henrike@webrtc.org | 91bac04 | 2014-08-26 22:04:04 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2004 The WebRTC 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 | #ifndef WEBRTC_SOUND_SOUNDINPUTSTREAMINTERFACE_H_ |
| 12 | #define WEBRTC_SOUND_SOUNDINPUTSTREAMINTERFACE_H_ |
| 13 | |
| 14 | #include "webrtc/base/constructormagic.h" |
| 15 | #include "webrtc/base/sigslot.h" |
| 16 | |
| 17 | namespace rtc { |
| 18 | |
| 19 | // Interface for consuming an input stream from a recording device. |
| 20 | // Semantics and thread-safety of StartReading()/StopReading() are the same as |
| 21 | // for rtc::Worker. |
| 22 | class SoundInputStreamInterface { |
| 23 | public: |
| 24 | virtual ~SoundInputStreamInterface() {} |
| 25 | |
| 26 | // Starts the reading of samples on the current thread. |
| 27 | virtual bool StartReading() = 0; |
| 28 | // Stops the reading of samples. |
| 29 | virtual bool StopReading() = 0; |
| 30 | |
| 31 | // Retrieves the current input volume for this stream. Nominal range is |
| 32 | // defined by SoundSystemInterface::k(Max|Min)Volume, but values exceeding the |
| 33 | // max may be possible in some implementations. This call retrieves the actual |
| 34 | // volume currently in use by the OS, not a cached value from a previous |
| 35 | // (Get|Set)Volume() call. |
| 36 | virtual bool GetVolume(int *volume) = 0; |
| 37 | |
| 38 | // Changes the input volume for this stream. Nominal range is defined by |
| 39 | // SoundSystemInterface::k(Max|Min)Volume. The effect of exceeding kMaxVolume |
| 40 | // is implementation-defined. |
| 41 | virtual bool SetVolume(int volume) = 0; |
| 42 | |
| 43 | // Closes this stream object. If currently reading then this may only be |
| 44 | // called from the reading thread. |
| 45 | virtual bool Close() = 0; |
| 46 | |
| 47 | // Get the latency of the stream. |
| 48 | virtual int LatencyUsecs() = 0; |
| 49 | |
| 50 | // Notifies the consumer of new data read from the device. |
| 51 | // The first parameter is a pointer to the data read, and is only valid for |
| 52 | // the duration of the call. |
| 53 | // The second parameter is the amount of data read in bytes (i.e., the valid |
| 54 | // length of the memory pointed to). |
| 55 | // The 3rd parameter is the stream that is issuing the callback. |
| 56 | sigslot::signal3<const void *, size_t, |
| 57 | SoundInputStreamInterface *> SignalSamplesRead; |
| 58 | |
| 59 | protected: |
| 60 | SoundInputStreamInterface() {} |
| 61 | |
| 62 | private: |
| 63 | DISALLOW_COPY_AND_ASSIGN(SoundInputStreamInterface); |
| 64 | }; |
| 65 | |
| 66 | } // namespace rtc |
| 67 | |
| 68 | #endif // WEBRTC_SOUND_SOUNDOUTPUTSTREAMINTERFACE_H_ |