FFmpeg (1.0 beta1) prevents Liquidsoap 2.0 from compiling on Raspbian Buster

[nordseele]

The ffmpeg library - or one of its sub-libraries (ffmpeg-decoder ?) v 1.0.0~beta1 - seems to prevent the compilation and installation of Liquidsoap 2.0 on a Raspberry Pi 3B running Rasbian Buster.

# OCAMLOPT -c decoder/ffmpeg_decoder.ml
# File "decoder/ffmpeg_decoder.ml", line 221, characters 15-27:
# 221 |   Av.seek ~fmt:`Millisecond ~min_ts ~max_ts ~ts container;
#                      ^^^^^^^^^^^^
# Error: The function applied to this argument has type
#          Avutil.Time_format.t -> Int64.t -> Av.seek_flag array -> unit
# This argument cannot be applied with label ~fmt
# make[2]: *** [../Makefile.rules:127: decoder/ffmpeg_decoder.cmx] Error 2
# make[2]: Leaving directory '/home/pi/.opam/4.12.0/.opam-switch/build/liquidsoap.2.0.0/src'
# make[1]: *** [../Makefile.rules:69: all-auto-ocaml-prog] Error 2
# make[1]: Leaving directory '/home/pi/.opam/4.12.0/.opam-switch/build/liquidsoap.2.0.0/src'
# make: *** [Makefile.rules:29: all-subdirs] Error 2

To Reproduce
New installation of Liquidsoap using OPAM on a Raspberry Pi 3B running Rasbian Buster (10).
New switch create 4.12.0

git clone https://github.com/savonet/liquidsoap.git
cd liquidsoap
opam pin add liquidsoap .

• Without any libraries, Liquidsoap 2.0 compiles successfully. 🟢

• If we add a few libraries like taglib mad lame cry samplerate alsa. Again, Liquidsoap 2.0 compiles successfully. 🟢

• Adding the FFmpeg library using opam install ffmpeg, compiling Liquidsoap 2.0 will fail with the following error 🔴

[ERROR] The compilation of liquidsoap failed at "/home/pi/.opam/opam-init/hooks/sandbox.sh build make".
#=== ERROR while compiling liquidsoap.2.0.0 ===================================#
# context     2.0.3 | linux/arm32 | ocaml-base-compiler.4.12.0 | pinned(git+file:///home/pi/liquidsoap#main#e0d0b7c1)
# path        ~/.opam/4.12.0/.opam-switch/build/liquidsoap.2.0.0
# command     ~/.opam/opam-init/hooks/sandbox.sh build make
# exit-code   2
# env-file    ~/.opam/log/liquidsoap-18400-6990f5.env
# output-file ~/.opam/log/liquidsoap-18400-6990f5.out
### output ###
# [...]
# OCAMLOPT -c decoder/ffmpeg_decoder.ml
# File "decoder/ffmpeg_decoder.ml", line 221, characters 15-27:
# 221 |   Av.seek ~fmt:`Millisecond ~min_ts ~max_ts ~ts container;
#                      ^^^^^^^^^^^^
# Error: The function applied to this argument has type
#          Avutil.Time_format.t -> Int64.t -> Av.seek_flag array -> unit
# This argument cannot be applied with label ~fmt
# make[2]: *** [../Makefile.rules:127: decoder/ffmpeg_decoder.cmx] Error 2
# make[2]: Leaving directory '/home/pi/.opam/4.12.0/.opam-switch/build/liquidsoap.2.0.0/src'
# make[1]: *** [../Makefile.rules:69: all-auto-ocaml-prog] Error 2
# make[1]: Leaving directory '/home/pi/.opam/4.12.0/.opam-switch/build/liquidsoap.2.0.0/src'
# make: *** [Makefile.rules:29: all-subdirs] Error 2
<><> Error report <><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
┌─ The following actions failed
│ λ build liquidsoap 2.0.0
└─ 
┌─ The following changes have been performed
│ ⊘ remove    liquidsoap         2.0.0
│ ↻ recompile mm                 0.7.1
│ ∗ install   alsa               0.3.0
│ ∗ install   ao                 0.2.3
│ ∗ install   bjack              0.1.6
│ ∗ install   conf-alsa          1
│ ∗ install   conf-ao            1
│ ∗ install   conf-ffmpeg        1
│ ∗ install   conf-jack          1
│ ∗ install   conf-ladspa        1
│ ∗ install   conf-libogg        1
│ ∗ install   conf-libopus       1
│ ∗ install   conf-libsamplerate 1
│ ∗ install   conf-libssl        3
│ ∗ install   conf-libvorbis     1
│ ∗ install   cry                0.6.5
│ ∗ install   faad               0.5.0
│ ∗ install   ffmpeg             1.0.0~beta1
│ ∗ install   ffmpeg-av          1.0.0~beta1
│ ∗ install   ffmpeg-avcodec     1.0.0~beta1
│ ∗ install   ffmpeg-avdevice    1.0.0~beta1
│ ∗ install   ffmpeg-avfilter    1.0.0~beta1
│ ∗ install   ffmpeg-avutil      1.0.0~beta1
│ ∗ install   ffmpeg-swresample  1.0.0~beta1
│ ∗ install   ffmpeg-swscale     1.0.0~beta1
│ ∗ install   ladspa             0.2.0
│ ∗ install   lame               0.3.4
│ ∗ install   mad                0.5.0
│ ∗ install   ogg                0.7.0
│ ∗ install   opus               0.2.0
│ ∗ install   samplerate         0.1.5
│ ∗ install   ssl                0.5.10
│ ∗ install   taglib             0.3.6
│ ∗ install   topkg              1.0.3
│ ∗ install   vorbis             0.8.0
│ ∗ install   xmlm               1.3.0
│ ∗ install   xmlplaylist        0.1.5
└─ 
<><> liquidsoap.2.0.0 troubleshooting <><><><><><><><><><><><><><><><><><><><><>
=> We're sorry that your liquidsoap install failed. Check out our installation
   instructions at: https://www.liquidsoap.info/doc-2.0.0/install.html#opam
   for more information.
The former state can be restored with:
    opam switch import "/home/pi/.opam/4.12.0/.opam-switch/backup/state-20210725170225.export"
Or you can retry to install your package selection with:
    opam install --restore

Expected behavior
The FFmpeg library is mandatory if one want to use the input.http() method in Liquidsoap 2.0.

I didn't pin a specific version of FFmpeg; By default, OPAM seems to get the 1.0 beta1 / Which version of Ffmpeg that is known to be working

pi@radio:~ $ opam install ffmpeg
The following actions will be performed:
  ∗ install   conf-ffmpeg       1           [required by ffmpeg-avcodec]
  ∗ install   ffmpeg-avutil     1.0.0~beta1 [required by ffmpeg]
  ∗ install   ffmpeg-swscale    1.0.0~beta1 [required by ffmpeg]
  ∗ install   ffmpeg-avfilter   1.0.0~beta1 [required by ffmpeg]
  ∗ install   ffmpeg-avcodec    1.0.0~beta1 [required by ffmpeg]
  ∗ install   ffmpeg-swresample 1.0.0~beta1 [required by ffmpeg]
  ∗ install   ffmpeg-av         1.0.0~beta1 [required by liquidsoap]
  ∗ install   ffmpeg-avdevice   1.0.0~beta1 [required by ffmpeg]
  ∗ install   ffmpeg            1.0.0~beta1
  ↻ recompile liquidsoap        2.0.0*      [uses ffmpeg-avcodec]

Version details

• OS: [e.g. Debian, OSX]
• Version [e.g. 1.3.4]

Install method

OPAM 2.0.3
I used the opam pin add method in order to obtain the latest version of Liquidsoap on Github.
Switch 4.12.0

[nordseele]

I tried the following commands. Ffmpeg 0.4.3 installs successfully.

I then tried to opam install liquidsoap again but Opam wants to upgrade ffmpeg to 1.0.0~beta1

opam remove ffmpeg-av ffmpeg conf-ffmpeg ffmpeg-avcodec ffmpeg-avfilter ffmpeg-avdevice ffmpeg-avutil ffmpeg-swresample ffmpeg-swscale

and install the stable version of Ffmpeg (0.4.3)

opam depext ffmpeg.0.4.3

opam install ffmpeg.0.4.3

opam install liquidsoap

<><> Processing actions <><><><><><><><><><><><><><><><><><><><><><><><><><><><>
∗ installed ffmpeg.0.4.3
Done.
pi@radio:~ $ opam install liquidsoap

<><> Synchronising pinned packages ><><><><><><><><><><><><><><><><><><><><><><>
[liquidsoap.2.0.0] no changes from git+file:///home/pi/liquidsoap#main

The following actions will be performed:
  ∗ install conf-ffmpeg       1                    [required by ffmpeg-av]
  ∗ install ffmpeg-avutil     1.0.0~beta1          [required by liquidsoap]
  ∗ install ffmpeg-swscale    1.0.0~beta1          [required by liquidsoap]
  ∗ install ffmpeg-avfilter   1.0.0~beta1          [required by liquidsoap]
  ∗ install ffmpeg-avcodec    1.0.0~beta1          [required by liquidsoap]
  ∗ install ffmpeg-swresample 1.0.0~beta1          [required by liquidsoap]
  ∗ install ffmpeg-av         1.0.0~beta1          [required by liquidsoap]
  ∗ install ffmpeg-avdevice   1.0.0~beta1          [required by liquidsoap]
  ∗ install liquidsoap        2.0.0*
  ↗ upgrade ffmpeg            0.4.3 to 1.0.0~beta1 [uses ffmpeg-avcodec]
===== ∗ 9   ↗ 1 =====
Do you want to continue? [Y/n] 

I tried to opam pin add ffmpeg 0.4.3 but this version conflicts with Liquidsoap 2.0 according to Opam. I'm not sure what to do next...

[smimram]

You need to install the latest git version of ffmpeg too first. For this you need to do something like this:

git clone https://github.com/savonet/ocaml-ffmpeg.git
cd ocaml-ffmpeg
opam pin add .

and answer y.

[nordseele]

Thanks @smimram !
Yes, this time it's working and Liquidsoap 2.0 compiles successfully !