summaryrefslogtreecommitdiffstats
path: root/media/libvpx/vp8/decoder/treereader.h
diff options
context:
space:
mode:
Diffstat (limited to 'media/libvpx/vp8/decoder/treereader.h')
-rw-r--r--media/libvpx/vp8/decoder/treereader.h48
1 files changed, 48 insertions, 0 deletions
diff --git a/media/libvpx/vp8/decoder/treereader.h b/media/libvpx/vp8/decoder/treereader.h
new file mode 100644
index 000000000..35ee69600
--- /dev/null
+++ b/media/libvpx/vp8/decoder/treereader.h
@@ -0,0 +1,48 @@
+/*
+ * 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 VP8_DECODER_TREEREADER_H_
+#define VP8_DECODER_TREEREADER_H_
+
+#include "vp8/common/treecoder.h"
+#include "dboolhuff.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef BOOL_DECODER vp8_reader;
+
+#define vp8_read vp8dx_decode_bool
+#define vp8_read_literal vp8_decode_value
+#define vp8_read_bit(R) vp8_read(R, vp8_prob_half)
+
+
+/* Intent of tree data structure is to make decoding trivial. */
+
+static int vp8_treed_read(
+ vp8_reader *const r, /* !!! must return a 0 or 1 !!! */
+ vp8_tree t,
+ const vp8_prob *const p
+)
+{
+ register vp8_tree_index i = 0;
+
+ while ((i = t[ i + vp8_read(r, p[i>>1])]) > 0) ;
+
+ return -i;
+}
+
+#ifdef __cplusplus
+} // extern "C"
+#endif
+
+#endif // VP8_DECODER_TREEREADER_H_