wbmpff.cpp

linux下的一款播放器

                if (m_ulDesiredFileOffset == m_ulFileOffset)
                {
                    // Compute the number of bytes to read
                    UINT32 ulBytesToRead = m_ulBytesPerRow * m_ulRowsPerPacket;
                    // Set the state for a read
                    m_ulState = kStateGetPacketReadDonePending;
                    // Read that many bytes
                    m_pFileObject->Read(ulBytesToRead);
                }
                else
                {
                    // We need to seek, so set the state
                    m_ulState = kStateGetPacketSeekDonePending;
                    // Seek to the desired offset
                    m_pFileObject->Seek(m_ulDesiredFileOffset, FALSE);
                }
            }
            else
            {
                // We're done, so send a stream done
                m_pFormatResponse->StreamDone(0);
            }
        }
        else
        {
            retVal = HXR_INVALID_PARAMETER;
        }
    }
    else
    {
        retVal = HXR_UNEXPECTED;
    }

    return retVal;
}

STDMETHODIMP CWBMPFileFormat::Seek(UINT32 ulOffset)
{
    HX_RESULT retVal = HXR_OK;

    if (m_pFormatResponse)
    {
        // Whenever we get a Seek(), we resend all
        // the packets
        m_ulNextRow = 0;
        // Reset the state
        m_ulState = kStateReady;
        // Tell the format response we're ready
        m_pFormatResponse->SeekDone(HXR_OK);
    }
    else
    {
        retVal = HXR_UNEXPECTED;
    }

    return retVal;
}

STDMETHODIMP CWBMPFileFormat::Close()
{
    HX_RESULT retVal = HXR_OK;

    // Close the file
    if (m_pFileObject)
    {
        m_pFileObject->Close();
    }
    HX_RELEASE(m_pContext);
    HX_RELEASE(m_pFileObject);
    HX_RELEASE(m_pFormatResponse);
    HX_RELEASE(m_pCommonClassFactory);
    HX_RELEASE(m_pFileHeader);
    m_ulState             = kStateReady;
    m_ulImageWidth        = 0;
    m_ulImageHeight       = 0;
    m_ulHeaderSize        = 0;
    m_ulDesiredFileOffset = 0;
    m_ulFileOffset        = 0;
    m_ulBytesPerRow       = 0;
    m_ulRowsPerPacket     = 0;
    m_ulNextRow           = 0;

    return retVal;
}

STDMETHODIMP CWBMPFileFormat::InitDone(HX_RESULT status)
{
    HX_RESULT retVal = HXR_OK;

    if (m_ulState == kStateFileInitDonePending)
    {
        // Set the state
        m_ulState = kStateReady;
        // Call back to the response interface
        m_pFormatResponse->InitDone(status);
    }
    else
    {
        retVal = HXR_UNEXPECTED;
    }

    return retVal;
}

STDMETHODIMP CWBMPFileFormat::ReadDone(HX_RESULT status, IHXBuffer* pBuffer)
{
    HX_RESULT retVal = HXR_OK;

    if (m_ulState == kStateFileHeaderReadDonePending)
    {
        retVal = status;
        if (SUCCEEDED(retVal))
        {
            // Save the header to be send as opaque
            // data in the stream header
            HX_RELEASE(m_pFileHeader);
            m_pFileHeader = pBuffer;
            m_pFileHeader->AddRef();
            // Set the file offset
            m_ulFileOffset = pBuffer->GetSize();
            // Parse the buffer to determine type, width, height
            // For now, we assume that the type will be Type 0,
            // since that's the only one the standard currently defines.
            retVal = ParseWBMPHeader(pBuffer->GetBuffer(),
                                     pBuffer->GetSize(),
                                     m_ulImageWidth,
                                     m_ulImageHeight,
                                     m_ulHeaderSize);
            if (SUCCEEDED(retVal))
            {
                // We assume type 0, which is 8 bits per pixel monochrome
                // where white = 1 and black = 0. If the width is not
                // a multiple of 8, then rows are padded up to a multiple
                // of 8. So compute how many bytes in a row.
                m_ulBytesPerRow = (m_ulImageWidth + 7) >> 3;
                // Each packet will hold an integral number of rows.
                // Determine how many rows per packet
                m_ulRowsPerPacket = kIdealPacketSize / m_ulBytesPerRow;
                // Create an IHXValues
                IHXValues* pFileHeader = NULL;
                retVal = m_pCommonClassFactory->CreateInstance(CLSID_IHXValues,
                                                               (void**) &pFileHeader);
                if (SUCCEEDED(retVal))
                {
                    // Set the stream count
                    pFileHeader->SetPropertyULONG32("StreamCount", 1);
                    // Set the state
                    m_ulState = kStateReady;
                    // Send the file header
                    m_pFormatResponse->FileHeaderReady(HXR_OK, pFileHeader);
                }
                HX_RELEASE(pFileHeader);
            }
        }

        if (FAILED(retVal))
        {
            // Set the state
            m_ulState = kStateFileHeaderCloseDonePending;
            // Close the file
            m_pFileObject->Close();
        }
    }
    else if (m_ulState == kStateGetPacketReadDonePending)
    {
        retVal = status;
        if (SUCCEEDED(retVal))
        {
            // Compute the number of rows in this buffer
            UINT32 ulNumRows = pBuffer->GetSize() / m_ulBytesPerRow;
            // Update the file offset
            m_ulFileOffset += pBuffer->GetSize();
            // Create a packet buffer
            IHXBuffer* pPacketBuffer = NULL;
            retVal = m_pCommonClassFactory->CreateInstance(CLSID_IHXBuffer, (void**) &pPacketBuffer);
            if (SUCCEEDED(retVal))
            {
                // Set the size
                retVal = pPacketBuffer->SetSize(pBuffer->GetSize() + 4);
                if (SUCCEEDED(retVal))
                {
                    // Set the starting row number in the buffer
                    // in big endian format
                    BYTE* pBuf = pPacketBuffer->GetBuffer();
                    pBuf[0] = (BYTE) ((m_ulNextRow & 0xFF000000) >> 24);
                    pBuf[1] = (BYTE) ((m_ulNextRow & 0x00FF0000) >> 16);
                    pBuf[2] = (BYTE) ((m_ulNextRow & 0x0000FF00) >>  8);
                    pBuf[3] = (BYTE)  (m_ulNextRow & 0x000000FF);
                    // Copy the data
                    memcpy(pBuf + 4, pBuffer->GetBuffer(), ulNumRows * m_ulBytesPerRow);
                    // Create a packet
                    IHXPacket* pPacket = NULL;
                    retVal = m_pCommonClassFactory->CreateInstance(CLSID_IHXPacket, (void**) &pPacket);
                    if (SUCCEEDED(retVal))
                    {
                        retVal = pPacket->Set(pPacketBuffer,    // opaque data
                                              0,                // time stamp
                                              0,                // stream 0
                                              HX_ASM_SWITCH_ON, // ASM flag
                                              0);               // ASM rule
                        if (SUCCEEDED(retVal))
                        {
                            // Update the next row
                            m_ulNextRow += ulNumRows;
                            // Set the state
                            m_ulState = kStateReady;
                            // Send the packet
                            m_pFormatResponse->PacketReady(retVal, pPacket);
                        }
                    }
                    HX_RELEASE(pPacket);
                }
            }
            HX_RELEASE(pPacketBuffer);
        }
        if (FAILED(retVal))
        {
            // Issue a StreamDone
            m_pFormatResponse->StreamDone(0);
            // Set the state
            m_ulState = kStateGetPacketCloseDonePending;
            // Close the file
            m_pFileObject->Close();
        }
    }
    else
    {
        retVal = HXR_UNEXPECTED;
    }

    return retVal;
}


STDMETHODIMP CWBMPFileFormat::SeekDone(HX_RESULT status)
{
    HX_RESULT retVal = HXR_OK;

    if (m_ulState == kStateFileHeaderSeekDonePending)
    {
        if (SUCCEEDED(status))
        {
            // Set the state
            m_ulState = kStateFileHeaderReadDonePending;
            // Read some header bytes
            m_pFileObject->Read(kHeaderReadSize);
        }
        else
        {
            // Set the state
            m_ulState = kStateFileHeaderCloseDonePending;
            // Close the file
            m_pFileObject->Close();
        }
    }
    else if (m_ulState == kStateGetPacketSeekDonePending)
    {
        if (SUCCEEDED(status))
        {
            // Set the file offset
            m_ulFileOffset = m_ulDesiredFileOffset;
            // Compute the number of bytes to read
            UINT32 ulBytesToRead = m_ulBytesPerRow * m_ulRowsPerPacket;
            // Set the state for a read
            m_ulState = kStateGetPacketReadDonePending;
            // Read that many bytes
            m_pFileObject->Read(ulBytesToRead);
        }
        else
        {
            // We failed, so issue a StreamDone()
            m_pFormatResponse->StreamDone(0);
            // Set the state
            m_ulState = kStateGetPacketCloseDonePending;
            // Close the file
            m_pFileObject->Close();
        }
    }
    else
    {
        retVal = HXR_UNEXPECTED;
    }

    return retVal;
}

STDMETHODIMP CWBMPFileFormat::CloseDone(HX_RESULT status)
{
    HX_RESULT retVal = HXR_OK;

    if (m_ulState == kStateFileHeaderCloseDonePending)
    {
        // We can release the file object
        HX_RELEASE(m_pFileObject);
        // Set the state
        m_ulState = kStateReady;
        // The only reason we would have gotten here during
        // reading the file header is if we failed, so 
        // respond that we failed
        m_pFormatResponse->FileHeaderReady(HXR_FAIL, NULL);
    }
    else if (m_ulState == kStateGetPacketCloseDonePending)
    {
        // We can release the file object
        HX_RELEASE(m_pFileObject);
        // Reset the state
        m_ulState = kStateReady;
        // Don't really have to do anything else, since
        // we have already issued a StreamDone() if we
        // ever encountered an error during GetPacket().
    }
    else
    {
        retVal = HXR_UNEXPECTED;
    }

    return retVal;
}

STDMETHODIMP CWBMPFileFormat::WriteDone(HX_RESULT status)
{
    // We don't ever write, so we don't expect to get this...
    return HXR_UNEXPECTED;
}

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

    if (ppIUnknown)
    {
        // Set default
        *ppIUnknown = NULL;
        // Create the object
        CWBMPFileFormat *pObj = new CWBMPFileFormat();
        if (pObj)
        {
            // QI for IUnknown
            retVal = pObj->QueryInterface(IID_IUnknown, (void**) ppIUnknown);
        }
        else
        {
            retVal = HXR_OUTOFMEMORY;
        }
        if (FAILED(retVal))
        {
            HX_DELETE(pObj);
        }
    }
    else
    {
        retVal = HXR_FAIL;
    }

    return HXR_OK;
}