It’s really important to understand the difference between codecs and containers. They are very different things, but often got mixed up.
Codecs do specify an algorithm to represent video- and audio data in a digital environment. The usage of a camera/microphone to record video/audio will lead to a loss of information, cause of the necessary analog to digital conversion. Typically the codec also does a compression and depending on the algorithm it can occur an additional data loss. Common video codecs are VP9 and AVC and common audio codecs are AAC and OPUS.
Containers on the other hand define the general structure of the file. In a video file for example they determine where the meta-, video-, audio data and subtitles has to be. The metadata are normally at the beginning or the end of the container file. In addition to the structure definition, also the usable set of codecs is determined by the container. Typical video containers are MKV and MP4 and typical audio containers are M4A and WAV.
$ video_details() {
mediainfo --Inform="General;Container=%Format%" "$@"
mediainfo --Inform="Video;Video-Codec=%Format%" "$@"
mediainfo --Inform="Audio;Audio-Codec=%Format%" "$@";
}
$ video_details "BVG – Ohne Uns.mp4"
Container=MPEG-4
Video-Codec=AVC
Audio-Codec=AAC