Changeset 1971 for pjproject/trunk/pjmedia/src/pjmedia/wsola.c

Timestamp:

May 30, 2008 11:24:37 AM (16 years ago)

Author:

nanang

Message:

Added another WSOLA implementation, PJMEDIA_WSOLA_IMP_WSOLA_LITE, this is used by small devices by default (replacing PJMEDIA_WSOLA_IMP_NULL)

File:

• pjproject/trunk/pjmedia/src/pjmedia/wsola.c (modified) (13 diffs)

pjproject/trunk/pjmedia/src/pjmedia/wsola.c

@@ -29 +29 @@
 #define THIS_FILE   "wsola.c"
 
-
-#if PJMEDIA_WSOLA_IMP==PJMEDIA_WSOLA_IMP_WSOLA
+#if (PJMEDIA_WSOLA_IMP==PJMEDIA_WSOLA_IMP_WSOLA) || \
+    (PJMEDIA_WSOLA_IMP==PJMEDIA_WSOLA_IMP_WSOLA_LITE)
+
 /*
  * WSOLA implementation using WSOLA
@@ -114 +115 @@
 };
 
+#if (PJMEDIA_WSOLA_IMP==PJMEDIA_WSOLA_IMP_WSOLA_LITE)
+
+/* In this implementation, waveform similarity comparison is done by calculating
+ * the difference of total level between template frame and the target buffer 
+ * for each template_cnt samples. The smallest difference value assumed to be 
+ * the most similar block. This seems to be naive, however some tests show
+ * acceptable results and the processing speed is amazing.
+ *
+ * diff level = (template[1]+..+template[n]) - (target[1]+..+target[n])
+ */
+static short *find_pitch(short *frm, short *beg, short *end, 
+                         unsigned template_cnt, int first)
+{
+    short *sr, *best=beg;
+    int best_corr = 0x7FFFFFFF;
+    int frm_sum = 0;
+    unsigned i;
+
+    for (i = 0; i<template_cnt; ++i)
+        frm_sum += frm[i];
+
+    for (sr=beg; sr!=end; ++sr) {
+        int corr = frm_sum;
+        int abs_corr = 0;
+
+        /* Do calculation on 8 samples at once */
+        for (i = 0; i<template_cnt; i+=8) {
+            corr -= (int)sr[i+0] +
+                    (int)sr[i+1] +
+                    (int)sr[i+2] +
+                    (int)sr[i+3] +
+                    (int)sr[i+4] +
+                    (int)sr[i+5] +
+                    (int)sr[i+6] +
+                    (int)sr[i+7];
+        }
+
+        /* Reverse back i if template_cnt is not multiplication of 8,
+         * the remaining samples will be processed below.
+         */
+        if (i != template_cnt)
+            i -= 8;
+
+        for (; i<template_cnt; ++i)
+            corr -= (int)sr[i];
+
+        abs_corr = corr > 0? corr : -corr;
+
+        if (first) {
+            if (abs_corr < best_corr) {
+                best_corr = abs_corr;
+                best = sr;
+            }
+        } else {
+            if (abs_corr <= best_corr) {
+                best_corr = abs_corr;
+                best = sr;
+            }
+        }
+    }
+
+    /*TRACE_((THIS_FILE, "found pitch at %u", best-beg));*/
+    return best;
+}
+
+#endif
 
 #if defined(PJ_HAS_FLOATING_POINT) && PJ_HAS_FLOATING_POINT!=0
@@ -121 +188 @@
 #include <math.h>
 
+#if (PJMEDIA_WSOLA_IMP==PJMEDIA_WSOLA_IMP_WSOLA)
+
 static short *find_pitch(short *frm, short *beg, short *end, 
                          unsigned template_cnt, int first)
@@ -131 +200 @@
         unsigned i;
 
+        /* Do calculation on 8 samples at once */
         for (i=0; i<template_cnt; i += 8) {
             corr += ((float)frm[i+0]) * ((float)sr[i+0]) + 
@@ -141 +211 @@
                     ((float)frm[i+7]) * ((float)sr[i+7]);
         }
+
+        /* Reverse back i if template_cnt is not multiplication of 8,
+         * the remaining samples will be processed below.
+         */
+        if (i != template_cnt)
+            i -= 8;
+
         for (; i<template_cnt; ++i) {
             corr += ((float)frm[i]) * ((float)sr[i]);
@@ -162 +239 @@
 }
 
+#endif
+
 static void overlapp_add(short dst[], unsigned count,
                          short l[], short r[],
@@ -204 +283 @@
 enum { WINDOW_MAX_VAL = (1 << WINDOW_BITS)-1 };
 
+#if (PJMEDIA_WSOLA_IMP==PJMEDIA_WSOLA_IMP_WSOLA)
+
 static short *find_pitch(short *frm, short *beg, short *end, 
                          unsigned template_cnt, int first)
@@ -215 +296 @@
         unsigned i;
 
+        /* Do calculation on 8 samples at once */
         for (i=0; i<template_cnt; i+=8) {
             corr += ((int)frm[i+0]) * ((int)sr[i+0]) + 
@@ -225 +307 @@
                     ((int)frm[i+7]) * ((int)sr[i+7]);
         }
+
+        /* Reverse back i if template_cnt is not multiplication of 8,
+         * the remaining samples will be processed below.
+         */
+        if (i != template_cnt)
+            i -= 8;
+
         for (; i<template_cnt; ++i) {
             corr += ((int)frm[i]) * ((int)sr[i]);
@@ -246 +335 @@
 }
 
+#endif
+
+
 static void overlapp_add(short dst[], unsigned count,
                          short l[], short r[],
@@ -360 +452 @@
         wsola->template_size = wsola->samples_per_frame;
 
+    /* Make sure minimal template size is 8, this is required by waveform 
+     * similarity calculation (find_pitch()). Moreover, smaller template size
+     * will reduce accuracy.
+     */
+    if (wsola->template_size < 8)
+        wsola->template_size = 8;
+
     wsola->buf = (short*)pj_pool_calloc(pool, wsola->buf_cnt, 
                                         sizeof(short));
@@ -470 +569 @@
         unsigned dist;
 
-        if (count <= (del_cnt << 1)) {
+        if ((count - del_cnt) <= frmsz) {
+        //if (count <= (del_cnt << 1)) {
             TRACE_((THIS_FILE, "Not enough samples to compress!"));
             return samples_del;
         }
 
-        start = buf + (frmsz >> 1);
+        //start = buf + (frmsz >> 1);
+        start = buf + del_cnt - samples_del;
         end = start + frmsz;
 
         if (end + frmsz > buf + count)
             end = buf+count-frmsz;
+
+        pj_assert(start < end);
 
         start = find_pitch(buf, start, end, wsola->template_size, 0);
@@ -818 +921 @@
 }
 
-
 #endif  /* #if PJMEDIA_WSOLA_IMP.. */