Then again, some of them do not know the difference between an undecidable
problem and an NP-hard problem...
+@section I have installed this library with my distro's package manager. Why does @command{configure} not see it?
+
+Distributions usually split libraries in several packages. The main package
+contains the files necessary to run programs using the library. The
+development package contains the files necessary to build programs using the
+library. Sometimes, docs and/or data are in a separate package too.
+
+To build FFmpeg, you need to install the development package. It is usually
+called @file{libfoo-dev} or @file{libfoo-devel}. You can remove it after the
+build is finished, but be sure to keep the main package.
+
@chapter Usage
@section ffmpeg does not work; what is wrong?
(default ~5 Mo) and @code{analyzeduration} (default 5,000,000 µs = 5 s). For
the subtitle stream to be detected, both values must be large enough.
+@section Why was the @command{ffmpeg} @option{-sameq} option removed? What to use instead?
+
+The @option{-sameq} option meant "same quantizer", and made sense only in a
+very limited set of cases. Unfortunately, a lot of people mistook it for
+"same quality" and used it in places where it did not make sense: it had
+roughly the expected visible effect, but achieved it in a very inefficient
+way.
+
+Each encoder has its own set of options to set the quality-vs-size balance,
+use the options for the encoder you are using to set the quality level to a
+point acceptable for your tastes. The most common options to do that are
+@option{-qscale} and @option{-qmax}, but you should peruse the documentation
+of the encoder you chose.
+
@chapter Development
@section Are there examples illustrating how to use the FFmpeg libraries, particularly libavcodec and libavformat?