akkoma/lib/pleroma/helpers/media_helper.ex

62 lines
1.8 KiB
Elixir

# 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.
"""
@ffmpeg_opts [{:sync, true}, {:stdout, true}]
def ffmpeg_resize_remote(uri, max_width, max_height) do
cmd = ~s"""
curl -L "#{uri}" |
ffmpeg -i pipe:0 -vf \
"scale='min(#{max_width},iw)':min'(#{max_height},ih)':force_original_aspect_ratio=decrease" \
-f image2 pipe:1 | \
cat
"""
with {:ok, [stdout: stdout_list]} <- Exexec.run(cmd, @ffmpeg_opts) do
{:ok, Enum.join(stdout_list)}
end
end
@doc "Returns a temporary path for an URI"
def temporary_path_for(uri) do
name = Path.basename(uri)
random = rand_uniform(999_999)
Path.join(System.tmp_dir(), "#{random}-#{name}")
end
@doc "Stores binary content fetched from specified URL as a temporary file."
@spec store_as_temporary_file(String.t(), binary()) :: {:ok, String.t()} | {:error, atom()}
def store_as_temporary_file(url, body) do
path = temporary_path_for(url)
with :ok <- File.write(path, body), do: {:ok, path}
end
@doc "Modifies image file at specified path by resizing to specified limit dimensions."
@spec mogrify_resize_to_limit(String.t(), String.t()) :: :ok | any()
def mogrify_resize_to_limit(path, resize_dimensions) do
with %Mogrify.Image{} <-
path
|> Mogrify.open()
|> Mogrify.resize_to_limit(resize_dimensions)
|> Mogrify.save(in_place: true) do
:ok
end
end
defp rand_uniform(high) do
Code.ensure_loaded(:rand)
if function_exported?(:rand, :uniform, 1) do
:rand.uniform(high)
else
# Erlang/OTP < 19
apply(:crypto, :rand_uniform, [1, high])
end
end
end