Elixir audio stream for users

Question

The following code transfers the file to the process. I want to broadcast audio / mp 3 to many users who hear it through html5 audio text. How to do it with File.stream! ?

 defmodule Test do def start do p = spawn(Test, :say, []) send p, {self, "a message"} end def say do receive do {from, msg} -> IO.puts "Process #{inspect self} says: #{msg}" stream_bytes = 128 File.stream!("./song.mp3", [], stream_bytes) |> Enum.each(fn chunk -> IO.inspect chunk end) say end end end 

$: iex test.ex

iex (1)> Test.start

output:

<171, 46, 254, 26, 163, 32, 178, 27, 0, 75, 17, 35, 4, 236, 51, 57, 5, 144, 154, 198, 166, 47, 62, 4, 61 , 85, 67, 135, 16, 34, 82, 49, 57, 176, 131, 96, 116, 152, 232, 24, 32, 140, 220, 67, 73, 128, 165, 178, 230, 202 , ... → <100, 220, 156, 191, 38, 0, 161, 117, 80, 16, 102, 91, 22, 5, 8, 66, 26, 7, 193, 155, 193, 66, 198, 28, 157, 244, 65, 131, 204, 240, 5, 172, 143, 44, 173, 85, 144, 2, 157, 144, 145, 97, 200, 236, 16, 49, 149, 150, 133, 67, ... → <150, 54, 37, 254, 192, 218, 218, 26, 69, 231, 88, 124, 33, 129, 169, 66, 117, 52, 214, 134 , 130, 103, 85, 130, 48, 6, 144, 221, 153, 132, 8, 181, 26, 27, 83, 140, 54, 117, 149, 7, 60, 144, 237, 248, 132 , 12, 210, 103, 116, ... → <57, 2, 143, 220, 198, 182, 22, 177, 231, 126, 187, 147, 33, 9, 1, 5, 164, 2, 36, 105, 47, 255, 255, 255, 255, 255, 245, 54, 51, 225, 104, 98, 1, 184, 148, 206, 50, 135, 230, 28, 50, 47, 144, 134, 53, 16, 64, 130, 192, 198, ... → ..............

how can i use javascript to read this binary data and hear it through an audio tag?

Answer 1

If you are using a proxy-based web framework, it should be strong enough. This is possible if you use the plug directly or use it from the phoenix (which is based on the plug-in).

Perhaps a similar plug would do the trick

 defmodule Audio do @chunk_size 128 def init(opts), do: opts def song(conn, _opts) do conn = conn |> send_chunked(200) |> put_resp_header("content-type", "audio/mpeg") File.stream!("/some/song/somewhere.mp3", [], @chunk_size) |> Enum.into(conn) end end 

Maybe you want to connect your plugin to a phoenix router like this

 defmodule MyApp.Router do use MyApp.Web, :router get "/the_song", Audio, :song end 

Then on your page

 <audio src="/the_song"> Your browser does not support the <code>audio</code> element. </audio>