Get all supported FPS camera values at Microsoft Media Foundation

Question

Get all supported FPS camera values at Microsoft Media Foundation

I want to get a list of all the FPS values supported by my webcam.

In How to set the frame rate of video capture , the msdn article says that I can request a system for the maximum and minimum supported FPS of a specific camera.

It also says:

The device may support other frame rates in this range.

And in MF_MT_FRAME_RATE_RANGE_MIN it says:

The device does not guarantee support for each increment in this range.

It seems that there is no way to get all the supported FPS values by the camera in the Media Foundation, just max and min.

I know that on Linux the v4l2-ctl --list-formats-extcommand prints a lot more supported FPS than just min and max.

Here are some examples from Linux using different cameras:

$ v4l2-ctl --list-formats-ext
ioctl: VIDIOC_ENUM_FMT
  Index       : 0
  Type        : Video Capture
  Pixel Format: 'YUYV'
  Name        : YUV 4:2:2 (YUYV)
    Size: Discrete 160x120
      Interval: Discrete 0.033s (30.000 fps)
      Interval: Discrete 0.036s (27.500 fps)
      Interval: Discrete 0.040s (25.000 fps)
      Interval: Discrete 0.044s (22.500 fps)
      Interval: Discrete 0.050s (20.000 fps)
      Interval: Discrete 0.057s (17.500 fps)
      Interval: Discrete 0.067s (15.000 fps)
      Interval: Discrete 0.080s (12.500 fps)
      Interval: Discrete 0.100s (10.000 fps)
      Interval: Discrete 0.133s (7.500 fps)
      Interval: Discrete 0.200s (5.000 fps)
    Size: Discrete 176x144
      Interval: Discrete 0.033s (30.000 fps)
      ...

and

$ v4l2-ctl --list-formats-ext
ioctl: VIDIOC_ENUM_FMT
    Index       : 0
    Type        : Video Capture
    Pixel Format: 'YUYV'
    Name        : YUV 4:2:2 (YUYV)
        Size: Discrete 640x360
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.040s (25.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 640x480
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.040s (25.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 320x240
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.040s (25.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 160x120
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.040s (25.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 960x544
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 1280x720
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.200s (5.000 fps)

and

$ v4l2-ctl --list-formats-ext    
ioctl: VIDIOC_ENUM_FMT
        Index       : 0
        Type        : Video Capture
        Pixel Format: 'YUYV'
        Name        : YUV 4:2:2 (YUYV)
                Size: Discrete 1280x720
                        Interval: Discrete 0.111s (9.000 fps)
                Size: Discrete 160x120
                        Interval: Discrete 0.033s (30.000 fps)
                Size: Discrete 320x240
                        Interval: Discrete 0.033s (30.000 fps)
                Size: Discrete 1280x800
                        Interval: Discrete 0.111s (9.000 fps)
                Size: Discrete 640x480
                        Interval: Discrete 0.033s (30.000 fps)

        Index       : 1
        Type        : Video Capture
        Pixel Format: 'MJPG' (compressed)
        Name        : MJPEG
                Size: Discrete 1280x720
                        Interval: Discrete 0.033s (30.000 fps)
                Size: Discrete 160x120
                        Interval: Discrete 0.033s (30.000 fps)
                Size: Discrete 320x240
                        Interval: Discrete 0.033s (30.000 fps)
                Size: Discrete 1280x800
                        Interval: Discrete 0.033s (30.000 fps)
                Size: Discrete 640x480
                        Interval: Discrete 0.033s (30.000 fps)

So, is there a way to get all supported FPS using a camera in the Microsoft Media Foundation, or is it really limited in this aspect?

+4

c ++ windows winapi ms-media-foundation

Yellow ray Jun 13 '15 at 4:16

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1 answer

Jeff · Accepted Answer · 2015-06-15T14:52:26+0000

The frame rate and other attributes can be obtained using a code similar to the following (error checking omitted for brevity):

Microsoft::WRL::ComPtr<IMFSourceReader> reader = nullptr;
/* reader code omitted */

IMFMediaType* mediaType = nullptr;
GUID          subtype { 0 };

UINT32 frameRate = 0;
UINT32 frameRateMin = 0;
UINT32 frameRateMax = 0;
UINT32 denominator = 0;
DWORD32 width, height;
DWORD index = 0;

HRESULT hr = S_OK;
while (hr == S_OK)
{
    hr = reader->GetNativeMediaType((DWORD) MF_SOURCE_READER_FIRST_VIDEO_STREAM, index, &mediaType);
    if (hr == MF_E_NO_MORE_TYPES)
        break;

    hr = mediaType->GetGUID(MF_MT_SUBTYPE, &subtype);
    hr = MFGetAttributeSize(mediaType, MF_MT_FRAME_SIZE, &width, &height);
    hr = MFGetAttributeRatio(mediaType, MF_MT_FRAME_RATE, &frameRate, &denominator);
    hr = MFGetAttributeRatio(mediaType, MF_MT_FRAME_RATE_RANGE_MIN, &frameRateMin, &denominator);
    hr = MFGetAttributeRatio(mediaType, MF_MT_FRAME_RATE_RANGE_MAX, &frameRateMax, &denominator);
    ++index;
}

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Get all supported FPS camera values ​​at Microsoft Media Foundation

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Get all supported FPS camera values at Microsoft Media Foundation