Retired Document
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PublicUtility/CABufferList.h
/* |
File: CABufferList.h |
Abstract: Part of CoreAudio Utility Classes |
Version: 1.1 |
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be used to endorse or promote products derived from the Apple Software |
without specific prior written permission from Apple. Except as |
expressly stated in this notice, no other rights or licenses, express or |
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FOR A PARTICULAR PURPOSE, REGARDING THE APPLE SOFTWARE OR ITS USE AND |
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Copyright (C) 2012 Apple Inc. All Rights Reserved. |
*/ |
#ifndef __CABufferList_h__ |
#define __CABufferList_h__ |
#include <stddef.h> |
#include "CAStreamBasicDescription.h" |
#include "CAXException.h" |
void CAShowAudioBufferList(const AudioBufferList &abl, int framesToPrint, const AudioStreamBasicDescription &fmt, const char *label=NULL); |
void CAShowAudioBufferList(const AudioBufferList &abl, int framesToPrint, int wordSize, const char *label=NULL); |
extern "C" void CAShowAudioBufferList(const AudioBufferList *abl, int framesToPrint, int wordSize); |
extern "C" int CrashIfClientProvidedBogusAudioBufferList(const AudioBufferList *abl, bool nullOK=false); |
/* ____________________________________________________________________________ |
// CABufferList - variable length buffer list |
This class is designed for use in non-simplistic cases. For AudioUnits, AUBufferList |
is preferred. |
CABufferList can be used in one of two ways: |
- as mutable pointers into non-owned memory |
- as an immutable array of buffers (owns its own memory). |
All buffers are assumed to have the same format (number of channels, word size), so that |
we can assume their mDataByteSizes are all the same. |
____________________________________________________________________________ */ |
class CABufferList { |
public: |
void * operator new(size_t /*size*/, int nBuffers) { |
return ::operator new(sizeof(CABufferList) + (nBuffers-1) * sizeof(AudioBuffer)); |
} |
static CABufferList * New(const char *name, const CAStreamBasicDescription &format) |
{ |
UInt32 numBuffers = format.NumberChannelStreams(), channelsPerBuffer = format.NumberInterleavedChannels(); |
return new(numBuffers) CABufferList(name, numBuffers, channelsPerBuffer); |
} |
static CABufferList * New(const CAStreamBasicDescription &format) { return New("", format); } |
static CABufferList * New(UInt32 numBuffers, UInt32 channelsPerBuffer, const char *name="") { |
return new(numBuffers) CABufferList(name, numBuffers, channelsPerBuffer); |
} |
protected: |
CABufferList(const char *name, UInt32 numBuffers, UInt32 channelsPerBuffer) : |
mName(name), |
mBufferMemory(NULL), |
mBufferCapacity(0) |
{ |
//XAssert(numBuffers > 0 /*&& channelsPerBuffer > 0*/); |
mABL.mNumberBuffers = numBuffers; |
AudioBuffer *buf = mABL.mBuffers; |
for (UInt32 i = mABL.mNumberBuffers; i--; ++buf) { |
buf->mNumberChannels = channelsPerBuffer; |
buf->mDataByteSize = 0; |
buf->mData = NULL; |
} |
} |
public: |
~CABufferList() |
{ |
if (mBufferMemory) |
delete[] mBufferMemory; |
} |
const char * Name() { return mName; } |
const AudioBufferList & GetBufferList() const { return mABL; } |
AudioBufferList & GetModifiableBufferList() { return _GetBufferList(); } |
UInt32 GetNumberBuffers() const { return mABL.mNumberBuffers; } |
UInt32 GetNumBytes() const |
{ |
return mABL.mBuffers[0].mDataByteSize; |
} |
void SetBytes(UInt32 nBytes, void *data) |
{ |
VerifyNotTrashingOwnedBuffer(); |
XAssert(mABL.mNumberBuffers == 1); |
mABL.mBuffers[0].mDataByteSize = nBytes; |
mABL.mBuffers[0].mData = data; |
} |
void CopyAllFrom(CABufferList *srcbl, CABufferList *ptrbl) |
// copies bytes from srcbl |
// make ptrbl reflect the length copied |
// note that srcbl may be same as ptrbl! |
{ |
// Note that this buffer *can* own memory and its pointers/lengths are not |
// altered; only its buffer contents, which are copied from srcbl. |
// The pointers/lengths in ptrbl are updated to reflect the addresses/lengths |
// of the copied data, and srcbl's contents are consumed. |
ptrbl->VerifyNotTrashingOwnedBuffer(); |
UInt32 nBytes = srcbl->GetNumBytes(); |
AudioBuffer *mybuf = mABL.mBuffers, *srcbuf = srcbl->mABL.mBuffers, |
*ptrbuf = ptrbl->mABL.mBuffers; |
for (UInt32 i = mABL.mNumberBuffers; i--; ++mybuf, ++srcbuf, ++ptrbuf) { |
memmove(mybuf->mData, srcbuf->mData, srcbuf->mDataByteSize); |
ptrbuf->mData = mybuf->mData; |
ptrbuf->mDataByteSize = srcbuf->mDataByteSize; |
} |
if (srcbl != ptrbl) |
srcbl->BytesConsumed(nBytes); |
} |
// copies data from another buffer list. |
void CopyDataFrom(const AudioBufferList &other) |
{ |
for (unsigned i = 0; i < other.mNumberBuffers; ++i) { |
XAssert(mBufferCapacity == 0 || other.mBuffers[i].mDataByteSize <= mBufferCapacity); |
memcpy(mABL.mBuffers[i].mData, other.mBuffers[i].mData, |
mABL.mBuffers[i].mDataByteSize = other.mBuffers[i].mDataByteSize); |
} |
} |
void AppendFrom(CABufferList *blp, UInt32 nBytes) |
{ |
// this may mutate a buffer that owns memory. |
AudioBuffer *mybuf = mABL.mBuffers, *srcbuf = blp->mABL.mBuffers; |
for (UInt32 i = mABL.mNumberBuffers; i--; ++mybuf, ++srcbuf) { |
XAssert(nBytes <= srcbuf->mDataByteSize); |
XAssert(mBufferCapacity == 0 || mybuf->mDataByteSize + nBytes <= mBufferCapacity); |
memcpy((Byte *)mybuf->mData + mybuf->mDataByteSize, srcbuf->mData, nBytes); |
mybuf->mDataByteSize += nBytes; |
} |
blp->BytesConsumed(nBytes); |
} |
void PadWithZeroes(UInt32 desiredBufferSize) |
// for cases where an algorithm (e.g. SRC) requires some |
// padding to create silence following end-of-file |
{ |
XAssert(mBufferCapacity == 0 || desiredBufferSize <= mBufferCapacity); |
if (GetNumBytes() > desiredBufferSize) return; |
AudioBuffer *buf = mABL.mBuffers; |
for (UInt32 i = mABL.mNumberBuffers; i--; ++buf) { |
memset((Byte *)buf->mData + buf->mDataByteSize, 0, desiredBufferSize - buf->mDataByteSize); |
buf->mDataByteSize = desiredBufferSize; |
} |
} |
void SetToZeroes(UInt32 nBytes) |
{ |
XAssert(mBufferCapacity == 0 || nBytes <= mBufferCapacity); |
AudioBuffer *buf = mABL.mBuffers; |
for (UInt32 i = mABL.mNumberBuffers; i--; ++buf) { |
memset((Byte *)buf->mData, 0, nBytes); |
buf->mDataByteSize = nBytes; |
} |
} |
void Reset() |
{ |
DeallocateBuffers(); |
} |
Boolean SameDataAs(const CABufferList* anotherBufferList) |
{ |
// check to see if two buffer lists point to the same memory. |
if (mABL.mNumberBuffers != anotherBufferList->mABL.mNumberBuffers) return false; |
for (UInt32 i = 0; i < mABL.mNumberBuffers; ++i) { |
if (mABL.mBuffers[i].mData != anotherBufferList->mABL.mBuffers[i].mData) return false; |
} |
return true; |
} |
void BytesConsumed(UInt32 nBytes) |
// advance buffer pointers, decrease buffer sizes |
{ |
VerifyNotTrashingOwnedBuffer(); |
AudioBuffer *buf = mABL.mBuffers; |
for (UInt32 i = mABL.mNumberBuffers; i--; ++buf) { |
XAssert(nBytes <= buf->mDataByteSize); |
buf->mData = (Byte *)buf->mData + nBytes; |
buf->mDataByteSize -= nBytes; |
} |
} |
void SetFrom(const AudioBufferList *abl) |
{ |
VerifyNotTrashingOwnedBuffer(); |
memcpy(&_GetBufferList(), abl, (char *)&abl->mBuffers[abl->mNumberBuffers] - (char *)abl); |
} |
void SetFrom(const CABufferList *blp) |
{ |
SetFrom(&blp->GetBufferList()); |
} |
void SetFrom(const AudioBufferList *abl, UInt32 nBytes) |
{ |
VerifyNotTrashingOwnedBuffer(); |
AudioBuffer *mybuf = mABL.mBuffers; |
const AudioBuffer *srcbuf = abl->mBuffers; |
for (UInt32 i = mABL.mNumberBuffers; i--; ++mybuf, ++srcbuf) { |
mybuf->mNumberChannels = srcbuf->mNumberChannels; |
mybuf->mDataByteSize = nBytes; |
mybuf->mData = srcbuf->mData; |
} |
} |
void SetFrom(const CABufferList *blp, UInt32 nBytes) |
{ |
SetFrom(&blp->GetBufferList(), nBytes); |
} |
AudioBufferList * ToAudioBufferList(AudioBufferList *abl) const |
{ |
memcpy(abl, &GetBufferList(), (char *)&abl->mBuffers[mABL.mNumberBuffers] - (char *)abl); |
return abl; |
} |
void AllocateBuffers(UInt32 nBytes); |
void AllocateBuffersAndCopyFrom(UInt32 nBytes, CABufferList *inCopyFromList, CABufferList *inSetPtrList); |
void DeallocateBuffers(); |
void UseExternalBuffer(Byte *ptr, UInt32 nBytes); |
void AdvanceBufferPointers(UInt32 nBytes) // $$$ ReducingSize |
// this is for bufferlists that function simply as |
// an array of pointers into another bufferlist, being advanced, |
// as in RenderOutput implementations |
{ |
VerifyNotTrashingOwnedBuffer(); |
AudioBuffer *buf = mABL.mBuffers; |
for (UInt32 i = mABL.mNumberBuffers; i--; ++buf) { |
buf->mData = (Byte *)buf->mData + nBytes; |
buf->mDataByteSize -= nBytes; |
} |
} |
void SetNumBytes(UInt32 nBytes) |
{ |
XAssert(mBufferCapacity == 0 || nBytes <= mBufferCapacity); |
AudioBuffer *buf = mABL.mBuffers; |
for (UInt32 i = mABL.mNumberBuffers; i--; ++buf) |
buf->mDataByteSize = nBytes; |
} |
void Print(const char *label=NULL, int nframes=0, int wordSize=0) const |
{ |
if (label == NULL) |
label = mName; |
printf("%s - ", label); |
CAShowAudioBufferList(&GetBufferList(), nframes, wordSize); |
if (mBufferMemory) |
printf(" owned memory @ 0x%p:\n", mBufferMemory); |
} |
UInt32 GetCapacityBytes() const { return mBufferCapacity; } |
protected: |
AudioBufferList & _GetBufferList() { return mABL; } // use with care |
// if we make this public, then we lose ability to call VerifyNotTrashingOwnedBuffer |
void VerifyNotTrashingOwnedBuffer() |
{ |
// This needs to be called from places where we are modifying the buffer pointers. |
// It's an error to modify the buffer pointers or lengths if we own the buffer memory. |
XAssert(mBufferMemory == NULL); |
} |
const char * mName; // for debugging |
Byte * mBufferMemory; |
UInt32 mBufferCapacity; // max mDataByteSize of each buffer |
AudioBufferList mABL; |
// don't add anything here |
}; |
#endif // __CABufferList_h__ |
Copyright © 2012 Apple Inc. All Rights Reserved. Terms of Use | Privacy Policy | Updated: 2012-10-16