summaryrefslogtreecommitdiffstats
path: root/vp8/decoder/dboolhuff.h
diff options
context:
space:
mode:
Diffstat (limited to 'vp8/decoder/dboolhuff.h')
-rw-r--r--vp8/decoder/dboolhuff.h138
1 files changed, 60 insertions, 78 deletions
diff --git a/vp8/decoder/dboolhuff.h b/vp8/decoder/dboolhuff.h
index f5c9822..c72bc03 100644
--- a/vp8/decoder/dboolhuff.h
+++ b/vp8/decoder/dboolhuff.h
@@ -1,60 +1,41 @@
/*
- * Copyright (c) 2010 The VP8 project authors. All Rights Reserved.
+ * Copyright (c) 2010 The WebM project authors. All Rights Reserved.
*
- * Use of this source code is governed by a BSD-style license and patent
- * grant that can be found in the LICENSE file in the root of the source
- * tree. All contributing project authors may be found in the AUTHORS
- * file in the root of the source tree.
+ * 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_ports/vpx_integer.h"
+#include "vpx/vpx_integer.h"
+
+typedef size_t VP8_BD_VALUE;
+
+# define VP8_BD_VALUE_SIZE ((int)sizeof(VP8_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 VP8_LOTS_OF_BITS (0x40000000)
+
-/* Size of the bool decoder backing storage
- *
- * This size was chosen to be greater than the worst case encoding of a
- * single macroblock. This was calcluated as follows (python):
- *
- * def max_cost(prob):
- * return max(prob_costs[prob], prob_costs[255-prob]) / 256;
- *
- * tree_nodes_cost = 7 * max_cost(255)
- * extra_bits_cost = sum([max_cost(bit) for bit in extra_bits])
- * sign_bit_cost = max_cost(128)
- * total_cost = tree_nodes_cost + extra_bits_cost + sign_bit_cost
- *
- * where the prob_costs table was taken from the C vp8_prob_cost table in
- * boolhuff.c and the extra_bits table was taken from the 11 extrabits for
- * a category 6 token as defined in vp8d_token_extra_bits2/detokenize.c
- *
- * This equation produced a maximum of 79 bits per coefficient. Scaling up
- * to the macroblock level:
- *
- * 79 bits/coeff * 16 coeff/block * 25 blocks/macroblock = 31600 b/mb
- *
- * 4096 bytes = 32768 bits > 31600
- */
-#define VP8_BOOL_DECODER_SZ 4096
-#define VP8_BOOL_DECODER_MASK (VP8_BOOL_DECODER_SZ-1)
-#define VP8_BOOL_DECODER_PTR_MASK (~(uintptr_t)(VP8_BOOL_DECODER_SZ))
struct vp8_dboolhuff_rtcd_vtable;
typedef struct
{
- unsigned int lowvalue;
- unsigned int range;
- unsigned int value;
- int count;
+ const unsigned char *user_buffer_end;
const unsigned char *user_buffer;
- unsigned int user_buffer_sz;
- unsigned char *decode_buffer;
- const unsigned char *read_ptr;
- unsigned char *write_ptr;
+ VP8_BD_VALUE value;
+ int count;
+ unsigned int range;
#if CONFIG_RUNTIME_CPU_DETECT
struct vp8_dboolhuff_rtcd_vtable *rtcd;
#endif
@@ -62,7 +43,6 @@ typedef struct
#define prototype_dbool_start(sym) int sym(BOOL_DECODER *br, \
const unsigned char *source, unsigned int source_sz)
-#define prototype_dbool_stop(sym) void sym(BOOL_DECODER *bc)
#define prototype_dbool_fill(sym) void sym(BOOL_DECODER *br)
#define prototype_dbool_debool(sym) int sym(BOOL_DECODER *br, int probability)
#define prototype_dbool_devalue(sym) int sym(BOOL_DECODER *br, int bits);
@@ -75,10 +55,6 @@ typedef struct
#define vp8_dbool_start vp8dx_start_decode_c
#endif
-#ifndef vp8_dbool_stop
-#define vp8_dbool_stop vp8dx_stop_decode_c
-#endif
-
#ifndef vp8_dbool_fill
#define vp8_dbool_fill vp8dx_bool_decoder_fill_c
#endif
@@ -92,20 +68,17 @@ typedef struct
#endif
extern prototype_dbool_start(vp8_dbool_start);
-extern prototype_dbool_stop(vp8_dbool_stop);
extern prototype_dbool_fill(vp8_dbool_fill);
extern prototype_dbool_debool(vp8_dbool_debool);
extern prototype_dbool_devalue(vp8_dbool_devalue);
typedef prototype_dbool_start((*vp8_dbool_start_fn_t));
-typedef prototype_dbool_stop((*vp8_dbool_stop_fn_t));
typedef prototype_dbool_fill((*vp8_dbool_fill_fn_t));
typedef prototype_dbool_debool((*vp8_dbool_debool_fn_t));
typedef prototype_dbool_devalue((*vp8_dbool_devalue_fn_t));
typedef struct vp8_dboolhuff_rtcd_vtable {
vp8_dbool_start_fn_t start;
- vp8_dbool_stop_fn_t stop;
vp8_dbool_fill_fn_t fill;
vp8_dbool_debool_fn_t debool;
vp8_dbool_devalue_fn_t devalue;
@@ -122,18 +95,7 @@ typedef struct vp8_dboolhuff_rtcd_vtable {
#define IF_RTCD(x) NULL
//#endif
-static unsigned char *br_ptr_advance(const unsigned char *_ptr,
- unsigned int n)
-{
- uintptr_t ptr = (uintptr_t)_ptr;
-
- ptr += n;
- ptr &= VP8_BOOL_DECODER_PTR_MASK;
-
- return (void *)ptr;
-}
-
-DECLARE_ALIGNED(16, extern const unsigned int, vp8dx_bitreader_norm[256]);
+DECLARE_ALIGNED(16, extern const unsigned char, vp8dx_bitreader_norm[256]);
/* wrapper functions to hide RTCD. static means inline means hopefully no
* penalty
@@ -146,12 +108,34 @@ static int vp8dx_start_decode(BOOL_DECODER *br,
#endif
return DBOOLHUFF_INVOKE(rtcd, start)(br, source, source_sz);
}
-static void vp8dx_stop_decode(BOOL_DECODER *br) {
- DBOOLHUFF_INVOKE(br->rtcd, stop)(br);
-}
static void vp8dx_bool_decoder_fill(BOOL_DECODER *br) {
DBOOLHUFF_INVOKE(br->rtcd, fill)(br);
}
+
+/*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 VP8DX_BOOL_DECODER_FILL(_count,_value,_bufptr,_bufend) \
+ do \
+ { \
+ int shift; \
+ for(shift = VP8_BD_VALUE_SIZE - 8 - ((_count) + 8); shift >= 0; ) \
+ { \
+ if((_bufptr) >= (_bufend)) { \
+ (_count) = VP8_LOTS_OF_BITS; \
+ break; \
+ } \
+ (_count) += 8; \
+ (_value) |= (VP8_BD_VALUE)*(_bufptr)++ << shift; \
+ shift -= 8; \
+ } \
+ } \
+ while(0)
+
+
static int vp8dx_decode_bool(BOOL_DECODER *br, int probability) {
/*
* Until optimized versions of this function are available, we
@@ -160,13 +144,18 @@ static int vp8dx_decode_bool(BOOL_DECODER *br, int probability) {
*return DBOOLHUFF_INVOKE(br->rtcd, debool)(br, probability);
*/
unsigned int bit = 0;
+ VP8_BD_VALUE value;
unsigned int split;
- unsigned int bigsplit;
- register unsigned int range = br->range;
- register unsigned int value = br->value;
+ VP8_BD_VALUE bigsplit;
+ int count;
+ unsigned int range;
+
+ value = br->value;
+ count = br->count;
+ range = br->range;
split = 1 + (((range - 1) * probability) >> 8);
- bigsplit = (split << 8);
+ bigsplit = (VP8_BD_VALUE)split << (VP8_BD_VALUE_SIZE - 8);
range = split;
@@ -185,23 +174,16 @@ static int vp8dx_decode_bool(BOOL_DECODER *br, int probability) {
}*/
{
- int count = br->count;
register unsigned int shift = vp8dx_bitreader_norm[range];
range <<= shift;
value <<= shift;
count -= shift;
-
- if (count <= 0)
- {
- value |= (*br->read_ptr) << (-count);
- br->read_ptr = br_ptr_advance(br->read_ptr, 1);
- count += 8 ;
- }
-
- br->count = count;
}
br->value = value;
+ br->count = count;
br->range = range;
+ if(count < 0)
+ vp8dx_bool_decoder_fill(br);
return bit;
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-01 08:36:29 +0000