Author: avin

I’ve recently created a Power BI Custom Visual for our BOQ report headers, as we have a specific header visual style that we want all reports to have:

Normally when theming a custom visual that you import as a file, you just need to use the guid property of the custom visual (in pbiviz.json) as the key in the theme JSON file. For example, we use BOQGroupHeader in both pbiviz.json and theme.json:

pbiviz.json

{
    "visual": {
        "name": "BOQGroupHeader",
        "displayName": "BOQ Group Header",
        "guid": "BOQGroupHeader",
    }
}

theme.json

{
    "visualStyles": {
        "BOQGroupHeader": {
          "*": {
            "background": [
              {
                "show": false
              }
            ],
            "title": [
              {
                "show": false
              }
            ]
          }
        }
    }
}

However, when users download the custom visual from Power BI Service as a Organisational Visual, the theme file does not work. This is because Microsoft must change the guid property of the visual to ensure it doesn’t collide with file imported visuals vs Organisational Visuals.

If you open up the pbix file, you can find that Microsoft add a suffix of _OrgStore to the Organisational Visual, and this needs to be added to the theme file for the custom visual then to use that theme.

So our new theme.json looks like:

{
    "visualStyles": {
        "BOQGroupHeader_OrgStore": {
          "*": {
            "background": [
              {
                "show": false
              }
            ],
            "title": [
              {
                "show": false
              }
            ]
          }
        }
    }
}

I recently wanted to trim and fade out an MP4 file. I wasn’t inclined at the effort of putting it in a non-linear editor and was looking for a quick way to achieve this.

I found that ffmpeg had the necessary functionality to do this. The command I used in the end was:

ffmpeg -i in.mp4 -ss 00:00:00 -t 00:05:00 -vf "fade=t=out:st=297:d=3" -af "afade=t=out:st=297:d=3" out.mp4

The commands are:

• -i in.mp4 is the input file
• -ss 00:00:00 is where the video should start from (set this to other than zero to trim the start)
• -t 00:05:00 is the duration of the video, trimming any video after that
• -vf "fade=t=out:st=297:d=3" is a video filter which fades out at 297 seconds (4:57) over a 3 second duration
• -af "afade=t=out:st=297:d=3" is the corresponding audio filter which fades out at 297 seconds (4:57) over a 3 second duration
• out.mp4 is the output file

The video and audio filters have several more properties you can play with, such as if you want to fade to white using a log curve for the audio fade.

You can also combine filter commands by separating them with a comma, if you want both a fade in and fade out, for example:

-vf "fade=t=in:st=0:d=3,fade=t=out:st=297:d=3" -af "afade=t=out:st=0:d=3,afade=t=out:st=297:d=3"