Index: webrtc/modules/audio_processing/test/analog_volume_mapper.h |
diff --git a/webrtc/modules/audio_processing/test/analog_volume_mapper.h b/webrtc/modules/audio_processing/test/analog_volume_mapper.h |
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index 0000000000000000000000000000000000000000..40cf8b6edcf622722c215c43e6f4ddb73aad6120 |
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+++ b/webrtc/modules/audio_processing/test/analog_volume_mapper.h |
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+/* |
+ * Copyright (c) 2017 The WebRTC 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 WEBRTC_MODULES_AUDIO_PROCESSING_TEST_ANALOG_VOLUME_MAPPER_H_ |
+#define WEBRTC_MODULES_AUDIO_PROCESSING_TEST_ANALOG_VOLUME_MAPPER_H_ |
+ |
+#include "webrtc/base/checks.h" |
+ |
+namespace webrtc { |
+ |
+// Class for simulating an analog gain controller controlled by |
+// webrtc::GainControl. The class wraps a mapping from the current |
+// level to a floating point scaling factor abstracting |
+// non-linearities in the gain curve of real analog microphones. The |
+// intended mode of operation is to use get_scaling_factor() to apply |
+// a gain factor to a signal. |
+class AnalogLevelMapper { |
+ public: |
+ enum class LevelToScalingMappingKind { |
peah-webrtc
2017/04/26 07:20:03
I really think it would be easier to see how to be
|
+ kIdentity, // Any level produces a constant scaling factor of 1.0f. |
+ kLinear // A level within [0, 255] is linearly scaled. 0 produces |
+ // 0.f, and 255 is 1.0f. |
+ }; |
+ |
+ explicit AnalogLevelMapper(LevelToScalingMappingKind mapping_kind) |
+ : mapping_kind_(mapping_kind) {} |
+ |
+ // |level| must be within [0, 255]. |
+ void set_analog_level(int level) { |
+ RTC_DCHECK_LE(0, level); |
+ RTC_DCHECK_LE(level, 255); |
+ level_ = level; |
+ } |
+ |
+ int analog_level() const { return level_; } |
+ |
+ float GetScalingFactor() const { |
+ switch (mapping_kind_) { |
+ case LevelToScalingMappingKind::kIdentity: { |
+ return 1.0f; |
+ } |
+ case LevelToScalingMappingKind::kLinear: { |
+ return static_cast<float>(level_) / 255.0f; |
+ } |
+ } |
+ } |
+ |
+ private: |
+ int level_ = 0; |
+ const LevelToScalingMappingKind mapping_kind_; |
+}; |
+} // namespace webrtc |
+ |
+#endif // WEBRTC_MODULES_AUDIO_PROCESSING_TEST_ANALOG_VOLUME_MAPPER_H_ |