It's not just space either, over the years I've owned a range of different devices, all recording video in different formats, codecs and qualities. Also, when you start thinking about backing up all those precious memories to a cloud service then size really starts to matter again. Storage space might have become a lot cheaper in recent years, but at the same time we're recording more and more high quality video. taking up loads of space? So did I, so I started looking for a way to reduce the size while keeping the perceived quality the same, and retaining all of the original metadata and timestamps. And even keeping the same codec, if you re-compress, you might want to use an even higher bitrate to avoid generation loss.Do you have loads of videos littering your drive from your phone, camera, GoPro etc. Therefore, taking the original bitrate may not work well. The same goes for the actual encoders implementing the codecs: x264 is more efficient than the reference H.264 encoder, etc. Each codec offers different quality at different bitrates – for example, H.264 is much more efficient than MPEG-4 Part II. If you are going from one codec to another, they might be less or more efficient. No – it wouldn't even make sense to do that. My question now is if I need to specify a quality/bitrate or if it is possible to tell ffmpeg to use the original bitrate somehow.
In the latter case, lower values mean better quality. Specify your own target with -b:v 2M (depending on your resolution) or even better, use constant quality with -q:v 5 (as suggested by Mulvya in the comments).
The defaults for mpeg4 are not well chosen, so the target bitrate is quite low. It works fine, except for the quality because ffmpeg is using a very low bitrate.
0 kommentar(er)
