1 | // Copyright 2011 Google Inc. All Rights Reserved. |
2 | // |
3 | // Use of this source code is governed by a BSD-style license |
4 | // that can be found in the COPYING file in the root of the source |
5 | // tree. An additional intellectual property rights grant can be found |
6 | // in the file PATENTS. All contributing project authors may |
7 | // be found in the AUTHORS file in the root of the source tree. |
8 | // ----------------------------------------------------------------------------- |
9 | // |
10 | // Cost tables for level and modes. |
11 | // |
12 | // Author: Skal (pascal.massimino@gmail.com) |
13 | |
14 | #ifndef WEBP_ENC_COST_ENC_H_ |
15 | #define WEBP_ENC_COST_ENC_H_ |
16 | |
17 | #include <assert.h> |
18 | #include <stdlib.h> |
19 | #include "src/enc/vp8i_enc.h" |
20 | |
21 | #ifdef __cplusplus |
22 | extern "C" { |
23 | #endif |
24 | |
25 | // On-the-fly info about the current set of residuals. Handy to avoid |
26 | // passing zillions of params. |
27 | typedef struct VP8Residual VP8Residual; |
28 | struct VP8Residual { |
29 | int first; |
30 | int last; |
31 | const int16_t* coeffs; |
32 | |
33 | int coeff_type; |
34 | ProbaArray* prob; |
35 | StatsArray* stats; |
36 | CostArrayPtr costs; |
37 | }; |
38 | |
39 | void VP8InitResidual(int first, int coeff_type, |
40 | VP8Encoder* const enc, VP8Residual* const res); |
41 | |
42 | int VP8RecordCoeffs(int ctx, const VP8Residual* const res); |
43 | |
44 | // Record proba context used. |
45 | static WEBP_INLINE int VP8RecordStats(int bit, proba_t* const stats) { |
46 | proba_t p = *stats; |
47 | // An overflow is inbound. Note we handle this at 0xfffe0000u instead of |
48 | // 0xffff0000u to make sure p + 1u does not overflow. |
49 | if (p >= 0xfffe0000u) { |
50 | p = ((p + 1u) >> 1) & 0x7fff7fffu; // -> divide the stats by 2. |
51 | } |
52 | // record bit count (lower 16 bits) and increment total count (upper 16 bits). |
53 | p += 0x00010000u + bit; |
54 | *stats = p; |
55 | return bit; |
56 | } |
57 | |
58 | // Cost of coding one event with probability 'proba'. |
59 | static WEBP_INLINE int VP8BitCost(int bit, uint8_t proba) { |
60 | return !bit ? VP8EntropyCost[proba] : VP8EntropyCost[255 - proba]; |
61 | } |
62 | |
63 | // Level cost calculations |
64 | extern const uint16_t VP8LevelCodes[MAX_VARIABLE_LEVEL][2]; |
65 | void VP8CalculateLevelCosts(VP8EncProba* const proba); |
66 | static WEBP_INLINE int VP8LevelCost(const uint16_t* const table, int level) { |
67 | return VP8LevelFixedCosts[level] |
68 | + table[(level > MAX_VARIABLE_LEVEL) ? MAX_VARIABLE_LEVEL : level]; |
69 | } |
70 | |
71 | // Mode costs |
72 | extern const uint16_t VP8FixedCostsUV[4]; |
73 | extern const uint16_t VP8FixedCostsI16[4]; |
74 | extern const uint16_t VP8FixedCostsI4[NUM_BMODES][NUM_BMODES][NUM_BMODES]; |
75 | |
76 | //------------------------------------------------------------------------------ |
77 | |
78 | #ifdef __cplusplus |
79 | } // extern "C" |
80 | #endif |
81 | |
82 | #endif // WEBP_ENC_COST_ENC_H_ |
83 | |