Changeset 2212 for pjproject/trunk/pjmedia/src/pjmedia/echo_suppress.c

Timestamp:

Aug 13, 2008 6:21:03 PM (16 years ago)

Author:

bennylp

Message:

More ticket #590: optimizations in the echo suppressor, gained more than 3x speed. Added entries in mips_test

File:

• pjproject/trunk/pjmedia/src/pjmedia/echo_suppress.c (modified) (14 diffs)

pjproject/trunk/pjmedia/src/pjmedia/echo_suppress.c

@@ -244 +244 @@
     float        best_corr;         /* Best correlation so far.             */
 
+    unsigned     sum_rec_level;     /* Running sum of level in rec_hist     */
+    float        rec_corr;          /* Running corr in rec_hist.            */
+
+    unsigned     sum_play_level0;   /* Running sum of level for first pos   */
+    float        play_corr0;        /* Running corr for first pos .         */
+
     float       *min_factor;        /* Array of minimum scaling factor      */
     float       *avg_factor;        /* Array of average scaling factor      */
@@ -354 +360 @@
     ec->residue = 0;
     ec->running_cnt = 0;
+    ec->sum_rec_level = ec->sum_play_level0 = 0;
+    ec->rec_corr = ec->play_corr0 = 0;
 }
 
@@ -376 +384 @@
     ec->residue = 0;
     ec->running_cnt = 0;
+    ec->sum_rec_level = ec->sum_play_level0 = 0;
+    ec->rec_corr = ec->play_corr0 = 0;
 
     PJ_LOG(4,(THIS_FILE, "Echo suppressor soft reset. Re-learning.."));
@@ -404 +414 @@
 {
     int prev_index;
-    unsigned i, frm_level, sum_rec_level;
-    float rec_corr;
+    unsigned i, j, frm_level, sum_play_level, ulaw;
+    pj_uint16_t old_rec_frm_level, old_play_frm_level;
+    float play_corr;
 
     ++ec->update_cnt;
@@ -415 +426 @@
     ++frm_level; /* to avoid division by zero */
 
+    /* Save the oldest frame level for later */
+    old_play_frm_level = ec->play_hist[0];
+
     /* Push current frame level to the back of the play history */
     pj_array_erase(ec->play_hist, sizeof(pj_uint16_t), ec->play_hist_cnt, 0);
@@ -423 +437 @@
     ++frm_level; /* to avoid division by zero */
 
+    /* Save the oldest frame level for later */
+    old_rec_frm_level = ec->rec_hist[0];
+
     /* Push to the back of the rec history */
     pj_array_erase(ec->rec_hist, sizeof(pj_uint16_t), ec->templ_cnt, 0);
@@ -438 +455 @@
 
     /* Calculate rec signal pattern */
-    rec_corr = 0;
-    sum_rec_level = 0;
-    for (i=0; i < ec->templ_cnt-1; ++i) {
-        float corr;
-        corr = (float)ec->rec_hist[i+1] / ec->rec_hist[i];
-        rec_corr += corr;
-        sum_rec_level += ec->rec_hist[i];
-    }
-    sum_rec_level += ec->rec_hist[i];
+    if (ec->sum_rec_level == 0) {
+        /* Buffer has just been filled up, do full calculation */
+        ec->rec_corr = 0;
+        ec->sum_rec_level = 0;
+        for (i=0; i < ec->templ_cnt-1; ++i) {
+            float corr;
+            corr = (float)ec->rec_hist[i+1] / ec->rec_hist[i];
+            ec->rec_corr += corr;
+            ec->sum_rec_level += ec->rec_hist[i];
+        }
+        ec->sum_rec_level += ec->rec_hist[i];
+    } else {
+        /* Update from previous calculation */
+        ec->sum_rec_level = ec->sum_rec_level - old_rec_frm_level + 
+                            ec->rec_hist[ec->templ_cnt-1];
+        ec->rec_corr = ec->rec_corr - ((float)ec->rec_hist[0] / 
+                                              old_rec_frm_level) +
+                       ((float)ec->rec_hist[ec->templ_cnt-1] /
+                               ec->rec_hist[ec->templ_cnt-2]);
+    }
 
     /* Iterate through the play history and calculate the signal correlation
@@ -453 +481 @@
      * to detect echo.
      */
-    for (i=0; i < ec->tail_cnt; ++i) {
-        unsigned j, end, sum_play_level, ulaw;
-        float play_corr = 0, corr_diff;
-
+    /* 
+     * First phase: do full calculation for the first position 
+     */
+    if (ec->sum_play_level0 == 0) {
+        /* Buffer has just been filled up, do full calculation */
         sum_play_level = 0;
-        for (j=i, end=i+ec->templ_cnt-1; j<end; ++j) {
+        play_corr = 0;
+        for (j=0; j<ec->templ_cnt-1; ++j) {
             float corr;
             corr = (float)ec->play_hist[j+1] / ec->play_hist[j];
@@ -465 +495 @@
         }
         sum_play_level += ec->play_hist[j];
+        ec->sum_play_level0 = sum_play_level;
+        ec->play_corr0 = play_corr;
+    } else {
+        /* Update from previous calculation */
+        ec->sum_play_level0 = ec->sum_play_level0 - old_play_frm_level + 
+                              ec->play_hist[ec->templ_cnt-1];
+        ec->play_corr0 = ec->play_corr0 - ((float)ec->play_hist[0] / 
+                                                  old_play_frm_level) +
+                         ((float)ec->play_hist[ec->templ_cnt-1] /
+                                 ec->play_hist[ec->templ_cnt-2]);
+        sum_play_level = ec->sum_play_level0;
+        play_corr = ec->play_corr0;
+    }
+    ec->tmp_corr[0] = FABS(play_corr - ec->rec_corr);
+    ec->tmp_factor[0] = (float)ec->sum_rec_level / sum_play_level;
+
+    /* Bail out if remote isn't talking */
+    ulaw = pjmedia_linear2ulaw(sum_play_level/ec->templ_cnt) ^ 0xFF;
+    if (ulaw < MIN_SIGNAL_ULAW) {
+        echo_supp_set_state(ec, ST_REM_SILENT, ulaw);
+        return;
+    }
+    /* Bail out if local user is talking */
+    if (ec->sum_rec_level > sum_play_level) {
+        echo_supp_set_state(ec, ST_LOCAL_TALK, ulaw);
+        return;
+    }
+
+    /*
+     * Second phase: do incremental calculation for the rest of positions
+     */
+    for (i=1; i < ec->tail_cnt; ++i) {
+        unsigned end;
+
+        end = i + ec->templ_cnt;
+
+        sum_play_level = sum_play_level - ec->play_hist[i-1] +
+                         ec->play_hist[end-1];
+        play_corr = play_corr - ((float)ec->play_hist[i]/ec->play_hist[i-1]) +
+                    ((float)ec->play_hist[end-1]/ec->play_hist[end-2]);
 
         /* Bail out if remote isn't talking */
@@ -474 +544 @@
 
         /* Bail out if local user is talking */
-        if (sum_rec_level >= sum_play_level) {
+        if (ec->sum_rec_level > sum_play_level) {
             echo_supp_set_state(ec, ST_LOCAL_TALK, ulaw);
             return;
@@ -482 +552 @@
         // disabled: not a good idea if mic throws out loud echo
         /* Also bail out if we suspect there's a doubletalk */
-        ulaw = pjmedia_linear2ulaw(sum_rec_level/ec->templ_cnt) ^ 0xFF;
+        ulaw = pjmedia_linear2ulaw(ec->sum_rec_level/ec->templ_cnt) ^ 0xFF;
         if (ulaw > MIN_SIGNAL_ULAW) {
             echo_supp_set_state(ec, ST_DOUBLETALK, ulaw);
@@ -490 +560 @@
 
         /* Calculate correlation and save to temporary array */
-        corr_diff = FABS(play_corr - rec_corr);
-        ec->tmp_corr[i] = corr_diff;
+        ec->tmp_corr[i] = FABS(play_corr - ec->rec_corr);
 
         /* Also calculate the gain factor between mic and speaker level */
-        ec->tmp_factor[i] = (float)sum_rec_level / sum_play_level;
+        ec->tmp_factor[i] = (float)ec->sum_rec_level / sum_play_level;
         pj_assert(ec->tmp_factor[i] < 1);
     }
@@ -653 +722 @@
                 factor = 1.0;
                 echo_supp_set_state(ec, ST_LOCAL_TALK, rec_level);
-            } else if (rec_level >= play_level) {
+            } else if (rec_level > play_level) {
                 /* Seems that both are talking. Scale the mic signal
                  * down a little bit to reduce echo, while allowing both
@@ -689 +758 @@
             factor = (factor + ec->last_factor) / 2;
         else
-            factor = (factor + ec->last_factor*9) / 10;
+            factor = (factor + ec->last_factor*19) / 20;
 
         /* Amplify frame */