AC3FrameParams Class Reference


Public Member Functions
	AC3FrameParams ()
void	setParamsFromHeader ()
Data Fields
unsigned	hdr0
unsigned	hdr1
unsigned	kbps
unsigned	samplingFreq
unsigned	frameSize

Detailed Description

Definition at line 27 of file AC3AudioStreamFramer.cpp.

Constructor & Destructor Documentation

AC3FrameParams::AC3FrameParams ( ) [inline]

Definition at line 29 of file AC3AudioStreamFramer.cpp.

00029 : samplingFreq(0) {}

Member Function Documentation

void AC3FrameParams::setParamsFromHeader ( )

Definition at line 199 of file AC3AudioStreamFramer.cpp.

References frameSize, hdr1, kbps, kbpsTable, and samplingFreq.

Referenced by AC3AudioStreamParser::parseFrame().

00199                                          {
00200   unsigned char byte4 = hdr1 >> 24;
00201 
00202   unsigned char kbpsIndex = (byte4&0x3E) >> 1;
00203   if (kbpsIndex > 18) kbpsIndex = 18;
00204   kbps = kbpsTable[kbpsIndex];
00205 
00206   unsigned char samplingFreqIndex = (byte4&0xC0) >> 6;
00207   switch (samplingFreqIndex) {
00208   case 0:
00209     samplingFreq = 48000;
00210     frameSize = 4*kbps;
00211     break;
00212   case 1:
00213     samplingFreq = 44100;
00214     frameSize = 2*(320*kbps/147 + (byte4&1));
00215     break;
00216   case 2:
00217   case 3: // not legal?
00218     samplingFreq = 32000;
00219     frameSize = 6*kbps;
00220   }
00221 }