public void SetFrameRate(MFRatio fps)
{
// Convert to a duration.
int hr = MFExtern.MFFrameRateToAverageTimePerFrame(fps.Numerator, fps.Denominator, out m_PerFrameInterval);
MFError.ThrowExceptionForHR(hr);
// Calculate 1/4th of this value, because we use it frequently.
m_PerFrame_1_4th = m_PerFrameInterval / 4;
}
protected MFRect CorrectAspectRatio(MFRect src, MFRatio srcPAR, MFRatio destPAR)
{
// Start with a rectangle the same size as src, but offset to the origin (0,0).
MFRect rc = new MFRect(0, 0, src.right - src.left, src.bottom - src.top);
// If the source and destination have the same PAR, there is nothing to do.
// Otherwise, adjust the image size, in two steps:
// 1. Transform from source PAR to 1:1
// 2. Transform from 1:1 to destination PAR.
if ((srcPAR.Numerator != destPAR.Numerator) || (srcPAR.Denominator != destPAR.Denominator))
{
// Correct for the source's PAR.
if (srcPAR.Numerator > srcPAR.Denominator)
{
// The source has "wide" pixels, so stretch the width.
rc.right = Utils.MulDiv(rc.right, srcPAR.Numerator, srcPAR.Denominator);
}
else if (srcPAR.Numerator > srcPAR.Denominator)
{
// The source has "tall" pixels, so stretch the height.
rc.bottom = Utils.MulDiv(rc.bottom, srcPAR.Denominator, srcPAR.Numerator);
}
// else: PAR is 1:1, which is a no-op.
// Next, correct for the target's PAR. This is the inverse operation of the previous.
if (destPAR.Numerator > destPAR.Denominator)
{
// The destination has "tall" pixels, so stretch the width.
rc.bottom = Utils.MulDiv(rc.bottom, destPAR.Denominator, destPAR.Numerator);
}
else if (destPAR.Numerator > destPAR.Denominator)
{
// The destination has "fat" pixels, so stretch the height.
rc.right = Utils.MulDiv(rc.right, destPAR.Numerator, destPAR.Denominator);
}
// else: PAR is 1:1, which is a no-op.
}
return rc;
}
// Sets the number of frames per second, as a ratio.
public void SetFrameRate(MFRatio ratio)
{
Utils.MFSetAttribute2UINT32asUINT64(GetMediaType(), MFAttributesClsid.MF_MT_FRAME_RATE, ratio.Numerator, ratio.Denominator);
}
public void SetPixelAspectRatio(MFRatio ratio)
{
Utils.MFSetAttribute2UINT32asUINT64(GetMediaType(), MFAttributesClsid.MF_MT_PIXEL_ASPECT_RATIO, ratio.Numerator, ratio.Denominator);
}
// Defaults to 1:1 (square pixels)
//
// The following versions return reasonable defaults if the relevant attribute is not present (zero/FALSE).
// This is useful for making quick comparisons betweeen media types.
//
public MFRatio GetPixelAspectRatio()
{
MFRatio PAR = new MFRatio();
try
{
Utils.MFGetAttribute2UINT32asUINT64(GetMediaType(), MFAttributesClsid.MF_MT_PIXEL_ASPECT_RATIO, out PAR.Numerator, out PAR.Denominator);
}
catch
{
PAR.Numerator = 1;
PAR.Denominator = 1;
}
return PAR;
}
// Gets the frames per second as a ratio.
public void GetFrameRate(out MFRatio pRatio)
{
GetFrameRate(out pRatio.Numerator, out pRatio.Denominator);
}
//-----------------------------------------------------------------------------
// CorrectAspectRatio
//
// Converts a rectangle from the source's pixel aspect ratio (PAR) to 1:1 PAR.
// Returns the corrected rectangle.
//
// For example, a 720 x 486 rect with a PAR of 9:10, when converted to 1x1 PAR,
// is stretched to 720 x 540.
//-----------------------------------------------------------------------------
private static Rectangle CorrectAspectRatio(Rectangle src, MFRatio srcPAR)
{
// Start with a rectangle the same size as src, but offset to the origin (0,0).
Rectangle rc = new Rectangle(0, 0, src.Right - src.Left, src.Bottom - src.Top);
int rcNewWidth = rc.Right;
int rcNewHeight = rc.Bottom;
if ((srcPAR.Numerator != 1) || (srcPAR.Denominator != 1))
{
// Correct for the source's PAR.
if (srcPAR.Numerator > srcPAR.Denominator)
{
// The source has "wide" pixels, so stretch the width.
rcNewWidth = MulDiv(rc.Right, srcPAR.Numerator, srcPAR.Denominator);
}
else if (srcPAR.Numerator < srcPAR.Denominator)
{
// The source has "tall" pixels, so stretch the height.
rcNewHeight = MulDiv(rc.Bottom, srcPAR.Denominator, srcPAR.Numerator);
}
// else: PAR is 1:1, which is a no-op.
}
rc = new Rectangle(0, 0, rcNewWidth, rcNewHeight);
return rc;
}
//-------------------------------------------------------------------
// SetVideoType
//
// Set the video format.
//-------------------------------------------------------------------
public int SetVideoType(IMFMediaType pType)
{
int hr = S_Ok;
Guid subtype;
MFRatio PAR = new MFRatio();
// Find the video subtype.
hr = pType.GetGUID(MFAttributesClsid.MF_MT_SUBTYPE, out subtype);
if (Failed(hr)) { goto done; }
// Choose a conversion function.
// (This also validates the format type.)
hr = SetConversionFunction(subtype);
if (Failed(hr)) { goto done; }
//
// Get some video attributes.
//
// Get the frame size.
hr = MFGetAttributeSize(pType, MFAttributesClsid.MF_MT_FRAME_SIZE, out m_width, out m_height);
if (Failed(hr)) { goto done; }
// Get the image stride.
hr = GetDefaultStride(pType, out m_lDefaultStride);
if (Failed(hr)) { goto done; }
// Get the pixel aspect ratio. Default: Assume square pixels (1:1)
hr = MFGetAttributeRatio(pType, MFAttributesClsid.MF_MT_PIXEL_ASPECT_RATIO, out PAR.Numerator, out PAR.Denominator);
if (Succeeded(hr))
{
m_PixelAR = PAR;
}
else
{
m_PixelAR.Numerator = m_PixelAR.Denominator = 1;
}
FourCC f = new FourCC(subtype);
m_format = (Format)f.ToInt32();
// Create Direct3D swap chains.
hr = CreateSwapChains();
if (Failed(hr)) { goto done; }
// Update the destination rectangle for the correct
// aspect ratio.
UpdateDestinationRect();
done:
if (Failed(hr))
{
m_format = Format.Unknown;
m_convertFn = null;
m_bmpconvertFn = null;
}
return hr;
}
//-------------------------------------------------------------------
// SetVideoType
//
// Set the video snapFormat.
//-------------------------------------------------------------------
public int SetVideoType(IMFMediaType pType)
{
Guid subtype;
var PAR = new MFRatio();
// Find the video subtype.
var hr = pType.GetGUID(MFAttributesClsid.MF_MT_SUBTYPE, out subtype);
try
{
if (Failed(hr))
throw new Exception();
// Choose a conversion function.
// (This also validates the snapFormat type.)
hr = SetConversionFunction(subtype);
if (Failed(hr))
throw new Exception();
//
// Get some video attributes.
//
// Get the frame size.
hr = CProcess.MfGetAttributeSize(pType, out width, out height);
if (Failed(hr))
throw new Exception();
// Get the image stride.
hr = GetDefaultStride(pType, out lDefaultStride);
if (Failed(hr))
throw new Exception();
// Get the pixel aspect ratio. Default: Assume square pixels (1:1)
hr = CProcess.MfGetAttributeRatio(pType, out PAR.Numerator, out PAR.Denominator);
if (Succeeded(hr))
{
pixelAR = PAR;
}
else
{
pixelAR.Numerator = pixelAR.Denominator = 1;
}
var f = new FourCC(subtype);
format = (Format) f.ToInt32();
// Create Direct3D swap chains.
hr = CreateSwapChains();
if (Failed(hr))
throw new Exception();
// Update the destination rectangle for the correct
// aspect ratio.
UpdateDestinationRect();
}
finally
{
if (Failed(hr))
{
format = Format.Unknown;
m_convertFn = null;
}
}
return hr;
}
