AudioGraph::Buffers Class Reference

Accumulates (non-interleaved) data during effect processing. More...

#include <AudioGraphBuffers.h>

Collaboration diagram for AudioGraph::Buffers:

Public Member Functions
	Buffers (size_t blockSize=512)
	Buffers (unsigned nChannels, size_t blockSize, size_t nBlocks, size_t padding=0)
unsigned	Channels () const
size_t	BufferSize () const
size_t	BlockSize () const
size_t	Position () const
size_t	Remaining () const
bool	IsRewound () const
void	Reinit (unsigned nChannels, size_t blockSize, size_t nBlocks, size_t padding=0)
float *const *	Positions () const
	Get array of positions in the buffers. More...
void	Discard (size_t drop, size_t keep)
	Discard some data at the (unchanging) positions. More...
void	Advance (size_t count)
	Move the positions. More...
void	Rewind ()
	Reset positions to starts of buffers. More...
size_t	Rotate ()
	Shift all data at and after the old position to position 0. More...
constSamplePtr	GetReadPosition (unsigned iChannel) const
	Get accumulated data for one channel. More...
float &	GetWritePosition (unsigned iChannel)
	Get writable position for one channel. More...
void	ClearBuffer (unsigned iChannel, size_t n)

Private Attributes
std::vector< std::vector< float > >	mBuffers
std::vector< float * >	mPositions
size_t	mBufferSize { 0 }
size_t	mBlockSize { 0 }

Detailed Description

Accumulates (non-interleaved) data during effect processing.

Invariant

BlockSize() > 0

BufferSize() > 0

BufferSize() % BlockSize() == 0

mBuffers.size() == mPositions.size()

all mBuffers[i].size() are equal to BufferSize()

all (mPositions[i] - mBuffers[i].data()) are equal and in range [0, BufferSize()]

Definition at line 30 of file AudioGraphBuffers.h.

Constructor & Destructor Documentation

Buffers() [1/2]

AudioGraph::Buffers::Buffers ( size_t  blockSize = 512 )

explicit

Precondition

blockSize > 0

Postcondition

BlockSize() == blockSize

BufferSize() == blockSize

IsRewound()

Definition at line 16 of file AudioGraphBuffers.cpp.

   : mBufferSize{ blockSize }, mBlockSize{ blockSize }
{
   assert(blockSize > 0);
   assert(IsRewound());
}

References IsRewound().

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Buffers() [2/2]

AudioGraph::Buffers::Buffers	(	unsigned	nChannels,
		size_t	blockSize,
		size_t	nBlocks,
		size_t	padding = 0
	)

Parameters

padding

extra allocation can work around a soxr library bug

Precondition

blockSize > 0

nBlocks > 0

Postcondition

Channels() == nChannels

BlockSize() == blockSize

BufferSize() == blockSize * nBlocks

Definition at line 23 of file AudioGraphBuffers.cpp.

{
   Reinit(nChannels, blockSize, nBlocks, padding);
}

Member Function Documentation

Advance()

void AudioGraph::Buffers::Advance

(

size_t

count

)

Move the positions.

Precondition

count <= Remaining()

Postcondition

Remaining() reduced by count

Definition at line 89 of file AudioGraphBuffers.cpp.

{
#ifndef NDEBUG
   sampleCount oldRemaining = Remaining();
#endif
   // Assert the pre
   assert(count <= Remaining());
 
#if 1
   // Bounds checking version not assuming the pre, new in 3.2
   if (mBuffers.empty())
      return;
 
   // First buffer; defend against excessive count
   auto iterP = mPositions.begin();
   auto iterB = mBuffers.begin();
   auto &position = *iterP;
   auto data = iterB->data();
   auto end = data + iterB->size();
   // invariant assumed, and preserved
   assert(data <= position && position <= end);
   count = std::min<size_t>(end - position, count);
   position += count;
   assert(data <= position && position <= end);
 
   // other buffers; assuming equal sizes and relative positions (invariants)
   for (const auto endB = mBuffers.end(); ++iterB != endB;) {
      auto &position = *++iterP;
      // invariant assumed, and preserved
      assert(iterB->data() <= position);
      assert(position <= iterB->data() + iterB->size());
   
      position += count;
 
      assert(iterB->data() <= position);
      assert(position <= iterB->data() + iterB->size());
   }
#else
   // Version that assumes the precondition,
   // which pre-3.2 did without known errors
   for (auto &position : mPositions)
      position += count;
#endif
   // Assert the post
   assert(Remaining() == oldRemaining - count);
}

References details::end().

Referenced by DownmixStage::Acquire(), and EffectStage::FetchProcessAndAdvance().

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BlockSize()

size_t AudioGraph::Buffers::BlockSize ( ) const

inline

Definition at line 52 of file AudioGraphBuffers.h.

{ return mBlockSize; }

Referenced by EffectStage::AcceptsBlockSize(), DownmixStage::AcceptsBuffers(), WaveTrackSink::Acquire(), EffectStage::Acquire(), MixerSource::Acquire(), WideSampleSource::Acquire(), WaveTrackSink::DoConsume(), EffectStage::EffectStage(), EffectStage::FetchProcessAndAdvance(), PerTrackEffect::ProcessPass(), PerTrackEffect::ProcessTrack(), and AudioGraph::Task::Task().

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BufferSize()

size_t AudioGraph::Buffers::BufferSize ( ) const

inline

Definition at line 51 of file AudioGraphBuffers.h.

{ return mBufferSize; }

Referenced by DownmixStage::AcceptsBlockSize(), and MixerSource::AcceptsBuffers().

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Channels()

unsigned AudioGraph::Buffers::Channels ( ) const

inline

Definition at line 50 of file AudioGraphBuffers.h.

{ return mBuffers.size(); }

Referenced by DownmixStage::AcceptsBuffers(), WideSampleSource::AcceptsBuffers(), WaveTrackSink::AcceptsBuffers(), MixerSource::Acquire(), DownmixStage::Acquire(), Mixer::Clear(), WaveTrackSink::DoConsume(), EffectStage::FetchProcessAndAdvance(), EffectStage::Process(), and PerTrackEffect::ProcessPass().

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ClearBuffer()

void AudioGraph::Buffers::ClearBuffer	(	unsigned	iChannel,
		size_t	n
	)

Zero-fill n places in one of the buffers, starting from its position

Definition at line 168 of file AudioGraphBuffers.cpp.

{
   if (iChannel < mPositions.size()) {
      auto p = mPositions[iChannel];
      auto &buffer = mBuffers[iChannel];
      auto end = buffer.data() + buffer.size();
      p = std::min(end, p);
      n = std::min<size_t>(end - p, n);
      std::fill(p, p + n, 0);
   }
}

References details::end(), anonymous_namespace{StretchingSequenceIntegrationTest.cpp}::iChannel, and min().

Referenced by DownmixStage::Acquire(), Mixer::Clear(), and PerTrackEffect::ProcessPass().

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Discard()

void AudioGraph::Buffers::Discard	(	size_t	drop,
		size_t	keep
	)

Discard some data at the (unchanging) positions.

Parameters

drop	how many values to discard
keep	how many following values are defined

Precondition

drop + keep <= Remaining()

Postcondition

Remaining() is unchanged

Definition at line 46 of file AudioGraphBuffers.cpp.

{
#ifndef NDEBUG
   sampleCount oldRemaining = Remaining();
#endif
   // Assert the pre
   assert(drop + keep <= Remaining());
 
#if 1
   // Bounds checking version not assuming the pre, new in 3.2
   if (mBuffers.empty())
      return;
 
   // First buffer
   auto iterP = mPositions.begin();
   auto iterB = mBuffers.begin();
   auto position = *iterP;
   auto data = iterB->data();
   auto end = data + iterB->size();
 
   // Defend against excessive input values
   end = std::max(data, std::min(end, position + drop + keep));
   position = std::min(end, position);
   drop = std::min<size_t>(end - position, drop);
   // i.e. usually keep * sizeof(float) :
   const size_t size = ((end - position) - drop) * sizeof(float);
   memmove(position, position + drop, size);
 
   // other buffers; assuming equal sizes and relative positions (invariants)
   for (const auto endB = mBuffers.end(); ++iterB != endB;) {
      position = *++iterP;
      memmove(position, position + drop, size);
   }
#else
   // Version that assumes the precondition,
   // which pre-3.2 did without known errors
   for (auto position : mPositions)
      memmove(position, position + drop, keep * sizeof(float));
#endif
   // Assert the post
   assert(oldRemaining == Remaining());
}

References details::end(), min(), and size.

Referenced by EffectStage::Acquire().

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GetReadPosition()

constSamplePtr AudioGraph::Buffers::GetReadPosition

(

unsigned

iChannel

)

const

Get accumulated data for one channel.

Last channel is replicated for all greater indices

Precondition

Channels() > 0

BufferSize() > 0

Postcondition

result: result != nullptr

Definition at line 155 of file AudioGraphBuffers.cpp.

{
   iChannel = std::min(iChannel, Channels() - 1);
   auto buffer = mBuffers[iChannel].data();
   return reinterpret_cast<constSamplePtr>(buffer);
}

References anonymous_namespace{StretchingSequenceIntegrationTest.cpp}::iChannel, and min().

Referenced by DownmixStage::Acquire(), WaveTrackSink::DoConsume(), and Mixer::Process().

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GetWritePosition()

float & AudioGraph::Buffers::GetWritePosition

(

unsigned

iChannel

)

Get writable position for one channel.

Precondition

iChannel < Channels()

BufferSize() > 0

Definition at line 162 of file AudioGraphBuffers.cpp.

{
   assert(iChannel < Channels());
   return mBuffers[iChannel].data()[ Position() ];
}

References anonymous_namespace{StretchingSequenceIntegrationTest.cpp}::iChannel.

Referenced by MixerSource::Acquire(), WideSampleSource::Acquire(), EffectStage::FetchProcessAndAdvance(), and anonymous_namespace{DownmixStage.cpp}::MixBuffers().

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IsRewound()

bool AudioGraph::Buffers::IsRewound ( ) const

inline

Definition at line 59 of file AudioGraphBuffers.h.

{ return BufferSize() == Remaining(); }

References BufferSize.

Referenced by Buffers().

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Position()

size_t AudioGraph::Buffers::Position ( ) const

inline

Definition at line 53 of file AudioGraphBuffers.h.

                           {
      return mBuffers.empty() ? 0
         : Positions()[0]
            - reinterpret_cast<const float*>(GetReadPosition(0));
   }

Referenced by WaveTrackSink::DoConsume().

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Positions()

float *const * AudioGraph::Buffers::Positions ( ) const

inline

Get array of positions in the buffers.

Definition at line 72 of file AudioGraphBuffers.h.

{ return mPositions.data(); }

Referenced by EffectStage::Process().

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Reinit()

void AudioGraph::Buffers::Reinit	(	unsigned	nChannels,
		size_t	blockSize,
		size_t	nBlocks,
		size_t	padding = 0
	)

Parameters

padding

extra allocation can work around a soxr library bug

Precondition

blockSize > 0

nBlocks > 0

Postcondition

Channels() == nChannels

BlockSize() == blockSize

BufferSize() == blockSize * nBlocks

Definition at line 30 of file AudioGraphBuffers.cpp.

{
   assert(blockSize > 0);
   assert(nBlocks > 0);
   mBuffers.resize(nChannels);
   mPositions.resize(nChannels);
   const auto bufferSize = blockSize * nBlocks;
   for (auto &buffer : mBuffers)
      // Guarantee initial zeroes (needed at least in last buffer sometimes)
      buffer.resize(bufferSize + padding, 0.0f);
   mBufferSize = bufferSize;
   mBlockSize = blockSize;
   Rewind();
}

Referenced by PerTrackEffect::ProcessPass().

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Remaining()

size_t AudioGraph::Buffers::Remaining ( ) const

inline

Definition at line 58 of file AudioGraphBuffers.h.

{ return BufferSize() - Position(); }

References BufferSize.

Referenced by WaveTrackSink::Acquire(), EffectStage::Acquire(), MixerSource::Acquire(), WideSampleSource::Acquire(), WaveTrackSink::DoConsume(), and EffectStage::FetchProcessAndAdvance().

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Rewind()

void AudioGraph::Buffers::Rewind

(

)

Reset positions to starts of buffers.

Postcondition

IsRewound()

Definition at line 136 of file AudioGraphBuffers.cpp.

{
   auto iterP = mPositions.begin();
   for (auto &buffer : mBuffers)
      *iterP++ = buffer.data();
   assert(IsRewound());
}

Referenced by WaveTrackSink::DoConsume(), EffectStage::EffectStage(), EffectStage::FetchProcessAndAdvance(), and PerTrackEffect::ProcessPass().

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Rotate()

size_t AudioGraph::Buffers::Rotate

(

)

Shift all data at and after the old position to position 0.

Returns

how many positions were shifted; other contents are unspecified

Postcondition

IsRewound()

Definition at line 144 of file AudioGraphBuffers.cpp.

{
   auto oldRemaining = Remaining();
   Rewind();
   const auto free = BufferSize() - oldRemaining;
   // Shift any partial block of unread data leftward
   Discard(free, oldRemaining);
   assert(IsRewound());
   return oldRemaining;
}

References BufferSize, and staffpad::vo::free().

Referenced by DownmixStage::Acquire(), and EffectStage::FetchProcessAndAdvance().

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Member Data Documentation

mBlockSize

size_t AudioGraph::Buffers::mBlockSize { 0 }

private

Definition at line 122 of file AudioGraphBuffers.h.

mBuffers

std::vector<std::vector<float> > AudioGraph::Buffers::mBuffers

private

Definition at line 119 of file AudioGraphBuffers.h.

mBufferSize

size_t AudioGraph::Buffers::mBufferSize { 0 }

private

Definition at line 121 of file AudioGraphBuffers.h.

mPositions

std::vector<float *> AudioGraph::Buffers::mPositions

private

Definition at line 120 of file AudioGraphBuffers.h.

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The documentation for this class was generated from the following files:

• AudioGraphBuffers.h
• AudioGraphBuffers.cpp