diff --git a/media/libmediametrics/include/media/MediaMetricsItem.h b/media/libmediametrics/include/media/MediaMetricsItem.h
index 428992c..cbf89c6 100644
--- a/media/libmediametrics/include/media/MediaMetricsItem.h
+++ b/media/libmediametrics/include/media/MediaMetricsItem.h
@@ -27,6 +27,7 @@
 #include <variant>
 
 #include <binder/Parcel.h>
+#include <log/log.h>
 #include <utils/Errors.h>
 #include <utils/Timers.h> // nsecs_t
 
@@ -469,16 +470,16 @@
     template <> // static
     status_t extract(std::string *val, const char **bufferpptr, const char *bufferptrmax) {
         const char *ptr = *bufferpptr;
-        while (*ptr != 0) {
+        do {
             if (ptr >= bufferptrmax) {
                 ALOGE("%s: buffer exceeded", __func__);
+                android_errorWriteLog(0x534e4554, "204445255");
                 return BAD_VALUE;
             }
-            ++ptr;
-        }
-        const size_t size = (ptr - *bufferpptr) + 1;
+        } while (*ptr++ != 0);
+        // ptr is terminator+1, == bufferptrmax if we finished entire buffer
         *val = *bufferpptr;
-        *bufferpptr += size;
+        *bufferpptr = ptr;
         return NO_ERROR;
     }
     template <> // static
diff --git a/media/libstagefright/rtsp/AAVCAssembler.cpp b/media/libstagefright/rtsp/AAVCAssembler.cpp
index 3f4d662..30cdbc9 100644
--- a/media/libstagefright/rtsp/AAVCAssembler.cpp
+++ b/media/libstagefright/rtsp/AAVCAssembler.cpp
@@ -295,6 +295,10 @@
 }
 
 void AAVCAssembler::checkSpsUpdated(const sp<ABuffer> &buffer) {
+    if (buffer->size() == 0) {
+        android_errorWriteLog(0x534e4554, "204077881");
+        return;
+    }
     const uint8_t *data = buffer->data();
     unsigned nalType = data[0] & 0x1f;
     if (nalType == 0x7) {