83 lines
2.6 KiB
C
83 lines
2.6 KiB
C
/*
|
|
* Frontend Status Monitor plugin for the Video Disk Recorder
|
|
*
|
|
* See the README file for copyright information and how to reach the author.
|
|
*
|
|
* AC3 Audio Header: http://www.atsc.org/standards/a_52a.pdf
|
|
*/
|
|
|
|
#include "femontools.h"
|
|
#include "femonac3.h"
|
|
|
|
unsigned int cFemonAC3::s_Bitrates[32] =
|
|
{
|
|
32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384, 448, 512, 576, 640, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
|
|
};
|
|
|
|
unsigned int cFemonAC3::s_Frequencies[4] =
|
|
{
|
|
480, 441, 320, 0
|
|
};
|
|
|
|
unsigned int cFemonAC3::s_Frames[3][32] =
|
|
{
|
|
{64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384, 448, 512, 640, 768, 896, 1024, 1152, 1280, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
|
|
{69, 87, 104, 121, 139, 174, 208, 243, 278, 348, 417, 487, 557, 696, 835, 975, 1114, 1253, 1393, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
|
|
{96, 120, 144, 168, 192, 240, 288, 336, 384, 480, 576, 672, 768, 960, 1152, 1344, 1536, 1728, 1920, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}
|
|
};
|
|
|
|
cFemonAC3::cFemonAC3(cFemonAC3If *audiohandler)
|
|
: m_AudioHandler(audiohandler)
|
|
{
|
|
}
|
|
|
|
cFemonAC3::~cFemonAC3()
|
|
{
|
|
}
|
|
|
|
bool cFemonAC3::processAudio(const uint8_t *buf, int len)
|
|
{
|
|
cBitStream bs(buf, len * 8);
|
|
|
|
if (!m_AudioHandler)
|
|
return false;
|
|
|
|
// skip PES header
|
|
if (!PesLongEnough(len))
|
|
return false;
|
|
bs.skipBits(8 * PesPayloadOffset(buf));
|
|
|
|
// http://rmworkshop.com/dvd_info/related_info/ac3hdr.htm
|
|
|
|
// AC3 audio detection
|
|
if (bs.getU16() != 0x0B77) // syncword
|
|
return false;
|
|
|
|
bs.skipBits(16); // CRC1
|
|
|
|
uint8_t fscod = bs.getBits(2); // sampling rate values
|
|
uint8_t frmsizcod = bs.getBits(6);// frame size code
|
|
|
|
m_AudioHandler->SetAC3Bitrate(1000 * s_Bitrates[frmsizcod >> 1]);
|
|
m_AudioHandler->SetAC3SamplingFrequency(100 * s_Frequencies[fscod]);
|
|
|
|
bs.skipBits(5); // bitstream id
|
|
int bsmod = bs.getBits(3); // bitstream mode
|
|
int acmod = bs.getBits(3); // audio coding mode
|
|
|
|
m_AudioHandler->SetAC3Bitstream(bsmod);
|
|
m_AudioHandler->SetAC3AudioCoding(acmod);
|
|
|
|
// 3 front channels
|
|
m_AudioHandler->SetAC3CenterMix(((acmod & 0x01) && (acmod != 0x01)) ? bs.getBits(2) : AUDIO_CENTER_MIX_LEVEL_INVALID);
|
|
// if a surround channel exists
|
|
m_AudioHandler->SetAC3SurroundMix((acmod & 0x04) ? bs.getBits(2) : AUDIO_SURROUND_MIX_LEVEL_INVALID);
|
|
// if in 2/0 mode
|
|
m_AudioHandler->SetAC3DolbySurround((acmod == 0x02) ? bs.getBits(2) : AUDIO_DOLBY_SURROUND_MODE_INVALID);
|
|
|
|
m_AudioHandler->SetAC3LFE(bs.getBit()); // low frequency effects on
|
|
m_AudioHandler->SetAC3Dialog(bs.getBits(5)); // dialog normalization
|
|
|
|
return true;
|
|
}
|