Hi all!
I would like to built a luminous object emitting a video in a dark scene, like a computer screen or a phone display.
(I have attached an image of what I intend).
What type of light should I use? The video is not built inside Houdini but it will be uploaded.

Thanks
Lucia

If the emissive area is rectangular, you can use a regular area light with a texture map. If not, a geometry light can be used for an arbitrary mesh. If the emission is not a very important contribution to your scene's total lighting, you can simply use an emissive shader. It is more efficient than a using a light when it doesn't contribute much to final color.

Thanks Jsmack,
I would like to import a playing video, in an object as a tv screen but it seems impossible!

You will need to convert the video to an image sequence first. Preferably, a RAT texture format image sequence for efficiency. ffmpeg is a free application you can use to convert most video formats to images such as jpg or png, and then you can use houdini or a houdini commandline tool ‘iconvert’ to convert from images to textures.

Once you have the texture sequence, it is a trivial matter to assign the texture to the light or material in question.