| // Copyright 2014 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef COBALT_MEDIA_BASE_AUDIO_BLOCK_FIFO_H_ |
| #define COBALT_MEDIA_BASE_AUDIO_BLOCK_FIFO_H_ |
| |
| #include "base/basictypes.h" |
| #include "base/memory/scoped_vector.h" |
| #include "cobalt/media/base/audio_bus.h" |
| #include "cobalt/media/base/media_export.h" |
| |
| namespace cobalt { |
| namespace media { |
| |
| // First-in first-out container for AudioBus elements. |
| // The FIFO is composed of blocks of AudioBus elements, it accepts interleaved |
| // data as input and will deinterleave it into the FIFO, and it only allows |
| // consuming a whole block of AudioBus element. |
| // This class is thread-unsafe. |
| class MEDIA_EXPORT AudioBlockFifo { |
| public: |
| // Creates a new AudioBlockFifo and allocates |blocks| memory, each block |
| // of memory can store |channels| of length |frames| data. |
| AudioBlockFifo(int channels, int frames, int blocks); |
| virtual ~AudioBlockFifo(); |
| |
| // Pushes interleaved audio data from |source| to the FIFO. |
| // The method will deinterleave the data into a audio bus. |
| // Push() will crash if the allocated space is insufficient. |
| void Push(const void* source, int frames, int bytes_per_sample); |
| |
| // Consumes a block of audio from the FIFO. Returns an AudioBus which |
| // contains the consumed audio data to avoid copying. |
| // Consume() will crash if the FIFO does not contain a block of data. |
| const AudioBus* Consume(); |
| |
| // Empties the FIFO without deallocating any memory. |
| void Clear(); |
| |
| // Number of available block of memory ready to be consumed in the FIFO. |
| int available_blocks() const { return available_blocks_; } |
| |
| // Number of available frames of data in the FIFO. |
| int GetAvailableFrames() const; |
| |
| // Number of unfilled frames in the whole FIFO. |
| int GetUnfilledFrames() const; |
| |
| // Dynamically increase |blocks| of memory to the FIFO. |
| void IncreaseCapacity(int blocks); |
| |
| private: |
| // The actual FIFO is a vector of audio buses. |
| ScopedVector<AudioBus> audio_blocks_; |
| |
| // Number of channels in AudioBus. |
| const int channels_; |
| |
| // Maximum number of frames of data one block of memory can contain. |
| // This value is set by |frames| in the constructor. |
| const int block_frames_; |
| |
| // Used to keep track which block of memory to be written. |
| int write_block_; |
| |
| // Used to keep track which block of memory to be consumed. |
| int read_block_; |
| |
| // Number of available blocks of memory to be consumed. |
| int available_blocks_; |
| |
| // Current write position in the current written block. |
| int write_pos_; |
| |
| DISALLOW_COPY_AND_ASSIGN(AudioBlockFifo); |
| }; |
| |
| } // namespace media |
| } // namespace cobalt |
| |
| #endif // COBALT_MEDIA_BASE_AUDIO_BLOCK_FIFO_H_ |