Now the problem is that this comes with very large list of options, which are difficult to setup, especially for newbies like me. Than everything’s difficult, once because the resulting quality is not always the same as the input file’s quality.

The Solution

Is to use presets. Thankfully ffmpeg with libx264 can be used with presets, i.e. NORMAL, HD etc. which means that you don’t have to setup a command by hand and the resulting quality is the same as the input quality.

Here’s a sample command using normal preset:

ffmpeg -i source.mp4 -acodec libfaac -ab 128k -ac 2 -vcodec libx264 -vpre normal -threads 0 -crf 22 output.mp4

here the source can be either mp4 or some other file format as FLV for instance.