can not connect to DV video decoder using MEDIASUBTYPE_YUY2

Pasc059 1 Reputation point
2020-11-02T18:49:50.077+00:00

Hello,

I try to write a 64bits DirectShow Transform Filter that i want to connect to a "DV Video Decoder" using the subtype MEDIASUBTYPE_YUY2, unfortunately without success. The only Subtype for wich the connection works is MEDIASUBTYPE_RGB24, and even with this subtype an "AVI Decompressor" filter is inserted (because of Intelligent connect). However the "DV Video Decoder" can output this subtype MEDIASUBTYPE_YUY2.

Someone has an idea?

regards, Pascal

Windows API - Win32
Windows API - Win32
A core set of Windows application programming interfaces (APIs) for desktop and server applications. Previously known as Win32 API.
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  1. Pasc059 1 Reputation point
    2020-11-03T15:51:25.737+00:00

    Hello,

    I found the reason why the MEDIASUBTYPE_YUY2 was not accepted. The input pin, which is created thru a class CDeinterlaceInputPin inherited from CTransformInputPin, specifies a ALLOCATOR_PROPERTIES::cBuffers value greater than 1 after a call to its GetAllocatorRequirements() method. The next call to the GetAllocator() method of CTransformInputPin return without error, but the next call to NotifyAllocator() of CTransformInputPin gives a Actual.cBuffers value of 1 when the media subtype is MEDIASUBTYPE_YUY2 and this method considers this situation as an error. If i specify the cBuffers value = 1, then the connection works, but not the rest of the filter. With the MEDIASUBTYPE_RGB24 there is no problem.

    So my question becomes, why the IMemAllocator transmitted in the NotifyAllocator() method of my CDeinterlaceInputPin() always give a ALLOCATOR_PROPERTIES::cBuffers of 1 for MEDIASUBTYPE_YUY2 (and not for MEDIASUBTYPE_RGB24 which is however more demanding)?

    regards

  2. Pasc059 1 Reputation point
    2020-11-04T16:50:20.383+00:00

    Hi,

    in fact this not only with MEDIASUBTYPE_YUY2 subtype that the DV Video Decoder does not accept ALLOCATOR_PROPERTIES::cBuffers value greater than 1. But with the MEDIASUBTYPE_RGB24, an AVI Decompressor filter is inserted (with intelligent connect) that accept ALLOCATOR_PROPERTIES::cBuffers greater than 1 with the MEDIASUBTYPE_RGB24 (but not with MEDIASUBTYPE_YUY2 ). Below the 2 graphs showing what happens when ALLOCATOR_PROPERTIES::cBuffers=1
    37521-graph-wyuy2.png

    and when ALLOCATOR_PROPERTIES::cBuffers>1
    37478-graph-wrgb24.png

    After that, i can connect the ouptut of my filter to a VMR9 renderer with MEDIASUBTYPE_RGB24 (however thru a Color space concerter filter), but not with MEDIASUBTYPE_YUY2, but perhaps i should create another post.
    Regards

  3. Pasc059 1 Reputation point
    2020-11-17T16:36:41.1+00:00

    Hi,

    I'm back on this issue.
    I foundthe reason why i could not connect the VMR9 render with the MEDIASUBTYPE_YUY2. It was because in the DecideBufferSize() method of my filter, i specified a cbAlign property different than 1 (but this is not a problem with MEDIASUBTYPE_RGB24 ).

    then other problems with MEDIASUBTYPE_YUY2, but i will submit another Question if needed.

    regards

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