Can I use conditional encoder configurations ?

[Russsgithub]

While using %ffmpeg as an encoder for output.icecast with a switch, i'd like to be able to change from %audio.copy to %audio(codec="libmp3lame", samplerate="44100", bitrate="320k") depending on a switch. The switch changes the stream from input.http ( which doesn't need encoding ) to a playlist which does need encoding.

I've tried this

pl = playlist('./playlist)
#### buffer for use in multiple places
pl = buffer(mksafe(pl))

s = input.http(.....) 
t = interactive.bool("switch")

s = switch([(t,s),({true}, pl)])

def enc()
  if t then
    (%ffmpeg(format="fdkaac", %audio.copy))
  else
    (%ffmpeg(format="mp3", %audio(codec = "libmp3lame", samplerate=44100,b="320k")))
  end
end
encoder = enc()
s = output.icecast(encoder, fallible = true, host="#{!out_url}", port=8000, password="#{!out_pass}", mount="#{!out_mount}", s)

but get this error

Error 5: this value has type
  (...) -> format(audio=ffmpeg.audio.copy(_),...)
but it should be a subtype of
  (...) -> format(audio=pcm(_),...)?

at the if t then line.

I've noticed there are issues with using %ffmpeg with mksafe(s) before it, but if I remove buffer(mksafe(s)) I get this error

Error 5: this value has type
  _ * 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,
    buffer_length : () -> float,
    status : () -> string,
    set_url : ({string}) -> unit,
    url : () -> string,
    stop : () -> unit,
    start : () -> unit,
    is_started : (() -> bool)
  }
but it should be a subtype of the type of the value at HttpStreamMixerv2_ffmpeg_pass_through.liq, line 216, char 52-73
  _ * _.{length : _}

at the switch line.

Thanks

[toots]

This is a feature that is being developed by @smimram as part of the 2.1.x branch. You might want to try the latest main to test it!

[Russsgithub]

@toots
@smimram
I thought I was, but have noticed some updates since I tried , so i'll give it a go.

Still getting errors

Error 5: this value has type
  (...) -> format(audio=ffmpeg.audio.copy(_),...)
but it should be a subtype of
  (...) -> format(audio=pcm(_),...)?

but it could be my script. I'll look into it further later.

Thanks

[smimram]

Any chance you could try #1946?

[Russsgithub]

@smimram

I've just tried this

def enc()
  if true == true then
    %ffmpeg(format="adts", %audio.copy)
  else
    %ffmpeg(format="adts", %audio(%fdkaac(channels=2, samplerate=48000, bitrate=320, afterburner=true, transmux="adts", aot="mpeg4_aac_lc", sbr_mode=false))) 
  end
end

enc = enc()

output.icecast(fallible=true, enc, format="audio/aac", host="HOST", password="PASS", port=8000, mount="MOUNT", s)

with the latest git main code, but got this error

Error 5: this value has type
  (...) -> format(audio=pcm(_),...)
but it should be a subtype of
  (...) -> format(audio=ffmpeg.audio.copy(_),...)

Thanks

[smimram]

Did you really try on the source-any branch? Here, your example is going through and I get the "expected" types:

enc   : () -> format(audio=any(), video=none, midi=none)
enc   : format(audio=any(), video=none, midi=none)

[Russsgithub]

@smimram
No. sorry I misunderstood your post, i'll try it now. Thanks

[Russsgithub]

Yep, apologies again for the mistake. This is working as expected , thanks.

[Russsgithub]

Will do in a couple of hours. Thanks On 17 Sep 2021 14:08, Romain Beauxis ***@***.***> wrote: That's a very interesting idea. I think the first thing we should consider here is a pro-active operator that allows you to test compatibility and particularly with ffmpeg copy encoder without having to setup the whole streaming machinery and catching it up. Would you mind sharing a quick example of your code so I can get an idea about how you're going at it? — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub<#1915 (reply in thread)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/AB627QOSXBFASUWHACC72XLUCM4T7ANCNFSM5D6CV2TA>. Triage notifications on the go with GitHub Mobile for iOS<https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android<https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub>.

[Russsgithub]

@toots

I'm writting this script for someone else but have there permission to share code, so I'll get a script together , i need to have a think.

Thanks

[toots]

I was looking at your script in relation to #19413 and had a couple of thoughts about how to do it with the current main branch.

First, I totally understand the need to relax the typing system as @smimram is trying to do, this'll make everything much easier to write. However, it's not clear if we can do it safely or, at least, this might need some time to be implemented right.

Meanwhile, here's how you can do it with the current typing system:

1. Encapsulate all sources + encoders operations in a single function
2. Use closures to store in list of existing sources

For 1. this means cramming everything that uses specific encoder type into a single function.

For 2. this means asking yourself what you really need to do on the created source and store that instead of the source itself.

Something like this:

def create_source_with_encoder(encoder, params) =
  s = single("/path/to/security.m4a")

  ....

  output.icecast(encoder, s, ...)
  
  def shutdown() =
    source.shutdown(s)
  end
  
  shutdown_callbacks := [( id, shutdown), ...!shutdown_callbacks]
end

if should_encode then
  create_source_with_encoder(%ffmpeg(format="adts", %audio(codec="aac"), ...), ...)
else
  create_source_with_encoder(%ffmpeg(format="adts", %audio.copy, ...), ...)
end  

def shutdown_source(id) =
  shutdown = list.assoc(id, !shutdown_callbacks)
  shutdown()
end

This way, you encapsulate the type of the encoder inside create_source_with_encoder, which becomes of type: (encoder('a), ...) -> unit and, similarly, your list of existing sources is just a list of shutdown callbacks of type () -> unit and you can live in peace mixing different encoders.

Hope this makes sense!

[Russsgithub]

Thanks.

I've tried to integrate this code with mine, but get syntax error at the end of shutdown on this line

shutdown_callbacks := (id, shutdown)::!shutdown_callbacks

To be honest I don't understand the double colon.

I have shutdown_callbacks initiated as ref([]),(i guess it is a list), id as a tuple (x,y) and shutdown as in your script.

[toots]

Thanks.

I've tried to integrate this code with mine, but get syntax error at the end of shutdown on this line

shutdown_callbacks := (id, shutdown)::!shutdown_callbacks

To be honest I don't understand the double colon.

I have shutdown_callbacks initiated as ref([]),(i guess it is a list), id as a tuple (x,y) and shutdown as in your script.

Oh my, sorry that was me mixing OCaml and liquidsoap syntax..

My example wasn't meant to be directly integrated to your script, just a quick schematic example of the ideas I was exposing.

I'd say we should first focus on confirming that the segfault with ffmpeg is fixed then we can play around cleaning up the script.. 🙂

[Russsgithub]

I was more integrating your ideas into my script.

I managed to get it running by replacing the ocaml code with list.add((id, shutdown),!shutdown_callbacks) but still get the encoder mismatch error got %ffmpeg(audio.copy) should be internal(a)

No stress though.

[Russsgithub]

Seg fault seems to be fixed, ran a 20 min test that didn't crash. On 21 Sep 2021 14:45, Romain Beauxis ***@***.***> wrote: Thanks. I've tried to integrate this code with mine, but get syntax error at the end of shutdown on this line shutdown_callbacks := (id, shutdown)::!shutdown_callbacks To be honest I don't understand the double colon. I have shutdown_callbacks initiated as ref([]),(i guess it is a list), id as a tuple (x,y) and shutdown as in your script. Oh my, sorry that was me mixing OCaml and liquidsoap syntax.. I'd say we should first focus on confirming that the segfault with ffmpeg is fixed then we can play around cleaning up the script.. 🙂 — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub<#1915 (reply in thread)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/AB627QJ6PEKLFG3B5DN6AFLUDCD7BANCNFSM5D6CV2TA>. Triage notifications on the go with GitHub Mobile for iOS<https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android<https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub>.

[toots]

Wonderful!