[Cin] offtopic: HDMI capture

Andrew Randrianasulu randrianasulu at gmail.com
Tue Nov 17 00:41:38 CET 2020

I did little research , and apparently there are some HDMI capture cards/USB 3.0 dongles.

But Magewell XI100DUSB-HDMI tend to cost $300 (!!) and while it was reported to work with Linux and standard (in-kernel) UVC driver it only supported 4:2:2 
8-bit per component  capture ....

[video4linux2,v4l2 @ 0x1e46dc0] The v4l2 frame is 0 bytes, but 4147200 bytes are expected. Flags: 0x00002045
 Input #0, video4linux2,v4l2, from '/dev/video0':
 Duration: N/A, bitrate: 995328 kb/s
 Stream #0:0: Video: rawvideo (YUY2 / 0x32595559), yuyv422, 1920x1080, 995328 kb/s, 30 fps, 30 tbr, 1000k tbn, 1000k tbc

(this bug was fixed, just showing where I get my info)

Unfortunately, there apparently was some another bug in Linux kernel:

Not enough bandwidth with Magewell XI100DUSB-HDMI
2018-01-19 20:12

Not sure if it was fixed or not.

Declink cards require their own SDK (non-free)

On windows it seems to be working ... with some effort:

there was ffmpeg page showing directshow capture on Windows, this lists some 10-bit formats like 

[dshow @ 0000007201cda8a0]   vcodec=v210  min s=3840x2160 fps=30 max s=3840x2160 fps=30
[dshow @ 0000007201cda8a0]   vcodec=r210  min s=1920x1080 fps=23.976 max s=1920x1080 fps=23.976

This codec is used in TV & film production and stores raw 10-bit RGB data. Each red, green, and blue color component is 10 bits wide.

The v210 format is a packed YUV 4:2:2 format with 10 bits per component.


But you probably need real ultrafast (NVME?) drive for working with those .... at least at higher resolutions.

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