1 files changed, 98 insertions, 0 deletions
diff --git a/media/libvpx/vp9/encoder/vp9_writer.h b/media/libvpx/vp9/encoder/vp9_writer.h
new file mode 100644
index 000000000..e347ea414
--- /dev/null
+++ b/media/libvpx/vp9/encoder/vp9_writer.h
@@ -0,0 +1,98 @@
+/*
+ *  Copyright (c) 2010 The WebM 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.
+ */
+
+#ifndef VP9_ENCODER_VP9_WRITER_H_
+#define VP9_ENCODER_VP9_WRITER_H_
+
+#include "vpx_ports/mem.h"
+
+#include "vp9/common/vp9_prob.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct vp9_writer {
+  unsigned int lowvalue;
+  unsigned int range;
+  int count;
+  unsigned int pos;
+  uint8_t *buffer;
+} vp9_writer;
+
+void vp9_start_encode(vp9_writer *bc, uint8_t *buffer);
+void vp9_stop_encode(vp9_writer *bc);
+
+static INLINE void vp9_write(vp9_writer *br, int bit, int probability) {
+  unsigned int split;
+  int count = br->count;
+  unsigned int range = br->range;
+  unsigned int lowvalue = br->lowvalue;
+  register unsigned int shift;
+
+  split = 1 + (((range - 1) * probability) >> 8);
+
+  range = split;
+
+  if (bit) {
+    lowvalue += split;
+    range = br->range - split;
+  }
+
+  shift = vp9_norm[range];
+
+  range <<= shift;
+  count += shift;
+
+  if (count >= 0) {
+    int offset = shift - count;
+
+    if ((lowvalue << (offset - 1)) & 0x80000000) {
+      int x = br->pos - 1;
+
+      while (x >= 0 && br->buffer[x] == 0xff) {
+        br->buffer[x] = 0;
+        x--;
+      }
+
+      br->buffer[x] += 1;
+    }
+
+    br->buffer[br->pos++] = (lowvalue >> (24 - offset));
+    lowvalue <<= offset;
+    shift = count;
+    lowvalue &= 0xffffff;
+    count -= 8;
+  }
+
+  lowvalue <<= shift;
+  br->count = count;
+  br->lowvalue = lowvalue;
+  br->range = range;
+}
+
+static INLINE void vp9_write_bit(vp9_writer *w, int bit) {
+  vp9_write(w, bit, 128);  // vp9_prob_half
+}
+
+static INLINE void vp9_write_literal(vp9_writer *w, int data, int bits) {
+  int bit;
+
+  for (bit = bits - 1; bit >= 0; bit--)
+    vp9_write_bit(w, 1 & (data >> bit));
+}
+
+#define vp9_write_prob(w, v) vp9_write_literal((w), (v), 8)
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
+#endif  // VP9_ENCODER_VP9_WRITER_H_