: Place your text on a track above your video and apply the Track Matte Key effect to the video layer, selecting the text track as the matte source.

: Use the "Mask" tool or the "Overlay" feature with a "Chroma Key" or "Blending" mode to reveal video through text shapes. Quick Actions for your MP4

If you are looking for "helpful text" in the context of video effects (like putting a video inside text), you can achieve this using the or Track Matte features in most editing software:

: If the file won't open, try playing it in a versatile player like VLC Media Player which supports almost all MP4 codecs.