In this page, we list the most common catches when migrating to a new version of Liquidsoap.
audio_to_stereo
should not be required in most situations anymore. liquidsoap
can handle channels conversions transparently now!
The type of the auth
function in input.harbor
has changed. Where before, you would do:
def auth(user, password) =
...end
You would now do:
def auth(params)
user = params.user
password = params.password
...end
Now that sources have their own methods, the actual list of methods attached to each source can vary from one to the next. For instance, playlist
has a reload
method but input.http
does not. This currently confuses the type checker and leads to errors that look like this:
At script.liq, line xxx, char yyy-zzz:5: this value has type
Error source(audio=?A, video=?B, midi=?C)
_ *
.{
time : () -> float,
shutdown : () -> unit,
fallible : bool,
skip : () -> unit,
seek : (float) -> float,
is_active : () -> bool,
is_up : () -> bool,
log :
{level : (() -> int?).{set : ((int) -> unit)}
},
self_sync : () -> bool,
duration : () -> float,
elapsed : () -> float,
remaining : () -> float,
on_track : ((([string * string]) -> unit)) -> unit,
on_leave : ((() -> unit)) -> unit,
on_shutdown : ((() -> unit)) -> unit,
on_metadata : ((([string * string]) -> unit)) -> unit,
is_ready : () -> bool,
id : () -> string,source(audio=?D, video=?E, midi=?F)?)
selected : (() ->
}122, char 2-21
but it should be a subtype of the type of the value at radio.liq, line _ * _.{reload : _}
In such cases, we recommend to give a little nudge to the typechecker by using the (s:source)
type annotation where a list of source is causing the issue. For instance:
s = fallback([
(s1:source),
(s2:source),
(s3:source) ])
This tells the type checker not to worry about the source methods and just focus on what matters, that they are actually sources.. 🙂
In order to provide as much compatibility as possible with the different HTTP procotols and implementation, we have decided to delegate HTTP support to external libraries which have large scale support and implementation. This means that, if you have installed liquidsoap
using opam
:
- You need to install the
ocurl
package to enable all HTTP request operators,http.get
,http.post
,http.put
,http.delete
andhttp.head
- You need to install the
ffmpeg
package (version1.0.0
or above) to enableinput.http
- You do not need to install the
ssl
package anymore to enable theirhttps
counter-part. These operators have been deprecated.
The parameters for cross
transitions was changed to take advantage of the new module system. Instead of passing multiple arguments related to the ending and starting track, those are regrouped into a single record. So, if you had a transition like this:
def transition(
ending_dB_level, starting_dB_level,
ending_metadata, starting_metadata,
ending_source, starting_source) =
...end
You would now do:
def transition(ending, starting) =
# Now you can use:
# - ending.db_level, ending.metadata, ending.source
# - starting.db_level, starting.metadata, starting.source
...end
Settings are now exported as records. Where you would before write:
set("decoder.decoders", ["MAD", "FFMPEG"])
You can now write:
settings.decoder.decoders.set(["MAD", "FFMPEG"])
Likewise, to get a setting’s value you can now do:
current_decoders = settings.decoder.decoders()
This provides many good features, in particular type-safety.
For convenience, we have added shorter versions of the most used settings. These are all shortcuts to their respective settings
values:
log.level.set(4)
log.file.set(true)
log.stdout.set(true)
init.daemon.set(true)
audio.samplerate.set(48000)
audio.channels.set(2)
video.frame.width.set(720)
video.frame.height.set(1280)
The register
operator could not be adapted to this new API and had to be removed, however, backward-compatible set
and get
operators are provided. Make sure to replace them as they should be removed in a future version.
The function insert_metadata
does not return a pair anymore, but a source with a method named insert_metadata
. This means that you should change the code
fs = insert_metadata(s)
# The function to insert metadata
f = fst(ms)
# The source with inserted metadata
s = snd(ms)
...# Using the function
f([("artist", "Bob")])
...# Using the source
output.pulseaudio(s)
to
s = insert_metadata(s)
...# Using the function
s.insert_metadata([("artist", "Bob")])
...# Using the source
output.pulseaudio(s)
Queueing for request-based sources has been simplified. The default_duration
and length
have been removed in favor of a simpler implementation. You can now pass a prefetch
parameter which tells the source how many requests should be queued in advance.
Should you need more advanced queueing strategy, request.dynamic.list
and request.dynamic
now export functions to retrieve and set their own queue of requests.
json_of
has been renamed json.stringify
and of_json
has been renamed json.parse
.
JSON export has been enhanced with a new generic json object export. Associative lists of type (string, 'a)
are now exported as lists. See our JSON documentation page for more details.
Convenience functions have been added to convert metadata to and from JSON object format: metadata.json.stringify
and metadata.json.parse
.
Starting with liquidsoap 2.0.0
, output operators return the empty value ()
while they previously returned a source.
This helps enforce the fact that outputs should be end-points of your scripting graphs. However, in some cases, this can cause issues while migrating old scripts, in particular if the returned value of an output was used in the script.
The way to fix this is to apply your operator to the source directly underneath the output. For instance, the following clock assignment:
s = ...
clock.assign_new([output.icecast(..., s)])
Should now be written:
s = ...
clock.assign_new([s], ...)
output.icecast(..., s)
Some operators have been deprecated. For most of them, we provide a backward-compatible support but it is good practice to update your script. You should see logs in your script when running deprecated operatords. Here’s a list of the most important ones:
playlist.safe
is replaced by:playlist(mksafe(..))
playlist.once
is replaced by:playlist
, settingreload_mode
argument to"never"
andloop
tofalse
rewrite_metadata
should be rewritten usingmap_metadata
fade.inital
andfade.final
are not needed anymoreget_process_output
is replaced by:process.read
get_process_lines
is replaced by:process.read.lines
test_process
is replaced by:process.test
system
is replaced by:process.run
add_timeout
is replaced by:thread.run.recurrent
on_blank
is replaced by:blank.detect
skip_blank
is replaced by:blank.skip
eat_blank
is replaced by:blank.eat
strip_blank
is replaced by:blank.strip
which
is replaced by:file.which
register_flow
: flow is no longer maintainedempty
is replaced by:source.fail
file.unlink
is replaced by:file.remove
string.utf8.escape
is replaced by:string.escape
The windows binary is statically built and, for this reason, we cannot enable both the %ffmpeg
encoder and any encoder that uses the same underlying libraries, for instance libmp3lame
for mp3
encoding. The technical reason is that both libraries import the same C symbols, which makes compilation fail.
The %ffmpeg
encoder provides all the functionalities of the internal encoders that conflict with it along with many more format we do not support otherwise. For this reason, it was decided to enable the %ffmpeg
encoder and disable all other encoders.
This means that, if you were previously using a different encoder than %ffmpeg
, you will need to adapt your script to use it. For instance, for mp3 encoding with variable bitrate:
%ffmpeg(format="mp3", %audio(codec="libmp3lame", q=7))