How can you transcode media to higher bitrates when there is no new information to be included?
In: Technology
You can run the transcode job and set the bitrate very high no problem. You’re right in that the image quality won’t be any higher than the original input (without something modifying the video in between, but we will ignore that).
However that doesn’t mean the bitrate you request is impossible. The encoder doesn’t know what the source is. It just gets a bunch of still images in a row and needs to encode them into a video file. It looks at them and does its best to preserve all the details it sees. Now some of those “details” will actually be the errors and artefacts of the lower bitrate decoded version, but dammit, it’s going to preserve them as best it can! All the bits that are available to it will be used to make the new output look as close to the input it was given!
For some types of video – like a cartoon with very little motion and a lot of stills – you might not reach your requested bitrate. The encoder does reserve the right to say “I’ve done my best, higher bitrates won’t help”. However that point can still be way higher than the original input.
Also don’t forget multiple codecs exist. I might convert from codec A to codec B. If codec B is worse than codec A, yeah it’s going to need more bits just to not go to crap relative to what codec A can do. An original master source would be preferable to the codec A file I have, but sometimes you make do with what you have.
Latest Answers