| /* |
| * Copyright (C) 2010 Google Inc. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of |
| * its contributors may be used to endorse or promote products derived |
| * from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY |
| * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
| * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY |
| * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
| * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
| * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #ifndef AudioChannel_h |
| #define AudioChannel_h |
| |
| #include "platform/PlatformExport.h" |
| #include "platform/audio/AudioArray.h" |
| #include "wtf/PassOwnPtr.h" |
| |
| namespace WebCore { |
| |
| // An AudioChannel represents a buffer of non-interleaved floating-point audio samples. |
| // The PCM samples are normally assumed to be in a nominal range -1.0 -> +1.0 |
| class PLATFORM_EXPORT AudioChannel { |
| WTF_MAKE_NONCOPYABLE(AudioChannel); |
| public: |
| // Memory can be externally referenced, or can be internally allocated with an AudioFloatArray. |
| |
| // Reference an external buffer. |
| AudioChannel(float* storage, size_t length) |
| : m_length(length) |
| , m_rawPointer(storage) |
| , m_silent(false) |
| { |
| } |
| |
| // Manage storage for us. |
| explicit AudioChannel(size_t length) |
| : m_length(length) |
| , m_rawPointer(0) |
| , m_silent(true) |
| { |
| m_memBuffer = adoptPtr(new AudioFloatArray(length)); |
| } |
| |
| // A "blank" audio channel -- must call set() before it's useful... |
| AudioChannel() |
| : m_length(0) |
| , m_rawPointer(0) |
| , m_silent(true) |
| { |
| } |
| |
| // Redefine the memory for this channel. |
| // storage represents external memory not managed by this object. |
| void set(float* storage, size_t length) |
| { |
| m_memBuffer.clear(); // cleanup managed storage |
| m_rawPointer = storage; |
| m_length = length; |
| m_silent = false; |
| } |
| |
| // How many sample-frames do we contain? |
| size_t length() const { return m_length; } |
| |
| // resizeSmaller() can only be called with a new length <= the current length. |
| // The data stored in the bus will remain undisturbed. |
| void resizeSmaller(size_t newLength); |
| |
| // Direct access to PCM sample data. Non-const accessor clears silent flag. |
| float* mutableData() |
| { |
| clearSilentFlag(); |
| return m_rawPointer ? m_rawPointer : m_memBuffer->data(); |
| } |
| |
| const float* data() const { return m_rawPointer ? m_rawPointer : m_memBuffer->data(); } |
| |
| // Zeroes out all sample values in buffer. |
| void zero() |
| { |
| if (m_silent) |
| return; |
| |
| m_silent = true; |
| |
| if (m_memBuffer.get()) |
| m_memBuffer->zero(); |
| else |
| memset(m_rawPointer, 0, sizeof(float) * m_length); |
| } |
| |
| // Clears the silent flag. |
| void clearSilentFlag() { m_silent = false; } |
| |
| bool isSilent() const { return m_silent; } |
| |
| // Scales all samples by the same amount. |
| void scale(float scale); |
| |
| // A simple memcpy() from the source channel |
| void copyFrom(const AudioChannel* sourceChannel); |
| |
| // Copies the given range from the source channel. |
| void copyFromRange(const AudioChannel* sourceChannel, unsigned startFrame, unsigned endFrame); |
| |
| // Sums (with unity gain) from the source channel. |
| void sumFrom(const AudioChannel* sourceChannel); |
| |
| // Returns maximum absolute value (useful for normalization). |
| float maxAbsValue() const; |
| |
| private: |
| size_t m_length; |
| |
| float* m_rawPointer; |
| OwnPtr<AudioFloatArray> m_memBuffer; |
| bool m_silent; |
| }; |
| |
| } // WebCore |
| |
| #endif // AudioChannel_h |