1 /*
2 * Copyright (C) 2016 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #ifndef V4L2_CAMERA_HAL_METADATA_RANGED_CONVERTER_H_
18 #define V4L2_CAMERA_HAL_METADATA_RANGED_CONVERTER_H_
19
20 #include <memory>
21
22 #include <android-base/macros.h>
23 #include "common.h"
24 #include "converter_interface.h"
25
26 namespace v4l2_camera_hal {
27
28 // An RangedConverter fits values converted by a wrapped converter
29 // to a stepped range (when going from metadata -> v4l2. The other
30 // direction remains unchanged).
31 template <typename TMetadata, typename TV4L2>
32 class RangedConverter : public ConverterInterface<TMetadata, TV4L2> {
33 public:
34 RangedConverter(
35 std::shared_ptr<ConverterInterface<TMetadata, TV4L2>> wrapped_converter,
36 TV4L2 min,
37 TV4L2 max,
38 TV4L2 step);
39
40 virtual int MetadataToV4L2(TMetadata value, TV4L2* conversion) override;
41 virtual int V4L2ToMetadata(TV4L2 value, TMetadata* conversion) override;
42
43 private:
44 std::shared_ptr<ConverterInterface<TMetadata, TV4L2>> wrapped_converter_;
45 const TV4L2 min_;
46 const TV4L2 max_;
47 const TV4L2 step_;
48
49 DISALLOW_COPY_AND_ASSIGN(RangedConverter);
50 };
51
52 // -----------------------------------------------------------------------------
53
54 template <typename TMetadata, typename TV4L2>
RangedConverter(std::shared_ptr<ConverterInterface<TMetadata,TV4L2>> wrapped_converter,TV4L2 min,TV4L2 max,TV4L2 step)55 RangedConverter<TMetadata, TV4L2>::RangedConverter(
56 std::shared_ptr<ConverterInterface<TMetadata, TV4L2>> wrapped_converter,
57 TV4L2 min,
58 TV4L2 max,
59 TV4L2 step)
60 : wrapped_converter_(std::move(wrapped_converter)),
61 min_(min),
62 max_(max),
63 step_(step) {
64 HAL_LOG_ENTER();
65 }
66
67 template <typename TMetadata, typename TV4L2>
MetadataToV4L2(TMetadata value,TV4L2 * conversion)68 int RangedConverter<TMetadata, TV4L2>::MetadataToV4L2(TMetadata value,
69 TV4L2* conversion) {
70 HAL_LOG_ENTER();
71
72 TV4L2 raw_conversion = 0;
73 int res = wrapped_converter_->MetadataToV4L2(value, &raw_conversion);
74 if (res) {
75 HAL_LOGE("Failed to perform underlying conversion.");
76 return res;
77 }
78
79 // Round down to step (steps start at min_).
80 raw_conversion -= (raw_conversion - min_) % step_;
81
82 // Clamp to range.
83 if (raw_conversion < min_) {
84 raw_conversion = min_;
85 } else if (raw_conversion > max_) {
86 raw_conversion = max_;
87 }
88
89 *conversion = raw_conversion;
90 return 0;
91 }
92
93 template <typename TMetadata, typename TV4L2>
V4L2ToMetadata(TV4L2 value,TMetadata * conversion)94 int RangedConverter<TMetadata, TV4L2>::V4L2ToMetadata(TV4L2 value,
95 TMetadata* conversion) {
96 HAL_LOG_ENTER();
97
98 return wrapped_converter_->V4L2ToMetadata(value, conversion);
99 }
100
101 } // namespace v4l2_camera_hal
102
103 #endif // V4L2_CAMERA_HAL_METADATA_RANGED_CONVERTER_H_
104