Blackmagic Design’s “Decklink Video Capture” filters

Pulling this out from Blackmagic Design Forum thread:

Generally, the recommended interface to the capture cards is the DeckLink API.

A DirectShow interface is available, but provides a subset of the functionality available from the complete DeckLink API.

Please note that the older, user-space DirectShow filters (DeckLink Video Capture) are deprecated in favour of the WDM filters (Blackmagic WDM Capture).

The WDM filters added support for 4K modes in Desktop Video 10.5+.

So the “Decklink Video Capture” filters that wrap the DeckLink SDK and provide convenient DirectShow interface are at their end of life.

Certainly, the most efficient and flexible way to interface Blackmagic Design hardware is to use their SDK (which is good and easy to use), however it does not give the immediate connectivity to Windows APIs. User mode filters were a good wrapper and provided typical functionality for capture and playback. They had their own issues (e.g. no VideoInfo2 support – interlaced formats treated as progressive and no support for progressive formats that collide with interlaces), also some reported 64-bit versions to be not quite stable.

WDM filters are around for some time, specifically they do offer 32-bit audio capture option which the other filters did not have. From what I remember they are lacking other capabilities availalble through SDK (update – e.g. no timecode support).

Apparently WMD filters do not offer playback option via DirectShow. This is not even mentioning the unfortunate Media Foundation – even though “Blackmagic WDM Render” is somehow around and with a certain luck is listed through MFTEnum:

    Blackmagic WDM Render #3
        MFT_ENUM_HARDWARE_URL_Attribute: \\?\decklink#avstream#5&2db0fd5&1&0000#{65e8773e-8f56-11d0-a3b9-00a0c9223196}\decklinkrender1 (Type VT_LPWSTR)
        MFT_INPUT_TYPES_Attributes: 
            MFMediaType_Video MFVideoFormat_UYVY
            MFMediaType_Video MFVideoFormat_v210
            MFMediaType_Video MFVideoFormat_UYVY
            MFMediaType_Video MFVideoFormat_v210
            MFMediaType_Video MFVideoFormat_UYVY
            MFMediaType_Video MFVideoFormat_v210
            MFMediaType_Video MFVideoFormat_UYVY
            MFMediaType_Video MFVideoFormat_v210
            MFMediaType_Video MFVideoFormat_UYVY
            MFMediaType_Video MFVideoFormat_v210
            MFMediaType_Video FourCC HDYC
            MFMediaType_Video FourCC HDYC
            MFMediaType_Video FourCC HDYC
            MFMediaType_Video FourCC HDYC
            MFMediaType_Video FourCC HDYC
            MFMediaType_Video FourCC HDYC
            MFMediaType_Video FourCC HDYC
            MFMediaType_Video FourCC HDYC
            MFMediaType_Audio MFAudioFormat_PCM
            MFMediaType_Audio MFAudioFormat_PCM
            
        MFT_TRANSFORM_CLSID_Attribute: {8AC3587A-4AE7-42D8-99E0-0A6013EEF90F} (Type VT_CLSID)
        MF_TRANSFORM_FLAGS_Attribute: MFT_ENUM_FLAG_HARDWARE

For more or less serious DirectShow development the best way was and is to wrap the DeckLink SDK with a custom filter and have all options that SDK provides.