Changeset 1333:986b64dde6be in mediastreamer2

Timestamp:

Mar 31, 2011 10:33:27 AM (2 years ago)

Author:

Simon Morlat <simon.morlat@…>

Branch:

default

Children:

1334:27399177e928, 1336:afbd05489f6e

Message:

implement smart sample thrower to synchronize both path of echo canceller. works well.

File:

• src/speexec.c (modified) (7 diffs)

src/speexec.c

@@ -31 +31 @@
 #include <malloc.h> /* for alloca */
 #endif
+
+typedef struct _AudioFlowController{
+        int target_samples;
+        int total_samples;
+        int current_pos;
+        int current_dropped;
+}AudioFlowController;
+
+void audio_flow_controller_init(AudioFlowController *ctl){
+        ctl->target_samples=0;
+        ctl->total_samples=0;
+        ctl->current_pos=0;
+        ctl->current_dropped=0;
+}
+
+void audio_flow_controller_set_target(AudioFlowController *ctl, int samples_to_drop, int total_samples){
+        ctl->target_samples=samples_to_drop;
+        ctl->total_samples=total_samples;
+        ctl->current_pos=0;
+        ctl->current_dropped=0;
+}
+
+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;
+                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;
+                        m->b_wptr-=todrop*2;
+                        //ms_message("th_dropped=%i, current_dropped=%i, %i samples dropped.",th_dropped,ctl->current_dropped,todrop);
+                        ctl->current_dropped+=todrop;
+                }
+        }
+        return m;
+}
+
 
 //#define EC_DUMP 1
@@ -41 +82 @@
 static const float smooth_factor=0.05;
 static const int framesize=128;
+static const int flow_control_interval_ms=5000;
 
 
@@ -55 +97 @@
         int nominal_ref_samples;
         int min_ref_samples;
+        AudioFlowController afc;
 #ifdef EC_DUMP
         FILE *echofile;
@@ -131 +174 @@
         s->min_ref_samples=-1;
         s->nominal_ref_samples=delay_samples;
+        audio_flow_controller_init(&s->afc);
 }
 
@@ -156 +200 @@
         if (f->inputs[0]!=NULL){
                 while((refm=ms_queue_get(f->inputs[0]))!=NULL){
-                        mblk_t *cp=dupmsg(refm);
+                        mblk_t *cp=dupmsg(audio_flow_controller_process(&s->afc,refm));
                         ms_bufferizer_put(&s->delayed_ref,cp);
                         ms_queue_put(f->outputs[0],refm);
@@ -176 +220 @@
                         refm->b_wptr+=nbytes;
                         ms_bufferizer_put(&s->delayed_ref,refm);
+                        ms_queue_put(f->outputs[0],dupmsg(refm));
                         if (!s->using_zeroes){
                                 ms_warning("Not enough ref samples, using zeroes");
@@ -211 +256 @@
 
         /*verify our ref buffer does not become too big, meaning that we are receiving more samples than we are sending*/
-        if (f->ticker->time % 5000 == 0 && s->min_ref_samples!=-1){
+        if (f->ticker->time % flow_control_interval_ms == 0 && s->min_ref_samples!=-1){
                 int diff=s->min_ref_samples-s->nominal_ref_samples;
                 if (diff>nbytes){
-                        int purge=diff-(nbytes/2);
-                        ms_warning("echo canceller: we are accumulating too much reference signal, purging now %i bytes",purge);
-                        ms_bufferizer_skip_bytes(&s->delayed_ref,purge);
+                        int purge=(diff-(nbytes/2))/2;
+                        ms_warning("echo canceller: we are accumulating too much reference signal, need to throw out %i samples",purge);
+                        audio_flow_controller_set_target(&s->afc,purge,(flow_control_interval_ms*s->samplerate)/1000);
                 }
                 s->min_ref_samples=-1;