pxcpngff.cpp

linux下的一款播放器

            pSession->AddRef();
            // Init the size
            retVal = pSession->InitSize(ulMaxNumPackets);
            if (SUCCEEDED(retVal))
            {
                // Parse the image, putting buffers into the session object
                HXxSize rImageDim;
                retVal = ParseBuffer(pBuffer, pSession, rImageDim);
                if (SUCCEEDED(retVal))
                {
                    // Now we can reduce our size to the number of packets we actually have
                    retVal = pSession->SetSize(pSession->GetNumPackets());
                    if (SUCCEEDED(retVal))
                    {
                        // Add the session to the map
                        retVal = m_pMapManager->AddEntry((void*) pSession, rulSessionHandle);
                        if (SUCCEEDED(retVal))
                        {
                            // AddRef the session since it's in the map
                            pSession->AddRef();
                            // Create an IHXValues object
                            IHXValues* pParam = NULL;
                            retVal             = m_pCommonClassFactory->CreateInstance(CLSID_IHXValues,
                                                                                       (void**) &pParam);
                            if (SUCCEEDED(retVal))
                            {
                                // Set properties in the IHXValues
                                pParam->SetPropertyULONG32("MaxPacketSize",    pSession->GetMaxPacketSize());
                                pParam->SetPropertyULONG32("MinPacketSize",    pSession->GetMinPacketSize());
                                pParam->SetPropertyULONG32("TotalBytes",       pSession->GetTotalBytes());
                                pParam->SetPropertyULONG32("TotalReqBytes",    pSession->GetTotalRequiredBytes());
                                pParam->SetPropertyULONG32("TotalNonReqBytes", pSession->GetTotalNonRequiredBytes());
                                pParam->SetPropertyULONG32("ImageWidth",       (UINT32) rImageDim.cx);
                                pParam->SetPropertyULONG32("ImageHeight",      (UINT32) rImageDim.cy);
                                // Set the outgoing parameters
                                rulNumPackets = pSession->GetNumPackets();
                                HX_RELEASE(rpParam);
                                rpParam = pParam;
                                rpParam->AddRef();
                            }
                            HX_RELEASE(pParam);
                        }
                    }
                }
            }
        }
        else
        {
            retVal = HXR_OUTOFMEMORY;
        }
        HX_RELEASE(pSession);
    }
    else
    {
        retVal = HXR_INVALID_PARAMETER;
    }

    return retVal;
}

STDMETHODIMP CRealPixPNGFileFormatCodec::GetImagePacket(UINT32           ulSessionHandle,
                                                        UINT32           ulPacketNum,
                                                        REF(IHXBuffer*) rpPacketBuffer,
                                                        REF(IHXBuffer*) rpOpaquePacketData,
                                                        REF(BOOL)        rbRequired)
{
    HX_RESULT retVal = HXR_FAIL;

    if (m_pMapManager)
    {
        PXParseSession* pSession = NULL;
        retVal                   = m_pMapManager->GetEntry(ulSessionHandle, (void**) &pSession);
        if (SUCCEEDED(retVal))
        {
            // Get the packet from the session
            retVal = pSession->GetPacket(ulPacketNum,
                                         rpPacketBuffer,
                                         rpOpaquePacketData,
                                         rbRequired);
        }
    }

    return retVal;
}

STDMETHODIMP CRealPixPNGFileFormatCodec::ReleaseImage(UINT32 ulSessionHandle)
{
    HX_RESULT retVal = HXR_FAIL;

    if (m_pMapManager)
    {
        PXParseSession* pSession = NULL;
        retVal                   = m_pMapManager->DeleteEntry(ulSessionHandle, (void**) &pSession);
        HX_RELEASE(pSession);
    }

    return retVal;
}

HX_RESULT STDAPICALLTYPE CRealPixPNGFileFormatCodec::HXCreateInstance(IUnknown** ppIUnknown)
{
    HX_RESULT retVal = HXR_OK;

    if (ppIUnknown)
    {
        // Create file format codec
        CRealPixPNGFileFormatCodec* pCodec = new CRealPixPNGFileFormatCodec();
        if (pCodec)
        {
            // QI for IUnknown
            retVal = pCodec->QueryInterface(IID_IUnknown, (void**) ppIUnknown);
        }
        else
        {
            retVal = HXR_OUTOFMEMORY;
        }
        if (FAILED(retVal))
        {
            HX_DELETE(pCodec);
        }
    }
    else
    {
        retVal = HXR_FAIL;
    }

    return retVal;
}

HX_RESULT CRealPixPNGFileFormatCodec::ParseBuffer(IHXBuffer*     pBuffer,
                                                  PXParseSession* pSession,
                                                  REF(HXxSize)    rImageDim)
{
    HX_RESULT retVal = HXR_OK;

    if (pBuffer && pSession)
    {
        UINT32 ulWidth  = 0;
        UINT32 ulHeight = 0;
        if (PXPNGDecode::GetIHDRInfo(pBuffer, ulWidth, ulHeight))
        {
            rImageDim.cx = (INT32) ulWidth;
            rImageDim.cy = (INT32) ulHeight;
        }

        // Find the beginning of the IDAT chunk
        UINT32    ulOffset  = 0;
        UINT32    ulBytes   = 0;
        BOOL      bComplete = FALSE;
        BOOL      bPresent  = PXPNGDecode::IsChunkPresent(pBuffer,
                                                          0x49444154, // IDAT chunk
                                                          ulOffset,
                                                          ulBytes,
                                                          bComplete);
        if (bPresent && bComplete)
        {
            UINT32 ulFirstBufferSize = 0;
            if (ulOffset + kMinIDATBytes > kDefaultPacketSize)
            {
                // Since the size of the all the chunks before the IDAT is
                // greater than the ideal packet size, then we'll just do
                // the minimum here.
                ulFirstBufferSize   = ulOffset + kMinIDATBytes;
            }
            else
            {
                // Since the size of all the chunks before the IDAT is
                // LESS than the ideal packet size, we'll allow some of
                // the IDAT chunk into the first packet.
                ulFirstBufferSize = kDefaultPacketSize;
                if (ulFirstBufferSize > pBuffer->GetSize())
                {
                    ulFirstBufferSize = pBuffer->GetSize();
                }
            }
            // Add the first packet buffer
            UINT32 ulNumBuffers = 1;
            // Add all the rest of the packets past the first
            ulNumBuffers       += (pBuffer->GetSize() - ulFirstBufferSize + kDefaultPacketSize - 1) /
                                  kDefaultPacketSize;
            // Now run through and create the buffers
            UINT32 ulCurOffset = 0;
            UINT32 ulCurSize   = ulFirstBufferSize;
            for (UINT32 i = 0; i < ulNumBuffers && SUCCEEDED(retVal); i++)
            {
                // Create a nested buffer
                CHXNestedBuffer* pNest = NULL;
                retVal                 = CHXNestedBuffer::CreateObject(&pNest);
                if (SUCCEEDED(retVal))
                {
                    // AddRef the object
                    pNest->AddRef();
                    // Init the nested buffer
                    retVal = pNest->Init(pBuffer, ulCurOffset, ulCurSize);
                    if (SUCCEEDED(retVal))
                    {
                        // QI for IHXBuffer
                        IHXBuffer* pData = NULL;
                        retVal            = pNest->QueryInterface(IID_IHXBuffer,
                                                                  (void**) &pData);
                        if (SUCCEEDED(retVal))
                        {
                            // Update the current offset and size
                            ulCurOffset += ulCurSize;
                            ulCurSize    = kDefaultPacketSize;
                            if (ulCurOffset + ulCurSize > pBuffer->GetSize())
                            {
                                ulCurSize = pBuffer->GetSize() - ulCurOffset;
                            }
                            // Create the opaque buffer
                            IHXBuffer* pOpaque = NULL;
                            retVal = m_pCommonClassFactory->CreateInstance(CLSID_IHXBuffer,
                                                                           (void**) &pOpaque);
                            if (SUCCEEDED(retVal))
                            {
                                // Set its size
                                retVal = pOpaque->SetSize(4);
                                if (SUCCEEDED(retVal))
                                {
                                    // Pack the opaque buffer with a seq num
                                    BYTE* pBuf = pOpaque->GetBuffer();
                                    Pack32(pBuf, i);
                                    // Add the packet
                                    retVal = pSession->AddPacket(pData, pOpaque, (i ? FALSE : TRUE));
                                }
                            }
                            HX_RELEASE(pOpaque);
                        }
                        HX_RELEASE(pData);
                    }
                }
                HX_RELEASE(pNest);
            }
        }
        else
        {
            retVal = HXR_OUTOFMEMORY;
        }
    }
    else
    {
        retVal = HXR_FAIL;
    }

    return retVal;
}

void CRealPixPNGFileFormatCodec::ReleaseAllSessions()
{
    if (m_pMapManager)
    {
        UINT32          ulHandle = 0;
        PXParseSession* pSession = NULL;
        HX_RESULT       retVal   = m_pMapManager->GetFirstEntry(ulHandle, (void**) &pSession);
        while (SUCCEEDED(retVal))
        {
            HX_RELEASE(pSession);
            retVal = m_pMapManager->GetNextEntry(ulHandle, (void**) &pSession);
        }
        m_pMapManager->DeleteAllEntries();
    }
}