static void ASBD_NtoB(const AudioStreamBasicDescription *infmt, AudioStreamBasicDescription *outfmt)
{
*(UInt64 *)&outfmt->mSampleRate = EndianU64_NtoB(*(UInt64 *)&infmt->mSampleRate);
outfmt->mFormatID = EndianU32_NtoB(infmt->mFormatID);
outfmt->mFormatFlags = EndianU32_NtoB(infmt->mFormatFlags);
outfmt->mBytesPerPacket = EndianU32_NtoB(infmt->mBytesPerPacket);
outfmt->mFramesPerPacket = EndianU32_NtoB(infmt->mFramesPerPacket);
outfmt->mBytesPerFrame = EndianU32_NtoB(infmt->mBytesPerFrame);
outfmt->mChannelsPerFrame = EndianU32_NtoB(infmt->mChannelsPerFrame);
outfmt->mBitsPerChannel = EndianU32_NtoB(infmt->mBitsPerChannel);
}
//FLAC__StreamMetadata_StreamInfo
void ACFLACCodec::GetMagicCookie(void* outMagicCookieData, UInt32& ioMagicCookieDataByteSize) const
{
Byte * buffer;
Byte * currPtr;
AudioFormatAtom * frmaAtom;
FullAtomHeader * flacAtom;
AudioTerminatorAtom * termAtom;
SInt32 atomSize;
UInt32 flacSize;
UInt32 chanSize;
UInt32 frmaSize;
UInt32 termSize;
FLAC__StreamMetadata_StreamInfo * config;
OSStatus status;
UInt32 tempMaxFrameBytes;
//RequireAction( sampleDesc != nil, return paramErr; );
config = nil;
frmaSize = sizeof(AudioFormatAtom);
flacSize = sizeof(FullAtomHeader) + sizeof(FLAC__StreamMetadata_StreamInfo);
chanSize = 0;
termSize = sizeof(AudioTerminatorAtom);
// if we're encoding more than two channels, add an AudioChannelLayout atom to describe the layout
if ( mOutputFormat.mChannelsPerFrame > 2 )
{
chanSize = sizeof(FullAtomHeader) + offsetof(AudioChannelLayout, mChannelDescriptions);
}
// create buffer of the required size
atomSize = frmaSize + flacSize + chanSize + termSize;
// Someone might have a stereo/mono cookie while we're trying to do surround.
if ((UInt32)atomSize > ioMagicCookieDataByteSize)
{
CODEC_THROW(kAudioCodecBadPropertySizeError);
}
tempMaxFrameBytes = kInputBufferPackets * mOutputFormat.mChannelsPerFrame * ((10 + kMaxSampleSize) / 8) + 1;
buffer = (Byte *)calloc( atomSize, 1 );
currPtr = buffer;
// fill in the atom stuff
frmaAtom = (AudioFormatAtom *) currPtr;
frmaAtom->size = EndianU32_NtoB( frmaSize );
frmaAtom->atomType = EndianU32_NtoB( kAudioFormatAtomType );
frmaAtom->format = EndianU32_NtoB( 'flac' );
currPtr += frmaSize;
// fill in the FLAC config
flacAtom = (FullAtomHeader *) currPtr;
flacAtom->size = EndianU32_NtoB( flacSize );
flacAtom->type = EndianU32_NtoB( 'flac' );
flacAtom->versionFlags = 0;
currPtr += sizeof(FullAtomHeader);
/*
unsigned min_blocksize, max_blocksize;
unsigned min_framesize, max_framesize;
unsigned sample_rate;
unsigned channels;
unsigned bits_per_sample;
FLAC__uint64 total_samples;
FLAC__byte md5sum[16];
*/
config = (FLAC__StreamMetadata_StreamInfo *) currPtr;
if (mCookieDefined)
{
config->min_blocksize = EndianU32_NtoB( mStreamInfo.min_blocksize );
config->max_blocksize = EndianU32_NtoB( mStreamInfo.max_blocksize );
config->min_framesize = EndianU32_NtoB( mStreamInfo.min_framesize );
config->max_framesize = EndianU32_NtoB( mStreamInfo.max_framesize );
config->sample_rate = EndianU32_NtoB( mStreamInfo.sample_rate );
config->channels = EndianU32_NtoB( mStreamInfo.channels );
config->bits_per_sample = EndianU32_NtoB( mStreamInfo.bits_per_sample );
config->total_samples = EndianU64_NtoB( mStreamInfo.total_samples );
config->md5sum[0] = mStreamInfo.md5sum[0];
config->md5sum[1] = mStreamInfo.md5sum[1];
config->md5sum[2] = mStreamInfo.md5sum[2];
config->md5sum[3] = mStreamInfo.md5sum[3];
config->md5sum[4] = mStreamInfo.md5sum[4];
config->md5sum[5] = mStreamInfo.md5sum[5];
config->md5sum[6] = mStreamInfo.md5sum[6];
config->md5sum[7] = mStreamInfo.md5sum[7];
config->md5sum[8] = mStreamInfo.md5sum[8];
config->md5sum[9] = mStreamInfo.md5sum[9];
config->md5sum[10] = mStreamInfo.md5sum[10];
config->md5sum[11] = mStreamInfo.md5sum[11];
config->md5sum[12] = mStreamInfo.md5sum[12];
config->md5sum[13] = mStreamInfo.md5sum[13];
config->md5sum[14] = mStreamInfo.md5sum[14];
config->md5sum[15] = mStreamInfo.md5sum[15];
}
else
{
config->min_blocksize = EndianU32_NtoB( kFLACDefaultFrameSize );
config->max_blocksize = EndianU32_NtoB( kFLACDefaultFrameSize );
config->min_framesize = EndianU32_NtoB( 0 );
config->max_framesize = EndianU32_NtoB( 0 );
config->sample_rate = EndianU32_NtoB( (UInt32)(mOutputFormat.mSampleRate) );
config->channels = EndianU32_NtoB(mOutputFormat.mChannelsPerFrame);
config->bits_per_sample = EndianU32_NtoB(mBitDepth);
config->total_samples = 0;
config->md5sum[0] = 0;
config->md5sum[1] = 0;
config->md5sum[2] = 0;
config->md5sum[3] = 0;
config->md5sum[4] = 0;
config->md5sum[5] = 0;
config->md5sum[6] = 0;
config->md5sum[7] = 0;
config->md5sum[8] = 0;
config->md5sum[9] = 0;
config->md5sum[10] = 0;
config->md5sum[11] = 0;
config->md5sum[12] = 0;
config->md5sum[13] = 0;
config->md5sum[14] = 0;
config->md5sum[15] = 0;
}
currPtr += sizeof(FLAC__StreamMetadata_StreamInfo);
// if we're encoding more than two channels, add an AudioChannelLayout atom to describe the layout
// Unfortunately there is no way to avoid dealing with an atom here
if ( mOutputFormat.mChannelsPerFrame > 2 )
{
AudioChannelLayoutTag tag;
FullAtomHeader * chan;
AudioChannelLayout * layout;
chan = (FullAtomHeader *) currPtr;
chan->size = EndianU32_NtoB( chanSize );
chan->type = EndianU32_NtoB( AudioChannelLayoutAID );
// version flags == 0
currPtr += sizeof(FullAtomHeader);
// we use a predefined set of layout tags so we don't need to write any channel descriptions
layout = (AudioChannelLayout *) currPtr;
tag = sChannelLayoutTags[mOutputFormat.mChannelsPerFrame - 1];
layout->mChannelLayoutTag = EndianU32_NtoB( tag );
layout->mChannelBitmap = 0;
layout->mNumberChannelDescriptions = 0;
currPtr += offsetof(AudioChannelLayout, mChannelDescriptions);
}
// fill in Terminator atom header
termAtom = (AudioTerminatorAtom *) currPtr;
termAtom->size = EndianU32_NtoB( termSize );
termAtom->atomType = EndianU32_NtoB( kAudioTerminatorAtomType );
// all good, return the new description
memcpy (outMagicCookieData, (const void *)(buffer), atomSize);
ioMagicCookieDataByteSize = atomSize;
status = noErr;
// delete any memory we allocated
if ( buffer != NULL )
{
delete buffer;
buffer = NULL;
}
}
