264: Mp4

Does anyone have strong opinions about using h264 for proxy media?

Supported by nearly all streaming protocols like HLS, DASH, and RTSP. Practical Quick Facts 264 mp4

This is the "brain" that compresses and decompressess the raw video data to make it small enough for storage and streaming. Does anyone have strong opinions about using h264

Plays on almost any device, including iPhones, Androids, smart TVs, and web browsers. along with audio (typically AAC)

Provides high-quality 1080p or 4K video at significantly lower bitrates and smaller file sizes than older standards.

The combination of H.264 video inside an MP4 container is the industry standard for several reasons:

This is the "box" that holds the H.264 video stream, along with audio (typically AAC), subtitles, and metadata. Why They Are Used Together