Many media formats (including all digital TV formats) encode a rolling hardware timestamp of 33 bits (or more) which won't be the same for two separate segments by random chance. Audio, video, subtitles and other metadata will be ordered differently in the stream because they all comes from sources that have their own separate clocks. Synchronization between clocks at different stages in the media pipeline will cause different frames in the sequence to be dropped, padded, made into keyframes, etc, which then affects every bit in subsequent frames. TV stations use time-based watermarks. TV stations use digital compositing software that may retain bits from previous frames on an ongoing basis. Many studio media pipelines still involve analog steps.
The list of complications goes on.
Unless your pipeline is lossless, uses only digital sources and uses totally synchronized clocks for all stages, you're about as likely to get an MD5 hash collision by accident as you are to get any two non-trivial sequences of compressed video to be bit-identical.