1 /* 2 * libjingle 3 * Copyright 2004--2010, Google Inc. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright notice, 9 * this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright notice, 11 * this list of conditions and the following disclaimer in the documentation 12 * and/or other materials provided with the distribution. 13 * 3. The name of the author may not be used to endorse or promote products 14 * derived from this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 17 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 18 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO 19 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #ifndef TALK_SOUND_SOUNDINPUTSTREAMINTERFACE_H_ 29 #define TALK_SOUND_SOUNDINPUTSTREAMINTERFACE_H_ 30 31 #include "talk/base/constructormagic.h" 32 #include "talk/base/sigslot.h" 33 34 namespace cricket { 35 36 // Interface for consuming an input stream from a recording device. 37 // Semantics and thread-safety of StartReading()/StopReading() are the same as 38 // for talk_base::Worker. 39 class SoundInputStreamInterface { 40 public: 41 virtual ~SoundInputStreamInterface() {} 42 43 // Starts the reading of samples on the current thread. 44 virtual bool StartReading() = 0; 45 // Stops the reading of samples. 46 virtual bool StopReading() = 0; 47 48 // Retrieves the current input volume for this stream. Nominal range is 49 // defined by SoundSystemInterface::k(Max|Min)Volume, but values exceeding the 50 // max may be possible in some implementations. This call retrieves the actual 51 // volume currently in use by the OS, not a cached value from a previous 52 // (Get|Set)Volume() call. 53 virtual bool GetVolume(int *volume) = 0; 54 55 // Changes the input volume for this stream. Nominal range is defined by 56 // SoundSystemInterface::k(Max|Min)Volume. The effect of exceeding kMaxVolume 57 // is implementation-defined. 58 virtual bool SetVolume(int volume) = 0; 59 60 // Closes this stream object. If currently reading then this may only be 61 // called from the reading thread. 62 virtual bool Close() = 0; 63 64 // Get the latency of the stream. 65 virtual int LatencyUsecs() = 0; 66 67 // Notifies the consumer of new data read from the device. 68 // The first parameter is a pointer to the data read, and is only valid for 69 // the duration of the call. 70 // The second parameter is the amount of data read in bytes (i.e., the valid 71 // length of the memory pointed to). 72 // The 3rd parameter is the stream that is issuing the callback. 73 sigslot::signal3<const void *, size_t, 74 SoundInputStreamInterface *> SignalSamplesRead; 75 76 protected: 77 SoundInputStreamInterface() {} 78 79 private: 80 DISALLOW_COPY_AND_ASSIGN(SoundInputStreamInterface); 81 }; 82 83 } // namespace cricket 84 85 #endif // TALK_SOUND_SOUNDOUTPUTSTREAMINTERFACE_H_ 86
