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 "../common.h"
23 #include "converter_interface.h"
24
25 namespace v4l2_camera_hal {
26
27 // An RangedConverter fits values converted by a wrapped converter
28 // to a stepped range (when going from metadata -> v4l2. The other
29 // direction remains unchanged).
30 template <typename TMetadata, typename TV4L2>
31 class RangedConverter : public ConverterInterface<TMetadata, TV4L2> {
32 public:
33 RangedConverter(
34 std::shared_ptr<ConverterInterface<TMetadata, TV4L2>> wrapped_converter,
35 TV4L2 min,
36 TV4L2 max,
37 TV4L2 step);
38
39 virtual int MetadataToV4L2(TMetadata value, TV4L2* conversion) override;
40 virtual int V4L2ToMetadata(TV4L2 value, TMetadata* conversion) override;
41
42 private:
43 std::shared_ptr<ConverterInterface<TMetadata, TV4L2>> wrapped_converter_;
44 const TV4L2 min_;
45 const TV4L2 max_;
46 const TV4L2 step_;
47
48 DISALLOW_COPY_AND_ASSIGN(RangedConverter);
49 };
50
51 // -----------------------------------------------------------------------------
52
53 template <typename TMetadata, typename TV4L2>
RangedConverter(std::shared_ptr<ConverterInterface<TMetadata,TV4L2>> wrapped_converter,TV4L2 min,TV4L2 max,TV4L2 step)54 RangedConverter<TMetadata, TV4L2>::RangedConverter(
55 std::shared_ptr<ConverterInterface<TMetadata, TV4L2>> wrapped_converter,
56 TV4L2 min,
57 TV4L2 max,
58 TV4L2 step)
59 : wrapped_converter_(std::move(wrapped_converter)),
60 min_(min),
61 max_(max),
62 step_(step) {
63 HAL_LOG_ENTER();
64 }
65
66 template <typename TMetadata, typename TV4L2>
MetadataToV4L2(TMetadata value,TV4L2 * conversion)67 int RangedConverter<TMetadata, TV4L2>::MetadataToV4L2(TMetadata value,
68 TV4L2* conversion) {
69 HAL_LOG_ENTER();
70
71 TV4L2 raw_conversion = 0;
72 int res = wrapped_converter_->MetadataToV4L2(value, &raw_conversion);
73 if (res) {
74 HAL_LOGE("Failed to perform underlying conversion.");
75 return res;
76 }
77
78 // Round down to step (steps start at min_).
79 raw_conversion -= (raw_conversion - min_) % step_;
80
81 // Clamp to range.
82 if (raw_conversion < min_) {
83 raw_conversion = min_;
84 } else if (raw_conversion > max_) {
85 raw_conversion = max_;
86 }
87
88 *conversion = raw_conversion;
89 return 0;
90 }
91
92 template <typename TMetadata, typename TV4L2>
V4L2ToMetadata(TV4L2 value,TMetadata * conversion)93 int RangedConverter<TMetadata, TV4L2>::V4L2ToMetadata(TV4L2 value,
94 TMetadata* conversion) {
95 HAL_LOG_ENTER();
96
97 return wrapped_converter_->V4L2ToMetadata(value, conversion);
98 }
99
100 } // namespace v4l2_camera_hal
101
102 #endif // V4L2_CAMERA_HAL_METADATA_RANGED_CONVERTER_H_
103