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      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:
     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   virtual ~SyncBuffer() {}
     29 
     30   // Returns the number of samples yet to play out form the buffer.
     31   size_t FutureLength() const;
     32 
     33   // Adds the contents of |append_this| to the back of the SyncBuffer. Removes
     34   // the same number of samples from the beginning of the SyncBuffer, to
     35   // maintain a constant buffer size. The |next_index_| is updated to reflect
     36   // the move of the beginning of "future" data.
     37   void PushBack(const AudioMultiVector& append_this);
     38 
     39   // Adds |length| zeros to the beginning of each channel. Removes
     40   // the same number of samples from the end of the SyncBuffer, to
     41   // maintain a constant buffer size. The |next_index_| is updated to reflect
     42   // the move of the beginning of "future" data.
     43   // Note that this operation may delete future samples that are waiting to
     44   // be played.
     45   void PushFrontZeros(size_t length);
     46 
     47   // Inserts |length| zeros into each channel at index |position|. The size of
     48   // the SyncBuffer is kept constant, which means that the last |length|
     49   // elements in each channel will be purged.
     50   virtual void InsertZerosAtIndex(size_t length, size_t position);
     51 
     52   // Overwrites each channel in this SyncBuffer with values taken from
     53   // |insert_this|. The values are taken from the beginning of |insert_this| and
     54   // are inserted starting at |position|. |length| values are written into each
     55   // channel. The size of the SyncBuffer is kept constant. That is, if |length|
     56   // and |position| are selected such that the new data would extend beyond the
     57   // end of the current SyncBuffer, the buffer is not extended.
     58   // The |next_index_| is not updated.
     59   virtual void ReplaceAtIndex(const AudioMultiVector& insert_this,
     60                               size_t length,
     61                               size_t position);
     62 
     63   // Same as the above method, but where all of |insert_this| is written (with
     64   // the same constraints as above, that the SyncBuffer is not extended).
     65   virtual void ReplaceAtIndex(const AudioMultiVector& insert_this,
     66                               size_t position);
     67 
     68   // Reads |requested_len| samples from each channel and writes them interleaved
     69   // into |output|. The |next_index_| is updated to point to the sample to read
     70   // next time.
     71   size_t GetNextAudioInterleaved(size_t requested_len, int16_t* output);
     72 
     73   // Adds |increment| to |end_timestamp_|.
     74   void IncreaseEndTimestamp(uint32_t increment);
     75 
     76   // Flushes the buffer. The buffer will contain only zeros after the flush, and
     77   // |next_index_| will point to the end, like when the buffer was first
     78   // created.
     79   void Flush();
     80 
     81   const AudioVector& Channel(size_t n) const { return *channels_[n]; }
     82   AudioVector& Channel(size_t n) { return *channels_[n]; }
     83 
     84   // Accessors and mutators.
     85   size_t next_index() const { return next_index_; }
     86   void set_next_index(size_t value);
     87   uint32_t end_timestamp() const { return end_timestamp_; }
     88   void set_end_timestamp(uint32_t value) { end_timestamp_ = value; }
     89   size_t dtmf_index() const { return dtmf_index_; }
     90   void set_dtmf_index(size_t value);
     91 
     92  private:
     93   size_t next_index_;
     94   uint32_t end_timestamp_;  // The timestamp of the last sample in the buffer.
     95   size_t dtmf_index_;  // Index to the first non-DTMF sample in the buffer.
     96 
     97   DISALLOW_COPY_AND_ASSIGN(SyncBuffer);
     98 };
     99 
    100 }  // namespace webrtc
    101 #endif  // WEBRTC_MODULES_AUDIO_CODING_NETEQ_SYNC_BUFFER_H_
    102