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|
/*****************************************************************
|
| AP4 - dac3 Atoms
|
| Copyright 2002-2019 Axiomatic Systems, LLC
|
|
| This file is part of Bento4/AP4 (MP4 Atom Processing Library).
|
| Unless you have obtained Bento4 under a difference license,
| this version of Bento4 is Bento4|GPL.
| Bento4|GPL is free software; you can redistribute it and/or modify
| it under the terms of the GNU General Public License as published by
| the Free Software Foundation; either version 2, or (at your option)
| any later version.
|
| Bento4|GPL is distributed in the hope that it will be useful,
| but WITHOUT ANY WARRANTY; without even the implied warranty of
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
| GNU General Public License for more details.
|
| You should have received a copy of the GNU General Public License
| along with Bento4|GPL; see the file COPYING. If not, write to the
| Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA
| 02111-1307, USA.
|
****************************************************************/
/*----------------------------------------------------------------------
| includes
+---------------------------------------------------------------------*/
#include "Ap4Dac3Atom.h"
#include "Ap4AtomFactory.h"
#include "Ap4Utils.h"
#include "Ap4Types.h"
/*----------------------------------------------------------------------
| dynamic cast support
+---------------------------------------------------------------------*/
AP4_DEFINE_DYNAMIC_CAST_ANCHOR(AP4_Dac3Atom)
/*----------------------------------------------------------------------
| AP4_Dac3Atom::Create
+---------------------------------------------------------------------*/
AP4_Dac3Atom*
AP4_Dac3Atom::Create(AP4_Size size, AP4_ByteStream& stream)
{
// read the raw bytes in a buffer
unsigned int payload_size = size-AP4_ATOM_HEADER_SIZE;
AP4_DataBuffer payload_data(payload_size);
AP4_Result result = stream.Read(payload_data.UseData(), payload_size);
if (AP4_FAILED(result)) return NULL;
// check the version
const AP4_UI08* payload = payload_data.GetData();
return new AP4_Dac3Atom(size, payload);
}
/*----------------------------------------------------------------------
| AP4_Dac3Atom::AP4_Dac3Atom
+---------------------------------------------------------------------*/
AP4_Dac3Atom::AP4_Dac3Atom(const AP4_Dac3Atom& other):
AP4_Atom(AP4_ATOM_TYPE_DAC3, other.m_Size32),
m_DataRate(other.m_DataRate),
m_StreamInfo(other.m_StreamInfo),
m_RawBytes(other.m_RawBytes)
{
}
/*----------------------------------------------------------------------
| AP4_Dac3Atom::AP4_Dac3Atom
+---------------------------------------------------------------------*/
AP4_Dac3Atom::AP4_Dac3Atom(const StreamInfo* m_StreamInfo):
AP4_Atom(AP4_ATOM_TYPE_DAC3, AP4_ATOM_HEADER_SIZE){
AP4_BitWriter bits(3);
bits.Write(m_StreamInfo->fscod, 2);
bits.Write(m_StreamInfo->bsid, 5);
bits.Write(m_StreamInfo->bsmod, 3);
bits.Write(m_StreamInfo->acmod, 3);
bits.Write(m_StreamInfo->lfeon, 1);
bits.Write(m_StreamInfo->bit_rate_code, 5);
bits.Write(0, 5); // reserved
m_RawBytes.SetData(bits.GetData(), bits.GetBitCount() / 8);
m_Size32 += m_RawBytes.GetDataSize();
}
/*----------------------------------------------------------------------
| AP4_Dac3Atom::AP4_Dac3Atom
+---------------------------------------------------------------------*/
AP4_Dac3Atom::AP4_Dac3Atom(AP4_UI32 size, const AP4_UI08* payload) :
AP4_Atom(AP4_ATOM_TYPE_DAC3, size),
m_DataRate(0)
{
// make a copy of our configuration bytes
unsigned int payload_size = size-AP4_ATOM_HEADER_SIZE;
m_RawBytes.SetData(payload, payload_size);
// sanity check
if (payload_size < 3) {
memset(&m_StreamInfo, 0, sizeof(m_StreamInfo));
return;
}
// parse the payload
m_DataRate = (payload[0]<<5)|(payload[1]>>3);
m_StreamInfo.fscod = (payload[0]>>6) & 0x03;
m_StreamInfo.bsid = (payload[0]>>1) & 0x1F;
m_StreamInfo.bsmod = ((payload[0]<<2) | (payload[1]>>6)) & 0x07;
m_StreamInfo.acmod = (payload[1]>>3) & 0x07;
m_StreamInfo.lfeon = (payload[1]>>2) & 0x01;
m_StreamInfo.bit_rate_code = ((payload[1]<<3) | (payload[2]>>5)) & 0x1F;
const unsigned int bit_rate_table[19] = {
32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384, 448, 512, 576, 640
};
if (m_StreamInfo.bit_rate_code < sizeof(bit_rate_table)/sizeof(bit_rate_table[0])) {
m_DataRate = bit_rate_table[m_StreamInfo.bit_rate_code];
}
}
/*----------------------------------------------------------------------
| AP4_Dac3Atom::WriteFields
+---------------------------------------------------------------------*/
AP4_Result
AP4_Dac3Atom::WriteFields(AP4_ByteStream& stream)
{
return stream.Write(m_RawBytes.GetData(), m_RawBytes.GetDataSize());
}
/*----------------------------------------------------------------------
| AP4_Dac3Atom::InspectFields
+---------------------------------------------------------------------*/
AP4_Result
AP4_Dac3Atom::InspectFields(AP4_AtomInspector& inspector)
{
inspector.AddField("data_rate", m_DataRate);
inspector.AddField("fscod", m_StreamInfo.fscod);
inspector.AddField("bsid", m_StreamInfo.bsid);
inspector.AddField("bsmod", m_StreamInfo.bsmod);
inspector.AddField("acmod", m_StreamInfo.acmod);
inspector.AddField("lfeon", m_StreamInfo.lfeon);
return AP4_SUCCESS;
}
AP4_UI08 AP4_Dac3Atom::GetChannels() const
{
static const AP4_UI08 CC[] = { 2, 1, 2, 3, 3, 4, 4, 5 };
return CC[m_StreamInfo.acmod] + m_StreamInfo.lfeon;
}
|
