Ways to reduce any video file size:
- Use a lower bitrate (lower visual quality),
- Reduce the resolution (less pixels),
- Reduce the duration (less time),
- Reduce the frame rate,
- Use a more efficient codec.
Which to choose depends on your reasons for wanting to reduce the size. There may be better ways, maybe without reducing anything at all (e.g. email a download-link instead of attaching the full file).
Smaller sizes aren’t ‘free’, you have to let go of some information.
- QuickTime uses fixed bitrate presets that it doesn’t show the details of to the user. Not ideal for this goal.
- 720p files are generally smaller than 1080p files, and often good enough for ‘talking head’ videos and presentations.
- “Recaps” are edits meant to be short, but still contain the important parts.
- 24-30 fps is enough for most uses. 48, 60 or even 120 fps is overkill for most uses after editing. Be mindful of the camera settings, and the properties of the first clip added to your editing project.
- E.g. H.265 HEVC produces much smaller files than H.264 AVC (up to roughly half size), but the recipient must have support for that through modern media player software and modern more powerful hardware.
➔ So, at what size is your source video file now, and at what size would you want it to be? What makes you want change the file size at all? Why is size a constraint for you?
There is other conversion software, that may have settings that allow for indicating a final size, or average bitrate, as a goal (somewhere in that vicinity), and multi-pass encoding to get more precise with that. In these cases, the quality will be somewhat unpredictable, except for experience. Other software may work with a settings for Constant Quality Factor/Constant Rate Factor, or else named presets (very low, low, medium, high, very high, extreme high quality). I find that I want a certain quality more than any particular size.
Note that any video conversion (re-encoding) is lossy. If done well, then viewers may not notice the very small quality difference.
My favorite conversion software are:
- HandBrake (a GUI for ffmpeg), with a nice balance of options and not being too complicated,
- ff·Works (a GUI for ffmpeg), with lots of detailed options that may take some getting used to.
Both have presets to load settings bases on what is it that you are encoding for, which should make it much easier for beginners and advanced users alike.
