AAC Codec for S60_3rd FP2 devices

[ruchirvasavada]

Hi,

In our application we were successfully using CMMFCodec to convert AAC data into PCM16. This was in FP1 devices.

Now same code is not working in FP2 devices. It crashes as soon as I try to create the codec with fourCC as AAC.

The crash code is -5, which is KErrNotSupported.

Does that mean the AAC Codec is no longer supported in FP2 devices..??? And if that is the case then is there any workaround to this problem...??

Thanks,
Ruchir

[qxiaoyuan]

hi ruchirvasavada, I find it seem truth, on N96, I use
iCodec = CMMFCodec::NewL(TUid::Uid(0x101faf81)
it will leave -1.
but I test, eaac+ codec exists.
iCodec = CMMFCodec::NewL(TUid::Uid(0x10207AA9)); // it is ok on n96
I use it can open aac audio.
and a example param is below, (not very correct, but ok for my test aac)

    configParams.Append(iSampleRate);
    configParams.Append(iChannel);
    configParams.Append(1);
    configParams.Append(4096);
    configParams.Append(1024);
    configParams.Append(iSampleRate);
    configParams.Append(0);
    configParams.Append(0);
    configParams.Append(16);
    configParams.Append(16000);
    configParams.Append(0);

[ruchirvasavada]

Thanks qxiaoyuan,

with your code, I could at least create a coded with eAAC+ format, but now my target is to convert AAC to PCM16. Where do I give the destination format detail or is it understood that destination is always PCM16?

Actually after trying code suggested by you, the ProcessL() method panics (don't know the panic code) any idea why..? If required I can put some code also.

Thanks,
Ruchir

[qxiaoyuan]

1. decode data is always PCM16.
2. aac codec can receive any frame data, but eaac+ decode must give it data with full frame.
so you need only transfer full frame data to it.

I research aac format, and do a little decode, which judge full frame edge.

TBool CAacCodec::DecodeAudio(const TDesC8& aSrc, TDes8& aDest)
{
    //FUNC_U_TRACE();
    TPtr8 pSrc(0, 0, 0);
    
    if ( iRemainData.Length() <= 0 )
    {
        pSrc.Set((TUint8*)aSrc.Ptr(), aSrc.Length(), aSrc.Length());
    }
    else
    {
        TInt len = iRemainData.Length() + aSrc.Length();
        if ( !iSrcBuf )
        {
            TInt maxLen = iRemainData.MaxLength() + 2 * aSrc.Length();
            iSrcBuf = HBufC8::NewL(maxLen);
            LOG_FORMAT(( _L("in CAacCodec::DecodeAudio, iSrcBuf.MaxLength() = %d"), iSrcBuf->Des().MaxLength() ));
        }
        else
        if ( len > iSrcBuf->Des().MaxLength() )
        {
            TInt maxLen = 2 * iSrcBuf->Des().MaxLength();
            maxLen = Max(maxLen, 2 * len);
            delete iSrcBuf;
            iSrcBuf = NULL;
            iSrcBuf = HBufC8::NewL(maxLen);
            LOG_FORMAT(( _L("in CAacCodec::DecodeAudio, iSrcBuf.MaxLength() = %d"), iSrcBuf->Des().MaxLength() ));
        }
        iSrcBuf->Des().Copy(iRemainData);
        iSrcBuf->Des().Append(aSrc);
        pSrc.Set((TUint8*)iSrcBuf->Ptr(), iSrcBuf->Length(), iSrcBuf->Des().MaxLength());
    }


    TInt frameNum = 0;
    TInt len = pSrc.Length();
    TInt lastFramePos = 0;
    const TUint8* datap = pSrc.Ptr();
    TInt i = 0;
    while ( i < (len - 6) )
    {
        if ( (datap[i] != 0xff) || ((datap[i+1] & 0xf0) != 0xf0) )
        {
            if ( (datap[i+2] & 0xf0) != 0xf0 )
            {
                //LOG_FORMAT((_L("datap[%d] = 0x%02x, datap[%d] = 0x%02x, datap[%d] = 0x%02x"), i, datap[i], i+1, datap[i+1], i+2, datap[i+2]));
            }
            i++;
            continue;
        }
        TInt frameSize = (datap[i + 2] << 24) | (datap[i + 3] << 16) | (datap[i + 4] << 8) | datap[i + 5];
        frameSize &= 0x0003ffc0;
        frameSize >>= 5;
        if ( frameSize + i >= len )
        {   //不完整的帧
            break;
        }
        frameNum++;
        lastFramePos = i;
        i += frameSize;
    }

    TInt remainLen = len - lastFramePos;
    if ( remainLen > 0 )
    {
        TInt l = Min(iRemainData.MaxLength(), remainLen);
        iRemainData.Copy(pSrc.Right(l));
    }

    if ( frameNum < 1 )
    {   //如果1个帧都没有, 那么无需转换
        LOG(_L("========== panic frameNum = 0 ============="));
        return EFalse;
    }


    pSrc.SetLength(lastFramePos);
    iSrc->SetPtr(pSrc);

    aDest.Zero();
    TPtr8 pDest((TUint8*)aDest.Ptr(), 0, aDest.MaxLength());
    iDest->SetPtr(pDest);
    

    TCodecProcessResult ret;
    TRAPD(perr, ret = iCodec->ProcessL(*iSrc, *iDest));
    if ( perr != KErrNone )
    {
        LOG_FORMAT((_L("iCodec->ProcessL leave = %d"), perr));
        return EFalse;
    }
    else
    if ( ret != TCodecProcessResult::EProcessComplete)
    {
        TBuf<300> phone;
        if ( ret == TCodecProcessResult::EProcessIncomplete) phone.Append(_L("EProcessIncomplete"));
        if ( ret == TCodecProcessResult::EEndOfData) phone.Append(_L("EEndOfData"));
        if ( ret == TCodecProcessResult::EDstNotFilled) phone.Append(_L("EDstNotFilled"));
        if ( ret == TCodecProcessResult::EProcessError) phone.Append(_L("EProcessError"));
        if ( ret == TCodecProcessResult::EProcessIncompleteRepositionRequest) phone.Append(_L("EProcessIncompleteRepositionRequest"));
        if ( ret == TCodecProcessResult::EProcessCompleteRepositionRequest) phone.Append(_L("EProcessCompleteRepositionRequest"));
        LOG_FORMAT((_L("iCodec->ProcessL = %S"), &phone));
        LOG_FORMAT(( _L("iDest->Data().Length() = %d"), iDest->Data().Length() ));
        return EFalse;
    }

    aDest.SetLength(iDest->Data().Length());
    return ETrue;
}

[ruchirvasavada]

Thank you very very much for those leads..

From your code, I managed to extract out the frame size and read that much data from the file.

But the ProcessL still leaves. The leave code is -1 (KErrNotFound). Does that mean the codec could not be found??

Any idea why that error..??

[mike.b]

Same problem for me tested on Nokia 6220 classic. Although I can successfully create decoder UID 0x10207aa9, and ConfigureL it with UID 0x10203622 (KUidMmfCodecAudioSettings), ProcessL function always fails with error -18 (KErrNotReady).

[qxiaoyuan]

Thank you very very much for those leads..

From your code, I managed to extract out the frame size and read that much data from the file.

But the ProcessL still leaves. The leave code is -1 (KErrNotFound). Does that mean the codec could not be found??

Any idea why that error..??

no, it means the data has some strange format, so codec can't decode, and normally I just ignore the frame data, jump next frame data, and it will work ok.

[mike.b]

Successfully solved here.

[bnvaikos]

Successfully solved here.

Hi
Plz have a look here
http://discussion.forum.nokia.com/fo...d.php?t=143284

I wanted to implement codec for s60 3rd & 5th ed.
But in sdk doc its mentioned that mmfcodec.h is not available in sdk then
from where I get it?

Please help.

thanks
bnvaikos