winamp/Src/Plugins/Input/in_flv/FLVAudioHeader.cpp

34 lines
874 B
C++

#include "FLVAudioHeader.h"
/*
(c) 2006 Nullsoft, Inc.
Author: Ben Allison benski@nullsoft.com
*/
/*
soundType 1 bit (byte & 0x01) >> 0 0: mono, 1: stereo
soundSize 1 bit (byte & 0x02)>> 1 0: 8-bit, 2: 16-bit
soundRate 2 bits (byte & 0x0C) >> 2 0: 5.5 kHz, 1: 11 kHz, 2: 22 kHz, 3: 44 kHz
soundFormat 4 bits (byte & 0xf0) >> 4 0: Uncompressed, 1: ADPCM, 2: MP3, 5: Nellymoser 8kHz mono, 6: Nellymoser
*/
bool FLVAudioHeader::Read(unsigned __int8 *data, size_t size)
{
if (size < 1)
return false; // header size too small
unsigned __int8 byte = data[0];
stereo = !!((byte & 0x01) >> 0);
bits = ((byte & 0x02) >> 1) ? 16 : 8;
switch ((byte & 0x0C) >> 2)
{
case 0: sampleRate = 5512; break;
case 1: sampleRate = 11025; break;
case 2: sampleRate = 22050; break;
case 3: sampleRate = 44100; break;
}
format = (byte & 0xf0) >> 4;
return true;
}