improve examples, fix tests

Author: mat-hek

examples/README.md

@@ -1,11 +1,4 @@
 # Membrane G.711 FFmpeg plugin examples
 
 To run, execute `elixir <example>`, e.g. `elixir decode_example.exs`.
-
-## A-law examples
-- `encode_example.exs` - Encodes a raw audio file to G.711 A-law format
-- `decode_example.exs` - Decodes a G.711 A-law file to raw audio
-
-## μ-law examples
-- `encode_mulaw_example.exs` - Encodes a raw audio file to G.711 μ-law format
-- `decode_mulaw_example.exs` - Decodes a G.711 μ-law file to raw audio
+You can choose between PCMA (A-law, default) and PCMU (μ-law) with `--encoding PCMA|PCMU` option.

examples/decode_example.exs

@@ -1,14 +1,15 @@
 # Decoding example
 #
-# The following pipeline takes a G.711 A-law file and decodes it to the raw audio.
+# The following pipeline takes a G.711 file and decodes it to the raw audio.
+# Use `--encoding` option to choose between `ALAW` (default) or `ULAW` variants
 
 Logger.configure(level: :info)
 
 Mix.install([
   {:membrane_g711_ffmpeg_plugin,
    path: __DIR__ |> Path.join("..") |> Path.expand(), override: true},
   :membrane_file_plugin,
-  :req
+  :membrane_hackney_plugin
 ])
 
 g711_alaw =
@@ -22,18 +23,29 @@ defmodule Decoding.Pipeline do
   use Membrane.Pipeline
 
   @impl true
-  def handle_init(_ctx, _opts) do
+  def handle_init(_ctx, opts) do
+    encoding = opts[:encoding]
+
+    {name, ext} =
+      case encoding do
+        :PCMA -> {"pcma", "al"}
+        :PCMU -> {"pcmu", "ul"}
+      end
+
+    url =
+      "https://raw.githubusercontent.com/membraneframework/static/gh-pages/samples/beep-#{name}-8kHz-mono.#{ext}"
+
     structure =
-      child(:source, %Membrane.File.Source{chunk_size: 40_960, location: "input.al"})
-      |> child(:decoder, Membrane.G711.FFmpeg.Decoder)
+      child(:source, %Membrane.Hackney.Source{location: url})
+      |> child(:decoder, %Membrane.G711.FFmpeg.Decoder{encoding: encoding})
       |> child(:sink, %Membrane.File.Sink{location: "output.raw"})
 
     {[spec: structure], %{}}
   end
 
   @impl true
   def handle_element_end_of_stream(:sink, _pad, _ctx, state) do
-    {[terminate: :shutdown], state}
+    {[terminate: :normal], state}
   end
 
   @impl true
@@ -42,8 +54,13 @@ defmodule Decoding.Pipeline do
   end
 end
 
+{opts, _rest} = OptionParser.parse!(System.argv(), strict: [encoding: :string])
+encoding = opts |> Keyword.get(:encoding, "PCMA") |> String.upcase() |> String.to_existing_atom()
+
 # Start and monitor the pipeline
-{:ok, _supervisor_pid, pipeline_pid} = Membrane.Pipeline.start_link(Decoding.Pipeline)
+{:ok, _supervisor_pid, pipeline_pid} =
+  Membrane.Pipeline.start_link(Decoding.Pipeline, encoding: encoding)
+
 ref = Process.monitor(pipeline_pid)
 
 # Wait for the pipeline to finish

examples/decode_mulaw_example.exs

@@ -1,6 +1,7 @@
 # Encoding example
 #
 # The following pipeline takes a raw audio file and encodes it as G.711 A-law.
+# Use `--encoding` option to choose between `ALAW` (default) or `ULAW` variants
 
 Logger.configure(level: :info)
 
@@ -10,39 +11,43 @@ Mix.install([
   :membrane_raw_audio_parser_plugin,
   :membrane_raw_audio_format,
   :membrane_file_plugin,
-  :req
+  :membrane_hackney_plugin
 ])
 
-raw_audio =
-  Req.get!(
-    "https://raw.githubusercontent.com/membraneframework/static/gh-pages/samples/beep-s16le-8kHz-mono.raw"
-  ).body
-
-File.write!("input.raw", raw_audio)
-
 defmodule Encoding.Pipeline do
   use Membrane.Pipeline
 
   @impl true
-  def handle_init(_ctx, _opts) do
+  def handle_init(_ctx, opts) do
+    encoding = opts[:encoding]
+
+    ext =
+      case encoding do
+        :PCMA -> "al"
+        :PCMU -> "ul"
+      end
+
+    url =
+      "https://raw.githubusercontent.com/membraneframework/static/gh-pages/samples/beep-s16le-8kHz-mono.raw"
+
     structure =
-      child(:source, %Membrane.File.Source{chunk_size: 40_960, location: "input.raw"})
+      child(:source, %Membrane.Hackney.Source{location: url})
       |> child(:parser, %Membrane.RawAudioParser{
         stream_format: %Membrane.RawAudio{
           sample_format: :s16le,
           sample_rate: 8000,
           channels: 1
         }
       })
-      |> child(:encoder, Membrane.G711.FFmpeg.Encoder)
-      |> child(:sink, %Membrane.File.Sink{location: "output.al"})
+      |> child(:encoder, %Membrane.G711.FFmpeg.Encoder{encoding: encoding})
+      |> child(:sink, %Membrane.File.Sink{location: "output.#{ext}"})
 
     {[spec: structure], %{}}
   end
 
   @impl true
   def handle_element_end_of_stream(:sink, _pad, _ctx, state) do
-    {[terminate: :shutdown], state}
+    {[terminate: :normal], state}
   end
 
   @impl true
@@ -51,12 +56,16 @@ defmodule Encoding.Pipeline do
   end
 end
 
+{opts, _rest} = OptionParser.parse!(System.argv(), strict: [encoding: :string])
+encoding = opts |> Keyword.get(:encoding, "PCMA") |> String.upcase() |> String.to_existing_atom()
+
 # Start and monitor the pipeline
-{:ok, _supervisor_pid, pipeline_pid} = Membrane.Pipeline.start_link(Encoding.Pipeline)
+{:ok, _supervisor_pid, pipeline_pid} =
+  Membrane.Pipeline.start_link(Encoding.Pipeline, encoding: encoding)
+
 ref = Process.monitor(pipeline_pid)
 
 # Wait for the pipeline to finish
 receive do
-  {:DOWN, ^ref, :process, _pipeline_pid, _reason} ->
-    System.stop()
+  {:DOWN, ^ref, :process, _pipeline_pid, _reason} -> :ok
 end

examples/encode_example.exs

@@ -14,27 +14,23 @@ defmodule Membrane.G711.FFmpeg.Decoder do
   alias Membrane.G711.FFmpeg.Common
   alias Membrane.{G711, RawAudio, RemoteStream}
 
-  def_options(
-    encoding: [
-      spec: :PCMA | :PCMU,
-      description: "G.711 encoding to decode (A-law or μ-law)",
-      default: :PCMA
-    ]
-  )
-
-  def_input_pad(:input,
+  def_options encoding: [
+                spec: :PCMA | :PCMU,
+                description: "G.711 encoding to decode (A-law or μ-law)",
+                default: :PCMA
+              ]
+
+  def_input_pad :input,
     flow_control: :auto,
     accepted_format:
       any_of(%RemoteStream{}, %G711{encoding: encoding} when encoding in [:PCMA, :PCMU])
-  )
 
-  def_output_pad(:output,
+  def_output_pad :output,
     flow_control: :auto,
     accepted_format: %RawAudio{
       channels: G711.num_channels(),
       sample_rate: G711.sample_rate()
     }
-  )
 
   @impl true
   def handle_init(_ctx, opts) do

examples/encode_mulaw_example.exs

@@ -19,27 +19,23 @@ defmodule Membrane.G711.FFmpeg.Encoder do
   alias Membrane.G711.FFmpeg.Common
   alias Membrane.{G711, RawAudio}
 
-  def_options(
-    encoding: [
-      spec: :PCMA | :PCMU,
-      description: "G.711 encoding to use (A-law or μ-law)",
-      default: :PCMA
-    ]
-  )
-
-  def_input_pad(:input,
+  def_options encoding: [
+                spec: :PCMA | :PCMU,
+                description: "G.711 encoding to use (A-law or μ-law)",
+                default: :PCMA
+              ]
+
+  def_input_pad :input,
     flow_control: :auto,
     accepted_format: %RawAudio{
       channels: G711.num_channels(),
       sample_rate: G711.sample_rate(),
       sample_format: :s16le
     }
-  )
 
-  def_output_pad(:output,
+  def_output_pad :output,
     flow_control: :auto,
     accepted_format: %G711{encoding: encoding} when encoding in [:PCMA, :PCMU]
-  )
 
   @impl true
   def handle_init(_ctx, opts) do