Video channel display black screen problem
<p>[TOC]</p>
<h3>I. Problem Phenomenon</h3>
<h4>1、Black screen on some channels of client preview/playback</h4>
<ul>
<li>Real-time preview on client side, black screen for some channels.</li>
</ul>
<p><img src="http://118.195.179.210:9000/server/index.php?s=/api/attachment/visitFile&amp;sign=fc5f6d2340fcdb7c32a0af36a0e7f7a2" alt="" /></p>
<ul>
<li>Client query video, no video for some channels.</li>
</ul>
<p><img src="http://118.195.179.210:9000/server/index.php?s=/api/attachment/visitFile&amp;sign=dd60dfe2b4d7ca8ebc826f93be3203ba" alt="" /></p>
<ul>
<li>The client plays back the video with a black screen on some channels.</li>
</ul>
<h4>2、Player playback of some channels black screen</h4>
<ul>
<li>The player plays back the video with a black screen on some channels.</li>
</ul>
<h4>3、GUI preview/playback black screen for some channels</h4>
<ul>
<li>Local real-time preview screen with black screen for some channels.</li>
<li>Local query playback video, some channels black screen.</li>
</ul>
<h3>II. Analysis steps</h3>
<p>Follow the steps below to investigate the causes of the problem one by one:
1、Check camera access;
2、Check the working status of the camera；
3、Check the main stream recording settings；
4、Check OSD settings；
5、Check if the camera type corresponds to the setting on the GUI；
6、Check whether the parameters of the main code stream resolution of the device and the corresponding access camera resolution are the same；</p>
<h3>III. Operating instructions</h3>
<h4>1、Check camera access</h4>
<ul>
<li>Check whether the camera is connected, if the camera is not connected, or poor contact, not stable, it will cause no image preview, or completely unable to preview.</li>
</ul>
<h4>2、Check the working status of the camera</h4>
<ul>
<li>Check whether the channel shows video loss, if the access camera, but shows video loss, there may be a fault in the camera, can not work properly.</li>
</ul>
<p><img src="http://118.195.179.210:9000/server/index.php?s=/api/attachment/visitFile&amp;sign=ac817cea4f1689afe9e7c9cb49bdd497" alt="" /></p>
<p><img src="http://118.195.179.210:9000/server/index.php?s=/api/attachment/visitFile&amp;sign=638d3215165b6e46bb93e043e4c6432b" alt="" /></p>
<h4>3、Check the main stream video settings</h4>
<ul>
<li>Check whether the main stream settings open channel, if the channel is not open, the client can not preview, but also can not query the video playback video.</li>
<li>GUI to open the video settings, the main stream interface, check whether the main stream enable is on.</li>
</ul>
<p><img src="http://118.195.179.210:9000/server/index.php?s=/api/attachment/visitFile&amp;sign=c7f9c8ee1e84daec752f076c49c315a8" alt="" /></p>
<ul>
<li>Right-click the device number on the platform, click on the parameter configuration, open the video settings, the main stream interface, check whether the channel is open.</li>
</ul>
<p><img src="http://118.195.179.210:9000/server/index.php?s=/api/attachment/visitFile&amp;sign=43110989454a2d74ab4febcb501196c2" alt="" /></p>
<h4>4、Check OSD settings</h4>
<ul>
<li>Check whether the OSD information overlay setting is on, if the OSD information overlay setting is not on, the video cannot be seen and the OSD overlay information cannot be displayed when the camera is not connected or when the camera is damaged.</li>
</ul>
<p><img src="http://118.195.179.210:9000/server/index.php?s=/api/attachment/visitFile&amp;sign=1058e75414c39a8036abff4a765ea0bb" alt="" /></p>
<h4>5、Check the camera type</h4>
<ul>
<li>The camera type needs to correspond to the GUI settings, a different type will result in no video output.</li>
</ul>
<p><img src="http://118.195.179.210:9000/server/index.php?s=/api/attachment/visitFile&amp;sign=409f6c6b7582026b8beca0f91a191aaa" alt="" /></p>
<h4>6、Check if the resolution corresponds</h4>
<ul>
<li>Whether the camera resolution is the same as the device main stream settings, some products do not automatically identify the camera resolution, you need to manually set the corresponding resolution parameters, the camera resolution does not correspond to the device settings will lead to the inability to see the video or splash screen phenomenon, so you need to carefully check whether the parameters of the main stream resolution and the resolution of the access camera correspond.</li>
</ul>
<p><img src="http://118.195.179.210:9000/server/index.php?s=/api/attachment/visitFile&amp;sign=4ee58ce62e90f49c6326fcffa1ed7fea" alt="" /></p>