git-svn-id: http://webrtc.googlecode.com/svn/trunk@4 4adac7df-926f-26a2-2b94-8c16560cd09d

modules/audio_coding/codecs/iSAC/main/source/arith_routines.c

@@ -0,0 +1,60 @@
+/*
+ *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "arith_routines.h"
+#include "settings.h"
+
+
+/*
+ * terminate and return byte stream;
+ * returns the number of bytes in the stream
+ */
+int WebRtcIsac_EncTerminate(Bitstr *streamdata) /* in-/output struct containing bitstream */
+{
+  WebRtc_UWord8 *stream_ptr;
+
+
+  /* point to the right place in the stream buffer */
+  stream_ptr = streamdata->stream + streamdata->stream_index;
+
+  /* find minimum length (determined by current interval width) */
+  if ( streamdata->W_upper > 0x01FFFFFF )
+  {
+    streamdata->streamval += 0x01000000;
+    /* add carry to buffer */
+    if (streamdata->streamval < 0x01000000)
+    {
+      /* propagate carry */
+      while ( !(++(*--stream_ptr)) );
+      /* put pointer back to the old value */
+      stream_ptr = streamdata->stream + streamdata->stream_index;
+    }
+    /* write remaining data to bitstream */
+    *stream_ptr++ = (WebRtc_UWord8) (streamdata->streamval >> 24);
+  }
+  else
+  {
+    streamdata->streamval += 0x00010000;
+    /* add carry to buffer */
+    if (streamdata->streamval < 0x00010000)
+    {
+      /* propagate carry */
+      while ( !(++(*--stream_ptr)) );
+      /* put pointer back to the old value */
+      stream_ptr = streamdata->stream + streamdata->stream_index;
+    }
+    /* write remaining data to bitstream */
+    *stream_ptr++ = (WebRtc_UWord8) (streamdata->streamval >> 24);
+    *stream_ptr++ = (WebRtc_UWord8) ((streamdata->streamval >> 16) & 0x00FF);
+  }
+
+  /* calculate stream length */
+  return (int)(stream_ptr - streamdata->stream);
+}