Add const qualifier to WebRtcPcm16b_Encode

BUG=909
R=kwiberg@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/28199004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@7831 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/modules/audio_coding/codecs/pcm16b/include/pcm16b.h b/webrtc/modules/audio_coding/codecs/pcm16b/include/pcm16b.h
index 86b32fe..52bc9cc 100644
--- a/webrtc/modules/audio_coding/codecs/pcm16b/include/pcm16b.h
+++ b/webrtc/modules/audio_coding/codecs/pcm16b/include/pcm16b.h
@@ -54,9 +54,9 @@
  * Returned value		: Size in bytes of speech8b
  */
 
-int16_t WebRtcPcm16b_Encode(int16_t *speech16b,
+int16_t WebRtcPcm16b_Encode(const int16_t* speech16b,
                             int16_t len,
-                            unsigned char *speech8b);
+                            unsigned char* speech8b);
 
 /****************************************************************************
  * WebRtcPcm16b_DecodeW16(...)
diff --git a/webrtc/modules/audio_coding/codecs/pcm16b/pcm16b.c b/webrtc/modules/audio_coding/codecs/pcm16b/pcm16b.c
index 2c6bea6..bc7a474 100644
--- a/webrtc/modules/audio_coding/codecs/pcm16b/pcm16b.c
+++ b/webrtc/modules/audio_coding/codecs/pcm16b/pcm16b.c
@@ -41,7 +41,7 @@
 
 
 /* Encoder with char Output (old version) */
-int16_t WebRtcPcm16b_Encode(int16_t *speech16b,
+int16_t WebRtcPcm16b_Encode(const int16_t *speech16b,
                             int16_t len,
                             unsigned char *speech8b)
 {
diff --git a/webrtc/modules/audio_coding/neteq/tools/neteq_performance_test.cc b/webrtc/modules/audio_coding/neteq/tools/neteq_performance_test.cc
index ebe0784..080b99b 100644
--- a/webrtc/modules/audio_coding/neteq/tools/neteq_performance_test.cc
+++ b/webrtc/modules/audio_coding/neteq/tools/neteq_performance_test.cc
@@ -64,9 +64,8 @@
   const int16_t* input_samples = audio_loop.GetNextBlock();
   if (!input_samples) exit(1);
   uint8_t input_payload[kInputBlockSizeSamples * sizeof(int16_t)];
-  size_t payload_len = WebRtcPcm16b_Encode(const_cast<int16_t*>(input_samples),
-                                           kInputBlockSizeSamples,
-                                           input_payload);
+  size_t payload_len =
+      WebRtcPcm16b_Encode(input_samples, kInputBlockSizeSamples, input_payload);
   assert(payload_len == kInputBlockSizeSamples * sizeof(int16_t));
 
   // Main loop.