xref: /aosp_15_r20/external/webrtc/modules/audio_coding/neteq/sync_buffer.h (revision d9f758449e529ab9291ac668be2861e7a55c2422)
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_SYNC_BUFFER_H_
12 #define MODULES_AUDIO_CODING_NETEQ_SYNC_BUFFER_H_
13 
14 #include <stddef.h>
15 #include <stdint.h>
16 
17 #include <vector>
18 
19 #include "api/audio/audio_frame.h"
20 #include "modules/audio_coding/neteq/audio_multi_vector.h"
21 #include "modules/audio_coding/neteq/audio_vector.h"
22 #include "rtc_base/buffer.h"
23 
24 namespace webrtc {
25 
26 class SyncBuffer : public AudioMultiVector {
27  public:
SyncBuffer(size_t channels,size_t length)28   SyncBuffer(size_t channels, size_t length)
29       : AudioMultiVector(channels, length),
30         next_index_(length),
31         end_timestamp_(0),
32         dtmf_index_(0) {}
33 
34   SyncBuffer(const SyncBuffer&) = delete;
35   SyncBuffer& operator=(const SyncBuffer&) = delete;
36 
37   // Returns the number of samples yet to play out from the buffer.
38   size_t FutureLength() const;
39 
40   // Adds the contents of `append_this` to the back of the SyncBuffer. Removes
41   // the same number of samples from the beginning of the SyncBuffer, to
42   // maintain a constant buffer size. The `next_index_` is updated to reflect
43   // the move of the beginning of "future" data.
44   void PushBack(const AudioMultiVector& append_this) override;
45 
46   // Like PushBack, but reads the samples channel-interleaved from the input.
47   void PushBackInterleaved(const rtc::BufferT<int16_t>& append_this);
48 
49   // Adds `length` zeros to the beginning of each channel. Removes
50   // the same number of samples from the end of the SyncBuffer, to
51   // maintain a constant buffer size. The `next_index_` is updated to reflect
52   // the move of the beginning of "future" data.
53   // Note that this operation may delete future samples that are waiting to
54   // be played.
55   void PushFrontZeros(size_t length);
56 
57   // Inserts `length` zeros into each channel at index `position`. The size of
58   // the SyncBuffer is kept constant, which means that the last `length`
59   // elements in each channel will be purged.
60   virtual void InsertZerosAtIndex(size_t length, size_t position);
61 
62   // Overwrites each channel in this SyncBuffer with values taken from
63   // `insert_this`. The values are taken from the beginning of `insert_this` and
64   // are inserted starting at `position`. `length` values are written into each
65   // channel. The size of the SyncBuffer is kept constant. That is, if `length`
66   // and `position` are selected such that the new data would extend beyond the
67   // end of the current SyncBuffer, the buffer is not extended.
68   // The `next_index_` is not updated.
69   virtual void ReplaceAtIndex(const AudioMultiVector& insert_this,
70                               size_t length,
71                               size_t position);
72 
73   // Same as the above method, but where all of `insert_this` is written (with
74   // the same constraints as above, that the SyncBuffer is not extended).
75   virtual void ReplaceAtIndex(const AudioMultiVector& insert_this,
76                               size_t position);
77 
78   // Reads `requested_len` samples from each channel and writes them interleaved
79   // into `output`. The `next_index_` is updated to point to the sample to read
80   // next time. The AudioFrame `output` is first reset, and the `data_`,
81   // `num_channels_`, and `samples_per_channel_` fields are updated.
82   void GetNextAudioInterleaved(size_t requested_len, AudioFrame* output);
83 
84   // Adds `increment` to `end_timestamp_`.
85   void IncreaseEndTimestamp(uint32_t increment);
86 
87   // Flushes the buffer. The buffer will contain only zeros after the flush, and
88   // `next_index_` will point to the end, like when the buffer was first
89   // created.
90   void Flush();
91 
Channel(size_t n)92   const AudioVector& Channel(size_t n) const { return *channels_[n]; }
Channel(size_t n)93   AudioVector& Channel(size_t n) { return *channels_[n]; }
94 
95   // Accessors and mutators.
next_index()96   size_t next_index() const { return next_index_; }
97   void set_next_index(size_t value);
end_timestamp()98   uint32_t end_timestamp() const { return end_timestamp_; }
set_end_timestamp(uint32_t value)99   void set_end_timestamp(uint32_t value) { end_timestamp_ = value; }
dtmf_index()100   size_t dtmf_index() const { return dtmf_index_; }
101   void set_dtmf_index(size_t value);
102 
103  private:
104   size_t next_index_;
105   uint32_t end_timestamp_;  // The timestamp of the last sample in the buffer.
106   size_t dtmf_index_;       // Index to the first non-DTMF sample in the buffer.
107 };
108 
109 }  // namespace webrtc
110 #endif  // MODULES_AUDIO_CODING_NETEQ_SYNC_BUFFER_H_
111