1 /* 2 * Copyright (c) 2012 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 MODULES_AUDIO_CODING_NETEQ_DTMF_BUFFER_H_ 12 #define MODULES_AUDIO_CODING_NETEQ_DTMF_BUFFER_H_ 13 14 #include <stddef.h> 15 #include <stdint.h> 16 17 #include <list> 18 19 namespace webrtc { 20 21 struct DtmfEvent { 22 uint32_t timestamp; 23 int event_no; 24 int volume; 25 int duration; 26 bool end_bit; 27 28 // Constructors DtmfEventDtmfEvent29 DtmfEvent() 30 : timestamp(0), event_no(0), volume(0), duration(0), end_bit(false) {} DtmfEventDtmfEvent31 DtmfEvent(uint32_t ts, int ev, int vol, int dur, bool end) 32 : timestamp(ts), event_no(ev), volume(vol), duration(dur), end_bit(end) {} 33 }; 34 35 // This is the buffer holding DTMF events while waiting for them to be played. 36 class DtmfBuffer { 37 public: 38 enum BufferReturnCodes { 39 kOK = 0, 40 kInvalidPointer, 41 kPayloadTooShort, 42 kInvalidEventParameters, 43 kInvalidSampleRate 44 }; 45 46 // Set up the buffer for use at sample rate `fs_hz`. 47 explicit DtmfBuffer(int fs_hz); 48 49 virtual ~DtmfBuffer(); 50 51 DtmfBuffer(const DtmfBuffer&) = delete; 52 DtmfBuffer& operator=(const DtmfBuffer&) = delete; 53 54 // Flushes the buffer. 55 virtual void Flush(); 56 57 // Static method to parse 4 bytes from `payload` as a DTMF event (RFC 4733) 58 // and write the parsed information into the struct `event`. Input variable 59 // `rtp_timestamp` is simply copied into the struct. 60 static int ParseEvent(uint32_t rtp_timestamp, 61 const uint8_t* payload, 62 size_t payload_length_bytes, 63 DtmfEvent* event); 64 65 // Inserts `event` into the buffer. The method looks for a matching event and 66 // merges the two if a match is found. 67 virtual int InsertEvent(const DtmfEvent& event); 68 69 // Checks if a DTMF event should be played at time `current_timestamp`. If so, 70 // the method returns true; otherwise false. The parameters of the event to 71 // play will be written to `event`. 72 virtual bool GetEvent(uint32_t current_timestamp, DtmfEvent* event); 73 74 // Number of events in the buffer. 75 virtual size_t Length() const; 76 77 virtual bool Empty() const; 78 79 // Set a new sample rate. 80 virtual int SetSampleRate(int fs_hz); 81 82 private: 83 typedef std::list<DtmfEvent> DtmfList; 84 85 int max_extrapolation_samples_; 86 int frame_len_samples_; // TODO(hlundin): Remove this later. 87 88 // Compares two events and returns true if they are the same. 89 static bool SameEvent(const DtmfEvent& a, const DtmfEvent& b); 90 91 // Merges `event` to the event pointed out by `it`. The method checks that 92 // the two events are the same (using the SameEvent method), and merges them 93 // if that was the case, returning true. If the events are not the same, false 94 // is returned. 95 bool MergeEvents(DtmfList::iterator it, const DtmfEvent& event); 96 97 // Method used by the sort algorithm to rank events in the buffer. 98 static bool CompareEvents(const DtmfEvent& a, const DtmfEvent& b); 99 100 DtmfList buffer_; 101 }; 102 103 } // namespace webrtc 104 #endif // MODULES_AUDIO_CODING_NETEQ_DTMF_BUFFER_H_ 105