1 files changed, 41 insertions, 0 deletions
diff --git a/lib/pleroma/helpers/media_helper.ex b/lib/pleroma/helpers/media_helper.ex
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+++ b/lib/pleroma/helpers/media_helper.ex
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+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Helpers.MediaHelper do
+  @moduledoc """
+  Handles common media-related operations.
+  """
+
+  def ffmpeg_resize(uri_or_path, %{max_width: max_width, max_height: max_height} = options) do
+    quality = options[:quality] || 1
+
+    cmd = ~s"""
+    ffmpeg -i #{uri_or_path} -f lavfi -i color=c=white \
+      -filter_complex "[0:v] scale='min(#{max_width},iw)':'min(#{max_height},ih)': \
+        force_original_aspect_ratio=decrease [scaled]; \
+        [1][scaled] scale2ref [bg][img]; [bg] setsar=1 [bg]; [bg][img] overlay=shortest=1" \
+      -loglevel quiet -f image2 -vcodec mjpeg -frames:v 1 -q:v #{quality} pipe:1
+    """
+
+    pid = Port.open({:spawn, cmd}, [:use_stdio, :in, :stream, :exit_status, :binary])
+    loop_recv(pid)
+  end
+
+  defp loop_recv(pid) do
+    loop_recv(pid, <<>>)
+  end
+
+  defp loop_recv(pid, acc) do
+    receive do
+      {^pid, {:data, data}} ->
+        loop_recv(pid, acc <> data)
+
+      {^pid, {:exit_status, 0}} ->
+        {:ok, acc}
+
+      {^pid, {:exit_status, status}} ->
+        {:error, status}
+    end
+  end
+end