diff --git a/media/libstagefright/MPEG4Extractor.cpp b/media/libstagefright/MPEG4Extractor.cpp
index fd1722b..5c0afa9 100644
--- a/media/libstagefright/MPEG4Extractor.cpp
+++ b/media/libstagefright/MPEG4Extractor.cpp
@@ -2018,10 +2018,10 @@
             *offset += chunk_size;
 
             if (mFileMetaData != NULL) {
-                ALOGV("chunk_data_size = %lld and data_offset = %lld",
-                        (long long)chunk_data_size, (long long)data_offset);
+                ALOGV("chunk_data_size = %" PRId64 " and data_offset = %" PRId64,
+                      chunk_data_size, data_offset);
 
-                if (chunk_data_size >= SIZE_MAX - 1) {
+                if (chunk_data_size < 0 || static_cast<uint64_t>(chunk_data_size) >= SIZE_MAX - 1) {
                     return ERROR_MALFORMED;
                 }
                 sp<ABuffer> buffer = new ABuffer(chunk_data_size + 1);