If the media type is FORMAT_VideoInfo, it means the format buffer is a VIDEOINFOHEADER struct; if the media type is FORMAT_VideoInfo2, it means the format buffer is a VIDEOINFOHEADER2 struct. So, what's different between VIDEOINFOHEADER and VIDEOINFOHEADER2?
VIDEOINFOHEADER and VIDEOINFOHEADER2 are very different, VIDEOINFOHEADER2 is not just an entended struct of VIDEOINFOHEADER. This means you cannot cast a pointer of VIDEOINFOHEADER2 to a pointer of VIDEOINFOHEADER.
INCORRECT:
if(pmt->formattype == FORMAT_VideoInfo || pmt->formattype == FORMAT_VideoInfo2)
{
VIDEOINFOHEADER *pVIH = (VIDEOINFOHEADER*)pmt->pbFormat;
// *** Wrong! ***
}
CORRECT:
if(pmt->formattype == FORMAT_VideoInfo)
{
VIDEOINFOHEADER *pVIH = (VIDEOINFOHEADER*)pmt->pbFormat;
// Now you can use pVIH.
}
else if(pmt->formattype == FORMAT_VideoInfo2)
{
VIDEOINFOHEADER2 *pVIH = (VIDEOINFOHEADER2*)pmt->pbFormat;
// Now you can use pVIH.
}
Reference in MSDN:
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