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/*
* $Id$
*
* (C) 2006-2010 see AUTHORS
*
* This file is part of mplayerc.
*
* Mplayerc 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 3 of the License, or
* (at your option) any later version.
*
* Mplayerc 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 this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
#include "stdafx.h"
#include "H264Nalu.h"
void CH264Nalu::SetBuffer(BYTE* pBuffer, int nSize, int nNALSize)
{
m_pBuffer = pBuffer;
m_nSize = nSize;
m_nNALSize = nNALSize;
m_nCurPos = 0;
m_nNextRTP = 0;
m_nNALStartPos = 0;
m_nNALDataPos = 0;
}
bool CH264Nalu::MoveToNextStartcode()
{
int nBuffEnd = (m_nNextRTP > 0) ? min (m_nNextRTP, m_nSize-4) : m_nSize-4;
for (int i=m_nCurPos; i<nBuffEnd; i++)
{
if ((*((DWORD*)(m_pBuffer+i)) & 0x00FFFFFF) == 0x00010000)
{
// Find next AnnexB Nal
m_nCurPos = i;
return true;
}
}
if ((m_nNALSize != 0) && (m_nNextRTP < m_nSize))
{
m_nCurPos = m_nNextRTP;
return true;
}
m_nCurPos = m_nSize;
return false;
}
bool CH264Nalu::ReadNext()
{
if (m_nCurPos >= m_nSize) return false;
if ((m_nNALSize != 0) && (m_nCurPos == m_nNextRTP))
{
// RTP Nalu type : (XX XX) XX XX NAL..., with XX XX XX XX or XX XX equal to NAL size
m_nNALStartPos = m_nCurPos;
m_nNALDataPos = m_nCurPos + m_nNALSize;
int nTemp = 0;
for (int i=0; i<m_nNALSize; i++)
{
nTemp = (nTemp << 8) + m_pBuffer[m_nCurPos++];
}
m_nNextRTP += nTemp + m_nNALSize;
MoveToNextStartcode();
}
else
{
// Remove trailing bits
while (m_pBuffer[m_nCurPos]==0x00 && ((*((DWORD*)(m_pBuffer+m_nCurPos)) & 0x00FFFFFF) != 0x00010000))
m_nCurPos++;
// AnnexB Nalu : 00 00 01 NAL...
m_nNALStartPos = m_nCurPos;
m_nCurPos += 3;
m_nNALDataPos = m_nCurPos;
MoveToNextStartcode();
}
forbidden_bit = (m_pBuffer[m_nNALDataPos]>>7) & 1;
nal_reference_idc = (m_pBuffer[m_nNALDataPos]>>5) & 3;
nal_unit_type = (NALU_TYPE) (m_pBuffer[m_nNALDataPos] & 0x1f);
return true;
}
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