vpx/vp8/common/treecoder.h
Timothy B. Terriberry c4d7e5e67e Eliminate more warnings.
This eliminates a large set of warnings exposed by the Mozilla build
 system (Use of C++ comments in ISO C90 source, commas at the end of
 enum lists, a couple incomplete initializers, and signed/unsigned
 comparisons).
It also eliminates many (but not all) of the warnings expose by newer
 GCC versions and _FORTIFY_SOURCE (e.g., calling fread and fwrite
 without checking the return values).
There are a few spurious warnings left on my system:

../vp8/encoder/encodemb.c:274:9: warning: 'sz' may be used
 uninitialized in this function
gcc seems to be unable to figure out that the value shortcut doesn't
 change between the two if blocks that test it here.

../vp8/encoder/onyx_if.c:5314:5: warning: comparison of unsigned
 expression >= 0 is always true
../vp8/encoder/onyx_if.c:5319:5: warning: comparison of unsigned
 expression >= 0 is always true
This is true, so far as it goes, but it's comparing against an enum, and the C
 standard does not mandate that enums be unsigned, so the checks can't be
 removed.

Change-Id: Iaf689ae3e3d0ddc5ade00faa474debe73b8d3395
2010-10-27 18:08:04 -07:00

91 lines
2.6 KiB
C

/*
* 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 __INC_TREECODER_H
#define __INC_TREECODER_H
typedef unsigned char vp8bc_index_t; /* probability index */
typedef unsigned char vp8_prob;
#define vp8_prob_half ( (vp8_prob) 128)
typedef signed char vp8_tree_index;
struct bool_coder_spec;
typedef struct bool_coder_spec bool_coder_spec;
typedef struct bool_writer bool_writer;
typedef struct bool_reader bool_reader;
typedef const bool_coder_spec c_bool_coder_spec;
typedef const bool_writer c_bool_writer;
typedef const bool_reader c_bool_reader;
# define vp8_complement( x) (255 - x)
/* We build coding trees compactly in arrays.
Each node of the tree is a pair of vp8_tree_indices.
Array index often references a corresponding probability table.
Index <= 0 means done encoding/decoding and value = -Index,
Index > 0 means need another bit, specification at index.
Nonnegative indices are always even; processing begins at node 0. */
typedef const vp8_tree_index vp8_tree[], *vp8_tree_p;
typedef const struct vp8_token_struct
{
int value;
int Len;
} vp8_token;
/* Construct encoding array from tree. */
void vp8_tokens_from_tree(struct vp8_token_struct *, vp8_tree);
void vp8_tokens_from_tree_offset(struct vp8_token_struct *, vp8_tree,
int offset);
/* Convert array of token occurrence counts into a table of probabilities
for the associated binary encoding tree. Also writes count of branches
taken for each node on the tree; this facilitiates decisions as to
probability updates. */
void vp8_tree_probs_from_distribution(
int n, /* n = size of alphabet */
vp8_token tok [ /* n */ ],
vp8_tree tree,
vp8_prob probs [ /* n-1 */ ],
unsigned int branch_ct [ /* n-1 */ ] [2],
const unsigned int num_events[ /* n */ ],
unsigned int Pfactor,
int Round
);
/* Variant of above using coder spec rather than hardwired 8-bit probs. */
void vp8bc_tree_probs_from_distribution(
int n, /* n = size of alphabet */
vp8_token tok [ /* n */ ],
vp8_tree tree,
vp8_prob probs [ /* n-1 */ ],
unsigned int branch_ct [ /* n-1 */ ] [2],
const unsigned int num_events[ /* n */ ],
c_bool_coder_spec *s
);
#endif