int ES_AAC::FindHeaders(uint8_t *buf, int buf_size)
{
if (es_found_frame)
return -1;
uint8_t *buf_ptr = buf;
if (stream_type == STREAM_TYPE_AUDIO_AAC)
{
if (buf_ptr[0] == 0xFF && (buf_ptr[1] & 0xF0) == 0xF0)
stream_type = STREAM_TYPE_AUDIO_AAC_ADTS;
else if (buf_ptr[0] == 0x56 && (buf_ptr[1] & 0xE0) == 0xE0)
stream_type = STREAM_TYPE_AUDIO_AAC_LATM;
}
// STREAM_TYPE_AUDIO_AAC_LATM
if (stream_type == STREAM_TYPE_AUDIO_AAC_LATM)
{
if ((buf_ptr[0] == 0x56 && (buf_ptr[1] & 0xE0) == 0xE0))
{
// TODO
if (buf_size < 16)
return -1;
cBitstream bs(buf_ptr, 16 * 8);
bs.skipBits(11);
m_FrameSize = bs.readBits(13) + 3;
if (!ParseLATMAudioMuxElement(&bs))
return 0;
es_found_frame = true;
m_DTS = c_pts;
m_PTS = c_pts;
c_pts += 90000 * 1024 / m_SampleRate;
return -1;
}
}
// STREAM_TYPE_AUDIO_AAC_ADTS
else if (stream_type == STREAM_TYPE_AUDIO_AAC_ADTS)
{
if(buf_ptr[0] == 0xFF && (buf_ptr[1] & 0xF0) == 0xF0)
{
// need at least 7 bytes for header
if (buf_size < 7)
return -1;
cBitstream bs(buf_ptr, 9 * 8);
bs.skipBits(15);
// check if CRC is present, means header is 9 byte long
int noCrc = bs.readBits(1);
if (!noCrc && (buf_size < 9))
return -1;
bs.skipBits(2); // profile
int SampleRateIndex = bs.readBits(4);
bs.skipBits(1); // private
m_Channels = bs.readBits(3);
bs.skipBits(4);
m_FrameSize = bs.readBits(13);
m_SampleRate = aac_sample_rates[SampleRateIndex & 0x0E];
es_found_frame = true;
m_DTS = c_pts;
m_PTS = c_pts;
c_pts += 90000 * 1024 / m_SampleRate;
return -1;
}
}
return 0;
}
int cParserAAC::FindHeaders(uint8_t *buf, int buf_size)
{
if (m_FoundFrame)
return -1;
uint8_t *buf_ptr = buf;
if (m_Stream->Type() == stAACLATM)
{
if ((buf_ptr[0] == 0x56 && (buf_ptr[1] & 0xE0) == 0xE0))
{
// TODO
if (buf_size < 16)
return -1;
cBitstream bs(buf_ptr, 16 * 8);
bs.skipBits(11);
m_FrameSize = bs.readBits(13) + 3;
if (!ParseLATMAudioMuxElement(&bs))
return 0;
m_FoundFrame = true;
m_DTS = m_curPTS;
m_PTS = m_curPTS;
if(!m_SampleRate)
m_SampleRate = aac_sample_rates[4];
m_curPTS += 90000 * 1024 / m_SampleRate;
return -1;
}
else if (m_DetectMuxMode && buf_ptr[0] == 0xFF && (buf_ptr[1] & 0xF0) == 0xF0)
{
m_Stream->SetType(stAACADTS);
INFOLOG("cParserAAC::FindHeaders - detected ADTS muxing mode");
return -1;
}
}
else if (m_Stream->Type() == stAACADTS)
{
if(buf_ptr[0] == 0xFF && (buf_ptr[1] & 0xF0) == 0xF0)
{
// need at least 7 bytes for header
if (buf_size < 7)
return -1;
cBitstream bs(buf_ptr, 9 * 8);
bs.skipBits(15);
// check if CRC is present, means header is 9 byte long
int noCrc = bs.readBits(1);
if (!noCrc && (buf_size < 9))
return -1;
bs.skipBits(2); // profile
int SampleRateIndex = bs.readBits(4);
bs.skipBits(1); // private
m_Channels = bs.readBits(3);
bs.skipBits(4);
m_FrameSize = bs.readBits(13);
m_SampleRate = aac_sample_rates[SampleRateIndex & 0x0E];
m_FoundFrame = true;
m_DTS = m_curPTS;
m_PTS = m_curPTS;
m_curPTS += 90000 * 1024 / m_SampleRate;
return -1;
}
else if (m_DetectMuxMode && buf_ptr[0] == 0x56 && (buf_ptr[1] & 0xE0) == 0xE0)
{
m_Stream->SetType(stAACLATM);
INFOLOG("cParserAAC::FindHeaders - detected LATM muxing mode");
return -1;
}
}
return 0;
}