Convert h264 to pgm

What is the difference between .h264 and .pgm?

Description: The H.264 Encoded Video File, commonly referred to by its file extension .h264, is a digital video file format that utilizes the H.264 codec. This codec, also known as MPEG-4 Part 10 or AVC (Advanced Video Coding), is widely recognized for its high compression efficiency, providing high-quality video at relatively low bitrates. This makes it ideal for use in various applications, from streaming video services and Blu-ray discs to digital television broadcasts and video conferencing.; A PGM file is a grayscale image file saved in the portable gray map (PGM) format and encoded with one or two bytes (8 or 16 bits) per pixel. It contains header information and a grid of numbers that represent different shades of gray from black (0) to white (up to 65,536). PGM files are typically stored in ASCII text format, but also have a binary representation.