frame;
int result;
result = 0;
frame = jb->voiceframes;
if (frame && frame->ts <= ts) {
result = frame->type;
}
return result;
}
/***********
* returns ts from next frame in jb->voiceframes
* or returns LONG_MAX if there is no frame
*/
static long get_next_framets(jitterbuffer *jb)
{
if (jb->voiceframes) {
return jb->voiceframes->ts;
}
return LONG_MAX;
}
/***********
* if there is a frame in jb->voiceframes and
* has a timestamp smaller/equal to ts
* this frame will be returned and
* removed from the queue
*/
static jb_frame *get_frame(jitterbuffer *jb, long ts)
{
jb_frame *frame;
frame = jb->voiceframes;
if (frame && frame->ts <= ts) {
if(frame->next == frame) {
jb->voiceframes = NULL;
}
else {
/* remove this frame */
frame->prev->next = frame->next;
frame->next->prev = frame->prev;
jb->voiceframes = frame->next;
}
return frame;
}
return NULL;
}
/***********
* if there is a frame in jb->voiceframes
* this frame will be unconditionally returned and
* removed from the queue
*/
static jb_frame *get_all_frames(jitterbuffer *jb)
{
jb_frame *frame;
frame = jb->voiceframes;
if (frame) {
if(frame->next == frame) {
jb->voiceframes = NULL;
}
else {
/* remove this frame */
frame->prev->next = frame->next;
frame->next->prev = frame->prev;
jb->voiceframes = frame->next;
}
return frame;
}
return NULL;
}
#endif // !(HAVE_SPEEX_DSP && HAVE_SPEEX_JB)
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