1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef MEDIA_BASE_AUDIO_SPLICER_H_ 6 #define MEDIA_BASE_AUDIO_SPLICER_H_ 7 8 #include <deque> 9 10 #include "base/memory/ref_counted.h" 11 #include "media/base/audio_timestamp_helper.h" 12 #include "media/base/media_export.h" 13 14 namespace media { 15 16 class AudioBuffer; 17 class AudioDecoderConfig; 18 19 // Helper class that handles filling gaps and resolving overlaps. 20 class MEDIA_EXPORT AudioSplicer { 21 public: 22 AudioSplicer(int samples_per_second); 23 ~AudioSplicer(); 24 25 // Resets the splicer state by clearing the output buffers queue, 26 // and resetting the timestamp helper. 27 void Reset(); 28 29 // Adds a new buffer full of samples or end of stream buffer to the splicer. 30 // Returns true if the buffer was accepted. False is returned if an error 31 // occurred. 32 bool AddInput(const scoped_refptr<AudioBuffer>& input); 33 34 // Returns true if the splicer has a buffer to return. 35 bool HasNextBuffer() const; 36 37 // Removes the next buffer from the output buffer queue and returns it. 38 // This should only be called if HasNextBuffer() returns true. 39 scoped_refptr<AudioBuffer> GetNextBuffer(); 40 41 private: 42 void AddOutputBuffer(const scoped_refptr<AudioBuffer>& buffer); 43 44 AudioTimestampHelper output_timestamp_helper_; 45 46 // Minimum gap size needed before the splicer will take action to 47 // fill a gap. This avoids periodically inserting and then dropping samples 48 // when the buffer timestamps are slightly off because of timestamp rounding 49 // in the source content. Unit is frames. 50 int min_gap_size_; 51 52 std::deque<scoped_refptr<AudioBuffer> > output_buffers_; 53 bool received_end_of_stream_; 54 55 DISALLOW_IMPLICIT_CONSTRUCTORS(AudioSplicer); 56 }; 57 58 } // namespace media 59 60 #endif 61
