Add Pleroma.Upload.Filter.HeifToJpeg based on vips

lib/pleroma/upload/filter/heif_to_jpeg.ex

@@ -0,0 +1,36 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2022 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Upload.Filter.HeifToJpeg do
+  @behaviour Pleroma.Upload.Filter
+  alias Pleroma.Upload
+  alias Vix.Vips.Operation
+
+  @type conversion :: action :: String.t() | {action :: String.t(), opts :: String.t()}
+  @type conversions :: conversion() | [conversion()]
+
+  @spec filter(Pleroma.Upload.t()) :: {:ok, :atom} | {:error, String.t()}
+  def filter(%Pleroma.Upload{content_type: "image/avif"} = upload), do: apply_filter(upload)
+  def filter(%Pleroma.Upload{content_type: "image/heic"} = upload), do: apply_filter(upload)
+  def filter(%Pleroma.Upload{content_type: "image/heif"} = upload), do: apply_filter(upload)
+
+  def filter(_), do: {:ok, :noop}
+
+  defp apply_filter(%Pleroma.Upload{name: name, path: path, tempfile: tempfile} = upload) do
+    ext = String.split(path, ".") |> List.last()
+
+    try do
+      name = name |> String.replace_suffix(ext, "jpg")
+      path = path |> String.replace_suffix(ext, "jpg")
+      {:ok, {vixdata, _vixflags}} = Operation.heifload(tempfile)
+      {:ok, jpegdata} = Operation.jpegsave_buffer(vixdata)
+      :ok = File.write(tempfile, jpegdata)
+
+      {:ok, :filtered, %Upload{upload | name: name, path: path, content_type: "image/jpeg"}}
+    rescue
+      e in ErlangError ->
+        {:error, "#{__MODULE__}: #{inspect(e)}"}
+    end
+  end
+end