CLI --quality option support for environment variables

[michaelGregoire]

So, I'm adding a couple custom scripts to my package.json to make rendering a little more configurable via environment variables. One of the scripts I added is the following:

"build:frames": "FRAMES=0-1000 QUALITY=50 remotion render --frames=$FRAMES --image-format='jpeg' --quality=$QUALITY src/index.jsx IDENTIFIER out/segment.mp4",

As you can see, I'm making the --frames and --quality configurable via environment variables in the command line. --frames works perfectly. However, --quality complains that the value provided by the environment variable is a string and seems to end up with an empty string.

Error: Quality option must be a number or undefined. Got string ("")

It would be great if the option passed the value through to parseInt() and then only throw the error when the output from parseInt() is NaN.

[JonnyBurger]

Hi @michaelGregoire! Thanks for filing the issue.

After some tinkering, I find that this is purely a behavior of the shell / npm scripts and not with Remotion - you cannot define env variables this way. For example:

"scripts": {
	"quality": "QUALITY=50 echo $QUALITY"
}

npm run quality will yield an empty string (this is also why you got this error message).

But what would work is QUALITY=50 npm run update. This probably makes more sense than defining a env variable and then hardcoding it in the same command.

Potentially interesting for you: You may also use the config file and script it with Typescript: https://www.remotion.dev/docs/config#setquality

[michaelGregoire]

Thanks @JonnyBurger. It turns out I was doing what I wanted to do initially wrong.

I had started with the following and it seemed to work for FRAMES, but when I added QUALITY, it failed:

"build:frames": "remotion render --frames=${FRAMES:0-100} --image-format='jpeg' --quality=${QUALITY:50} src/index.jsx IDENTIFIER out/segment.mp4",

…so I moved on to what I previously showed you, which as you already know doesn't work:

"build:frames": "FRAMES=0-1000 QUALITY=50 remotion render --frames=$FRAMES --image-format='jpeg' --quality=$QUALITY src/index.jsx IDENTIFIER out/segment.mp4",

So I was misremembering how to do the first method. What I needed to do was the following, which works:

"build:frames": "remotion render --frames=${FRAMES:-0-100} --image-format='jpeg' --quality=${QUALITY:-50} src/index.jsx IDENTIFIER out/segment.mp4",

Now, I can override with environment variables like so:

FRAMES=0-1000 QUALITY=70 npm run build:frames

[JonnyBurger]

Perfect, glad the problem is resolved!