faq.md

Frequently asked questions {#chap:faq}

TODO: this chapter still has to be written

Errors

TODO: common errors => link to corresponding section

That source is fallible

We must catchup

Too much CPU is used

Check the samplerate conversion settings

encoding blank

This error means that a clock is getting late in liquidsoap. This can be caused by an overloaded CPU, if your script is doing too much encoding or processing: in that case, you should reduce the load on your machine or simplify your liquidsoap script. The latency may also be caused by some lag, for example a network lag will cause the icecast output to hang, making the clock late.

The first kind of latency is problematic because it tends to accumulate, eventually leading to the restarting of outputs:

Too much latency!
Resetting active source...

The second kind of latency can often be ignored: if you are streaming to an icecast server, there are several buffers between you and your listeners which make this problem invisible to them. But in more realtime applications, even small lags will result in glitches.

In some situations, it is possible to isolate some parts of a script from the latency caused by other parts. For example, it is possible to produce a clean script and back it up into a file, independently of its output to icecast (which again is sensitive to network lags). For more details on those techniques, read about clocks.

Cannot decode "file" as

This log message informs you that liquidsoap failed to decode a file, not necessarily because it cannot handle the file, but also possibly because the file does not contain the expected media type. For example, if video is expected, an audio file will be rejected.

The case of mono files is often surprising. Since liquidsoap does not implicitly convert between media formats, input files must be stereo if the output expects stereo data. As a result, people often get this error message on files which they expected to play correctly. The simple way to fix this is to use the audio_to_stereo() operator to allow any kind of audio on its input, and produce stereo as expected on its output.

Clock errors

Read about clocks for the errors a source cannot belong to two clocks and cannot unify two nested clocks.

Example of a type error due to contents mismatch

where we have to drop audio or something

A type error with () when accessing a non-existent field

Warnings

Unused sources

This expression should have type unit

This one is explained in there:

Warning 3: This expression should have type unit.

Runtime errors

not_found

example of a list.hd([])

internal errors

examples of an http.get on an non-existent url