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 WEBRTC_MODULES_AUDIO_CODING_NETEQ_SYNC_BUFFER_H_
12 #define WEBRTC_MODULES_AUDIO_CODING_NETEQ_SYNC_BUFFER_H_
13 
14 #include "webrtc/base/constructormagic.h"
15 #include "webrtc/modules/audio_coding/neteq/audio_multi_vector.h"
16 #include "webrtc/typedefs.h"
17 
18 namespace webrtc {
19 
20 class SyncBuffer : public AudioMultiVector {
21  public:
SyncBuffer(size_t channels,size_t length)22   SyncBuffer(size_t channels, size_t length)
23       : AudioMultiVector(channels, length),
24         next_index_(length),
25         end_timestamp_(0),
26         dtmf_index_(0) {}
27 
28   // Returns the number of samples yet to play out form the buffer.
29   size_t FutureLength() const;
30 
31   // Adds the contents of |append_this| to the back of the SyncBuffer. Removes
32   // the same number of samples from the beginning of the SyncBuffer, to
33   // maintain a constant buffer size. The |next_index_| is updated to reflect
34   // the move of the beginning of "future" data.
35   void PushBack(const AudioMultiVector& append_this) override;
36 
37   // Adds |length| zeros to the beginning of each channel. Removes
38   // the same number of samples from the end of the SyncBuffer, to
39   // maintain a constant buffer size. The |next_index_| is updated to reflect
40   // the move of the beginning of "future" data.
41   // Note that this operation may delete future samples that are waiting to
42   // be played.
43   void PushFrontZeros(size_t length);
44 
45   // Inserts |length| zeros into each channel at index |position|. The size of
46   // the SyncBuffer is kept constant, which means that the last |length|
47   // elements in each channel will be purged.
48   virtual void InsertZerosAtIndex(size_t length, size_t position);
49 
50   // Overwrites each channel in this SyncBuffer with values taken from
51   // |insert_this|. The values are taken from the beginning of |insert_this| and
52   // are inserted starting at |position|. |length| values are written into each
53   // channel. The size of the SyncBuffer is kept constant. That is, if |length|
54   // and |position| are selected such that the new data would extend beyond the
55   // end of the current SyncBuffer, the buffer is not extended.
56   // The |next_index_| is not updated.
57   virtual void ReplaceAtIndex(const AudioMultiVector& insert_this,
58                               size_t length,
59                               size_t position);
60 
61   // Same as the above method, but where all of |insert_this| is written (with
62   // the same constraints as above, that the SyncBuffer is not extended).
63   virtual void ReplaceAtIndex(const AudioMultiVector& insert_this,
64                               size_t position);
65 
66   // Reads |requested_len| samples from each channel and writes them interleaved
67   // into |output|. The |next_index_| is updated to point to the sample to read
68   // next time.
69   size_t GetNextAudioInterleaved(size_t requested_len, int16_t* output);
70 
71   // Adds |increment| to |end_timestamp_|.
72   void IncreaseEndTimestamp(uint32_t increment);
73 
74   // Flushes the buffer. The buffer will contain only zeros after the flush, and
75   // |next_index_| will point to the end, like when the buffer was first
76   // created.
77   void Flush();
78 
Channel(size_t n)79   const AudioVector& Channel(size_t n) const { return *channels_[n]; }
Channel(size_t n)80   AudioVector& Channel(size_t n) { return *channels_[n]; }
81 
82   // Accessors and mutators.
next_index()83   size_t next_index() const { return next_index_; }
84   void set_next_index(size_t value);
end_timestamp()85   uint32_t end_timestamp() const { return end_timestamp_; }
set_end_timestamp(uint32_t value)86   void set_end_timestamp(uint32_t value) { end_timestamp_ = value; }
dtmf_index()87   size_t dtmf_index() const { return dtmf_index_; }
88   void set_dtmf_index(size_t value);
89 
90  private:
91   size_t next_index_;
92   uint32_t end_timestamp_;  // The timestamp of the last sample in the buffer.
93   size_t dtmf_index_;  // Index to the first non-DTMF sample in the buffer.
94 
95   RTC_DISALLOW_COPY_AND_ASSIGN(SyncBuffer);
96 };
97 
98 }  // namespace webrtc
99 #endif  // WEBRTC_MODULES_AUDIO_CODING_NETEQ_SYNC_BUFFER_H_
100