I have a standard HDMI Capture Card which takes an HDMI signal and turns it into a USB signal that goes into my computer (in my case a Mac Air M1).  I have tested this card with HDMI output from a laptop and a Samsung Galaxy, and it works.  My computer gets the live video stream.
However, when I connect it to the HDMI output from the DJI RC-Pro controller, it does NOT work.  I get the "rainbow of death" .


* I have verified that the HDMI output on my RC-Pro works - when I plug it into a monitor, it displays the drone's camera image. This also proves that my HDMI cable is good.  
* I have verified that the HDMI Capture card works - when I give it video from another HDMI source (like my other laptop or android phone) it works.  * I have also tried with USB-video output, but ran into another problem (see https://forum.dji.com/forum.php?mod=viewthread&tid=292354)

So there must be some problem in the way that the RC-Pro talks to the capture card.  Has anyone experienced this or does anyone understand why this might happen?


--- Mandarin translation courtesy of GPT-4.  May have errors. ---

我有一个标准的HDMI采集卡，它可以将HDMI信号转换为USB信号，然后输入到我的电脑中（在我这里是Mac Air M1）。我已经用笔记本电脑和Samsung Galaxy的HDMI输出测试过这张卡，它是有效的。我的电脑可以接收到实时的视频流。

然而，当我将其连接到DJI RC-Pro控制器的HDMI输出时，它就不起作用了。我得到的是“死亡彩虹”。

* 我已经确认我的RC-Pro的HDMI输出是有效的 - 当我将它插入一个显示器时，它显示出无人机的摄像头图像。这也证明我的HDMI线是好的。
* 我已经确认HDMI采集卡是有效的 - 当我从另一个HDMI源（比如我的其他笔记本或安卓手机）给它视频时，它是有效的。
* 我也尝试过使用USB视频输出，但遇到了另一个问题（请参阅https://forum.dji.com/forum.php?mod=viewthread&tid=292354）

所以，RC-Pro与采集卡之间的通信方式可能存在某种问题。有人遇到过这种情况吗？或者有人明白为什么会这样吗？

Hi there. Thank you for reaching out and we're sorry for the trouble. We will coordinate this concern of yours to our relevant team for further clarification. Kindly please provide us a picture showing how you setup the DJI RC Pro connected to the external device using the said accessory so we can check it further. Please keep us posted. Thank you.

I found the solution - It turned out I had to adjust the HDMI Resolution on the RC-Pro (Settings -> Display -> HDMI -> HDMI Resolution), then after that, video capture worked.

What was odd was that - if I recall correctly, It was originally set to 1920x1080, and not working.  Then when I changed it to 1280x720 it worked, but then I changed it back to 1920x1080, it still worked.  At 3840x2160, it does not work.  

Here is a video showing the problem and the fix: https://photos.google.com/photo/ ... 6CTLwf-GnYHdimbulnP

And here is the proof that it works.