1/*
2 *  Copyright (c) 2012 The WebM project authors. All Rights Reserved.
3 *
4 *  Use of this source code is governed by a BSD-style license
5 *  that can be found in the LICENSE file in the root of the source
6 *  tree. An additional intellectual property rights grant can be found
7 *  in the file PATENTS.  All contributing project authors may
8 *  be found in the AUTHORS file in the root of the source tree.
9 */
10
11
12#include <math.h>
13#include <stddef.h>
14#include <stdio.h>
15#include <stdlib.h>
16#include <string.h>
17#include <sys/types.h>
18
19#include "test/acm_random.h"
20#include "third_party/googletest/src/include/gtest/gtest.h"
21#include "vpx/vpx_integer.h"
22
23#include "vp8/encoder/boolhuff.h"
24#include "vp8/decoder/dboolhuff.h"
25
26namespace {
27const int num_tests = 10;
28
29// In a real use the 'decrypt_state' parameter will be a pointer to a struct
30// with whatever internal state the decryptor uses. For testing we'll just
31// xor with a constant key, and decrypt_state will point to the start of
32// the original buffer.
33const uint8_t secret_key[16] = {
34  0x01, 0x12, 0x23, 0x34, 0x45, 0x56, 0x67, 0x78,
35  0x89, 0x9a, 0xab, 0xbc, 0xcd, 0xde, 0xef, 0xf0
36};
37
38void encrypt_buffer(uint8_t *buffer, size_t size) {
39  for (size_t i = 0; i < size; ++i) {
40    buffer[i] ^= secret_key[i & 15];
41  }
42}
43
44void test_decrypt_cb(void *decrypt_state, const uint8_t *input,
45                     uint8_t *output, int count) {
46  const size_t offset = input - reinterpret_cast<uint8_t*>(decrypt_state);
47  for (int i = 0; i < count; i++) {
48    output[i] = input[i] ^ secret_key[(offset + i) & 15];
49  }
50}
51
52}  // namespace
53
54using libvpx_test::ACMRandom;
55
56TEST(VP8, TestBitIO) {
57  ACMRandom rnd(ACMRandom::DeterministicSeed());
58  for (int n = 0; n < num_tests; ++n) {
59    for (int method = 0; method <= 7; ++method) {   // we generate various proba
60      const int kBitsToTest = 1000;
61      uint8_t probas[kBitsToTest];
62
63      for (int i = 0; i < kBitsToTest; ++i) {
64        const int parity = i & 1;
65        probas[i] =
66            (method == 0) ? 0 : (method == 1) ? 255 :
67            (method == 2) ? 128 :
68            (method == 3) ? rnd.Rand8() :
69            (method == 4) ? (parity ? 0 : 255) :
70            // alternate between low and high proba:
71            (method == 5) ? (parity ? rnd(128) : 255 - rnd(128)) :
72            (method == 6) ?
73                (parity ? rnd(64) : 255 - rnd(64)) :
74                (parity ? rnd(32) : 255 - rnd(32));
75      }
76      for (int bit_method = 0; bit_method <= 3; ++bit_method) {
77        const int random_seed = 6432;
78        const int kBufferSize = 10000;
79        ACMRandom bit_rnd(random_seed);
80        BOOL_CODER bw;
81        uint8_t bw_buffer[kBufferSize];
82        vp8_start_encode(&bw, bw_buffer, bw_buffer + kBufferSize);
83
84        int bit = (bit_method == 0) ? 0 : (bit_method == 1) ? 1 : 0;
85        for (int i = 0; i < kBitsToTest; ++i) {
86          if (bit_method == 2) {
87            bit = (i & 1);
88          } else if (bit_method == 3) {
89            bit = bit_rnd(2);
90          }
91          vp8_encode_bool(&bw, bit, static_cast<int>(probas[i]));
92        }
93
94        vp8_stop_encode(&bw);
95
96        BOOL_DECODER br;
97        encrypt_buffer(bw_buffer, kBufferSize);
98        vp8dx_start_decode(&br, bw_buffer, kBufferSize,
99                           test_decrypt_cb,
100                           reinterpret_cast<void *>(bw_buffer));
101        bit_rnd.Reset(random_seed);
102        for (int i = 0; i < kBitsToTest; ++i) {
103          if (bit_method == 2) {
104            bit = (i & 1);
105          } else if (bit_method == 3) {
106            bit = bit_rnd(2);
107          }
108          GTEST_ASSERT_EQ(vp8dx_decode_bool(&br, probas[i]), bit)
109              << "pos: "<< i << " / " << kBitsToTest
110              << " bit_method: " << bit_method
111              << " method: " << method;
112        }
113      }
114    }
115  }
116}
117