Changeset 6064

Timestamp:

Sep 6, 2019 5:19:40 AM (5 years ago)

Author:

nanang

Message:

Re #2228: Fixed bugs in PCM shifting in G722 codec.

File:

• pjproject/trunk/pjmedia/src/pjmedia-codec/g722.c (modified) (6 diffs)

pjproject/trunk/pjmedia/src/pjmedia-codec/g722.c

@@ -144 +144 @@
     g722_enc_t           encoder;
     g722_dec_t           decoder;
-    unsigned             pcm_shift;
-    pj_int16_t           pcm_clip_mask;
+    pj_int16_t           pcm_shift_val;
+    pj_int16_t           pcm_min;
+    pj_int16_t           pcm_max;
     pj_bool_t            plc_enabled;
     pj_bool_t            vad_enabled;
@@ -463 +464 @@
     g722_data->vad_enabled = (attr->setting.vad != 0);
     g722_data->plc_enabled = (attr->setting.plc != 0);
-    g722_data->pcm_shift = g722_codec_factory.pcm_shift;
-    g722_data->pcm_clip_mask = (pj_int16_t)(1<<g722_codec_factory.pcm_shift)-1;
-    g722_data->pcm_clip_mask <<= (16-g722_codec_factory.pcm_shift);
+    g722_data->pcm_shift_val = 1 << (pj_int16_t)g722_codec_factory.pcm_shift;
+    g722_data->pcm_max = 0x7FFF / g722_data->pcm_shift_val;
+    g722_data->pcm_min = -0x7FFF / g722_data->pcm_shift_val - 1;
 
     TRACE_((THIS_FILE, "G722 codec opened: vad=%d, plc=%d",
@@ -586 +587 @@
 
     /* Adjust input signal level from 16-bit to 14-bit */
-    if (g722_data->pcm_shift) {
+    if (g722_data->pcm_shift_val > 1) {
         pj_int16_t *p, *end;
 
@@ -592 +593 @@
         end = p + input->size/2;
         while (p < end) {
-            *p++ >>= g722_data->pcm_shift;
+            *p = *p / g722_data->pcm_shift_val;
+            ++p;
         }
     }
@@ -656 +658 @@
 
     /* Adjust input signal level from 14-bit to 16-bit */
-    if (g722_data->pcm_shift) {
+    if (g722_data->pcm_shift_val > 1) {
         pj_int16_t *p, *end;
 
@@ -663 +665 @@
         while (p < end) {
 #if PJMEDIA_G722_STOP_PCM_SHIFT_ON_CLIPPING
-            /* If there is clipping, stop the PCM shifting */
-            if (*p & g722_data->pcm_clip_mask) {
-                g722_data->pcm_shift = 0;
+            /* If there is clipping, reduce/stop the PCM shifting */
+            if (*p < g722_data->pcm_min || *p > g722_data->pcm_max) {
+                g722_data->pcm_shift_val /= 2;
+                g722_data->pcm_max = 0x7FFF/g722_data->pcm_shift_val;
+                g722_data->pcm_min = -0x7FFF/g722_data->pcm_shift_val-1;
                 break;
             }
-#endif
-            *p++ <<= g722_data->pcm_shift;
+#else
+            /* Avoid PCM shift overflow if we don't stop on clipping */
+            if (*p < g722_data->pcm_min)
+                *p = g722_data->pcm_min;
+            else if (*p > g722_data->pcm_max)
+                *p = g722_data->pcm_max;
+            
+#endif
+            *p = *p * g722_data->pcm_shift_val;
+            ++p;
         }
     }