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authorJohn Koleszar <jkoleszar@google.com>2012-11-27 13:59:17 -0800
committerJohn Koleszar <jkoleszar@google.com>2012-11-27 14:12:30 -0800
commitfcccbcbb395ce4cf31b54ce1245cc28e5e3ef4c1 (patch)
tree68e128e48e3f5ab1de1c163fa3a12ea47f5d8d51 /vp9/decoder/vp9_dboolhuff.h
parent3bf7b131c8ebb6b4d63a8b70d69066dcbc4ed896 (diff)
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Add vp9_ prefix to all vp9 files
Support for gyp which doesn't support multiple objects in the same static library having the same basename. Change-Id: Ib947eefbaf68f8b177a796d23f875ccdfa6bc9dc
Diffstat (limited to 'vp9/decoder/vp9_dboolhuff.h')
-rw-r--r--vp9/decoder/vp9_dboolhuff.h153
1 files changed, 153 insertions, 0 deletions
diff --git a/vp9/decoder/vp9_dboolhuff.h b/vp9/decoder/vp9_dboolhuff.h
new file mode 100644
index 000000000..d46d81bb4
--- /dev/null
+++ b/vp9/decoder/vp9_dboolhuff.h
@@ -0,0 +1,153 @@
+/*
+ * 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 DBOOLHUFF_H
+#define DBOOLHUFF_H
+#include <stddef.h>
+#include <limits.h>
+#include "vpx_ports/config.h"
+#include "vpx_ports/mem.h"
+#include "vpx/vpx_integer.h"
+
+typedef size_t VP9_BD_VALUE;
+
+# define VP9_BD_VALUE_SIZE ((int)sizeof(VP9_BD_VALUE)*CHAR_BIT)
+/*This is meant to be a large, positive constant that can still be efficiently
+ loaded as an immediate (on platforms like ARM, for example).
+ Even relatively modest values like 100 would work fine.*/
+# define VP9_LOTS_OF_BITS (0x40000000)
+
+typedef struct {
+ const unsigned char *user_buffer_end;
+ const unsigned char *user_buffer;
+ VP9_BD_VALUE value;
+ int count;
+ unsigned int range;
+} BOOL_DECODER;
+
+DECLARE_ALIGNED(16, extern const unsigned char, vp9_norm[256]);
+
+int vp9_start_decode(BOOL_DECODER *br,
+ const unsigned char *source,
+ unsigned int source_sz);
+
+void vp9_bool_decoder_fill(BOOL_DECODER *br);
+
+int vp9_decode_uniform(BOOL_DECODER *br, int n);
+int vp9_decode_term_subexp(BOOL_DECODER *br, int k, int num_syms);
+int vp9_inv_recenter_nonneg(int v, int m);
+
+/*The refill loop is used in several places, so define it in a macro to make
+ sure they're all consistent.
+ An inline function would be cleaner, but has a significant penalty, because
+ multiple BOOL_DECODER fields must be modified, and the compiler is not smart
+ enough to eliminate the stores to those fields and the subsequent reloads
+ from them when inlining the function.*/
+#define VP9DX_BOOL_DECODER_FILL(_count,_value,_bufptr,_bufend) \
+ do \
+ { \
+ int shift = VP9_BD_VALUE_SIZE - 8 - ((_count) + 8); \
+ int loop_end, x; \
+ int bits_left = (int)(((_bufend)-(_bufptr))*CHAR_BIT); \
+ \
+ x = shift + CHAR_BIT - bits_left; \
+ loop_end = 0; \
+ if(x >= 0) \
+ { \
+ (_count) += VP9_LOTS_OF_BITS; \
+ loop_end = x; \
+ if(!bits_left) break; \
+ } \
+ while(shift >= loop_end) \
+ { \
+ (_count) += CHAR_BIT; \
+ (_value) |= (VP9_BD_VALUE)*(_bufptr)++ << shift; \
+ shift -= CHAR_BIT; \
+ } \
+ } \
+ while(0) \
+
+
+static int decode_bool(BOOL_DECODER *br, int probability) {
+ unsigned int bit = 0;
+ VP9_BD_VALUE value;
+ unsigned int split;
+ VP9_BD_VALUE bigsplit;
+ int count;
+ unsigned int range;
+
+ split = 1 + (((br->range - 1) * probability) >> 8);
+
+ if (br->count < 0)
+ vp9_bool_decoder_fill(br);
+
+ value = br->value;
+ count = br->count;
+
+ bigsplit = (VP9_BD_VALUE)split << (VP9_BD_VALUE_SIZE - 8);
+
+ range = split;
+
+ if (value >= bigsplit) {
+ range = br->range - split;
+ value = value - bigsplit;
+ bit = 1;
+ }
+
+ {
+ register unsigned int shift = vp9_norm[range];
+ range <<= shift;
+ value <<= shift;
+ count -= shift;
+ }
+ br->value = value;
+ br->count = count;
+ br->range = range;
+
+ return bit;
+}
+
+static int decode_value(BOOL_DECODER *br, int bits) {
+ int z = 0;
+ int bit;
+
+ for (bit = bits - 1; bit >= 0; bit--) {
+ z |= (decode_bool(br, 0x80) << bit);
+ }
+
+ return z;
+}
+
+static int bool_error(BOOL_DECODER *br) {
+ /* Check if we have reached the end of the buffer.
+ *
+ * Variable 'count' stores the number of bits in the 'value' buffer, minus
+ * 8. The top byte is part of the algorithm, and the remainder is buffered
+ * to be shifted into it. So if count == 8, the top 16 bits of 'value' are
+ * occupied, 8 for the algorithm and 8 in the buffer.
+ *
+ * When reading a byte from the user's buffer, count is filled with 8 and
+ * one byte is filled into the value buffer. When we reach the end of the
+ * data, count is additionally filled with VP9_LOTS_OF_BITS. So when
+ * count == VP9_LOTS_OF_BITS - 1, the user's data has been exhausted.
+ */
+ if ((br->count > VP9_BD_VALUE_SIZE) && (br->count < VP9_LOTS_OF_BITS)) {
+ /* We have tried to decode bits after the end of
+ * stream was encountered.
+ */
+ return 1;
+ }
+
+ /* No error. */
+ return 0;
+}
+
+#endif