Digital video files: mid-stream changes

[peter_b]

Nowadays digital broadcasts are concatenated clips wrapped in a transport stream.
Recording that stream (e.g. as MPEG-TS / ".ts" file) can therefore contain different encodings with different technical properties inside.
So called "mid-stream changes".

Most applications however, expect one videofile to have one set of properties:

• resolution (width * height)
• framerate (fps)
• audio/video codec
• audio samplerate/channels
• etc.

Here I'll collect some information about how to analyze - and possibly fix such files.

[peter_b]

This command will list all resolutions (width/height) found within a digital videofile:

Code: Select all

$ cat $VIDEO_IN | grep "width\|height" | sort | uniq

For example, applying this to an off-the-air recording (=one MPEG-TS file) may return:

height=594
height=720
width=1056
width=1280

This is actually a real-world example: The resolution of the TV show is different than the commercial breaks in between.