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How to control bitrate MEDIASUBTYPE_H264 directshow?

I have a webcam logitech c920that represents encoded h264 capture pin(subtype:) MEDIASUBTYPE_H264.

The h264 pin supports the following permissions:

FORMAT_VideoInfo - subtype: MEDIASUBTYPE_H264 640x480 @ 30 fps  
FORMAT_VideoInfo - subtype: MEDIASUBTYPE_H264 160x90 @ 30 fps  
FORMAT_VideoInfo - subtype: MEDIASUBTYPE_H264 160x120 @ 30 fps  
FORMAT_VideoInfo - subtype: MEDIASUBTYPE_H264 176x144 @ 30 fps  
FORMAT_VideoInfo - subtype: MEDIASUBTYPE_H264 320x180 @ 30 fps  
FORMAT_VideoInfo - subtype: MEDIASUBTYPE_H264 320x240 @ 30 fps  
FORMAT_VideoInfo - subtype: MEDIASUBTYPE_H264 352x288 @ 30 fps  
FORMAT_VideoInfo - subtype: MEDIASUBTYPE_H264 432x240 @ 30 fps  
FORMAT_VideoInfo - subtype: MEDIASUBTYPE_H264 640x360 @ 30 fps  
FORMAT_VideoInfo - subtype: MEDIASUBTYPE_H264 800x448 @ 30 fps  
FORMAT_VideoInfo - subtype: MEDIASUBTYPE_H264 800x600 @ 30 fps  
FORMAT_VideoInfo - subtype: MEDIASUBTYPE_H264 864x480 @ 30 fps  
FORMAT_VideoInfo - subtype: MEDIASUBTYPE_H264 960x720 @ 30 fps  
FORMAT_VideoInfo - subtype: MEDIASUBTYPE_H264 1024x576 @ 30 fps  
FORMAT_VideoInfo - subtype: MEDIASUBTYPE_H264 1280x720 @ 30 fps  
FORMAT_VideoInfo - subtype: MEDIASUBTYPE_H264 1600x896 @ 30 fps  
FORMAT_VideoInfo - subtype: MEDIASUBTYPE_H264 1920x1080 @ 30 fps

In my testing, it always uses 3 Mbps regardless of the resolution selected. This is too much, especially for lower resolutions.

Any idea on how to programmatically select the desired bitrate using directshow? Or maybe another API?

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Logitech , 80/20 HW/SW, ( GOP) . , , . , , /fps:

Required bandwidth for size:  ( 1920 , 1080 )  @ 30  is 2.81771 Mbit 
Required bandwidth for size:  ( 1920 , 1080 )  @ 25  is 2.81672 Mbit 
Required bandwidth for size:  ( 1920 , 1080 )  @ 20  is 2.82701 Mbit 
Required bandwidth for size:  ( 1920 , 1080 )  @ 15  is 2.83327 Mbit 
Required bandwidth for size:  ( 1920 , 1080 )  @ 10  is 2.83594 Mbit 
Required bandwidth for size:  ( 1920 , 1080 )  @ 5  is 2.8431 Mbit 
Required bandwidth for size:  ( 1280 , 720 )  @ 30  is 2.82013 Mbit 
Required bandwidth for size:  ( 1280 , 720 )  @ 25  is 2.82436 Mbit 
Required bandwidth for size:  ( 1280 , 720 )  @ 20  is 2.83217 Mbit 
Required bandwidth for size:  ( 1280 , 720 )  @ 15  is 2.83696 Mbit 
Required bandwidth for size:  ( 1280 , 720 )  @ 10  is 2.83721 Mbit 
Required bandwidth for size:  ( 1280 , 720 )  @ 5  is 2.45272 Mbit 
Required bandwidth for size:  ( 864 , 480 )  @ 30  is 2.82089 Mbit 
Required bandwidth for size:  ( 864 , 480 )  @ 25  is 2.82313 Mbit 
Required bandwidth for size:  ( 864 , 480 )  @ 20  is 2.83131 Mbit 
Required bandwidth for size:  ( 864 , 480 )  @ 15  is 2.83343 Mbit 
Required bandwidth for size:  ( 864 , 480 )  @ 10  is 2.79526 Mbit 
Required bandwidth for size:  ( 864 , 480 )  @ 5  is 1.15564 Mbit 
Required bandwidth for size:  ( 320 , 180 )  @ 30  is 1.90123 Mbit 
Required bandwidth for size:  ( 320 , 180 )  @ 25  is 1.89367 Mbit 
Required bandwidth for size:  ( 320 , 180 )  @ 20  is 1.26006 Mbit 
Required bandwidth for size:  ( 320 , 180 )  @ 15  is 0.957935 Mbit 
Required bandwidth for size:  ( 320 , 180 )  @ 10  is 0.637158 Mbit 
Required bandwidth for size:  ( 320 , 180 )  @ 5  is 0.328456 Mbit

, . !

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IAMStreamConfig, GetStreamCaps(), , , pFormat VIDEOINFO, dwBitRate. IAMStreamConfig:: SetFormat .

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