Elixir 向用户流式传输音频

Question

以下代码将文件流式传输到进程。我想直播 audio/mp3 许多用户将通过 html5 音频标签听到它。如何通过 File.stream! 完成？

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

输出：

<<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, 51, 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、……>> ...............

如何使用 JavaScript 读取此二进制数据并通过音频标签收听？

Answer 1

如果您使用的是基于插件的 Web 框架，它应该相当简单。如果您直接使用插件，或者如果您在 phoenix（基于插件）中使用它，这是可能的。

也许像这样的插头可以解决问题

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

也许您想像这样将插头连接到 phoenix 路由器

defmodule MyApp.Router do
  use MyApp.Web, :router

  get "/the_song", Audio, :song
end

然后在您的页面中

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

Elixir 向用户流式传输音频

Elixir stream audio to users

streaming

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html5-audio

audio-streaming