Retired Document
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PublicUtility/CAStreamBasicDescription.h
/* |
File: CAStreamBasicDescription.h |
Abstract: Part of CoreAudio Utility Classes |
Version: 1.1 |
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*/ |
#ifndef __CAStreamBasicDescription_h__ |
#define __CAStreamBasicDescription_h__ |
#if !defined(__COREAUDIO_USE_FLAT_INCLUDES__) |
#include <CoreAudio/CoreAudioTypes.h> |
#include <CoreFoundation/CoreFoundation.h> |
#else |
#include "CoreAudioTypes.h" |
#include "CoreFoundation.h" |
#endif |
#include "CADebugMacros.h" |
#include <string.h> // for memset, memcpy |
#include <stdio.h> // for FILE * |
#pragma mark This file needs to compile on more earlier versions of the OS, so please keep that in mind when editing it |
extern char *CAStringForOSType (OSType t, char *writeLocation); |
// define Leopard specific symbols for backward compatibility if applicable |
#if COREAUDIOTYPES_VERSION < 1050 |
typedef Float32 AudioSampleType; |
enum { kAudioFormatFlagsCanonical = kAudioFormatFlagIsFloat | kAudioFormatFlagsNativeEndian | kAudioFormatFlagIsPacked }; |
#endif |
#if COREAUDIOTYPES_VERSION < 1051 |
typedef Float32 AudioUnitSampleType; |
enum { |
kLinearPCMFormatFlagsSampleFractionShift = 7, |
kLinearPCMFormatFlagsSampleFractionMask = (0x3F << kLinearPCMFormatFlagsSampleFractionShift), |
}; |
#endif |
// define the IsMixable format flag for all versions of the system |
#if (MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_3) |
enum { kIsNonMixableFlag = kAudioFormatFlagIsNonMixable }; |
#else |
enum { kIsNonMixableFlag = (1L << 6) }; |
#endif |
//============================================================================= |
// CAStreamBasicDescription |
// |
// This is a wrapper class for the AudioStreamBasicDescription struct. |
// It adds a number of convenience routines, but otherwise adds nothing |
// to the footprint of the original struct. |
//============================================================================= |
class CAStreamBasicDescription : |
public AudioStreamBasicDescription |
{ |
// Constants |
public: |
static const AudioStreamBasicDescription sEmpty; |
enum CommonPCMFormat { |
kPCMFormatOther = 0, |
kPCMFormatFloat32 = 1, |
kPCMFormatInt16 = 2, |
kPCMFormatFixed824 = 3 |
}; |
// Construction/Destruction |
public: |
CAStreamBasicDescription(); |
CAStreamBasicDescription(const AudioStreamBasicDescription &desc); |
CAStreamBasicDescription( double inSampleRate, UInt32 inFormatID, |
UInt32 inBytesPerPacket, UInt32 inFramesPerPacket, |
UInt32 inBytesPerFrame, UInt32 inChannelsPerFrame, |
UInt32 inBitsPerChannel, UInt32 inFormatFlags); |
CAStreamBasicDescription( double inSampleRate, UInt32 inNumChannels, CommonPCMFormat pcmf, bool inIsInterleaved) { |
unsigned wordsize; |
mSampleRate = inSampleRate; |
mFormatID = kAudioFormatLinearPCM; |
mFormatFlags = kAudioFormatFlagsNativeEndian | kAudioFormatFlagIsPacked; |
mFramesPerPacket = 1; |
mChannelsPerFrame = inNumChannels; |
mBytesPerFrame = mBytesPerPacket = 0; |
mReserved = 0; |
switch (pcmf) { |
default: |
return; |
case kPCMFormatFloat32: |
wordsize = 4; |
mFormatFlags |= kAudioFormatFlagIsFloat; |
break; |
case kPCMFormatInt16: |
wordsize = 2; |
mFormatFlags |= kAudioFormatFlagIsSignedInteger; |
break; |
case kPCMFormatFixed824: |
wordsize = 4; |
mFormatFlags |= kAudioFormatFlagIsSignedInteger | (24 << kLinearPCMFormatFlagsSampleFractionShift); |
break; |
} |
mBitsPerChannel = wordsize * 8; |
if (inIsInterleaved) |
mBytesPerFrame = mBytesPerPacket = wordsize * inNumChannels; |
else { |
mFormatFlags |= kAudioFormatFlagIsNonInterleaved; |
mBytesPerFrame = mBytesPerPacket = wordsize; |
} |
} |
// Assignment |
CAStreamBasicDescription& operator=(const AudioStreamBasicDescription& v) { SetFrom(v); return *this; } |
void SetFrom(const AudioStreamBasicDescription &desc) |
{ |
memcpy(this, &desc, sizeof(AudioStreamBasicDescription)); |
} |
bool FromText(const char *inTextDesc) { return FromText(inTextDesc, *this); } |
static bool FromText(const char *inTextDesc, AudioStreamBasicDescription &outDesc); |
// return true if parsing was successful |
static const char *sTextParsingUsageString; |
// _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ |
// |
// interrogation |
bool IsPCM() const { return mFormatID == kAudioFormatLinearPCM; } |
bool PackednessIsSignificant() const |
{ |
Assert(IsPCM(), "PackednessIsSignificant only applies for PCM"); |
return (SampleWordSize() << 3) != mBitsPerChannel; |
} |
bool AlignmentIsSignificant() const |
{ |
return PackednessIsSignificant() || (mBitsPerChannel & 7) != 0; |
} |
bool IsInterleaved() const |
{ |
return !IsPCM() || !(mFormatFlags & kAudioFormatFlagIsNonInterleaved); |
} |
bool IsSignedInteger() const |
{ |
return IsPCM() && (mFormatFlags & kAudioFormatFlagIsSignedInteger); |
} |
bool IsFloat() const |
{ |
return IsPCM() && (mFormatFlags & kAudioFormatFlagIsFloat); |
} |
bool IsNativeEndian() const |
{ |
return (mFormatFlags & kAudioFormatFlagIsBigEndian) == kAudioFormatFlagsNativeEndian; |
} |
// for sanity with interleaved/deinterleaved possibilities, never access mChannelsPerFrame, use these: |
UInt32 NumberInterleavedChannels() const { return IsInterleaved() ? mChannelsPerFrame : 1; } |
UInt32 NumberChannelStreams() const { return IsInterleaved() ? 1 : mChannelsPerFrame; } |
UInt32 NumberChannels() const { return mChannelsPerFrame; } |
UInt32 SampleWordSize() const { |
return (mBytesPerFrame > 0 && NumberInterleavedChannels()) ? mBytesPerFrame / NumberInterleavedChannels() : 0; |
} |
UInt32 FramesToBytes(UInt32 nframes) const { return nframes * mBytesPerFrame; } |
UInt32 BytesToFrames(UInt32 nbytes) const { |
Assert(mBytesPerFrame > 0, "bytesPerFrame must be > 0 in BytesToFrames"); |
return nbytes / mBytesPerFrame; |
} |
bool SameChannelsAndInterleaving(const CAStreamBasicDescription &a) const |
{ |
return this->NumberChannels() == a.NumberChannels() && this->IsInterleaved() == a.IsInterleaved(); |
} |
bool IdentifyCommonPCMFormat(CommonPCMFormat &outFormat, bool *outIsInterleaved=NULL) const |
{ // return true if it's a valid PCM format. |
outFormat = kPCMFormatOther; |
// trap out patently invalid formats. |
if (mFormatID != kAudioFormatLinearPCM || mFramesPerPacket != 1 || mBytesPerFrame != mBytesPerPacket || mBitsPerChannel/8 > mBytesPerFrame || mChannelsPerFrame == 0) |
return false; |
bool interleaved = (mFormatFlags & kAudioFormatFlagIsNonInterleaved) == 0; |
if (outIsInterleaved != NULL) *outIsInterleaved = interleaved; |
unsigned wordsize = mBytesPerFrame; |
if (interleaved) { |
if (wordsize % mChannelsPerFrame != 0) return false; |
wordsize /= mChannelsPerFrame; |
} |
if ((mFormatFlags & kAudioFormatFlagIsBigEndian) == kAudioFormatFlagsNativeEndian |
&& wordsize * 8 == mBitsPerChannel) { |
// packed and native endian, good |
if (mFormatFlags & kLinearPCMFormatFlagIsFloat) { |
// float: reject nonsense bits |
if (mFormatFlags & (kLinearPCMFormatFlagIsSignedInteger | kLinearPCMFormatFlagsSampleFractionMask)) |
return false; |
if (wordsize == 4) |
outFormat = kPCMFormatFloat32; |
} else if (mFormatFlags & kLinearPCMFormatFlagIsSignedInteger) { |
// signed int |
unsigned fracbits = (mFormatFlags & kLinearPCMFormatFlagsSampleFractionMask) >> kLinearPCMFormatFlagsSampleFractionShift; |
if (wordsize == 4 && fracbits == 24) |
outFormat = kPCMFormatFixed824; |
else if (wordsize == 2 && fracbits == 0) |
outFormat = kPCMFormatInt16; |
} |
} |
return true; |
} |
bool IsCommonFloat32(bool *outIsInterleaved=NULL) const { |
CommonPCMFormat fmt; |
return IdentifyCommonPCMFormat(fmt, outIsInterleaved) && fmt == kPCMFormatFloat32; |
} |
bool IsCommonFixed824(bool *outIsInterleaved=NULL) const { |
CommonPCMFormat fmt; |
return IdentifyCommonPCMFormat(fmt, outIsInterleaved) && fmt == kPCMFormatFixed824; |
} |
bool IsCommonInt16(bool *outIsInterleaved=NULL) const { |
CommonPCMFormat fmt; |
return IdentifyCommonPCMFormat(fmt, outIsInterleaved) && fmt == kPCMFormatInt16; |
} |
// _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ |
// |
// manipulation |
void SetCanonical(UInt32 nChannels, bool interleaved) |
// note: leaves sample rate untouched |
{ |
mFormatID = kAudioFormatLinearPCM; |
int sampleSize = SizeOf32(AudioSampleType); |
mFormatFlags = kAudioFormatFlagsCanonical; |
mBitsPerChannel = 8 * sampleSize; |
mChannelsPerFrame = nChannels; |
mFramesPerPacket = 1; |
if (interleaved) |
mBytesPerPacket = mBytesPerFrame = nChannels * sampleSize; |
else { |
mBytesPerPacket = mBytesPerFrame = sampleSize; |
mFormatFlags |= kAudioFormatFlagIsNonInterleaved; |
} |
} |
bool IsCanonical() const |
{ |
if (mFormatID != kAudioFormatLinearPCM) return false; |
UInt32 reqFormatFlags; |
UInt32 flagsMask = (kLinearPCMFormatFlagIsFloat | kLinearPCMFormatFlagIsBigEndian | kLinearPCMFormatFlagIsSignedInteger | kLinearPCMFormatFlagIsPacked | kLinearPCMFormatFlagsSampleFractionMask); |
bool interleaved = (mFormatFlags & kAudioFormatFlagIsNonInterleaved) == 0; |
unsigned sampleSize = SizeOf32(AudioSampleType); |
reqFormatFlags = kAudioFormatFlagsCanonical; |
UInt32 reqFrameSize = interleaved ? (mChannelsPerFrame * sampleSize) : sampleSize; |
return ((mFormatFlags & flagsMask) == reqFormatFlags |
&& mBitsPerChannel == 8 * sampleSize |
&& mFramesPerPacket == 1 |
&& mBytesPerFrame == reqFrameSize |
&& mBytesPerPacket == reqFrameSize); |
} |
void SetAUCanonical(UInt32 nChannels, bool interleaved) |
{ |
mFormatID = kAudioFormatLinearPCM; |
#if CA_PREFER_FIXED_POINT |
mFormatFlags = kAudioFormatFlagsCanonical | (kAudioUnitSampleFractionBits << kLinearPCMFormatFlagsSampleFractionShift); |
#else |
mFormatFlags = kAudioFormatFlagsCanonical; |
#endif |
mChannelsPerFrame = nChannels; |
mFramesPerPacket = 1; |
mBitsPerChannel = 8 * SizeOf32(AudioUnitSampleType); |
if (interleaved) |
mBytesPerPacket = mBytesPerFrame = nChannels * SizeOf32(AudioUnitSampleType); |
else { |
mBytesPerPacket = mBytesPerFrame = SizeOf32(AudioUnitSampleType); |
mFormatFlags |= kAudioFormatFlagIsNonInterleaved; |
} |
} |
void ChangeNumberChannels(UInt32 nChannels, bool interleaved) |
// alter an existing format |
{ |
Assert(IsPCM(), "ChangeNumberChannels only works for PCM formats"); |
UInt32 wordSize = SampleWordSize(); // get this before changing ANYTHING |
if (wordSize == 0) |
wordSize = (mBitsPerChannel + 7) / 8; |
mChannelsPerFrame = nChannels; |
mFramesPerPacket = 1; |
if (interleaved) { |
mBytesPerPacket = mBytesPerFrame = nChannels * wordSize; |
mFormatFlags &= ~kAudioFormatFlagIsNonInterleaved; |
} else { |
mBytesPerPacket = mBytesPerFrame = wordSize; |
mFormatFlags |= kAudioFormatFlagIsNonInterleaved; |
} |
} |
// _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ |
// |
// other |
bool IsEqual(const AudioStreamBasicDescription &other, bool interpretingWildcards=true) const; |
void Print() const { |
Print (stdout); |
} |
void Print(FILE* file) const { |
PrintFormat (file, "", "AudioStreamBasicDescription:"); |
} |
void PrintFormat(FILE *f, const char *indent, const char *name) const { |
char buf[256]; |
fprintf(f, "%s%s %s\n", indent, name, AsString(buf, sizeof(buf))); |
} |
void PrintFormat2(FILE *f, const char *indent, const char *name) const { // no trailing newline |
char buf[256]; |
fprintf(f, "%s%s %s", indent, name, AsString(buf, sizeof(buf))); |
} |
char * AsString(char *buf, size_t bufsize) const; |
static void Print (const AudioStreamBasicDescription &inDesc) |
{ |
CAStreamBasicDescription desc(inDesc); |
desc.Print (); |
} |
OSStatus Save(CFPropertyListRef *outData) const; |
OSStatus Restore(CFPropertyListRef &inData); |
// Operations |
static bool IsMixable(const AudioStreamBasicDescription& inDescription) { return (inDescription.mFormatID == kAudioFormatLinearPCM) && ((inDescription.mFormatFlags & kIsNonMixableFlag) == 0); } |
static void NormalizeLinearPCMFormat(AudioStreamBasicDescription& ioDescription); |
static void NormalizeLinearPCMFormat(bool inNativeEndian, AudioStreamBasicDescription& ioDescription); |
static void ResetFormat(AudioStreamBasicDescription& ioDescription); |
static void FillOutFormat(AudioStreamBasicDescription& ioDescription, const AudioStreamBasicDescription& inTemplateDescription); |
static void GetSimpleName(const AudioStreamBasicDescription& inDescription, char* outName, UInt32 inMaxNameLength, bool inAbbreviate, bool inIncludeSampleRate = false); |
#if CoreAudio_Debug |
static void PrintToLog(const AudioStreamBasicDescription& inDesc); |
#endif |
}; |
bool operator<(const AudioStreamBasicDescription& x, const AudioStreamBasicDescription& y); |
bool operator==(const AudioStreamBasicDescription& x, const AudioStreamBasicDescription& y); |
#if TARGET_OS_MAC || (TARGET_OS_WIN32 && (_MSC_VER > 600)) |
inline bool operator!=(const AudioStreamBasicDescription& x, const AudioStreamBasicDescription& y) { return !(x == y); } |
inline bool operator<=(const AudioStreamBasicDescription& x, const AudioStreamBasicDescription& y) { return (x < y) || (x == y); } |
inline bool operator>=(const AudioStreamBasicDescription& x, const AudioStreamBasicDescription& y) { return !(x < y); } |
inline bool operator>(const AudioStreamBasicDescription& x, const AudioStreamBasicDescription& y) { return !((x < y) || (x == y)); } |
#endif |
bool SanityCheck(const AudioStreamBasicDescription& x); |
#endif // __CAStreamBasicDescription_h__ |
Copyright © 2012 Apple Inc. All Rights Reserved. Terms of Use | Privacy Policy | Updated: 2012-10-16