static void discard_well_choosed_samples(mblk_t *m, int nsamples, int todrop)
{
int i;
int16_t *samples = (int16_t *) m->b_rptr;
int min_diff = 32768;
int pos = 0;
#ifdef TWO_SAMPLES_CRITERIA
for (i = 0; i < nsamples - 1; ++i) {
int tmp = abs((int) samples[i] - (int) samples[i + 1]);
#else
for (i = 0; i < nsamples - 2; ++i) {
int tmp = abs((int) samples[i] - (int) samples[i + 1]) + abs((int) samples[i + 1] - (int) samples[i + 2]);
#endif
if (tmp <= min_diff) {
pos = i;
min_diff = tmp;
}
}
/*ms_message("min_diff=%i at pos %i",min_diff, pos);*/
#ifdef TWO_SAMPLES_CRITERIA
memmove(samples + pos, samples + pos + 1, (nsamples - pos - 1) * 2);
#else
memmove(samples + pos + 1, samples + pos + 2, (nsamples - pos - 2) * 2);
#endif
todrop--;
m->b_wptr -= 2;
nsamples--;
if (todrop > 0) {
/*repeat the same process again*/
discard_well_choosed_samples(m, nsamples, todrop);
}
}
mblk_t *audio_flow_controller_process(AudioFlowController *ctl, mblk_t *m)
{
if (ctl->total_samples > 0 && ctl->target_samples > 0) {
int nsamples = (m->b_wptr - m->b_rptr) / 2;
if (ctl->target_samples * 16 > ctl->total_samples) {
ms_warning("Too many samples to drop, dropping entire frames");
freemsg(m);
ctl->current_pos += nsamples;
m=NULL;
} else {
int th_dropped;
int todrop;
ctl->current_pos += nsamples;
th_dropped = (ctl->target_samples * ctl->current_pos) / ctl->total_samples;
todrop = th_dropped - ctl->current_dropped;
if (todrop > 0) {
if (todrop > nsamples) todrop = nsamples;
discard_well_choosed_samples(m, nsamples, todrop);
/*ms_message("th_dropped=%i, current_dropped=%i, %i samples dropped.",th_dropped,ctl->current_dropped,todrop);*/
ctl->current_dropped += todrop;
}
}
if (ctl->current_pos >= ctl->total_samples) ctl->target_samples = 0; /*stop discarding*/
}
return m;
}
static void discard_well_choosed_samples(mblk_t *m, int nsamples, int todrop){
int i;
int16_t *samples=(int16_t*)m->b_rptr;
int min_diff=32768;
int pos=0;
#ifdef TWO_SAMPLES_CRITERIA
for(i=0;i<nsamples-1;++i){
int tmp=abs((int)samples[i]- (int)samples[i+1]);
#else
for(i=0;i<nsamples-2;++i){
int tmp=abs((int)samples[i]- (int)samples[i+1])+abs((int)samples[i+1]- (int)samples[i+2]);
#endif
if (tmp<=min_diff){
pos=i;
min_diff=tmp;
}
}
/*ms_message("min_diff=%i at pos %i",min_diff, pos);*/
#ifdef TWO_SAMPLES_CRITERIA
memmove(samples+pos,samples+pos+1,(nsamples-pos-1)*2);
#else
memmove(samples+pos+1,samples+pos+2,(nsamples-pos-2)*2);
#endif
todrop--;
m->b_wptr-=2;
nsamples--;
if (todrop>0){
/*repeat the same process again*/
discard_well_choosed_samples(m,nsamples,todrop);
}
}
mblk_t * audio_flow_controller_process(AudioFlowController *ctl, mblk_t *m){
if (ctl->total_samples>0 && ctl->target_samples>0){
int nsamples=(m->b_wptr-m->b_rptr)/2;
if (ctl->target_samples*16>ctl->total_samples){
ms_warning("Too many samples to drop, dropping entire frames");
m->b_wptr=m->b_rptr;
ctl->current_pos+=nsamples;
}else{
int th_dropped;
int todrop;
ctl->current_pos+=nsamples;
th_dropped=(ctl->target_samples*ctl->current_pos)/ctl->total_samples;
todrop=th_dropped-ctl->current_dropped;
if (todrop>0){
if (todrop>nsamples) todrop=nsamples;
discard_well_choosed_samples(m,nsamples,todrop);
/*ms_message("th_dropped=%i, current_dropped=%i, %i samples dropped.",th_dropped,ctl->current_dropped,todrop);*/
ctl->current_dropped+=todrop;
}
}
if (ctl->current_pos>=ctl->total_samples) ctl->target_samples=0;/*stop discarding*/
}
return m;
}
//#define EC_DUMP 1
#ifdef ANDROID
#define EC_DUMP_PREFIX "/sdcard"
#else
#define EC_DUMP_PREFIX "."
#endif
static const float smooth_factor=0.05;
static const int framesize=64;
static const int flow_control_interval_ms=5000;
typedef struct SpeexECState{
SpeexEchoState *ecstate;
SpeexPreprocessState *den;
MSBufferizer delayed_ref;
MSBufferizer ref;
MSBufferizer echo;
int framesize;
int filterlength;
int samplerate;
int delay_ms;
int tail_length_ms;
int nominal_ref_samples;
int min_ref_samples;
AudioFlowController afc;
uint64_t flow_control_time;
char *state_str;
#ifdef EC_DUMP
FILE *echofile;
FILE *reffile;
FILE *cleanfile;
#endif
bool_t echostarted;
bool_t bypass_mode;
bool_t using_zeroes;
}SpeexECState;
static void speex_ec_init(MSFilter *f){
SpeexECState *s=(SpeexECState *)ms_new(SpeexECState,1);
s->samplerate=8000;
ms_bufferizer_init(&s->delayed_ref);
ms_bufferizer_init(&s->echo);
ms_bufferizer_init(&s->ref);
s->delay_ms=0;
s->tail_length_ms=250;
s->ecstate=NULL;
s->framesize=framesize;
s->den = NULL;
s->state_str=NULL;
s->using_zeroes=FALSE;
s->echostarted=FALSE;
s->bypass_mode=FALSE;
#ifdef EC_DUMP
{
char *fname=ms_strdup_printf("%s/msspeexec-%p-echo.raw", EC_DUMP_PREFIX,f);
s->echofile=fopen(fname,"w");
ms_free(fname);
fname=ms_strdup_printf("%s/msspeexec-%p-ref.raw", EC_DUMP_PREFIX,f);
s->reffile=fopen(fname,"w");
ms_free(fname);
fname=ms_strdup_printf("%s/msspeexec-%p-clean.raw", EC_DUMP_PREFIX,f);
s->cleanfile=fopen(fname,"w");
ms_free(fname);
}
#endif
f->data=s;
}
