topic Re: Decoding AAC raw frames ... in Intel® Integrated Performance Primitives

Decoding AAC raw frames ...

Maciej_K_ — Fri, 07 Sep 2007 16:19:24 GMT

Hello,

My device delivers raw AAC frames. They are not packed into ATDS or MP4. Can I decode them using UMC::AACDecoder from IPP 5.2 ?

Re: Decoding AAC raw frames ...

Vladimir_Dudnik — Wed, 19 Sep 2007 09:19:39 GMT

Hello,

there is comment from our expert:

Intel IPPAAC decoder supports 3 packed formats ADIF, ADTS and MP4. For decoder initialization it is necessary to know sampling frequency and Audio Object Type so at least one frame (the first) should has header. If you know sampling frequency and Audio Object Type you can add one ADIF header to the first frame or ADTS header to all frames.

Regards,
Vladimir

Re: Decoding AAC raw frames ...

Maciej_K_ — Thu, 20 Sep 2007 07:00:10 GMT

Thanks,
I found the previous post on AAC on this forum and that solution worked for me. I couldn't understand it on first time, so I'll repeat codec initialization steps below :

MediaData *m_in;
AudioData *m_out;

...

AACDecoderParams cParams;
cParams.m_info_in.stream_type = AAC_MPEG4_STREAM;
...
m_pDecoder->Init( &cParams );

BYTE AudioSpecificConfig[2] = { 0x14, 0x10 }; // profile, sampling rate, channels
m_in->SetBufferPointer( AudioSpecificConfig, 2 );
m_in->SetDataSize( 2 );
m_pDecoder->GetFrame( m_in, m_out /*unused*/ ); // returns UMC_ERR_SYNC

If several frames are packed into single chunk decoder sources have to be modified as in previous post.