The Samsung charger is extremely fast, your experience is completely normal. My phone will completely charge after about an hour when it is nearly completely drained at the end of the night. The Samsung charger outputs 3X more power than a traditional USB charger.
As for the movie, that all depends on your settings. Those settings include screen brightness level, whether wi-fi was on or not, whether Bluetooth was on or not, what apps were running in the background, the source of this video (online streaming or playing locally off of the phone's built-in storage or an SD card), and how your phone was outputting volume (through the headphone jack, its built-in speaker, or via a Bluetooth audio device). The playback abilities also depend on the movie file type, resolution, and bitrate of the file you were playing back. A 30Mbps 4K video is going to consume more power than a 720p 2Mbps video.